If an interrupt cannot be injected for some reason (say, page fault
when fetching the IDT descriptor), the interrupt is marked for
reinjection. However, if an NMI is queued at this time, the NMI
will be injected instead and the NMI will be lost.
Fix by deferring the NMI injection until the interrupt has been
injected successfully.
Analyzed by Jan Kiszka.
Signed-off-by: Avi Kivity <avi@redhat.com>
There is a potential issue that, when guest using pagetable without vmexit when
EPT enabled, guest would use PAT/PCD/PWT bits to index PAT msr for it's memory,
which would be inconsistent with host side and would cause host MCE due to
inconsistent cache attribute.
The patch set IGMT bit in EPT entry to ignore guest PAT and use WB as default
memory type to protect host (notice that all memory mapped by KVM should be WB).
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
With pages out of sync invlpg needs to be trapped. For now simply nuke
the entry.
Untested on AMD.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Convert gfn_to_pfn to use get_user_pages_fast, which can do lockless
pagetable lookups on x86. Kernel compilation on 4-way guest is 3.7%
faster on VMX.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Commit 1c0f4f5011829dac96347b5f84ba37c2252e1e08 left a useless access
of VM_ENTRY_INTR_INFO_FIELD in vmx_intr_assist behind. Clean this up.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
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>
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>
As we execute real mode guests in VM86 mode, exception have to be
reinjected appropriately when the guest triggered them. For this purpose
the patch adopts the real-mode injection pattern used in vmx_inject_irq
to vmx_queue_exception, additionally taking care that the IP is set
correctly for #BP exceptions. Furthermore it extends
handle_rmode_exception to reinject all those exceptions that can be
raised in real mode.
This fixes the execution of himem.exe from FreeDOS and also makes its
debug.com work properly.
Note that guest debugging in real mode is broken now. This has to be
fixed by the scheduled debugging infrastructure rework (will be done
once base patches for QEMU have been accepted).
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Since checking for vcpu->arch.rmode.active is already done whenever we
call handle_rmode_exception(), checking it inside the function is redundant.
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Instead of looking at failed injections in the vm entry path, move
processing to the exit path in vmx_complete_interrupts(). This simplifes
the logic and removes any state that is hidden in vmx registers.
Signed-off-by: Avi Kivity <avi@qumranet.com>
The vmx code assumes that IDT-Vectoring can only be set when an exception
is injected due to the exception in question. That's not true, however:
if the exception is injected correctly, and later another exception occurs
but its delivery is blocked due to a fault, then we will incorrectly assume
the first exception was not delivered.
Fix by unconditionally dequeuing the pending exception, and requeuing it
(or the second exception) if we see it in the IDT-Vectoring field.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Instead of processing nmi injection failure in the vm entry path, move
it to the vm exit path (vm_complete_interrupts()). This separates nmi
injection from nmi post-processing, and moves the nmi state from the VT
state into vcpu state (new variable nmi_injected specifying an injection
in progress).
Signed-off-by: Avi Kivity <avi@qumranet.com>
Currently most interrupt exit processing is handled on the entry path,
which is confusing. Move the NMI IRET fault processing to a new function,
vmx_complete_interrupts(), which is called on the vmexit path.
Signed-off-by: Avi Kivity <avi@qumranet.com>
As suggested by Avi, introduce accessors to read/write guest registers.
This simplifies the ->cache_regs/->decache_regs interface, and improves
register caching which is important for VMX, where the cost of
vmcs_read/vmcs_write is significant.
[avi: fix warnings]
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
MSR_IA32_FEATURE_LOCKED is just a bit in fact, which shouldn't be prefixed with
MSR_. So is MSR_IA32_FEATURE_VMXON_ENABLED.
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
As well as discard fake accessed bit and dirty bit of EPT.
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
When an event (such as an interrupt) is injected, and the stack is
shadowed (and therefore write protected), the guest will exit. The
current code will see that the stack is shadowed and emulate a few
instructions, each time postponing the injection. Eventually the
injection may succeed, but at that time the guest may be unwilling
to accept the interrupt (for example, the TPR may have changed).
This occurs every once in a while during a Windows 2008 boot.
Fix by unshadowing the fault address if the fault was due to an event
injection.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Fix a potention issue caused by kvm_mmu_slot_remove_write_access(). The
old behavior don't sync EPT TLB with modified EPT entry, which result
in inconsistent content of EPT TLB and EPT table.
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Older linux guests (in this case, 2.6.9) can attempt to
access the performance counter MSRs without a fixup section, and injecting
a GPF kills the guest. Work around by allowing the guest to write those MSRs.
Tested by me on RHEL-4 i386 and x86_64 guests, as well as F-9 guests.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
The function ept_update_paging_mode_cr0() write to
CPU_BASED_VM_EXEC_CONTROL based on vmcs_config.cpu_based_exec_ctrl. That's
wrong because the variable may not consistent with the content in the
CPU_BASE_VM_EXEC_CONTROL MSR.
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
VMX hardware can cache the contents of a vcpu's vmcs. This cache needs
to be flushed when migrating a vcpu to another cpu, or (which is the case
that interests us here) when disabling hardware virtualization on a cpu.
The current implementation of decaching iterates over the list of all vcpus,
picks the ones that are potentially cached on the cpu that is being offlined,
and flushes the cache. The problem is that it uses mutex_trylock() to gain
exclusive access to the vcpu, which fires off a (benign) warning about using
the mutex in an interrupt context.
To avoid this, and to make things generally nicer, add a new per-cpu list
of potentially cached vcus. This makes the decaching code much simpler. The
list is vmx-specific since other hardware doesn't have this issue.
[andrea: fix crash on suspend/resume]
Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
KVM turns off hardware virtualization extensions during reboot, in order
to disassociate the memory used by the virtualization extensions from the
processor, and in order to have the system in a consistent state.
Unfortunately virtual machines may still be running while this goes on,
and once virtualization extensions are turned off, any virtulization
instruction will #UD on execution.
Fix by adding an exception handler to virtualization instructions; if we get
an exception during reboot, we simply spin waiting for the reset to complete.
If it's a true exception, BUG() so we can have our stack trace.
Signed-off-by: Avi Kivity <avi@qumranet.com>
This patch moves the trace entry for APIC accesses from the VMX code to the
generic lapic code. This way APIC accesses from SVM will also be traced.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Noticed by sparse:
arch/x86/kvm/vmx.c:1583:6: warning: symbol 'vmx_disable_intercept_for_msr' was not declared. Should it be static?
arch/x86/kvm/x86.c:3406:5: warning: symbol 'kvm_task_switch_16' was not declared. Should it be static?
arch/x86/kvm/x86.c:3429:5: warning: symbol 'kvm_task_switch_32' was not declared. Should it be static?
arch/x86/kvm/mmu.c:1968:6: warning: symbol 'kvm_mmu_remove_one_alloc_mmu_page' was not declared. Should it be static?
arch/x86/kvm/mmu.c:2014:6: warning: symbol 'mmu_destroy_caches' was not declared. Should it be static?
arch/x86/kvm/lapic.c:862:5: warning: symbol 'kvm_lapic_get_base' was not declared. Should it be static?
arch/x86/kvm/i8254.c:94:5: warning: symbol 'pit_get_gate' was not declared. Should it be static?
arch/x86/kvm/i8254.c:196:5: warning: symbol '__pit_timer_fn' was not declared. Should it be static?
arch/x86/kvm/i8254.c:561:6: warning: symbol '__inject_pit_timer_intr' was not declared. Should it be static?
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Switching msrs can occur either synchronously as a result of calls to
the msr management functions (usually in response to the guest touching
virtualized msrs), or asynchronously when preempting a kvm thread that has
guest state loaded. If we're unlucky enough to have the two at the same
time, host msrs are corrupted and the machine goes kaput on the next syscall.
Most easily triggered by Windows Server 2008, as it does a lot of msr
switching during bootup.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Clear CR4.VMXE in hardware_disable. There's no reason to leave it set
after doing a VMXOFF.
VMware Workstation 6.5 checks CR4.VMXE as a proxy for whether the CPU is
in VMX mode, so leaving VMXE set means we'll refuse to power on. With this
change the user can power on after unloading the kvm-intel module. I
tested on kvm-67 and kvm-69.
Signed-off-by: Eli Collins <ecollins@vmware.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Migrate the PIT timer to the physical CPU which vcpu0 is scheduled on,
similarly to what is done for the LAPIC timers, otherwise PIT interrupts
will be delayed until an unrelated event causes an exit.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
[aliguory: plug leak]
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
The function get_tdp_level() provided the number of tdp level for EPT and
NPT rather than the NPT specific macro.
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Avi Kivity