Commit 3741aec4 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: SVM: Stuff next_rip on emulated INT3 injection if NRIPS is supported 



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: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Fixes: 66b7138f ("KVM: SVM: Emulate nRIP feature when reinjecting INT3")
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarMaciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <cd328309a3b88604daa2359ad56f36cb565ce2d4.1651440202.git.maciej.szmigiero@oracle.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent cd9e6da8

arch/x86/kvm/svm/svm.c

+5 −1
Original line number Diff line number Diff line
@@ -392,6 +392,10 @@ 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;

	}
@@ -3709,7 +3713,7 @@ 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.