| Message ID | 20210204023536.3397005-1-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: SVM: Remove bogus WARN and emulation if guest #GPs with EFER.SVME=1 | expand |
On 04/02/21 03:35, Sean Christopherson wrote: > Immediately reinject #GP (if intercepted) if the VMware backdoor is > disabled and the instruction is not affected by the erratum that causes > bogus #GPs on SVM instructions. It is completely reasonable for the > guest to take a #GP(0) with EFER.SVME=1, e.g. when probing an MSR, and > attempting emulation on an unknown instruction is obviously not good. > > Fixes: b3f4e11adc7d ("KVM: SVM: Add emulation support for #GP triggered by SVM instructions") > Cc: Bandan Das <bsd@redhat.com> > Cc: Maxim Levitsky <mlevitsk@redhat.com> > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/kvm/svm/svm.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index f53e6377a933..707a2f85bcc6 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -2263,7 +2263,8 @@ static int gp_interception(struct vcpu_svm *svm) > opcode = svm_instr_opcode(vcpu); > > if (opcode == NONE_SVM_INSTR) { > - WARN_ON_ONCE(!enable_vmware_backdoor); > + if (!enable_vmware_backdoor) > + goto reinject; > > /* > * VMware backdoor emulation on #GP interception only handles > Squashed, thanks. Paolo
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index f53e6377a933..707a2f85bcc6 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2263,7 +2263,8 @@ static int gp_interception(struct vcpu_svm *svm) opcode = svm_instr_opcode(vcpu); if (opcode == NONE_SVM_INSTR) { - WARN_ON_ONCE(!enable_vmware_backdoor); + if (!enable_vmware_backdoor) + goto reinject; /* * VMware backdoor emulation on #GP interception only handles
Immediately reinject #GP (if intercepted) if the VMware backdoor is disabled and the instruction is not affected by the erratum that causes bogus #GPs on SVM instructions. It is completely reasonable for the guest to take a #GP(0) with EFER.SVME=1, e.g. when probing an MSR, and attempting emulation on an unknown instruction is obviously not good. Fixes: b3f4e11adc7d ("KVM: SVM: Add emulation support for #GP triggered by SVM instructions") Cc: Bandan Das <bsd@redhat.com> Cc: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/svm/svm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)