| Message ID | 20241111102749.82761-5-iorlov@amazon.com |
|---|---|
| State | New |
| Headers | show |
| Series | Enhance event delivery error handling | expand |
On Mon, Nov 11, 2024, Ivan Orlov wrote: > Handle MMIO during vectoring error in check_emulate_instruction to > prevent infinite loop on SVM and eliminate the difference in how the > situation when the guest accesses MMIO during vectoring is handled on > SVM and VMX. > > Signed-off-by: Ivan Orlov <iorlov@amazon.com> > --- > V1 -> V2: > - Detect the unhandleable vectoring error in svm_check_emulate_instruction > instead of handling it in the common MMU code (which is specific for > cached MMIO) > > arch/x86/kvm/svm/svm.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index c1e29307826b..b69f0f98c576 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -4797,9 +4797,16 @@ static void svm_enable_smi_window(struct kvm_vcpu *vcpu) > static int svm_check_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type, > void *insn, int insn_len) > { > - bool smep, smap, is_user; > + bool smep, smap, is_user, is_vect; > u64 error_code; > > + is_vect = to_svm(vcpu)->vmcb->control.exit_int_info & > + SVM_EXITINTINFO_TYPE_MASK; > + > + /* Emulation is not possible when MMIO happens during event vectoring. */ > + if (kvm_is_emul_type_mmio(emul_type) && is_vect) Same nit here, omit the local variable. > + return X86EMUL_UNHANDLEABLE_VECTORING_IO; > + > /* Emulation is always possible when KVM has access to all guest state. */ > if (!sev_guest(vcpu->kvm)) > return X86EMUL_CONTINUE; > -- > 2.43.0 >
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index c1e29307826b..b69f0f98c576 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4797,9 +4797,16 @@ static void svm_enable_smi_window(struct kvm_vcpu *vcpu) static int svm_check_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type, void *insn, int insn_len) { - bool smep, smap, is_user; + bool smep, smap, is_user, is_vect; u64 error_code; + is_vect = to_svm(vcpu)->vmcb->control.exit_int_info & + SVM_EXITINTINFO_TYPE_MASK; + + /* Emulation is not possible when MMIO happens during event vectoring. */ + if (kvm_is_emul_type_mmio(emul_type) && is_vect) + return X86EMUL_UNHANDLEABLE_VECTORING_IO; + /* Emulation is always possible when KVM has access to all guest state. */ if (!sev_guest(vcpu->kvm)) return X86EMUL_CONTINUE;
Handle MMIO during vectoring error in check_emulate_instruction to prevent infinite loop on SVM and eliminate the difference in how the situation when the guest accesses MMIO during vectoring is handled on SVM and VMX. Signed-off-by: Ivan Orlov <iorlov@amazon.com> --- V1 -> V2: - Detect the unhandleable vectoring error in svm_check_emulate_instruction instead of handling it in the common MMU code (which is specific for cached MMIO) arch/x86/kvm/svm/svm.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)