From: Sean Christopherson seanjc@google.com
[ Upstream commit 3741aec4c38fa4123ab08ae552f05366d4fd05d8 ]
If NRIPS is supported in hardware but disabled in KVM, set next_rip to the next RIP when advancing RIP as part of emulating INT3 injection. There is no flag to tell the CPU that KVM isn't using next_rip, and so leaving next_rip is left as is will result in the CPU pushing garbage onto the stack when vectoring the injected event.
Reviewed-by: Maxim Levitsky mlevitsk@redhat.com Fixes: 66b7138f9136 ("KVM: SVM: Emulate nRIP feature when reinjecting INT3") Signed-off-by: Sean Christopherson seanjc@google.com Signed-off-by: Maciej S. Szmigiero maciej.szmigiero@oracle.com Message-Id: cd328309a3b88604daa2359ad56f36cb565ce2d4.1651440202.git.maciej.szmigiero@oracle.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kvm/svm/svm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index e4c736d74fcb..e5a154f0d2ab 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -390,6 +390,10 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu) */ (void)svm_skip_emulated_instruction(vcpu); rip = kvm_rip_read(vcpu); + + if (boot_cpu_has(X86_FEATURE_NRIPS)) + svm->vmcb->control.next_rip = rip; + svm->int3_rip = rip + svm->vmcb->save.cs.base; svm->int3_injected = rip - old_rip; } @@ -3616,7 +3620,7 @@ static void svm_complete_interrupts(struct kvm_vcpu *vcpu) /* * If NextRIP isn't enabled, KVM must manually advance RIP prior to * injecting the soft exception/interrupt. That advancement needs to - * be unwound if vectoring didn't complete. Note, the _new_ event may + * be unwound if vectoring didn't complete. Note, the new event may * not be the injected event, e.g. if KVM injected an INTn, the INTn * hit a #NP in the guest, and the #NP encountered a #PF, the #NP will * be the reported vectored event, but RIP still needs to be unwound.