[PATCH 4/8] KVM: SVM: Stuff next_rip on emualted INT3 injection if NRIPS is supported

Sean Christopherson
2022-04-02T01:09:32Z

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.

Fixes: 66b7138f9136 ("KVM: SVM: Emulate nRIP feature when reinjecting INT3")
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/svm.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 30cef3b10838..6ea8f16e39ac 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -391,6 +391,10 @@ 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;
}
--
2.35.1.1094.g7c7d902a7c-goog