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-rw-r--r--arch/x86/kvm/svm/svm.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index be25831830b0..f14f4ab97a80 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4360,7 +4360,21 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
is_user = svm_get_cpl(vcpu) == 3;
if (smap && (!smep || is_user)) {
pr_err_ratelimited("KVM: SEV Guest triggered AMD Erratum 1096\n");
- kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
+
+ /*
+ * If the fault occurred in userspace, arbitrarily inject #GP
+ * to avoid killing the guest and to hopefully avoid confusing
+ * the guest kernel too much, e.g. injecting #PF would not be
+ * coherent with respect to the guest's page tables. Request
+ * triple fault if the fault occurred in the kernel as there's
+ * no fault that KVM can inject without confusing the guest.
+ * In practice, the triple fault is moot as no sane SEV kernel
+ * will execute from user memory while also running with SMAP=1.
+ */
+ if (is_user)
+ kvm_inject_gp(vcpu, 0);
+ else
+ kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
}
resume_guest: