diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-08-27 14:40:34 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-09-24 14:31:07 +0200 |
| commit | 738fece46dc5e1bb1309a827a2b69056143b3d13 (patch) | |
| tree | 33246d9a226b6b7953d686a9eaf9d1a1b674e964 | |
| parent | c83fad65e2cae1aa570a519b33e8ebf00f6e7227 (diff) | |
| download | linux-738fece46dc5e1bb1309a827a2b69056143b3d13.tar.bz2 | |
KVM: x86: Exit to userspace on emulation skip failure
Kill a few birds with one stone by forcing an exit to userspace on skip
emulation failure. This removes a reference to EMULATE_FAIL, fixes a
bug in handle_ept_misconfig() where it would exit to userspace without
setting run->exit_reason, and fixes a theoretical bug in SVM's
task_switch_interception() where it would overwrite run->exit_reason on
a return of EMULATE_USER_EXIT.
Note, this technically doesn't fully fix task_switch_interception()
as it now incorrectly handles EMULATE_FAIL, but in practice there is no
bug as EMULATE_FAIL will never be returned for EMULTYPE_SKIP.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/svm.c | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 9 |
2 files changed, 9 insertions, 4 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index c7aa55e192c0..fc40052fa334 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3885,8 +3885,8 @@ static int task_switch_interception(struct vcpu_svm *svm) int_type == SVM_EXITINTINFO_TYPE_SOFT || (int_type == SVM_EXITINTINFO_TYPE_EXEPT && (int_vec == OF_VECTOR || int_vec == BP_VECTOR))) { - if (skip_emulated_instruction(&svm->vcpu) != EMULATE_DONE) - goto fail; + if (skip_emulated_instruction(&svm->vcpu) == EMULATE_USER_EXIT) + return 0; } if (int_type != SVM_EXITINTINFO_TYPE_SOFT) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 64d584d48c60..802dfb926ca7 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6306,6 +6306,13 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type) return EMULATE_DONE; } + if (emulation_type & EMULTYPE_SKIP) { + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; + vcpu->run->internal.ndata = 0; + return EMULATE_USER_EXIT; + } + kvm_queue_exception(vcpu, UD_VECTOR); if (!is_guest_mode(vcpu) && kvm_x86_ops->get_cpl(vcpu) == 0) { @@ -6641,8 +6648,6 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, inject_emulated_exception(vcpu); return EMULATE_DONE; } - if (emulation_type & EMULTYPE_SKIP) - return EMULATE_FAIL; return handle_emulation_failure(vcpu, emulation_type); } } |