Commit da01f64e authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: nSVM: Clear exit_code_hi in VMCB when synthesizing nested VM-Exits 



Explicitly clear exit_code_hi in the VMCB when synthesizing "normal"
nested VM-Exits, as the full exit code is a 64-bit value (spoiler alert),
and all exit codes for non-failing VMRUN use only bits 31:0.

Cc: Jim Mattson <jmattson@google.com>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Cc: stable@vger.kernel.org
Reviewed-by: default avatarYosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251113225621.1688428-2-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent af62fe24

arch/x86/kvm/svm/svm.c

+2 −0
Original line number Diff line number Diff line
@@ -2435,6 +2435,7 @@ static bool check_selective_cr0_intercepted(struct kvm_vcpu *vcpu, 


	if (cr0 ^ val) {

		svm->vmcb->control.exit_code = SVM_EXIT_CR0_SEL_WRITE;

		svm->vmcb->control.exit_code_hi = 0;

		ret = (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE);

	}
@@ -4611,6 +4612,7 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu, 
	if (static_cpu_has(X86_FEATURE_NRIPS))

		vmcb->control.next_rip  = info->next_rip;

	vmcb->control.exit_code = icpt_info.exit_code;

	vmcb->control.exit_code_hi = 0;

	vmexit = nested_svm_exit_handled(svm);



	ret = (vmexit == NESTED_EXIT_DONE) ? X86EMUL_INTERCEPTED

arch/x86/kvm/svm/svm.h

+4 −3
Original line number Diff line number Diff line
@@ -765,6 +765,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm); 
static inline int nested_svm_simple_vmexit(struct vcpu_svm *svm, u32 exit_code)

{

	svm->vmcb->control.exit_code	= exit_code;

	svm->vmcb->control.exit_code_hi	= 0;

	svm->vmcb->control.exit_info_1	= 0;

	svm->vmcb->control.exit_info_2	= 0;

	return nested_svm_vmexit(svm);