> On 23 Aug 2019, at 4:07, Sean Christopherson <sean.j.christopherson@xxxxxxxxx> wrote:
>
> The VMware backdoor hooks #GP faults on IN{S}, OUT{S}, and RDPMC, none
> of which generate a non-zero error code for their #GP. Re-injecting #GP
> instead of attempting emulation on a non-zero error code will allow a
> future patch to move #GP injection (for emulation failure) into
> kvm_emulate_instruction() without having to plumb in the error code.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Reviewed-by: Liran Alon <liran.alon@xxxxxxxxxx>
-Liran
> ---
> arch/x86/kvm/svm.c | 6 +++++-
> arch/x86/kvm/vmx/vmx.c | 7 ++++++-
> 2 files changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 5a42f9c70014..b96a119690f4 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -2772,11 +2772,15 @@ static int gp_interception(struct vcpu_svm *svm)
>
> WARN_ON_ONCE(!enable_vmware_backdoor);
>
> + if (error_code) {
> + kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);
> + return 1;
> + }
> er = kvm_emulate_instruction(vcpu, EMULTYPE_VMWARE);
> if (er == EMULATE_USER_EXIT)
> return 0;
> else if (er != EMULATE_DONE)
> - kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);
> + kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
> return 1;
> }
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 6ecf773825e2..3ee0dd304bc7 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -4509,11 +4509,16 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
>
> if (!vmx->rmode.vm86_active && is_gp_fault(intr_info)) {
> WARN_ON_ONCE(!enable_vmware_backdoor);
> +
> + if (error_code) {
> + kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);
> + return 1;
> + }
> er = kvm_emulate_instruction(vcpu, EMULTYPE_VMWARE);
> if (er == EMULATE_USER_EXIT)
> return 0;
> else if (er != EMULATE_DONE)
> - kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);
> + kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
> return 1;
> }
>
> --
> 2.22.0
>
