Commit Graph

23 Commits

Author SHA1 Message Date
Gleb Natapov
62c49cc976 KVM: Do not take reference to mm during async #PF
It turned to be totally unneeded. The reason the code was introduced is
so that KVM can prefault swapped in page, but prefault can fail even
if mm is pinned since page table can change anyway. KVM handles this
situation correctly though and does not inject spurious page faults.

Fixes:
 "INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected" warning while
 running LTP inside a KVM guest using the recent -next kernel.

Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-06 15:00:02 +03:00
Gleb Natapov
e08759215b KVM: Resolve RCU vs. async page fault problem
"Page ready" async PF can kick vcpu out of idle state much like IRQ.
We need to tell RCU about this.

Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-05 19:26:14 +03:00
Ingo Molnar
c5905afb0e static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]()
So here's a boot tested patch on top of Jason's series that does
all the cleanups I talked about and turns jump labels into a
more intuitive to use facility. It should also address the
various misconceptions and confusions that surround jump labels.

Typical usage scenarios:

        #include <linux/static_key.h>

        struct static_key key = STATIC_KEY_INIT_TRUE;

        if (static_key_false(&key))
                do unlikely code
        else
                do likely code

Or:

        if (static_key_true(&key))
                do likely code
        else
                do unlikely code

The static key is modified via:

        static_key_slow_inc(&key);
        ...
        static_key_slow_dec(&key);

The 'slow' prefix makes it abundantly clear that this is an
expensive operation.

I've updated all in-kernel code to use this everywhere. Note
that I (intentionally) have not pushed through the rename
blindly through to the lowest levels: the actual jump-label
patching arch facility should be named like that, so we want to
decouple jump labels from the static-key facility a bit.

On non-jump-label enabled architectures static keys default to
likely()/unlikely() branches.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: a.p.zijlstra@chello.nl
Cc: mathieu.desnoyers@efficios.com
Cc: davem@davemloft.net
Cc: ddaney.cavm@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-24 10:05:59 +01:00
Chris Wright
5202397df8 KVM guest: remove KVM guest pv mmu support
This has not been used for some years now.  It's time to remove it.

Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:17:08 +02:00
Glauber Costa
d910f5c106 KVM guest: KVM Steal time registration
This patch implements the kvm bits of the steal time infrastructure.
The most important part of it, is the steal time clock. It is an
continuous clock that shows the accumulated amount of steal time
since vcpu creation. It is supposed to survive cpu offlining/onlining.

[marcelo: fix build with CONFIG_KVM_GUEST=n]

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Eric B Munson <emunson@mgebm.net>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Avi Kivity <avi@redhat.com>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-24 11:49:36 +03:00
Sedat Dilek
775077a063 KVM guest: Fix section mismatch derived from kvm_guest_cpu_online()
WARNING: arch/x86/built-in.o(.text+0x1bb74): Section mismatch in reference from the function kvm_guest_cpu_online() to the function .cpuinit.text:kvm_guest_cpu_init()
The function kvm_guest_cpu_online() references
the function __cpuinit kvm_guest_cpu_init().
This is often because kvm_guest_cpu_online lacks a __cpuinit
annotation or the annotation of kvm_guest_cpu_init is wrong.

This patch fixes the warning.

Tested with linux-next (next-20101231)

Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:25 -03:00
Avi Kivity
a63512a4d7 KVM guest: Fix kvm clock initialization when it's configured out
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:30:56 +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
6c047cd982 KVM paravirt: Handle async PF in non preemptable context
If async page fault is received by idle task or when preemp_count is
not zero guest cannot reschedule, so do sti; hlt and wait for page to be
ready. vcpu can still process interrupts while it waits for the page to
be ready.

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 11:23:19 +02:00
Gleb Natapov
631bc48782 KVM: Handle async PF in a guest.
When async PF capability is detected hook up special page fault handler
that will handle async page fault events and bypass other page faults to
regular page fault handler. Also add async PF handling to nested SVM
emulation. Async PF always generates exit to L1 where vcpu thread will
be scheduled out until page is available.

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 11:23:16 +02:00
Gleb Natapov
fd10cde929 KVM paravirt: Add async PF initialization to PV guest.
Enable async PF in a guest if async PF capability is discovered.

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 11:23:14 +02:00
Gleb Natapov
ca3f10172e KVM paravirt: Move kvm_smp_prepare_boot_cpu() from kvmclock.c to kvm.c.
Async PF also needs to hook into smp_prepare_boot_cpu so move the hook
into generic 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 11:23:10 +02:00
Marcelo Tosatti
6ba6617875 KVM guest: do not batch pte updates from interrupt context
Commit b8bcfe997e made paravirt pte updates synchronous in interrupt
context.

Unfortunately the KVM pv mmu code caches the lazy/nonlazy mode
internally, so a pte update from interrupt context during a lazy mmu
operation can be batched while it should be performed synchronously.

https://bugzilla.redhat.com/show_bug.cgi?id=518022

Drop the internal mode variable and use paravirt_get_lazy_mode(), which
returns the correct state.

Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 18:10:50 +03:00
Rakib Mullick
d3ac88157c x86, kvm: Fix section mismatches in kvm.c
The function paravirt_ops_setup() has been refering the
variable no_timer_check, which is a __initdata. Thus generates
the following warning. paravirt_ops_setup() function is called
from kvm_guest_init() which is a __init function. So to fix
this we mark paravirt_ops_setup as __init.

The sections-check output that warned us about this was:

   LD      arch/x86/built-in.o
  WARNING: arch/x86/built-in.o(.text+0x166ce): Section mismatch in
  reference from the function paravirt_ops_setup() to the variable
  .init.data:no_timer_check
  The function paravirt_ops_setup() references
  the variable __initdata no_timer_check.
  This is often because paravirt_ops_setup lacks a __initdata
  annotation or the annotation of no_timer_check is wrong.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Acked-by: Avi Kivity <avi@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <b9df5fa10907012240y356427b8ta4bd07f0efc6a049@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-03 14:34:22 +02:00
Linus Torvalds
6cd8e300b4 Merge branch 'kvm-updates/2.6.31' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.31' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (138 commits)
  KVM: Prevent overflow in largepages calculation
  KVM: Disable large pages on misaligned memory slots
  KVM: Add VT-x machine check support
  KVM: VMX: Rename rmode.active to rmode.vm86_active
  KVM: Move "exit due to NMI" handling into vmx_complete_interrupts()
  KVM: Disable CR8 intercept if tpr patching is active
  KVM: Do not migrate pending software interrupts.
  KVM: inject NMI after IRET from a previous NMI, not before.
  KVM: Always request IRQ/NMI window if an interrupt is pending
  KVM: Do not re-execute INTn instruction.
  KVM: skip_emulated_instruction() decode instruction if size is not known
  KVM: Remove irq_pending bitmap
  KVM: Do not allow interrupt injection from userspace if there is a pending event.
  KVM: Unprotect a page if #PF happens during NMI injection.
  KVM: s390: Verify memory in kvm run
  KVM: s390: Sanity check on validity intercept
  KVM: s390: Unlink vcpu on destroy - v2
  KVM: s390: optimize float int lock: spin_lock_bh --> spin_lock
  KVM: s390: use hrtimer for clock wakeup from idle - v2
  KVM: s390: Fix memory slot versus run - v3
  ...
2009-06-11 10:03:30 -07:00
Marcelo Tosatti
a90ede7b17 KVM: x86: paravirt skip pit-through-ioapic boot check
Skip the test which checks if the PIT is properly routed when
using the IOAPIC, aimed at buggy hardware.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:24 +03:00
Jeremy Fitzhardinge
38f4b8c0da Merge commit 'origin/master' into for-linus/xen/master
* commit 'origin/master': (4825 commits)
  Fix build errors due to CONFIG_BRANCH_TRACER=y
  parport: Use the PCI IRQ if offered
  tty: jsm cleanups
  Adjust path to gpio headers
  KGDB_SERIAL_CONSOLE check for module
  Change KCONFIG name
  tty: Blackin CTS/RTS
  Change hardware flow control from poll to interrupt driven
  Add support for the MAX3100 SPI UART.
  lanana: assign a device name and numbering for MAX3100
  serqt: initial clean up pass for tty side
  tty: Use the generic RS485 ioctl on CRIS
  tty: Correct inline types for tty_driver_kref_get()
  splice: fix deadlock in splicing to file
  nilfs2: support nanosecond timestamp
  nilfs2: introduce secondary super block
  nilfs2: simplify handling of active state of segments
  nilfs2: mark minor flag for checkpoint created by internal operation
  nilfs2: clean up sketch file
  nilfs2: super block operations fix endian bug
  ...

Conflicts:
	arch/x86/include/asm/thread_info.h
	arch/x86/lguest/boot.c
	drivers/xen/manage.c
2009-04-07 13:34:16 -07:00
Jeremy Fitzhardinge
b407fc57b8 x86/paravirt: flush pending mmu updates on context switch
Impact: allow preemption during lazy mmu updates

If we're in lazy mmu mode when context switching, leave
lazy mmu mode, but remember the task's state in
TIF_LAZY_MMU_UPDATES.  When we resume the task, check this
flag and re-enter lazy mmu mode if its set.

This sets things up for allowing lazy mmu mode while preemptible,
though that won't actually be active until the next change.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2009-03-29 23:36:00 -07:00
Jeremy Fitzhardinge
71ff49d71b x86: with the last user gone, remove set_pte_present
Impact: cleanup

set_pte_present() is no longer used, directly or indirectly,
so remove it.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
LKML-Reference: <1237406613-2929-2-git-send-email-jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-19 14:04:19 +01:00
Eduardo Habkost
f86399396c x86, paravirt_ops: use unsigned long instead of u32 for alloc_p*() pfn args
This patch changes the pfn args from 'u32' to 'unsigned long'
on alloc_p*() functions on paravirt_ops, and the corresponding
implementations for Xen and VMI. The prototypes for CONFIG_PARAVIRT=n
are already using unsigned long, so paravirt.h now matches the prototypes
on asm-x86/pgalloc.h.

It shouldn't result in any changes on generated code on 32-bit, with
or without CONFIG_PARAVIRT. On both cases, 'codiff -f' didn't show any
change after applying this patch.

On 64-bit, there are (expected) binary changes only when CONFIG_PARAVIRT
is enabled, as the patch is really supposed to change the size of the
pfn args.

[ v2: KVM_GUEST: use the right parameter type on kvm_release_pt() ]

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Acked-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-22 05:34:44 +02:00
Marcelo Tosatti
096d14a3b5 x86: KVM guest: hypercall batching
Batch pte updates and tlb flushes in lazy MMU mode.

[avi:
 - adjust to mmu_op
 - helper for getting para_state without debug warnings]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:28 +03:00
Marcelo Tosatti
1da8a77bdc x86: KVM guest: hypercall based pte updates and TLB flushes
Hypercall based pte updates are faster than faults, and also allow use
of the lazy MMU mode to batch operations.

Don't report the feature if two dimensional paging is enabled.

[avi:
 - guest/host split
 - fix 32-bit truncation issues
 - adjust to mmu_op
 - adjust to ->release_*() renamed
 - add ->release_pud()]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:28 +03:00
Marcelo Tosatti
0cf1bfd273 x86: KVM guest: add basic paravirt support
Add basic KVM paravirt support. Avoid vm-exits on IO delays.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:25 +03:00