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| author | Joerg Roedel <joerg.roedel@amd.com> | 2010-11-29 17:51:49 +0100 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-01-12 11:30:07 +0200 |
| commit | fc3a9157d3148ab91039c75423da8ef97be3e105 (patch) | |
| tree | bd356d2ec06e34554691913419ac18cef1fcf3c9 /arch/x86/kvm/x86.c | |
| parent | 2030753de70a8aed39543ed09c2360665b3af481 (diff) | |
| download | lwn-fc3a9157d3148ab91039c75423da8ef97be3e105.tar.gz lwn-fc3a9157d3148ab91039c75423da8ef97be3e105.zip | |
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>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 47e5a41cc40e..8b4d5fc08012 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4314,13 +4314,19 @@ EXPORT_SYMBOL_GPL(kvm_inject_realmode_interrupt); static int handle_emulation_failure(struct kvm_vcpu *vcpu) { + int r = EMULATE_DONE; + ++vcpu->stat.insn_emulation_fail; trace_kvm_emulate_insn_failed(vcpu); - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; + if (!is_guest_mode(vcpu)) { + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; + vcpu->run->internal.ndata = 0; + r = EMULATE_FAIL; + } kvm_queue_exception(vcpu, UD_VECTOR); - return EMULATE_FAIL; + + return r; } static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva) |