From 35c6f649bbb2e3f367116307273f998f0bf3e08e Mon Sep 17 00:00:00 2001 From: Brijesh Singh Date: Mon, 4 Dec 2017 10:57:39 -0600 Subject: KVM: SVM: Do not install #UD intercept when SEV is enabled On #UD, x86_emulate_instruction() fetches the data from guest memory and decodes the instruction bytes to assist further. When SEV is enabled, the instruction bytes will be encrypted using the guest-specific key and the hypervisor will no longer able to fetch the instruction bytes to assist UD handling. By not installing intercept we let the guest receive and handle #UD. Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Joerg Roedel Cc: Borislav Petkov Cc: Tom Lendacky Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Borislav Petkov Signed-off-by: Brijesh Singh --- arch/x86/kvm/svm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index f350e9bac9eb..3e848f952b4f 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1443,8 +1443,10 @@ static void init_vmcb(struct vcpu_svm *svm) svm->vmcb->control.int_ctl |= V_GIF_ENABLE_MASK; } - if (sev_guest(svm->vcpu.kvm)) + if (sev_guest(svm->vcpu.kvm)) { svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE; + clr_exception_intercept(svm, UD_VECTOR); + } mark_all_dirty(svm->vmcb); -- cgit v1.2.3-55-g7522