Commit Graph

836 Commits

Author SHA1 Message Date
Xiao Guangrong
77d197b2ca KVM: x86: abstract the operation for read/write emulation
The operations of read emulation and write emulation are very similar, so we
can abstract the operation of them, in larter patch, it is used to cleanup the
same code

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-09-25 19:17:17 +03:00
Xiao Guangrong
ca7d58f375 KVM: x86: fix broken read emulation spans a page boundary
If the range spans a page boundary, the mmio access can be broke, fix it as
write emulation.

And we already get the guest physical address, so use it to read guest data
directly to avoid walking guest page table again

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-09-25 19:17:17 +03:00
Xiao Guangrong
4f0226482d KVM: MMU: trace mmio page fault
Add tracepoints to trace mmio page fault

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24 11:50:41 +03:00
Xiao Guangrong
ce88decffd KVM: MMU: mmio page fault support
The idea is from Avi:

| We could cache the result of a miss in an spte by using a reserved bit, and
| checking the page fault error code (or seeing if we get an ept violation or
| ept misconfiguration), so if we get repeated mmio on a page, we don't need to
| search the slot list/tree.
| (https://lkml.org/lkml/2011/2/22/221)

When the page fault is caused by mmio, we cache the info in the shadow page
table, and also set the reserved bits in the shadow page table, so if the mmio
is caused again, we can quickly identify it and emulate it directly

Searching mmio gfn in memslots is heavy since we need to walk all memeslots, it
can be reduced by this feature, and also avoid walking guest page table for
soft mmu.

[jan: fix operator precedence issue]

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24 11:50:40 +03:00
Xiao Guangrong
c37079586f KVM: MMU: remove bypass_guest_pf
The idea is from Avi:
| Maybe it's time to kill off bypass_guest_pf=1.  It's not as effective as
| it used to be, since unsync pages always use shadow_trap_nonpresent_pte,
| and since we convert between the two nonpresent_ptes during sync and unsync.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24 11:50:33 +03:00
Xiao Guangrong
bebb106a5a KVM: MMU: cache mmio info on page fault path
If the page fault is caused by mmio, we can cache the mmio info, later, we do
not need to walk guest page table and quickly know it is a mmio fault while we
emulate the mmio instruction

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24 11:50:26 +03:00
Xiao Guangrong
af7cc7d1ee KVM: x86: introduce vcpu_mmio_gva_to_gpa to cleanup the code
Introduce vcpu_mmio_gva_to_gpa to translate the gva to gpa, we can use it
to cleanup the code between read emulation and write emulation

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24 11:50:25 +03:00
Glauber Costa
c9aaa8957f KVM: Steal time implementation
To implement steal time, we need the hypervisor to pass the guest
information about how much time was spent running other processes
outside the VM, while the vcpu had meaningful work to do - halt
time does not count.

This information is acquired through the run_delay field of
delayacct/schedstats infrastructure, that counts time spent in a
runqueue but not running.

Steal time is a per-cpu information, so the traditional MSR-based
infrastructure is used. A new msr, KVM_MSR_STEAL_TIME, holds the
memory area address containing information about steal time

This patch contains the hypervisor part of the steal time infrasructure,
and can be backported independently of the guest portion.

[avi, yongjie: export delayacct_on, to avoid build failures in some configs]

Signed-off-by: Glauber Costa <glommer@redhat.com>
Tested-by: Eric B Munson <emunson@mgebm.net>
CC: Rik van Riel <riel@redhat.com>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Yongjie Ren <yongjie.ren@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-14 12:59:14 +03:00
Yang, Wei
a01c8f9b4e KVM: Enable ERMS feature support for KVM
This patch exposes ERMS feature to KVM guests.

The REP MOVSB/STOSB instruction can enhance fast strings attempts to
move as much of the data with larger size load/stores as possible.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:25 +03:00
Yang, Wei
176f61da82 KVM: Expose RDWRGSFS bit to KVM guests
This patch exposes RDWRGSFS bit to KVM guests.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:24 +03:00
Yang, Wei
74dc2b4ffe KVM: Add RDWRGSFS support when setting CR4
This patch adds RDWRGSFS support when setting CR4.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:23 +03:00
Yang, Wei Y
4a00efdf0c KVM: Enable DRNG feature support for KVM
This patch exposes DRNG feature to KVM guests.

The RDRAND instruction can provide software with sequences of
random numbers generated from white noise.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:21 +03:00
Andre Przywara
02668b061d KVM: fix XSAVE bit scanning (now properly)
commit 123108f1c1aafd51d6a5c79cc04d7999dd88a930 tried to fix KVMs
XSAVE valid feature scanning, but it was wrong. It was not considering
the sparse nature of this bitfield, instead reading values from
uninitialized members of the entries array.
This patch now separates subleaf indicies from KVM's array indicies
and fills the entry before querying it's value.
This fixes AVX support in KVM guests.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:20 +03:00
Yang, Wei Y
611c120f74 KVM: Mask function7 ebx against host capability word9
This patch masks CPUID leaf 7 ebx against host capability word9.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Shan, Haitao <haitao.shan@intel.com>
Signed-off-by: Li, Xin <xin.li@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:14 +03:00
Yang, Wei Y
c68b734fba KVM: Add SMEP support when setting CR4
This patch adds SMEP handling when setting CR4.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Shan, Haitao <haitao.shan@intel.com>
Signed-off-by: Li, Xin <xin.li@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:13 +03:00
Avi Kivity
9dac77fa40 KVM: x86 emulator: fold decode_cache into x86_emulate_ctxt
This saves a lot of pointless casts x86_emulate_ctxt and decode_cache.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 13:16:09 +03:00
Avi Kivity
36dd9bb5ce KVM: x86 emulator: rename decode_cache::eip to _eip
The name eip conflicts with a field of the same name in x86_emulate_ctxt,
which we plan to fold decode_cache into.

The name _eip is unfortunate, but what's really needed is a refactoring
here, not a better name.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 13:16:09 +03:00
Takuya Yoshikawa
9d74191ab1 KVM: x86 emulator: Use the pointers ctxt and c consistently
We should use the local variables ctxt and c when the emulate_ctxt and
decode appears many times.  At least, we need to be consistent about
how we use these in a function.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 13:15:57 +03:00
Nadav Har'El
6a4d755060 KVM: nVMX: Implement VMPTRST
This patch implements the VMPTRST instruction.

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 11:45:13 +03:00
Nadav Har'El
27d6c86521 KVM: nVMX: Implement VMCLEAR
This patch implements the VMCLEAR instruction.

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 11:45:12 +03:00
Nadav Har'El
064aea7747 KVM: nVMX: Decoding memory operands of VMX instructions
This patch includes a utility function for decoding pointer operands of VMX
instructions issued by L1 (a guest hypervisor)

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 11:45:11 +03:00
Nadav Har'El
5e1746d620 KVM: nVMX: Allow setting the VMXE bit in CR4
This patch allows the guest to enable the VMXE bit in CR4, which is a
prerequisite to running VMXON.

Whether to allow setting the VMXE bit now depends on the architecture (svm
or vmx), so its checking has moved to kvm_x86_ops->set_cr4(). This function
now returns an int: If kvm_x86_ops->set_cr4() returns 1, __kvm_set_cr4()
will also return 1, and this will cause kvm_set_cr4() will throw a #GP.

Turning on the VMXE bit is allowed only when the nested VMX feature is
enabled, and turning it off is forbidden after a vmxon.

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 11:45:10 +03:00
Takuya Yoshikawa
b5c9ff731f KVM: x86 emulator: Avoid clearing the whole decode_cache
During tracing the emulator, we noticed that init_emulate_ctxt()
sometimes took a bit longer time than we expected.

This patch is for mitigating the problem by some degree.

By looking into the function, we soon notice that it clears the whole
decode_cache whose size is about 2.5K bytes now.  Furthermore, most of
the bytes are taken for the two read_cache arrays, which are used only
by a few instructions.

Considering the fact that we are not assuming the cache arrays have
been cleared when we store actual data, we do not need to clear the
arrays: 2K bytes elimination.  In addition, we can avoid clearing the
fetch_cache and regs arrays.

This patch changes the initialization not to clear the arrays.

On our 64-bit host, init_emulate_ctxt() becomes 0.3 to 0.5us faster with
this patch applied.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 11:45:09 +03:00
Takuya Yoshikawa
adf52235b4 KVM: x86 emulator: Clean up init_emulate_ctxt()
Use a local pointer to the emulate_ctxt for simplicity.  Then, arrange
the hard-to-read mode selection lines neatly.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 11:45:08 +03:00
Jan Kiszka
d780592b99 KVM: Clean up error handling during VCPU creation
So far kvm_arch_vcpu_setup is responsible for freeing the vcpu struct if
it fails. Move this confusing resonsibility back into the hands of
kvm_vm_ioctl_create_vcpu. Only kvm_arch_vcpu_setup of x86 is affected,
all other archs cannot fail.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 11:45:08 +03:00
Avi Kivity
24c82e576b KVM: Sanitize cpuid
Instead of blacklisting known-unsupported cpuid leaves, whitelist known-
supported leaves.  This is more conservative and prevents us from reporting
features we don't support.  Also whitelist a few more leaves while at it.

Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 11:45:07 +03:00
Xiao Guangrong
8b0cedff04 KVM: use __copy_to_user/__clear_user to write guest page
Simply use __copy_to_user/__clear_user to write guest page since we have
already verified the user address when the memslot is set

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 11:45:03 +03:00
Takuya Yoshikawa
7b105ca290 KVM: x86 emulator: Stop passing ctxt->ops as arg of emul functions
Dereference it in the actual users.

This not only cleans up the emulator but also makes it easy to convert
the old emulation functions to the new em_xxx() form later.

Note: Remove some inline keywords to let the compiler decide inlining.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 11:44:59 +03:00
Avi Kivity
1aa366163b KVM: x86 emulator: consolidate segment accessors
Instead of separate accessors for the segment selector and cached descriptor,
use one accessor for both.  This simplifies the code somewhat.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:47:39 -04:00
BrillyWu@viatech.com.cn
4429d5dc11 KVM: Add CPUID support for VIA CPU
The CPUIDs for Centaur are added, and then the features of
PadLock hardware engine on VIA CPU, such as "ace", "ace_en"
and so on, can be passed into the kvm guest.

Signed-off-by: Brilly Wu <brillywu@viatech.com.cn>
Signed-off-by: Kary Jin <karyjin@viatech.com.cn>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:55 -04:00
Gleb Natapov
2aab2c5b2b KVM: call cache_all_regs() only once during instruction emulation
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:54 -04:00
Gleb Natapov
0004c7c257 KVM: Fix compound mmio
mmio_index should be taken into account when copying data from
userspace.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:52 -04:00
Gleb Natapov
8d7d810255 KVM: mmio_fault_cr2 is not used
Remove unused variable mmio_fault_cr2.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:49 -04:00
Avi Kivity
13db70eca6 KVM: x86 emulator: drop x86_emulate_ctxt::vcpu
No longer used.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:24 -04:00
Avi Kivity
5197b808a7 KVM: Avoid using x86_emulate_ctxt.vcpu
We can use container_of() instead.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:22 -04:00
Avi Kivity
bcaf5cc543 KVM: x86 emulator: add new ->wbinvd() callback
Instead of calling kvm_emulate_wbinvd() directly.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:20 -04:00
Avi Kivity
d6aa10003b KVM: x86 emulator: add ->fix_hypercall() callback
Artificial, but needed to remove direct calls to KVM.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:18 -04:00
Avi Kivity
6c3287f7c5 KVM: x86 emulator: add new ->halt() callback
Instead of reaching into vcpu internals.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:17 -04:00
Avi Kivity
3cb16fe78c KVM: x86 emulator: make emulate_invlpg() an emulator callback
Removing direct calls to KVM.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:15 -04:00
Avi Kivity
2d04a05bd7 KVM: x86 emulator: emulate CLTS internally
Avoid using ctxt->vcpu; we can do everything with ->get_cr() and ->set_cr().

A side effect is that we no longer activate the fpu on emulated CLTS; but that
should be very rare.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:14 -04:00
Avi Kivity
1ac9d0cfb0 KVM: x86 emulator: add and use new callbacks set_idt(), set_gdt()
Replacing direct calls to realmode_lgdt(), realmode_lidt().

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:08 -04:00
Avi Kivity
2953538ebb KVM: x86 emulator: drop vcpu argument from intercept callback
Making the emulator caller agnostic.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:05 -04:00
Avi Kivity
717746e382 KVM: x86 emulator: drop vcpu argument from cr/dr/cpl/msr callbacks
Making the emulator caller agnostic.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:03 -04:00
Avi Kivity
4bff1e86ad KVM: x86 emulator: drop vcpu argument from segment/gdt/idt callbacks
Making the emulator caller agnostic.

[Takuya Yoshikawa: fix typo leading to LDT failures]

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:35:20 -04:00
Avi Kivity
ca1d4a9e77 KVM: x86 emulator: drop vcpu argument from pio callbacks
Making the emulator caller agnostic.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:11 -04:00
Avi Kivity
0f65dd70a4 KVM: x86 emulator: drop vcpu argument from memory read/write callbacks
Making the emulator caller agnostic.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:10 -04:00
Joerg Roedel
7c4c0f4fd5 KVM: X86: Update last_guest_tsc in vcpu_put
The last_guest_tsc is used in vcpu_load to adjust the
tsc_offset since tsc-scaling is merged. So the
last_guest_tsc needs to be updated in vcpu_put instead of
the the last_host_tsc. This is fixed with this patch.

Reported-by: Jan Kiszka <jan.kiszka@web.de>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:10 -04:00
Serge E. Hallyn
71f9833bb1 KVM: fix push of wrong eip when doing softint
When doing a soft int, we need to bump eip before pushing it to
the stack.  Otherwise we'll do the int a second time.

[apw@canonical.com: merged eip update as per Jan's recommendation.]
Signed-off-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:09 -04:00
Gleb Natapov
7ae441eac5 KVM: emulator: do not needlesly sync registers from emulator ctxt to vcpu
Currently we sync registers back and forth before/after exiting
to userspace for IO, but during IO device model shouldn't need to
read/write the registers, so we can as well skip those sync points. The
only exaception is broken vmware backdor interface. The new code sync
registers content during IO only if registers are read from/written to
by userspace in the middle of the IO operation and this almost never
happens in practise.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-05-11 07:57:08 -04:00
Joerg Roedel
92a1f12d25 KVM: X86: Implement userspace interface to set virtual_tsc_khz
This patch implements two new vm-ioctls to get and set the
virtual_tsc_khz if the machine supports tsc-scaling. Setting
the tsc-frequency is only possible before userspace creates
any vcpu.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:06 -04:00
Joerg Roedel
857e40999e KVM: X86: Delegate tsc-offset calculation to architecture code
With TSC scaling in SVM the tsc-offset needs to be
calculated differently. This patch propagates this
calculation into the architecture specific modules so that
this complexity can be handled there.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:05 -04:00
Joerg Roedel
8f6055cbaf KVM: X86: Make tsc_delta calculation a function of guest tsc
The calculation of the tsc_delta value to ensure a
forward-going tsc for the guest is a function of the
host-tsc. This works as long as the guests tsc_khz is equal
to the hosts tsc_khz. With tsc-scaling hardware support this
is not longer true and the tsc_delta needs to be calculated
using guest_tsc values.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:04 -04:00
Joerg Roedel
1e993611d0 KVM: X86: Let kvm-clock report the right tsc frequency
This patch changes the kvm_guest_time_update function to use
TSC frequency the guest actually has for updating its clock.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:04 -04:00
Joerg Roedel
cfec82cb7d KVM: SVM: Add intercept check for emulated cr accesses
This patch adds all necessary intercept checks for
instructions that access the crX registers.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:01 -04:00
Joerg Roedel
8a76d7f25f KVM: x86: Add x86 callback for intercept check
This patch adds a callback into kvm_x86_ops so that svm and
vmx code can do intercept checks on emulated instructions.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:01 -04:00
Joerg Roedel
775fde8648 KVM: x86 emulator: Don't write-back cpu-state on X86EMUL_INTERCEPTED
This patch prevents the changed CPU state to be written back
when the emulator detected that the instruction was
intercepted by the guest.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:00 -04:00
Avi Kivity
c4f035c60d KVM: x86 emulator: add framework for instruction intercepts
When running in guest mode, certain instructions can be intercepted by
hardware.  This also holds for nested guests running on emulated
virtualization hardware, in particular instructions emulated by kvm
itself.

This patch adds a framework for intercepting instructions.  If an
instruction is marked for interception, and if we're running in guest
mode, a callback is called to check whether an intercept is needed or
not.  The callback is called at three points in time: immediately after
beginning execution, after checking privilge exceptions, and after
checking memory exception.  This suits the different interception points
defined for different instructions and for the various virtualization
instruction sets.

In addition, a new X86EMUL_INTERCEPT is defined, which any callback or
memory access may define, allowing the more complicated intercepts to be
implemented in existing callbacks.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:00 -04:00
Avi Kivity
5037f6f324 KVM: x86 emulator: define callbacks for using the guest fpu within the emulator
Needed for emulating fpu instructions.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:56:58 -04:00
Avi Kivity
cef4dea07f KVM: 16-byte mmio support
Since sse instructions can issue 16-byte mmios, we need to support them.  We
can't increase the kvm_run mmio buffer size to 16 bytes without breaking
compatibility, so instead we break the large mmios into two smaller 8-byte
ones.  Since the bus is 64-bit we aren't breaking any atomicity guarantees.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:56:58 -04:00
Avi Kivity
5287f194bf KVM: Split mmio completion into a function
Make room for sse mmio completions.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:56:58 -04:00
Avi Kivity
70252a1053 KVM: extend in-kernel mmio to handle >8 byte transactions
Needed for coalesced mmio using sse.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:56:58 -04:00
Gleb Natapov
1499e54af0 KVM: x86: better fix for race between nmi injection and enabling nmi window
Fix race between nmi injection and enabling nmi window in a simpler way.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-05-11 07:56:57 -04:00
Marcelo Tosatti
c761e5868e Revert "KVM: Fix race between nmi injection and enabling nmi window"
This reverts commit f86368493e.

Simpler fix to follow.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-05-11 07:56:57 -04:00
Glauber Costa
3291892450 KVM: expose async pf through our standard mechanism
As Avi recently mentioned, the new standard mechanism for exposing features
is KVM_GET_SUPPORTED_CPUID, not spamming CAPs. For some reason async pf
missed that.

So expose async_pf here.

Signed-off-by: Glauber Costa <glommer@redhat.com>
CC: Gleb Natapov <gleb@redhat.com>
CC: Avi Kivity <avi@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:56:57 -04:00
Avi Kivity
f6e7847589 KVM: Use kvm_get_rflags() and kvm_set_rflags() instead of the raw versions
Some rflags bits are owned by the host, not guest, so we need to use
kvm_get_rflags() to strip those bits away or kvm_set_rflags() to add them
back.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:56:54 -04:00
Andre Przywara
bd22f5cfcf KVM: move and fix substitue search for missing CPUID entries
If KVM cannot find an exact match for a requested CPUID leaf, the
code will try to find the closest match instead of simply confessing
it's failure.
The implementation was meant to satisfy the CPUID specification, but
did not properly check for extended and standard leaves and also
didn't account for the index subleaf.
Beside that this rule only applies to CPUID intercepts, which is not
the only user of the kvm_find_cpuid_entry() function.

So fix this algorithm and call it from kvm_emulate_cpuid().
This fixes a crash of newer Linux kernels as KVM guests on
AMD Bulldozer CPUs, where bogus values were returned in response to
a CPUID intercept.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-04-06 13:15:56 +03:00
Andre Przywara
20800bc940 KVM: fix XSAVE bit scanning
When KVM scans the 0xD CPUID leaf for propagating the XSAVE save area
leaves, it assumes that the leaves are contigious and stops at the
first zero one. On AMD hardware there is a gap, though, as LWP uses
leaf 62 to announce it's state save area.
So lets iterate through all 64 possible leaves and simply skip zero
ones to also cover later features.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-04-06 13:15:55 +03:00
Linus Torvalds
f2e1fbb5f2 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Flush TLB if PGD entry is changed in i386 PAE mode
  x86, dumpstack: Correct stack dump info when frame pointer is available
  x86: Clean up csum-copy_64.S a bit
  x86: Fix common misspellings
  x86: Fix misspelling and align params
  x86: Use PentiumPro-optimized partial_csum() on VIA C7
2011-03-18 10:45:21 -07:00
Lucas De Marchi
0d2eb44f63 x86: Fix common misspellings
They were generated by 'codespell' and then manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: trivial@kernel.org
LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 10:39:30 +01:00
Nikola Ciprich
1aa8ceef03 KVM: fix kvmclock regression due to missing clock update
commit 387b9f97750444728962b236987fbe8ee8cc4f8c moved kvm_request_guest_time_update(vcpu),
breaking 32bit SMP guests using kvm-clock. Fix this by moving (new) clock update function
to proper place.

Signed-off-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:33 -03:00
Gleb Natapov
5601d05b8c KVM: emulator: Fix io permission checking for 64bit guest
Current implementation truncates upper 32bit of TR base address during IO
permission bitmap check. The patch fixes this.

Reported-and-tested-by: Francis Moreau <francis.moro@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:33 -03:00
Xiao Guangrong
48c0e4e906 KVM: MMU: move mmu pages calculated out of mmu lock
kvm_mmu_calculate_mmu_pages need to walk all memslots and it's protected by
kvm->slots_lock, so move it out of mmu spinlock

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:32 -03:00
Lai Jiangshan
1260edbe7d KVM: better readability of efer_reserved_bits
use EFER_SCE, EFER_LME and EFER_LMA instead of magic numbers.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:31 -03:00
Lai Jiangshan
d170c41906 KVM: Clear async page fault hash after switching to real mode
The hash array of async gfns may still contain some left gfns after
kvm_clear_async_pf_completion_queue() called, need to clear them.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:31 -03:00
Jan Kiszka
038f8c110e KVM: x86: Convert tsc_write_lock to raw_spinlock
Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:30 -03:00
Gleb Natapov
7049467b53 KVM: remove isr_ack logic from PIC
isr_ack logic was added by e48258009d to avoid unnecessary IPIs. Back
then it made sense, but now the code checks that vcpu is ready to accept
interrupt before sending IPI, so this logic is no longer needed. The
patch removes it.

Fixes a regression with Debian/Hurd.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Reported-and-tested-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:30 -03:00
Jan Kiszka
e935b8372c KVM: Convert kvm_lock to raw_spinlock
Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:30 -03:00
Avi Kivity
f86368493e KVM: Fix race between nmi injection and enabling nmi window
The interrupt injection logic looks something like

  if an nmi is pending, and nmi injection allowed
    inject nmi
  if an nmi is pending
    request exit on nmi window

the problem is that "nmi is pending" can be set asynchronously by
the PIT; if it happens to fire between the two if statements, we
will request an nmi window even though nmi injection is allowed.  On
SVM, this has disasterous results, since it causes eflags.TF to be
set in random guest code.

The fix is simple; make nmi_pending synchronous using the standard
vcpu->requests mechanism; this ensures the code above is completely
synchronous wrt nmi_pending.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:30 -03:00
Avi Kivity
4005996e42 KVM: Drop ad-hoc vendor specific instruction restriction
Use the new support in the emulator, and drop the ad-hoc code in x86.c.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:28 -03:00
Avi Kivity
3e90943907 KVM: Drop bogus x86_decode_insn() error check
x86_decode_insn() doesn't return X86EMUL_* values, so the check
for X86EMUL_PROPOGATE_FAULT will always fail.  There is a proper
check later on, so there is no need for a replacement for this
code.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:28 -03:00
Glauber Costa
12f9a48f7b KVM: x86: release kvmclock page on reset
When a vcpu is reset, kvmclock page keeps being written to this days.
This is wrong and inconsistent: a cpu reset should take it to its
initial state.

Signed-off-by: Glauber Costa <glommer@redhat.com>
CC: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:28 -03:00
john cooper
91c9c3eda4 KVM: x86: handle guest access to BBL_CR_CTL3 MSR
A correction to Intel cpu model CPUID data (patch queued)
caused winxp to BSOD when booted with a Penryn model.
This was traced to the CPUID "model" field correction from
6 -> 23 (as is proper for a Penryn class of cpu).  Only in
this case does the problem surface.

The cause for this failure is winxp accessing the BBL_CR_CTL3
MSR which is unsupported by current kvm, appears to be a
legacy MSR not fully characterized yet existing in current
silicon, and is apparently carried forward in MSR space to
accommodate vintage code as here.  It is not yet conclusive
whether this MSR implements any of its legacy functionality
or is just an ornamental dud for compatibility.  While I
found no silicon version specific documentation link to
this MSR, a general description exists in Intel's developer's
reference which agrees with the functional behavior of
other bootloader/kernel code I've examined accessing
BBL_CR_CTL3.  Regrettably winxp appears to be setting bit #19
called out as "reserved" in the above document.

So to minimally accommodate this MSR, kvm msr get will provide
the equivalent mock data and kvm msr write will simply toss the
guest passed data without interpretation.  While this treatment
of BBL_CR_CTL3 addresses the immediate problem, the approach may
be modified pending clarification from Intel.

Signed-off-by: john cooper <john.cooper@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:27 -03:00
Xiao Guangrong
6b7e2d0991 KVM: Add "exiting guest mode" state
Currently we keep track of only two states: guest mode and host
mode.  This patch adds an "exiting guest mode" state that tells
us that an IPI will happen soon, so unless we need to wait for the
IPI, we can avoid it completely.

Also
1: No need atomically to read/write ->mode in vcpu's thread

2: reorganize struct kvm_vcpu to make ->mode and ->requests
   in the same cache line explicitly

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:26 -03:00
Jan Kiszka
9ca5231831 KVM: x86: Remove user space triggerable MCE error message
This case is a pure user space error we do not need to record. Moreover,
it can be misused to flood the kernel log. Remove it.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:26 -03:00
Xiao Guangrong
63f42e023e KVM: fix rcu usage warning in kvm_arch_vcpu_ioctl_set_sregs()
Fix:

[ 1001.499596] ===================================================
[ 1001.499599] [ INFO: suspicious rcu_dereference_check() usage. ]
[ 1001.499601] ---------------------------------------------------
[ 1001.499604] include/linux/kvm_host.h:301 invoked rcu_dereference_check() without protection!
	......
[ 1001.499636] Pid: 6035, comm: qemu-system-x86 Not tainted 2.6.37-rc6+ #62
[ 1001.499638] Call Trace:
[ 1001.499644]  [] lockdep_rcu_dereference+0x9d/0xa5
[ 1001.499653]  [] gfn_to_memslot+0x8d/0xc8 [kvm]
[ 1001.499661]  [] gfn_to_hva+0x16/0x3f [kvm]
[ 1001.499669]  [] kvm_read_guest_page+0x1e/0x5e [kvm]
[ 1001.499681]  [] kvm_read_guest_page_mmu+0x53/0x5e [kvm]
[ 1001.499699]  [] load_pdptrs+0x3f/0x9c [kvm]
[ 1001.499705]  [] ? vmx_set_cr0+0x507/0x517 [kvm_intel]
[ 1001.499717]  [] kvm_arch_vcpu_ioctl_set_sregs+0x1f3/0x3c0 [kvm]
[ 1001.499727]  [] kvm_vcpu_ioctl+0x6a5/0xbc5 [kvm]

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:26 -03:00
Linus Torvalds
55065bc527 Merge branch 'kvm-updates/2.6.38' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.38' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (142 commits)
  KVM: Initialize fpu state in preemptible context
  KVM: VMX: when entering real mode align segment base to 16 bytes
  KVM: MMU: handle 'map_writable' in set_spte() function
  KVM: MMU: audit: allow audit more guests at the same time
  KVM: Fetch guest cr3 from hardware on demand
  KVM: Replace reads of vcpu->arch.cr3 by an accessor
  KVM: MMU: only write protect mappings at pagetable level
  KVM: VMX: Correct asm constraint in vmcs_load()/vmcs_clear()
  KVM: MMU: Initialize base_role for tdp mmus
  KVM: VMX: Optimize atomic EFER load
  KVM: VMX: Add definitions for more vm entry/exit control bits
  KVM: SVM: copy instruction bytes from VMCB
  KVM: SVM: implement enhanced INVLPG intercept
  KVM: SVM: enhance mov DR intercept handler
  KVM: SVM: enhance MOV CR intercept handler
  KVM: SVM: add new SVM feature bit names
  KVM: cleanup emulate_instruction
  KVM: move complete_insn_gp() into x86.c
  KVM: x86: fix CR8 handling
  KVM guest: Fix kvm clock initialization when it's configured out
  ...
2011-01-13 10:14:24 -08:00
Avi Kivity
e5c3014282 KVM: Initialize fpu state in preemptible context
init_fpu() (which is indirectly called by the fpu switching code) assumes
it is in process context.  Rather than makeing init_fpu() use an atomic
allocation, which can cause a task to be killed, make sure the fpu is
already initialized when we enter the run loop.

KVM-Stable-Tag.
Reported-and-tested-by: Kirill A. Shutemov <kas@openvz.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 12:02:26 +02:00
Avi Kivity
aff48baa34 KVM: Fetch guest cr3 from hardware on demand
Instead of syncing the guest cr3 every exit, which is expensince on vmx
with ept enabled, sync it only on demand.

[sheng: fix incorrect cr3 seen by Windows XP]

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:31:16 +02:00
Avi Kivity
9f8fe5043f KVM: Replace reads of vcpu->arch.cr3 by an accessor
This allows us to keep cr3 in the VMCS, later on.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:31:15 +02:00
Andre Przywara
dc25e89e07 KVM: SVM: copy instruction bytes from VMCB
In case of a nested page fault or an intercepted #PF newer SVM
implementations provide a copy of the faulting instruction bytes
in the VMCB.
Use these bytes to feed the instruction emulator and avoid the costly
guest instruction fetch in this case.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:31:07 +02:00
Andre Przywara
51d8b66199 KVM: cleanup emulate_instruction
emulate_instruction had many callers, but only one used all
parameters. One parameter was unused, another one is now
hidden by a wrapper function (required for a future addition
anyway), so most callers use now a shorter parameter list.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:31:00 +02:00
Andre Przywara
db8fcefaa7 KVM: move complete_insn_gp() into x86.c
move the complete_insn_gp() helper function out of the VMX part
into the generic x86 part to make it usable by SVM.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:30:59 +02:00
Andre Przywara
eea1cff9ab KVM: x86: fix CR8 handling
The handling of CR8 writes in KVM is currently somewhat cumbersome.
This patch makes it look like the other CR register handlers
and fixes a possible issue in VMX, where the RIP would be incremented
despite an injected #GP.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:30:58 +02:00
Takuya Yoshikawa
175504cdbf KVM: Take missing slots_lock for kvm_io_bus_unregister_dev()
In KVM_CREATE_IRQCHIP, kvm_io_bus_unregister_dev() is called without taking
slots_lock in the error handling path.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:30:55 +02:00
Lai Jiangshan
a355c85c5f KVM: return true when user space query KVM_CAP_USER_NMI extension
userspace may check this extension in runtime.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:30:54 +02:00
Avi Kivity
61cfab2e83 KVM: Correct kvm_pio tracepoint count field
Currently, we record '1' for count regardless of the real count.  Fix.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:30:52 +02:00
Xiao Guangrong
fb67e14fc9 KVM: MMU: retry #PF for softmmu
Retry #PF for softmmu only when the current vcpu has the same cr3 as the time
when #PF occurs

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:30:41 +02:00
Joerg Roedel
fc3a9157d3 KVM: X86: Don't report L2 emulation failures to user-space
This patch prevents that emulation failures which result
from emulating an instruction for an L2-Guest results in
being reported to userspace.
Without this patch a malicious L2-Guest would be able to
kill the L1 by triggering a race-condition between an vmexit
and the instruction emulator.
With this patch the L2 will most likely only kill itself in
this situation.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:30:07 +02:00
Avi Kivity
6389ee9463 KVM: Pull extra page fault information into struct x86_exception
Currently page fault cr2 and nesting infomation are carried outside
the fault data structure.  Instead they are placed in the vcpu struct,
which results in confusion as global variables are manipulated instead
of passing parameters.

Fix this issue by adding address and nested fields to struct x86_exception,
so this struct can carry all information associated with a fault.

Signed-off-by: Avi Kivity <avi@redhat.com>
Tested-by: Joerg Roedel <joerg.roedel@amd.com>
Tested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:30:02 +02:00
Avi Kivity
ab9ae31387 KVM: Push struct x86_exception info the various gva_to_gpa variants
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:59 +02:00
Avi Kivity
bcc55cba9f KVM: x86 emulator: make emulator memory callbacks return full exception
This way, they can return #GP, not just #PF.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:54 +02:00
Avi Kivity
da9cb575b1 KVM: x86 emulator: introduce struct x86_exception to communicate faults
Introduce a structure that can contain an exception to be passed back
to main kvm code.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:53 +02:00
Avi Kivity
945ee35e07 KVM: Mask KVM_GET_SUPPORTED_CPUID data with Linux cpuid info
This allows Linux to mask cpuid bits if, for example, nx is enabled on only
some cpus.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:17 +02:00
Xiao Guangrong
c4806acdce KVM: MMU: fix apf prefault if nested guest is enabled
If apf is generated in L2 guest and is completed in L1 guest, it will
prefault this apf in L1 guest's mmu context.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:14 +02:00
Xiao Guangrong
e5f3f02796 KVM: MMU: clear apfs if page state is changed
If CR0.PG is changed, the page fault cann't be avoid when the prefault address
is accessed later

And it also fix a bug: it can retry a page enabled #PF in page disabled context
if mmu is shadow page

This idear is from Gleb Natapov

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:12 +02:00
Jan Kiszka
d89f5eff70 KVM: Clean up vm creation and release
IA64 support forces us to abstract the allocation of the kvm structure.
But instead of mixing this up with arch-specific initialization and
doing the same on destruction, split both steps. This allows to move
generic destruction calls into generic code.

It also fixes error clean-up on failures of kvm_create_vm for IA64.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:09 +02:00
Xiao Guangrong
e6d53e3b0d KVM: avoid unnecessary wait for a async pf
In current code, it checks async pf completion out of the wait context,
like this:

if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
		    !vcpu->arch.apf.halted)
			r = vcpu_enter_guest(vcpu);
		else {
			......
			kvm_vcpu_block(vcpu)
			 ^- waiting until 'async_pf.done' is not empty
}

kvm_check_async_pf_completion(vcpu)
 ^- delete list from async_pf.done

So, if we check aysnc pf completion first, it can be blocked at
kvm_vcpu_block

Fixed by mark the vcpu is unhalted in kvm_check_async_pf_completion()
path

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:00 +02:00
Xiao Guangrong
c7d28c2404 KVM: fix searching async gfn in kvm_async_pf_gfn_slot
Don't search later slots if the slot is empty

Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:59 +02:00
Jan Kiszka
2eec734374 KVM: x86: Avoid issuing wbinvd twice
Micro optimization to avoid calling wbinvd twice on the CPU that has to
emulate it. As we might be preempted between smp_call_function_many and
the local wbinvd, the cache might be filled again so that real work
could be done uselessly.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:52 +02:00
Takuya Yoshikawa
515a01279a KVM: pre-allocate one more dirty bitmap to avoid vmalloc()
Currently x86's kvm_vm_ioctl_get_dirty_log() needs to allocate a bitmap by
vmalloc() which will be used in the next logging and this has been causing
bad effect to VGA and live-migration: vmalloc() consumes extra systime,
triggers tlb flush, etc.

This patch resolves this issue by pre-allocating one more bitmap and switching
between two bitmaps during dirty logging.

Performance improvement:
  I measured performance for the case of VGA update by trace-cmd.
  The result was 1.5 times faster than the original one.

  In the case of live migration, the improvement ratio depends on the workload
  and the guest memory size. In general, the larger the memory size is the more
  benefits we get.

Note:
  This does not change other architectures's logic but the allocation size
  becomes twice. This will increase the actual memory consumption only when
  the new size changes the number of pages allocated by vmalloc().

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:46 +02:00
Marcelo Tosatti
982c25658c KVM: MMU: remove kvm_mmu_set_base_ptes
Unused.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:23:38 +02:00
Gleb Natapov
fc5f06fac6 KVM: Send async PF when guest is not in userspace too.
If guest indicates that it can handle async pf in kernel mode too send
it, but only if interrupts are enabled.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:22 +02:00
Gleb Natapov
6adba52742 KVM: Let host know whether the guest can handle async PF in non-userspace context.
If guest can detect that it runs in non-preemptable context it can
handle async PFs at any time, so let host know that it can send async
PF even if guest cpu is not in userspace.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:21 +02:00
Gleb Natapov
7c90705bf2 KVM: Inject asynchronous page fault into a PV guest if page is swapped out.
Send async page fault to a PV guest if it accesses swapped out memory.
Guest will choose another task to run upon receiving the fault.

Allow async page fault injection only when guest is in user mode since
otherwise guest may be in non-sleepable context and will not be able
to reschedule.

Vcpu will be halted if guest will fault on the same page again or if
vcpu executes kernel code.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:17 +02:00
Gleb Natapov
344d9588a9 KVM: Add PV MSR to enable asynchronous page faults delivery.
Guest enables async PF vcpu functionality using this MSR.

Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:12 +02:00
Gleb Natapov
49c7754ce5 KVM: Add memory slot versioning and use it to provide fast guest write interface
Keep track of memslots changes by keeping generation number in memslots
structure. Provide kvm_write_guest_cached() function that skips
gfn_to_hva() translation if memslots was not changed since previous
invocation.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:08 +02:00
Gleb Natapov
56028d0861 KVM: Retry fault before vmentry
When page is swapped in it is mapped into guest memory only after guest
tries to access it again and generate another fault. To save this fault
we can map it immediately since we know that guest is going to access
the page. Do it only when tdp is enabled for now. Shadow paging case is
more complicated. CR[034] and EFER registers should be switched before
doing mapping and then switched back.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:06 +02:00
Gleb Natapov
af585b921e KVM: Halt vcpu if page it tries to access is swapped out
If a guest accesses swapped out memory do not swap it in from vcpu thread
context. Schedule work to do swapping and put vcpu into halted state
instead.

Interrupts will still be delivered to the guest and if interrupt will
cause reschedule guest will continue to run another task.

[avi: remove call to get_user_pages_noio(), nacked by Linus; this
      makes everything synchrnous again]

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:21:39 +02:00
Linus Torvalds
72eb6a7914 Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
  gameport: use this_cpu_read instead of lookup
  x86: udelay: Use this_cpu_read to avoid address calculation
  x86: Use this_cpu_inc_return for nmi counter
  x86: Replace uses of current_cpu_data with this_cpu ops
  x86: Use this_cpu_ops to optimize code
  vmstat: User per cpu atomics to avoid interrupt disable / enable
  irq_work: Use per cpu atomics instead of regular atomics
  cpuops: Use cmpxchg for xchg to avoid lock semantics
  x86: this_cpu_cmpxchg and this_cpu_xchg operations
  percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
  percpu,x86: relocate this_cpu_add_return() and friends
  connector: Use this_cpu operations
  xen: Use this_cpu_inc_return
  taskstats: Use this_cpu_ops
  random: Use this_cpu_inc_return
  fs: Use this_cpu_inc_return in buffer.c
  highmem: Use this_cpu_xx_return() operations
  vmstat: Use this_cpu_inc_return for vm statistics
  x86: Support for this_cpu_add, sub, dec, inc_return
  percpu: Generic support for this_cpu_add, sub, dec, inc_return
  ...

Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
2011-01-07 17:02:58 -08:00
Avi Kivity
010c520e20 KVM: Don't reset mmu context unnecessarily when updating EFER
The only bit of EFER that affects the mmu is NX, and this is already
accounted for (LME only takes effect when changing cr0).

Based on a patch by Hillf Danton.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-02 12:05:15 +02:00
Tejun Heo
0a3aee0da4 x86: Use this_cpu_ops to optimize code
Go through x86 code and replace __get_cpu_var and get_cpu_var
instances that refer to a scalar and are not used for address
determinations.

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-30 12:20:28 +01:00
Avi Kivity
3e26f23091 KVM: Fix preemption counter leak in kvm_timer_init()
Based on a patch from Thomas Meyer.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-12-16 12:39:31 +02:00
Joerg Roedel
24d1b15f72 KVM: SVM: Do not report xsave in supported cpuid
To support xsave properly for the guest the SVM module need
software support for it. As long as this is not present do
not report the xsave as supported feature in cpuid.
As a side-effect this patch moves the bit() helper function
into the x86.h file so that it can be used in svm.c too.

KVM-Stable-Tag.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-12-08 17:28:37 +02:00
Sheng Yang
3ea3aa8cf6 KVM: Fix OSXSAVE after migration
CPUID's OSXSAVE is a mirror of CR4.OSXSAVE bit. We need to update the CPUID
after migration.

KVM-Stable-Tag.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-12-08 17:28:31 +02:00
Jan Kiszka
453d9c57e2 KVM: x86: Issue smp_call_function_many with preemption disabled
smp_call_function_many is specified to be called only with preemption
disabled. Fulfill this requirement.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-11-05 14:42:27 -02:00
Vasiliy Kulikov
97e69aa62f KVM: x86: fix information leak to userland
Structures kvm_vcpu_events, kvm_debugregs, kvm_pit_state2 and
kvm_clock_data are copied to userland with some padding and reserved
fields unitialized.  It leads to leaking of contents of kernel stack
memory.  We have to initialize them to zero.

In patch v1 Jan Kiszka suggested to fill reserved fields with zeros
instead of memset'ting the whole struct.  It makes sense as these
fields are explicitly marked as padding.  No more fields need zeroing.

KVM-Stable-Tag.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-11-05 14:42:27 -02:00
Michael S. Tsirkin
edde99ce05 KVM: Write protect memory after slot swap
I have observed the following bug trigger:

1. userspace calls GET_DIRTY_LOG
2. kvm_mmu_slot_remove_write_access is called and makes a page ro
3. page fault happens and makes the page writeable
   fault is logged in the bitmap appropriately
4. kvm_vm_ioctl_get_dirty_log swaps slot pointers

a lot of time passes

5. guest writes into the page
6. userspace calls GET_DIRTY_LOG

At point (5), bitmap is clean and page is writeable,
thus, guest modification of memory is not logged
and GET_DIRTY_LOG returns an empty bitmap.

The rule is that all pages are either dirty in the current bitmap,
or write-protected, which is violated here.

It seems that just moving kvm_mmu_slot_remove_write_access down
to after the slot pointer swap should fix this bug.

KVM-Stable-Tag.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-11-05 14:42:25 -02:00
Linus Torvalds
1765a1fe5d Merge branch 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (321 commits)
  KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pages
  KVM: Fix signature of kvm_iommu_map_pages stub
  KVM: MCE: Send SRAR SIGBUS directly
  KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED
  KVM: fix typo in copyright notice
  KVM: Disable interrupts around get_kernel_ns()
  KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address
  KVM: MMU: move access code parsing to FNAME(walk_addr) function
  KVM: MMU: audit: check whether have unsync sps after root sync
  KVM: MMU: audit: introduce audit_printk to cleanup audit code
  KVM: MMU: audit: unregister audit tracepoints before module unloaded
  KVM: MMU: audit: fix vcpu's spte walking
  KVM: MMU: set access bit for direct mapping
  KVM: MMU: cleanup for error mask set while walk guest page table
  KVM: MMU: update 'root_hpa' out of loop in PAE shadow path
  KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn()
  KVM: x86: Fix constant type in kvm_get_time_scale
  KVM: VMX: Add AX to list of registers clobbered by guest switch
  KVM guest: Move a printk that's using the clock before it's ready
  KVM: x86: TSC catchup mode
  ...
2010-10-24 12:47:25 -07:00
Huang Ying
5854dbca9b KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED
Now we have MCG_SER_P (and corresponding SRAO/SRAR MCE) support in
kernel and QEMU-KVM, the MCG_SER_P should be added into
KVM_MCE_CAP_SUPPORTED to make all these code really works.

Reported-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:15 +02:00
Nicolas Kaiser
9611c18777 KVM: fix typo in copyright notice
Fix typo in copyright notice.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:14 +02:00
Avi Kivity
395c6b0a9d KVM: Disable interrupts around get_kernel_ns()
get_kernel_ns() wants preemption disabled.  It doesn't make a lot of sense
during the get/set ioctls (no way to make them non-racy) but the callee wants
it.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:14 +02:00
Jan Kiszka
50933623e5 KVM: x86: Fix constant type in kvm_get_time_scale
Older gcc versions complain about the improper type (for x86-32), 4.5
seems to fix this silently. However, we should better use the right type
initially.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:08 +02:00
Zachary Amsden
c285545f81 KVM: x86: TSC catchup mode
Negate the effects of AN TYM spell while kvm thread is preempted by tracking
conversion factor to the highest TSC rate and catching the TSC up when it has
fallen behind the kernel view of time.  Note that once triggered, we don't
turn off catchup mode.

A slightly more clever version of this is possible, which only does catchup
when TSC rate drops, and which specifically targets only CPUs with broken
TSC, but since these all are considered unstable_tsc(), this patch covers
all necessary cases.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:05 +02:00
Zachary Amsden
34c238a1d1 KVM: x86: Rename timer function
This just changes some names to better reflect the usage they
will be given.  Separated out to keep confusion to a minimum.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:05 +02:00
Zachary Amsden
5f4e3f8827 KVM: x86: Make math work for other scales
The math in kvm_get_time_scale relies on the fact that
NSEC_PER_SEC < 2^32.  To use the same function to compute
arbitrary time scales, we must extend the first reduction
step to shrink the base rate to a 32-bit value, and
possibly reduce the scaled rate into a 32-bit as well.

Note we must take care to avoid an arithmetic overflow
when scaling up the tps32 value (this could not happen
with the fixed scaled value of NSEC_PER_SEC, but can
happen with scaled rates above 2^31.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:04 +02:00
Mohammed Gamal
63995653ad KVM: Add kvm_inject_realmode_interrupt() wrapper
This adds a wrapper function kvm_inject_realmode_interrupt() around the
emulator function emulate_int_real() to allow real mode interrupt injection.

[avi: initialize operand and address sizes before emulating interrupts]
[avi: initialize rip for real mode interrupt injection]
[avi: clear interrupt pending flag after emulating interrupt injection]

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:01 +02:00
Avi Kivity
f4f5105087 KVM: Convert PIC lock from raw spinlock to ordinary spinlock
The PIC code used to be called from preempt_disable() context, which
wasn't very good for PREEMPT_RT.  That is no longer the case, so move
back from raw_spinlock_t to spinlock_t.

Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:56 +02:00
Zachary Amsden
28e4639adf KVM: x86: Fix kvmclock bug
If preempted after kvmclock values are updated, but before hardware
virtualization is entered, the last tsc time as read by the guest is
never set.  It underflows the next time kvmclock is updated if there
has not yet been a successful entry / exit into hardware virt.

Fix this by simply setting last_tsc to the newly read tsc value so
that any computed nsec advance of kvmclock is nulled.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:56 +02:00
Joerg Roedel
0959ffacf3 KVM: MMU: Don't track nested fault info in error-code
This patch moves the detection whether a page-fault was
nested or not out of the error code and moves it into a
separate variable in the fault struct.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:55 +02:00
Avi Kivity
b463a6f744 KVM: Non-atomic interrupt injection
Change the interrupt injection code to work from preemptible, interrupts
enabled context.  This works by adding a ->cancel_injection() operation
that undoes an injection in case we were not able to actually enter the guest
(this condition could never happen with atomic injection).

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:54 +02:00
Avi Kivity
3842d135ff KVM: Check for pending events before attempting injection
Instead of blindly attempting to inject an event before each guest entry,
check for a possible event first in vcpu->requests.  Sites that can trigger
event injection are modified to set KVM_REQ_EVENT:

- interrupt, nmi window opening
- ppr updates
- i8259 output changes
- local apic irr changes
- rflags updates
- gif flag set
- event set on exit

This improves non-injecting entry performance, and sets the stage for
non-atomic injection.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:50 +02:00
Joerg Roedel
4c62a2dc92 KVM: X86: Report SVM bit to userspace only when supported
This patch fixes a bug in KVM where it _always_ reports the
support of the SVM feature to userspace. But KVM only
supports SVM on AMD hardware and only when it is enabled in
the kernel module. This patch fixes the wrong reporting.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:48 +02:00
Joerg Roedel
ff03a073e7 KVM: MMU: Add kvm_mmu parameter to load_pdptrs function
This function need to be able to load the pdptrs from any
mmu context currently in use. So change this function to
take an kvm_mmu parameter to fit these needs.
As a side effect this patch also moves the cached pdptrs
from vcpu_arch into the kvm_mmu struct.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:41 +02:00
Joerg Roedel
d47f00a62b KVM: X86: Propagate fetch faults
KVM currently ignores fetch faults in the instruction
emulator. With nested-npt we could have such faults. This
patch adds the code to handle these.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:41 +02:00
Joerg Roedel
d4f8cf664e KVM: MMU: Propagate the right fault back to the guest after gva_to_gpa
This patch implements logic to make sure that either a
page-fault/page-fault-vmexit or a nested-page-fault-vmexit
is propagated back to the guest.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:40 +02:00
Joerg Roedel
02f59dc9f1 KVM: MMU: Introduce init_kvm_nested_mmu()
This patch introduces the init_kvm_nested_mmu() function
which is used to re-initialize the nested mmu when the l2
guest changes its paging mode.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:39 +02:00
Joerg Roedel
3d06b8bfd4 KVM: MMU: Introduce kvm_read_nested_guest_page()
This patch introduces the kvm_read_guest_page_x86 function
which reads from the physical memory of the guest. If the
guest is running in guest-mode itself with nested paging
enabled it will read from the guest's guest physical memory
instead.
The patch also changes changes the code to use this function
where it is necessary.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:38 +02:00
Joerg Roedel
ec92fe44e7 KVM: X86: Add kvm_read_guest_page_mmu function
This patch adds a function which can read from the guests
physical memory or from the guest's guest physical memory.
This will be used in the two-dimensional page table walker.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:37 +02:00
Joerg Roedel
14dfe855f9 KVM: X86: Introduce pointer to mmu context used for gva_to_gpa
This patch introduces the walk_mmu pointer which points to
the mmu-context currently used for gva_to_gpa translations.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:35 +02:00
Joerg Roedel
c30a358d33 KVM: MMU: Add infrastructure for two-level page walker
This patch introduces a mmu-callback to translate gpa
addresses in the walk_addr code. This is later used to
translate l2_gpa addresses into l1_gpa addresses.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:34 +02:00
Joerg Roedel
8df25a328a KVM: MMU: Track page fault data in struct vcpu
This patch introduces a struct with two new fields in
vcpu_arch for x86:

	* fault.address
	* fault.error_code

This will be used to correctly propagate page faults back
into the guest when we could have either an ordinary page
fault or a nested page fault. In the case of a nested page
fault the fault-address is different from the original
address that should be walked. So we need to keep track
about the real fault-address.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:33 +02:00
Jes Sorensen
7b91409822 KVM: x86: Emulate MSR_EBC_FREQUENCY_ID
Some operating systems store data about the host processor at the
time of installation, and when booted on a more uptodate cpu tries
to read MSR_EBC_FREQUENCY_ID. This has been found with XP.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:27 +02:00
Jes Sorensen
84e0cefa8d KVM: Fix guest kernel crash on MSR_K7_CLK_CTL
MSR_K7_CLK_CTL is a no longer documented MSR, which is only relevant
on said old AMD CPU models. This change returns the expected value,
which the Linux kernel is expecting to avoid writing back the MSR,
plus it ignores all writes to the MSR.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:55 +02:00
Avi Kivity
e90aa41e6c KVM: Don't save/restore MSR_IA32_PERF_STATUS
It is read/only; restoring it only results in annoying messages.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:51 +02:00
Avi Kivity
c41a15dd46 KVM: Fix pio trace direction
out = write, in = read, not the other way round.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:49 +02:00
Avi Kivity
217fc9cfca KVM: Fix build error due to 64-bit division in nsec_to_cycles()
Use do_div() instead.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:43 +02:00
Gleb Natapov
d2ddd1c483 KVM: x86 emulator: get rid of "restart" in emulation context.
x86_emulate_insn() will return 1 if instruction can be restarted
without re-entering a guest.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:34 +02:00
Zachary Amsden
1d5f066e0b KVM: x86: Fix a possible backwards warp of kvmclock
Kernel time, which advances in discrete steps may progress much slower
than TSC.  As a result, when kvmclock is adjusted to a new base, the
apparent time to the guest, which runs at a much higher, nsec scaled
rate based on the current TSC, may have already been observed to have
a larger value (kernel_ns + scaled tsc) than the value to which we are
setting it (kernel_ns + 0).

We must instead compute the clock as potentially observed by the guest
for kernel_ns to make sure it does not go backwards.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:24 +02:00
Zachary Amsden
ca84d1a24c KVM: x86: Add clock sync request to hardware enable
If there are active VCPUs which are marked as belonging to
a particular hardware CPU, request a clock sync for them when
enabling hardware; the TSC could be desynchronized on a newly
arriving CPU, and we need to recompute guests system time
relative to boot after a suspend event.

This covers both cases.

Note that it is acceptable to take the spinlock, as either
no other tasks will be running and no locks held (BSP after
resume), or other tasks will be guaranteed to drop the lock
relatively quickly (AP on CPU_STARTING).

Noting we now get clock synchronization requests for VCPUs
which are starting up (or restarting), it is tempting to
attempt to remove the arch/x86/kvm/x86.c CPU hot-notifiers
at this time, however it is not correct to do so; they are
required for systems with non-constant TSC as the frequency
may not be known immediately after the processor has started
until the cpufreq driver has had a chance to run and query
the chipset.

Updated: implement better locking semantics for hardware_enable

Removed the hack of dropping and retaking the lock by adding the
semantic that we always hold kvm_lock when hardware_enable is
called.  The one place that doesn't need to worry about it is
resume, as resuming a frozen CPU, the spinlock won't be taken.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:24 +02:00
Zachary Amsden
46543ba45f KVM: x86: Robust TSC compensation
Make the match of TSC find TSC writes that are close to each other
instead of perfectly identical; this allows the compensator to also
work in migration / suspend scenarios.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:23 +02:00
Zachary Amsden
759379dd68 KVM: x86: Add helper functions for time computation
Add a helper function to compute the kernel time and convert nanoseconds
back to CPU specific cycles.  Note that these must not be called in preemptible
context, as that would mean the kernel could enter software suspend state,
which would cause non-atomic operation.

Also, convert the KVM_SET_CLOCK / KVM_GET_CLOCK ioctls to use the kernel
time helper, these should be bootbased as well.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:23 +02:00
Zachary Amsden
48434c20e1 KVM: x86: Fix deep C-state TSC desynchronization
When CPUs with unstable TSCs enter deep C-state, TSC may stop
running.  This causes us to require resynchronization.  Since
we can't tell when this may potentially happen, we assume the
worst by forcing re-compensation for it at every point the VCPU
task is descheduled.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:23 +02:00
Zachary Amsden
e48672fa25 KVM: x86: Unify TSC logic
Move the TSC control logic from the vendor backends into x86.c
by adding adjust_tsc_offset to x86 ops.  Now all TSC decisions
can be done in one place.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:23 +02:00
Zachary Amsden
6755bae8e6 KVM: x86: Warn about unstable TSC
If creating an SMP guest with unstable host TSC, issue a warning

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:22 +02:00
Zachary Amsden
8cfdc00085 KVM: x86: Make cpu_tsc_khz updates use local CPU
This simplifies much of the init code; we can now simply always
call tsc_khz_changed, optionally passing it a new value, or letting
it figure out the existing value (while interrupts are disabled, and
thus, by inference from the rule, not raceful against CPU hotplug or
frequency updates, which will issue IPIs to the local CPU to perform
this very same task).

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:22 +02:00
Zachary Amsden
f38e098ff3 KVM: x86: TSC reset compensation
Attempt to synchronize TSCs which are reset to the same value.  In the
case of a reliable hardware TSC, we can just re-use the same offset, but
on non-reliable hardware, we can get closer by adjusting the offset to
match the elapsed time.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:22 +02:00
Zachary Amsden
99e3e30aee KVM: x86: Move TSC offset writes to common code
Also, ensure that the storing of the offset and the reading of the TSC
are never preempted by taking a spinlock.  While the lock is overkill
now, it is useful later in this patch series.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:22 +02:00
Zachary Amsden
ae38436b78 KVM: x86: Drop vm_init_tsc
This is used only by the VMX code, and is not done properly;
if the TSC is indeed backwards, it is out of sync, and will
need proper handling in the logic at each and every CPU change.
For now, drop this test during init as misguided.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:21 +02:00
Dave Hansen
39de71ec53 KVM: rename x86 kvm->arch.n_alloc_mmu_pages
arch.n_alloc_mmu_pages is a poor choice of name. This value truly
means, "the number of pages which _may_ be allocated".  But,
reading the name, "n_alloc_mmu_pages" implies "the number of allocated
mmu pages", which is dead wrong.

It's really the high watermark, so let's give it a name to match:
nr_max_mmu_pages.  This change will make the next few patches
much more obvious and easy to read.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:18 +02:00
Mohammed Gamal
8ec4722dd2 KVM: Separate emulation context initialization in a separate function
The code for initializing the emulation context is duplicated at two
locations (emulate_instruction() and kvm_task_switch()). Separate it
in a separate function and call it from there.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:04 +02:00
Mohammed Gamal
160ce1f1a8 KVM: x86 emulator: Allow accessing IDT via emulator ops
The patch adds a new member get_idt() to x86_emulate_ops.
It also adds a function to get the idt in order to be used by the emulator.

This is needed for real mode interrupt injection and the emulation of int
instructions.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:50:59 +02:00
Gleb Natapov
4fc40f076f KVM: x86 emulator: check io permissions only once for string pio
Do not recheck io permission on every iteration.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:50:29 +02:00
Gleb Natapov
e85d28f8e8 KVM: x86 emulator: don't update vcpu state if instruction is restarted
No need to update vcpu state since instruction is in the middle of the
emulation.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:50:27 +02:00
Avi Kivity
9aabc88fc8 KVM: x86 emulator: store x86_emulate_ops in emulation context
It doesn't ever change, so we don't need to pass it around everywhere.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:50:21 +02:00
Andre Przywara
6d886fd042 x86, cpu: Fix allowed CPUID bits for KVM guests
The AMD extensions to AVX (FMA4, XOP) work on the same YMM register set
as AVX, so they are safe for guests to use, as long as AVX itself
is allowed. Add F16C and AES on the way for the same reasons.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
LKML-Reference: <1283778860-26843-4-git-send-email-andre.przywara@amd.com>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-09-08 13:34:15 -07:00
Andre Przywara
7ef8aa72ab x86, cpu: Fix renamed, not-yet-shipping AMD CPUID feature bit
The AMD SSE5 feature set as-it has been replaced by some extensions
to the AVX instruction set. Thus the bit formerly advertised as SSE5
is re-used for one of these extensions (XOP).
Although this changes the /proc/cpuinfo output, it is not user visible, as
there are no CPUs (yet) having this feature.
To avoid confusion this should be added to the stable series, too.

Cc: stable@kernel.org [.32.x .34.x, .35.x]
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
LKML-Reference: <1283778860-26843-2-git-send-email-andre.przywara@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-09-08 13:32:55 -07:00
Linus Torvalds
3dc8d7f07e Merge branch 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: PIT: free irq source id in handling error path
  KVM: destroy workqueue on kvm_create_pit() failures
  KVM: fix poison overwritten caused by using wrong xstate size
2010-08-22 11:27:36 -07:00
Xiaotian Feng
f45755b834 KVM: fix poison overwritten caused by using wrong xstate size
fpu.state is allocated from task_xstate_cachep, the size of task_xstate_cachep
is xstate_size. xstate_size is set from cpuid instruction, which is often
smaller than sizeof(struct xsave_struct). kvm is using sizeof(struct xsave_struct)
to fill in/out fpu.state.xsave, as what we allocated for fpu.state is
xstate_size, kernel will write out of memory and caused poison/redzone/padding
overwritten warnings.

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Reviewed-by: Sheng Yang <sheng@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Sheng Yang <sheng@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-15 14:10:15 +03:00
Linus Torvalds
d9a73c0016 Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  um, x86: Cast to (u64 *) inside set_64bit()
  x86-32, asm: Directly access per-cpu GDT
  x86-64, asm: Directly access per-cpu IST
  x86, asm: Merge cmpxchg_486_u64() and cmpxchg8b_emu()
  x86, asm: Move cmpxchg emulation code to arch/x86/lib
  x86, asm: Clean up and simplify <asm/cmpxchg.h>
  x86, asm: Clean up and simplify set_64bit()
  x86: Add memory modify constraints to xchg() and cmpxchg()
  x86-64: Simplify loading initial_gs
  x86: Use symbolic MSR names
  x86: Remove redundant K6 MSRs
2010-08-06 10:07:34 -07:00
Wei Yongjun
c19b8bd60e KVM: x86 emulator: fix xchg instruction emulation
If the destination is a memory operand and the memory cannot
map to a valid page, the xchg instruction emulation and locked
instruction will not work on io regions and stuck in endless
loop. We should emulate exchange as write to fix it.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-02 06:40:53 +03:00
Gleb Natapov
68be080345 KVM: x86: never re-execute instruction with enabled tdp
With tdp enabled we should get into emulator only when emulating io, so
reexecution will always bring us back into emulator.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-02 06:40:51 +03:00
Avi Kivity
908e75f3e7 KVM: Expose MCE control MSRs to userspace
Userspace needs to reset and save/restore these MSRs.

The MCE banks are not exposed since their number varies from vcpu to vcpu.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-02 06:40:36 +03:00
Xiao Guangrong
aea924f606 KVM: PIT: stop vpit before freeing irq_routing
Fix:
general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
......
Call Trace:
 [<ffffffffa0159bd1>] ? kvm_set_irq+0xdd/0x24b [kvm]
 [<ffffffff8106ea8b>] ? trace_hardirqs_off_caller+0x1f/0x10e
 [<ffffffff813ad17f>] ? sub_preempt_count+0xe/0xb6
 [<ffffffff8106d273>] ? put_lock_stats+0xe/0x27
...
RIP  [<ffffffffa0159c72>] kvm_set_irq+0x17e/0x24b [kvm]

This bug is triggered when guest is shutdown, is because we freed
irq_routing before pit thread stopped

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-02 06:40:35 +03:00
Gleb Natapov
a6f177efaa KVM: Reenter guest after emulation failure if due to access to non-mmio address
When shadow pages are in use sometimes KVM try to emulate an instruction
when it accesses a shadowed page. If emulation fails KVM un-shadows the
page and reenter guest to allow vcpu to execute the instruction. If page
is not in shadow page hash KVM assumes that this was attempt to do MMIO
and reports emulation failure to userspace since there is no way to fix
the situation. This logic has a race though. If two vcpus tries to write
to the same shadowed page simultaneously both will enter emulator, but
only one of them will find the page in shadow page hash since the one who
founds it also removes it from there, so another cpu will report failure
to userspace and will abort the guest.

Fix this by checking (in addition to checking shadowed page hash) that
page that caused the emulation belongs to valid memory slot. If it is
then reenter the guest to allow vcpu to reexecute the instruction.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-02 06:40:34 +03:00
Sheng Yang
f5f48ee15c KVM: VMX: Execute WBINVD to keep data consistency with assigned devices
Some guest device driver may leverage the "Non-Snoop" I/O, and explicitly
WBINVD or CLFLUSH to a RAM space. Since migration may occur before WBINVD or
CLFLUSH, we need to maintain data consistency either by:
1: flushing cache (wbinvd) when the guest is scheduled out if there is no
wbinvd exit, or
2: execute wbinvd on all dirty physical CPUs when guest wbinvd exits.

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:47:21 +03:00
Avi Kivity
3e00750947 KVM: Simplify vcpu_enter_guest() mmu reload logic slightly
No need to reload the mmu in between two different vcpu->requests checks.

kvm_mmu_reload() may trigger KVM_REQ_TRIPLE_FAULT, but that will be caught
during atomic guest entry later.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:47:19 +03:00
Sheng Yang
6c3f604117 KVM: x86: Enable AVX for guest
Enable Intel(R) Advanced Vector Extension(AVX) for guest.

The detection of AVX feature includes OSXSAVE bit testing. When OSXSAVE bit is
not set, even if AVX is supported, the AVX instruction would result in UD as
well. So we're safe to expose AVX bits to guest directly.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:47:10 +03:00
Avi Kivity
7ac77099ce KVM: Prevent internal slots from being COWed
If a process with a memory slot is COWed, the page will change its address
(despite having an elevated reference count).  This breaks internal memory
slots which have their physical addresses loaded into vmcs registers (see
the APIC access memory slot).

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:47:08 +03:00
Avi Kivity
a8eeb04a44 KVM: Add mini-API for vcpu->requests
Makes it a little more readable and hackable.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:47:05 +03:00
Avi Kivity
b74a07beed KVM: Remove kernel-allocated memory regions
Equivalent (and better) functionality is provided by user-allocated memory
regions.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:47:01 +03:00
Avi Kivity
a1f4d39500 KVM: Remove memory alias support
As advertised in feature-removal-schedule.txt.  Equivalent support is provided
by overlapping memory regions.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:47:00 +03:00
Avi Kivity
d1ac91d8a2 KVM: Consolidate load/save temporary buffer allocation and freeing
Instead of three temporary variables and three free calls, have one temporary
variable (with four names) and one free call.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:46:57 +03:00
Avi Kivity
a1a005f36e KVM: Fix xsave and xcr save/restore memory leak
We allocate temporary kernel buffers for these structures, but never free them.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:46:56 +03:00
Sheng Yang
2d5b5a6655 KVM: x86: XSAVE/XRSTOR live migration support
This patch enable save/restore of xsave state.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:46:37 +03:00
Avi Kivity
2390218b6a KVM: Fix mov cr3 #GP at wrong instruction
On Intel, we call skip_emulated_instruction() even if we injected a #GP,
resulting in the #GP pointing at the wrong address.

Fix by injecting the exception and skipping the instruction at the same place,
so we can do just one or the other.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:46:35 +03:00
Avi Kivity
a83b29c6ad KVM: Fix mov cr4 #GP at wrong instruction
On Intel, we call skip_emulated_instruction() even if we injected a #GP,
resulting in the #GP pointing at the wrong address.

Fix by injecting the exception and skipping the instruction at the same place,
so we can do just one or the other.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:46:34 +03:00
Avi Kivity
49a9b07edc KVM: Fix mov cr0 #GP at wrong instruction
On Intel, we call skip_emulated_instruction() even if we injected a #GP,
resulting in the #GP pointing at the wrong address.

Fix by injecting the exception and skipping the instruction at the same place,
so we can do just one or the other.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:46:32 +03:00
Dexuan Cui
2acf923e38 KVM: VMX: Enable XSAVE/XRSTOR for guest
This patch enable guest to use XSAVE/XRSTOR instructions.

We assume that host_xcr0 would use all possible bits that OS supported.

And we loaded xcr0 in the same way we handled fpu - do it as late as we can.

Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:46:31 +03:00
Lai Jiangshan
7bee342a9e KVM: x86: use linux/uaccess.h instead of asm/uaccess.h
Should use linux/uaccess.h instead of asm/uaccess.h

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:39:25 +03:00
Jan Kiszka
10ab25cd6b KVM: x86: Propagate fpu_alloc errors
Memory allocation may fail. Propagate such errors.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:39:22 +03:00
Avi Kivity
221d059d15 KVM: Update Red Hat copyrights
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:51 +03:00
Sheng Yang
98918833a3 KVM: x86: Use FPU API
Convert KVM to use generic FPU API.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:49 +03:00
Sheng Yang
7cf30855e0 KVM: x86: Use unlazy_fpu() for host FPU
We can avoid unnecessary fpu load when userspace process
didn't use FPU frequently.

Derived from Avi's idea.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:48 +03:00
Avi Kivity
9373662463 KVM: Consolidate arch specific vcpu ioctl locking
Now that all arch specific ioctls have centralized locking, it is easy to
move it to the central dispatcher.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:48 +03:00
Avi Kivity
526b78ad1a KVM: x86: Lock arch specific vcpu ioctls centrally
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:47 +03:00
Avi Kivity
2122ff5eab KVM: move vcpu locking to dispatcher for generic vcpu ioctls
All vcpu ioctls need to be locked, so instead of locking each one specifically
we lock at the generic dispatcher.

This patch only updates generic ioctls and leaves arch specific ioctls alone.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:47 +03:00
Xiao Guangrong
1683b2416e KVM: x86: cleanup unused local variable
fix:
 arch/x86/kvm/x86.c: In function ‘handle_emulation_failure’:
 arch/x86/kvm/x86.c:3844: warning: unused variable ‘ctxt’

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:35:46 +03:00
Sheng Yang
aad827034e KVM: VMX: Only reset MMU when necessary
Only modifying some bits of CR0/CR4 needs paging mode switch.

Modify EFER.NXE bit would result in reserved bit updates.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:35:45 +03:00
Sheng Yang
62ad07551a KVM: x86: Clean up duplicate assignment
mmu.free() already set root_hpa to INVALID_PAGE, no need to do it again in the
destory_kvm_mmu().

kvm_x86_ops->set_cr4() and set_efer() already assign cr4/efer to
vcpu->arch.cr4/efer, no need to do it again later.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:35:44 +03:00
Gleb Natapov
6d77dbfc88 KVM: inject #UD if instruction emulation fails and exit to userspace
Do not kill VM when instruction emulation fails. Inject #UD and report
failure to userspace instead. Userspace may choose to reenter guest if
vcpu is in userspace (cpl == 3) in which case guest OS will kill
offending process and continue running.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:35:40 +03:00
Avi Kivity
d94e1dc9af KVM: Get rid of KVM_REQ_KICK
KVM_REQ_KICK poisons vcpu->requests by having a bit set during normal
operation.  This causes the fast path check for a clear vcpu->requests
to fail all the time, triggering tons of atomic operations.

Fix by replacing KVM_REQ_KICK with a vcpu->guest_mode atomic.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:37 +03:00
Gleb Natapov
54b8486f46 KVM: x86 emulator: do not inject exception directly into vcpu
Return exception as a result of instruction emulation and handle
injection in KVM code.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:37 +03:00
Gleb Natapov
95cb229530 KVM: x86 emulator: move interruptibility state tracking out of emulator
Emulator shouldn't access vcpu directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:36 +03:00
Gleb Natapov
4d2179e1e9 KVM: x86 emulator: handle shadowed registers outside emulator
Emulator shouldn't access vcpu directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:36 +03:00
Gleb Natapov
ef050dc039 KVM: x86 emulator: set RFLAGS outside x86 emulator code
Removes the need for set_flags() callback.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:35 +03:00
Gleb Natapov
95c5588652 KVM: x86 emulator: advance RIP outside x86 emulator code
Return new RIP as part of instruction emulation result instead of
updating KVM's RIP from x86 emulator code.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:35 +03:00
Gleb Natapov
3457e4192e KVM: handle emulation failure case first
If emulation failed return immediately.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:34 +03:00
Gleb Natapov
8fe681e984 KVM: do not inject #PF in (read|write)_emulated() callbacks
Return error to x86 emulator instead of injection exception behind its back.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:34 +03:00
Gleb Natapov
f181b96d4c KVM: remove export of emulator_write_emulated()
It is not called directly outside of the file it's defined in anymore.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:34 +03:00
Gleb Natapov
c3cd7ffaf5 KVM: x86 emulator: x86_emulate_insn() return -1 only in case of emulation failure
Currently emulator returns -1 when emulation failed or IO is needed.
Caller tries to guess whether emulation failed by looking at other
variables. Make it easier for caller to recognise error condition by
always returning -1 in case of failure. For this new emulator
internal return value X86EMUL_IO_NEEDED is introduced. It is used to
distinguish between error condition (which returns X86EMUL_UNHANDLEABLE)
and condition that requires IO exit to userspace to continue emulation.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:33 +03:00
Gleb Natapov
411c35b7ef KVM: fill in run->mmio details in (read|write)_emulated function
Fill in run->mmio details in (read|write)_emulated function just like
pio does. There is no point in filling only vcpu fields there just to
copy them into vcpu->run a little bit later.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:33 +03:00
Gleb Natapov
338dbc9781 KVM: x86 emulator: make (get|set)_dr() callback return error if it fails
Make (get|set)_dr() callback return error if it fails instead of
injecting exception behind emulator's back.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:32 +03:00
Gleb Natapov
0f12244fe7 KVM: x86 emulator: make set_cr() callback return error if it fails
Make set_cr() callback return error if it fails instead of injecting #GP
behind emulator's back.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:31 +03:00
Gleb Natapov
5951c44237 KVM: x86 emulator: add get_cached_segment_base() callback to x86_emulate_ops
On VMX it is expensive to call get_cached_descriptor() just to get segment
base since multiple vmcs_reads are done instead of only one. Introduce
new call back get_cached_segment_base() for efficiency.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:31 +03:00
Gleb Natapov
3fb1b5dbd3 KVM: x86 emulator: add (set|get)_msr callbacks to x86_emulate_ops
Add (set|get)_msr callbacks to x86_emulate_ops instead of calling
them directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:30 +03:00
Gleb Natapov
35aa5375d4 KVM: x86 emulator: add (set|get)_dr callbacks to x86_emulate_ops
Add (set|get)_dr callbacks to x86_emulate_ops instead of calling
them directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:30 +03:00
Avi Kivity
1c11e71357 KVM: VMX: Avoid writing HOST_CR0 every entry
cr0.ts may change between entries, so we copy cr0 to HOST_CR0 before each
entry.  That is slow, so instead, set HOST_CR0 to have TS set unconditionally
(which is a safe value), and issue a clts() just before exiting vcpu context
if the task indeed owns the fpu.

Saves ~50 cycles/exit.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:28 +03:00
Takuya Yoshikawa
914ebccd2d KVM: x86: avoid unnecessary bitmap allocation when memslot is clean
Although we always allocate a new dirty bitmap in x86's get_dirty_log(),
it is only used as a zero-source of copy_to_user() and freed right after
that when memslot is clean. This patch uses clear_user() instead of doing
this unnecessary zero-source allocation.

Performance improvement: as we can expect easily, the time needed to
allocate a bitmap is completely reduced. In my test, the improved ioctl
was about 4 to 10 times faster than the original one for clean slots.
Furthermore, reducing memory allocations and copies will produce good
effects to caches too.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:27 +03:00
H. Peter Anvin
d3608b5681 Merge remote branch 'origin/x86/urgent' into x86/asm 2010-07-27 23:28:28 -07:00
Avi Kivity
7a73c0283d KVM: Use kmalloc() instead of vmalloc() for KVM_[GS]ET_MSR
We don't need more than a page, and vmalloc() is slower (much
slower recently due to a regression).

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-07-23 09:07:14 +03:00
Brian Gerst
8c06585d64 x86: Remove redundant K6 MSRs
MSR_K6_EFER is unused, and MSR_K6_STAR is redundant with MSR_STAR.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1279371808-24804-1-git-send-email-brgerst@gmail.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-07-21 21:23:05 -07:00
Linus Torvalds
98edb6ca41 Merge branch 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (269 commits)
  KVM: x86: Add missing locking to arch specific vcpu ioctls
  KVM: PPC: Add missing vcpu_load()/vcpu_put() in vcpu ioctls
  KVM: MMU: Segregate shadow pages with different cr0.wp
  KVM: x86: Check LMA bit before set_efer
  KVM: Don't allow lmsw to clear cr0.pe
  KVM: Add cpuid.txt file
  KVM: x86: Tell the guest we'll warn it about tsc stability
  x86, paravirt: don't compute pvclock adjustments if we trust the tsc
  x86: KVM guest: Try using new kvm clock msrs
  KVM: x86: export paravirtual cpuid flags in KVM_GET_SUPPORTED_CPUID
  KVM: x86: add new KVMCLOCK cpuid feature
  KVM: x86: change msr numbers for kvmclock
  x86, paravirt: Add a global synchronization point for pvclock
  x86, paravirt: Enable pvclock flags in vcpu_time_info structure
  KVM: x86: Inject #GP with the right rip on efer writes
  KVM: SVM: Don't allow nested guest to VMMCALL into host
  KVM: x86: Fix exception reinjection forced to true
  KVM: Fix wallclock version writing race
  KVM: MMU: Don't read pdptrs with mmu spinlock held in mmu_alloc_roots
  KVM: VMX: enable VMXON check with SMX enabled (Intel TXT)
  ...
2010-05-21 17:16:21 -07:00
Avi Kivity
8fbf065d62 KVM: x86: Add missing locking to arch specific vcpu ioctls
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-19 11:41:11 +03:00
Sheng Yang
a3d204e285 KVM: x86: Check LMA bit before set_efer
kvm_x86_ops->set_efer() would execute vcpu->arch.efer = efer, so the
checking of LMA bit didn't work.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-19 11:41:09 +03:00
Avi Kivity
f78e917688 KVM: Don't allow lmsw to clear cr0.pe
The current lmsw implementation allows the guest to clear cr0.pe, contrary
to the manual, which breaks EMM386.EXE.

Fix by ORing the old cr0.pe with lmsw's operand.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-19 11:41:08 +03:00
Glauber Costa
371bcf646d KVM: x86: Tell the guest we'll warn it about tsc stability
This patch puts up the flag that tells the guest that we'll warn it
about the tsc being trustworthy or not. By now, we also say
it is not.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-19 11:41:06 +03:00
Glauber Costa
84478c829d KVM: x86: export paravirtual cpuid flags in KVM_GET_SUPPORTED_CPUID
Right now, we were using individual KVM_CAP entities to communicate
userspace about which cpuids we support. This is suboptimal, since it
generates a delay between the feature arriving in the host, and
being available at the guest.

A much better mechanism is to list para features in KVM_GET_SUPPORTED_CPUID.
This makes userspace automatically aware of what we provide. And if we
ever add a new cpuid bit in the future, we have to do that again,
which create some complexity and delay in feature adoption.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-19 11:41:03 +03:00
Glauber Costa
11c6bffa42 KVM: x86: change msr numbers for kvmclock
Avi pointed out a while ago that those MSRs falls into the pentium
PMU range. So the idea here is to add new ones, and after a while,
deprecate the old ones.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-19 11:41:01 +03:00
Roedel, Joerg
b69e8caef5 KVM: x86: Inject #GP with the right rip on efer writes
This patch fixes a bug in the KVM efer-msr write path. If a
guest writes to a reserved efer bit the set_efer function
injects the #GP directly. The architecture dependent wrmsr
function does not see this, assumes success and advances the
rip. This results in a #GP in the guest with the wrong rip.
This patch fixes this by reporting efer write errors back to
the architectural wrmsr function.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-19 11:36:39 +03:00
Joerg Roedel
3f0fd2927b KVM: x86: Fix exception reinjection forced to true
The patch merged recently which allowed to mark an exception
as reinjected has a bug as it always marks the exception as
reinjected. This breaks nested-svm shadow-on-shadow
implementation.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-19 11:36:37 +03:00
Avi Kivity
9ed3c444ab KVM: Fix wallclock version writing race
Wallclock writing uses an unprotected global variable to hold the version;
this can cause one guest to interfere with another if both write their
wallclock at the same time.

Acked-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-19 11:36:36 +03:00
Marcelo Tosatti
f1d86e469b KVM: x86: properly update ready_for_interrupt_injection
The recent changes to emulate string instructions without entering guest
mode exposed a bug where pending interrupts are not properly reflected
in ready_for_interrupt_injection.

The result is that userspace overwrites a previously queued interrupt,
when irqchip's are emulated in userspace.

Fix by always updating state before returning to userspace.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-19 11:36:33 +03:00
Linus Torvalds
4d7b4ac22f Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits)
  perf tools: Add mode to build without newt support
  perf symbols: symbol inconsistency message should be done only at verbose=1
  perf tui: Add explicit -lslang option
  perf options: Type check all the remaining OPT_ variants
  perf options: Type check OPT_BOOLEAN and fix the offenders
  perf options: Check v type in OPT_U?INTEGER
  perf options: Introduce OPT_UINTEGER
  perf tui: Add workaround for slang < 2.1.4
  perf record: Fix bug mismatch with -c option definition
  perf options: Introduce OPT_U64
  perf tui: Add help window to show key associations
  perf tui: Make <- exit menus too
  perf newt: Add single key shortcuts for zoom into DSO and threads
  perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed
  perf newt: Fix the 'A'/'a' shortcut for annotate
  perf newt: Make <- exit the ui_browser
  x86, perf: P4 PMU - fix counters management logic
  perf newt: Make <- zoom out filters
  perf report: Report number of events, not samples
  perf hist: Clarify events_stats fields usage
  ...

Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
2010-05-18 08:19:03 -07:00
Joerg Roedel
ce7ddec4bb KVM: x86: Allow marking an exception as reinjected
This patch adds logic to kvm/x86 which allows to mark an
injected exception as reinjected. This allows to remove an
ugly hack from svm_complete_interrupts that prevented
exceptions from being reinjected at all in the nested case.
The hack was necessary because an reinjected exception into
the nested guest could cause a nested vmexit emulation. But
reinjected exceptions must not intercept. The downside of
the hack is that a exception that in injected could get
lost.
This patch fixes the problem and puts the code for it into
generic x86 files because. Nested-VMX will likely have the
same problem and could reuse the code.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:19:26 +03:00
Joerg Roedel
d4330ef2fb KVM: x86: Add callback to let modules decide over some supported cpuid bits
This patch adds the get_supported_cpuid callback to
kvm_x86_ops. It will be used in do_cpuid_ent to delegate the
decission about some supported cpuid bits to the
architecture modules.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:19:23 +03:00
Avi Kivity
8d3b932309 Merge remote branch 'tip/perf/core'
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:19:15 +03:00
Avi Kivity
87bc3bf972 KVM: MMU: Drop cr4.pge from shadow page role
Since commit bf47a760f6, we no longer handle ptes with the global bit
set specially, so there is no reason to distinguish between shadow pages
created with cr4.gpe set and clear.

Such tracking is expensive when the guest toggles cr4.pge, so drop it.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:18:03 +03:00
Lai Jiangshan
90d83dc3d4 KVM: use the correct RCU API for PROVE_RCU=y
The RCU/SRCU API have already changed for proving RCU usage.

I got the following dmesg when PROVE_RCU=y because we used incorrect API.
This patch coverts rcu_deference() to srcu_dereference() or family API.

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
2 locks held by qemu-system-x86/8550:
 #0:  (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm]
 #1:  (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm]

stack backtrace:
Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27
Call Trace:
 [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3
 [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm]
 [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm]
 [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm]
 [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm]
 [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel]
 [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm]
 [<ffffffff810a8692>] ? unlock_page+0x27/0x2c
 [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1
 [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm]
 [<ffffffff81060cfa>] ? up_read+0x23/0x3d
 [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6
 [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db
 [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241
 [<ffffffff810e416c>] ? do_sys_open+0x104/0x116
 [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13
 [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a
 [<ffffffff810021db>] system_call_fastpath+0x16/0x1b

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:18:01 +03:00
Avi Kivity
9beeaa2d68 Merge branch 'perf'
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:17:58 +03:00
Gleb Natapov
19d0443726 KVM: fix emulator_task_switch() return value.
emulator_task_switch() should return -1 for failure and 0 for success to
the caller, just like x86_emulate_insn() does.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:17:49 +03:00