KVM: x86: Do not return soft events in vcpu_events
PATCH 1/1 KVM: x86: Do not return soft events in vcpu_events
From: Jan Kiszka <[email protected]>
Based on Gleb's suggestion: To avoid that user space migrates a pending software exception or interrupt, mask them out on KVM_GET_VCPU_EVENTS. Without this, user space would try to reinject them, and we would have to reconstruct the proper instruction length for VMX event injection. Now the pending event will be reinjected via executing the triggering instruction again.
--- arch/x86/kvm/x86.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-)
arch/x86/kvm/x86.c +6 -3
@@ -2121,14 +2121,17 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu, {vcpu_load (vcpu); - events->exception.injected = vcpu->arch.exception.pending; + events->exception.injected = + vcpu->arch.exception.pending && + !kvm_exception_is_soft (vcpu->arch.exception.nr); events->exception.nr = vcpu->arch.exception.nr; events->exception.has_error_code = vcpu->arch.exception.has_error_code; events->exception.error_code = vcpu->arch.exception.error_code; - events->interrupt.injected = vcpu->arch.interrupt.pending; + events->interrupt.injected = + vcpu->arch.interrupt.pending && !vcpu->arch.interrupt.soft; events->interrupt.nr = vcpu->arch.interrupt.nr; - events->interrupt.soft = vcpu->arch.interrupt.soft; + events->interrupt.soft =0 ; events->nmi.injected = vcpu->arch.nmi_injected; events->nmi.pending = vcpu->arch.nmi_pending;
Quoted 10 lines · Jan Kiszka
From: Jan Kiszka <[email protected]>
Based on Gleb's suggestion: To avoid that user space migrates a pending software exception or interrupt, mask them out on
KVM_GET_VCPU_EVENTS. Without this, user space would try to reinject them, and we would have to reconstruct the proper instruction length for VMX event injection. Now the pending event will be reinjected via executing the triggering instruction again.Signed-off-by Jan Kiszka <[email protected]>
Looks good to me.
Quoted 19 lines
--- arch/x86/kvm/x86.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-)arch/x86/kvm/x86.c +3
-1@@ -2121,14 +2121,17 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu, {vcpu_load (vcpu); - events->exception.injected = vcpu->arch.exception.pending; + events->exception.injected = + vcpu->arch.exception.pending && + !kvm_exception_is_soft (vcpu->arch.exception.nr); events->exception.nr = vcpu->arch.exception.nr; events->exception.has_error_code = vcpu->arch.exception.has_error_code; events->exception.error_code = vcpu->arch.exception.error_code;
arch/x86/kvm/x86.c static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu, · line 2137
Quoted 10 lines
arch/x86/kvm/x86.c +3
-2- events->interrupt.injected = vcpu->arch.interrupt.pending; + events->interrupt.injected = + vcpu->arch.interrupt.pending && !vcpu->arch.interrupt.soft; events->interrupt.nr = vcpu->arch.interrupt.nr; - events->interrupt.soft = vcpu->arch.interrupt.soft; + events->interrupt.soft =0 ; events->nmi.injected = vcpu->arch.nmi_injected; events->nmi.pending = vcpu->arch.nmi_pending;
--
Gleb.