We currently walk the shadow page tables in two places: direct map (for
real mode and two dimensional paging) and paging mode shadow. Since we
anticipate requiring a third walk (for invlpg), it makes sense to have
a generic facility for shadow walk.
This patch adds such a shadow walker, walks the page tables and calls a
method for every spte encountered. The method can examine the spte,
modify it, or even instantiate it. The walk can be aborted by returning
nonzero from the method.
Signed-off-by: Avi Kivity <avi@qumranet.com>
In all cases the shadow root level is available in mmu.shadow_root_level,
so there is no need to pass it as a parameter.
Signed-off-by: Avi Kivity <avi@qumranet.com>
kvm/ia64 uses the virtio drivers to optimize its I/O subsytem.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
The two paths are equivalent except for one argument, which is already
available. Merge the two codepaths.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Before enabling notify_acked_irq for ia64, leave the related APIs as
nop-op first.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
sparse says:
arch/x86/kvm/x86.c:107:32: warning: symbol 'kvm_find_assigned_dev' was not declared. Should it be static?
arch/x86/kvm/i8254.c:225:6: warning: symbol 'kvm_pit_ack_irq' was not declared. Should it be static?
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This patch modifies mode switching and vmentry function in order to
drive invalid guest state emulation.
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This adds the invalid guest state handler function which invokes the x86
emulator until getting the guest to a VMX-friendly state.
[avi: leave atomic context if scheduling]
[guillaume: return to atomic context correctly]
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
The patch adds the module parameter required to enable emulating invalid
guest state, as well as the emulation_required flag used to drive
emulation whenever needed.
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This patch adds functions to check whether guest state is VMX compliant.
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Even though we don't share irqs at the moment, we should ensure
regular user processes don't try to allocate system resources.
We check for capability to access IO devices (CAP_SYS_RAWIO) before
we request_irq on behalf of the guest.
Noticed by Avi.
Signed-off-by: Amit Shah <amit.shah@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Spurious acks can be generated, for example if the PIC is being reset.
Handle those acks gracefully rather than flooding the log with warnings.
Signed-off-by: Avi Kivity <avi@qumranet.com>
The irq ack during pic reset has three problems:
- Ignores slave/master PIC, using gsi 0-8 for both.
- Generates an ACK even if the APIC is in control.
- Depends upon IMR being clear, which is broken if the irq was masked
at the time it was generated.
The last one causes the BIOS to hang after the first reboot of
Windows installation, since PIT interrupts stop.
[avi: fix check whether pic interrupts are seen by cpu]
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
The vcpu thread can be preempted after the guest_debug_pre() callback,
resulting in invalid debug registers on the new vcpu.
Move it inside the non-preemptable section.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
We're in a hot path. We can't use kmalloc() because
it might impact performance. So, we just stick the buffer that
we need into the kvm_vcpu_arch structure. This is used very
often, so it is not really a waste.
We also have to move the buffer structure's definition to the
arch-specific x86 kvm header.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
[sheng: fix KVM_GET_LAPIC using wrong size]
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
On my machine with gcc 3.4, kvm uses ~2k of stack in a few
select functions. This is mostly because gcc fails to
notice that the different case: statements could have their
stack usage combined. It overflows very nicely if interrupts
happen during one of these large uses.
This patch uses two methods for reducing stack usage.
1. dynamically allocate large objects instead of putting
on the stack.
2. Use a union{} member for all of the case variables. This
tricks gcc into combining them all into a single stack
allocation. (There's also a comment on this)
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Based on a patch from: Amit Shah <amit.shah@qumranet.com>
This patch adds support for handling PCI devices that are assigned to
the guest.
The device to be assigned to the guest is registered in the host kernel
and interrupt delivery is handled. If a device is already assigned, or
the device driver for it is still loaded on the host, the device
assignment is failed by conveying a -EBUSY reply to the userspace.
Devices that share their interrupt line are not supported at the moment.
By itself, this patch will not make devices work within the guest.
The VT-d extension is required to enable the device to perform DMA.
Another alternative is PVDMA.
Signed-off-by: Amit Shah <amit.shah@qumranet.com>
Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Userspace may specify memory slots that are backed by mmio pages rather than
normal RAM. In some cases it is not enough to identify these mmio pages
by pfn_valid(). This patch adds checking the PageReserved as well.
Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
We're currently facing timing problems in guests that do
calibration under heavy load, and then the load vanishes.
This means we'll have a much lower lpj than we actually should,
and delays end up taking less time than they should, which is a
nasty bug.
Solution is to pass on the lpj value from host to guest, and have it
preset.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
KVM intends to use paravirt code to calibrate khz. Xen
current code will do just fine. So as a first step, factor out
code to pvclock.c.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
The PIT injection logic is problematic under the following cases:
1) If there is a higher priority vector to be delivered by the time
kvm_pit_timer_intr_post is invoked ps->inject_pending won't be set.
This opens the possibility for missing many PIT event injections (say if
guest executes hlt at this point).
2) ps->inject_pending is racy with more than two vcpus. Since there's no locking
around read/dec of pt->pending, two vcpu's can inject two interrupts for a single
pt->pending count.
Fix 1 by using an irq ack notifier: only reinject when the previous irq
has been acked. Fix 2 with appropriate locking around manipulation of
pending count and irq_ack by the injection / ack paths.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Based on a patch from: Ben-Ami Yassour <benami@il.ibm.com>
which was based on a patch from: Amit Shah <amit.shah@qumranet.com>
Notify IRQ acking on PIC/APIC emulation. The previous patch missed two things:
- Edge triggered interrupts on IOAPIC
- PIC reset with IRR/ISR set should be equivalent to ack (LAPIC probably
needs something similar).
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
CC: Amit Shah <amit.shah@qumranet.com>
CC: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This can be used by kvm subsystems that are interested in when
interrupts are acked, for example time drift compensation.
Signed-off-by: Avi Kivity <avi@qumranet.com>
When we use TID=N userspace mappings, we must ensure that kernel mappings have
been destroyed when entering userspace. Using TID=1/TID=0 for kernel/user
mappings and running userspace with PID=0 means that userspace can't access the
kernel mappings, but the kernel can directly access userspace.
The net is that we don't need to flush the TLB on privilege switches, but we do
on guest context switches (which are far more infrequent). Guest boot time
performance improvement: about 30%.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Track which TLB entries need to be written, instead of overwriting everything
below the high water mark. Typically only a single guest TLB entry will be
modified in a single exit.
Guest boot time performance improvement: about 15%.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
We're saving the host TLB state to memory on every exit, but never using it.
Originally I had thought that we'd want to restore host TLB for heavyweight
exits, but that could actually hurt when context switching to an unrelated host
process (i.e. not qemu).
Since this decreases the performance penalty of all exits, this patch improves
guest boot time by about 15%.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Allow host userspace to program hardware debug registers to set breakpoints
inside guests.
Signed-off-by: Jerone Young <jyoung5@us.ibm.com>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Netware writes to DEBUGCTL and reads from the DEBUGCTL and LAST*IP MSRs
without further checks and is really confused to receive a #GP during that.
To make it happy we should just make them stubs, which is exactly what SVM
already does.
Writes to DEBUGCTL that are vendor-specific are resembled to behave as if the
virtual CPU does not know them.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Usually HOST_RSP retains its value across guest entries. Take advantage
of this and avoid a vmwrite() when this is so.
Signed-off-by: Avi Kivity <avi@qumranet.com>
This patch adds a trace point for the instruction emulation on embedded powerpc
utilizing the KVM_TRACE interface.
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This patch adds trace points to track powerpc TLB activities using the
KVM_TRACE infrastructure.
Signed-off-by: Jerone Young <jyoung5@us.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This patch enables KVM_TRACE to build for PowerPC arch. This means just
adding sections to Kconfig and Makefile.
Signed-off-by: Jerone Young <jyoung5@us.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
The current kvmtrace code uses get_cycles() while the interpretation would be
easier using using nanoseconds. ktime_get() should give at least the same
accuracy as get_cycles on all architectures (even better on 32bit archs) but
at a better unit (e.g. comparable between hosts with different frequencies.
[avi: avoid ktime_t in public header]
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
