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| author | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-04 19:46:15 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-05 12:01:06 +0200 |
| commit | ef54bcfeea6c8b04e2a4f9396e16d88558aa2eee (patch) | |
| tree | b55206cb61665de87690edff04c6f8d21889913d /arch/x86/kvm/x86.c | |
| parent | 5e352519519623a0b62587c606280e534d0cf1d9 (diff) | |
| download | lwn-ef54bcfeea6c8b04e2a4f9396e16d88558aa2eee.tar.gz lwn-ef54bcfeea6c8b04e2a4f9396e16d88558aa2eee.zip | |
KVM: x86: skip writeback on injection of nested exception
If a nested page fault happens during emulation, we will inject a vmexit,
not a page fault. However because writeback happens after the injection,
we will write ctxt->eip from L2 into the L1 EIP. We do not write back
if an instruction caused an interception vmexit---do the same for page
faults.
Suggested-by: Gleb Natapov <gleb@kernel.org>
Reviewed-by: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e4ed85e07a01..354194671902 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -408,12 +408,14 @@ void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault) } EXPORT_SYMBOL_GPL(kvm_inject_page_fault); -void kvm_propagate_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault) +static bool kvm_propagate_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault) { if (mmu_is_nested(vcpu) && !fault->nested_page_fault) vcpu->arch.nested_mmu.inject_page_fault(vcpu, fault); else vcpu->arch.mmu.inject_page_fault(vcpu, fault); + + return fault->nested_page_fault; } void kvm_inject_nmi(struct kvm_vcpu *vcpu) @@ -4929,16 +4931,18 @@ static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask) } } -static void inject_emulated_exception(struct kvm_vcpu *vcpu) +static bool inject_emulated_exception(struct kvm_vcpu *vcpu) { struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt; if (ctxt->exception.vector == PF_VECTOR) - kvm_propagate_fault(vcpu, &ctxt->exception); - else if (ctxt->exception.error_code_valid) + return kvm_propagate_fault(vcpu, &ctxt->exception); + + if (ctxt->exception.error_code_valid) kvm_queue_exception_e(vcpu, ctxt->exception.vector, ctxt->exception.error_code); else kvm_queue_exception(vcpu, ctxt->exception.vector); + return false; } static void init_emulate_ctxt(struct kvm_vcpu *vcpu) @@ -5300,8 +5304,9 @@ restart: } if (ctxt->have_exception) { - inject_emulated_exception(vcpu); r = EMULATE_DONE; + if (inject_emulated_exception(vcpu)) + return r; } else if (vcpu->arch.pio.count) { if (!vcpu->arch.pio.in) { /* FIXME: return into emulator if single-stepping. */ |