| Message ID | 20241217181458.68690-6-iorlov@amazon.com |
|---|---|
| State | New |
| Headers | show |
| Series | Enhance event delivery error handling | expand |
On Tue, Dec 17, 2024, Ivan Orlov wrote: > Detect unhandleable vectoring in check_emulate_instruction to prevent > infinite loop on SVM and eliminate the difference in how intercepted #PF > 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) > V2 -> V3: > - Use more generic function to check if emulation is allowed when > vectoring > > arch/x86/kvm/svm/svm.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index dd15cc635655..e89c6fc2c4e6 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -4802,6 +4802,12 @@ static int svm_check_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type, > bool smep, smap, is_user; > u64 error_code; > > + /* Check that emulation is possible during event vectoring */ > + if ((to_svm(vcpu)->vmcb->control.exit_int_info & > + SVM_EXITINTINFO_TYPE_MASK) && Let this poke out. Alternatively, and probably preferably, capture "svm" locally and it fits nicely on one line (there's an existing user of to_svm() in this helper). My objection to a local variable was specifically about a local "is_event_vectoring", not about local variables in general. > + !kvm_can_emulate_event_vectoring(emul_type)) > + return X86EMUL_UNHANDLEABLE_VECTORING; > + > /* 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 dd15cc635655..e89c6fc2c4e6 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4802,6 +4802,12 @@ static int svm_check_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type, bool smep, smap, is_user; u64 error_code; + /* Check that emulation is possible during event vectoring */ + if ((to_svm(vcpu)->vmcb->control.exit_int_info & + SVM_EXITINTINFO_TYPE_MASK) && + !kvm_can_emulate_event_vectoring(emul_type)) + return X86EMUL_UNHANDLEABLE_VECTORING; + /* Emulation is always possible when KVM has access to all guest state. */ if (!sev_guest(vcpu->kvm)) return X86EMUL_CONTINUE;
Detect unhandleable vectoring in check_emulate_instruction to prevent infinite loop on SVM and eliminate the difference in how intercepted #PF 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) V2 -> V3: - Use more generic function to check if emulation is allowed when vectoring arch/x86/kvm/svm/svm.c | 6 ++++++ 1 file changed, 6 insertions(+)