KVM: inject #UD if instruction emulation fails and exit to userspace
Do not kill VM when instruction emulation fails. Inject #UD and report
failure to userspace instead. Userspace may choose to reenter guest if
vcpu is in userspace (cpl == 3) in which case guest OS will kill
offending process and continue running.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 41fe038..134260c 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1535,7 +1535,7 @@
string = (io_info & SVM_IOIO_STR_MASK) != 0;
in = (io_info & SVM_IOIO_TYPE_MASK) != 0;
if (string || in)
- return !(emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DO_MMIO);
+ return emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DONE;
port = io_info >> 16;
size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT;
@@ -2386,16 +2386,12 @@
static int invlpg_interception(struct vcpu_svm *svm)
{
- if (emulate_instruction(&svm->vcpu, 0, 0, 0) != EMULATE_DONE)
- pr_unimpl(&svm->vcpu, "%s: failed\n", __func__);
- return 1;
+ return emulate_instruction(&svm->vcpu, 0, 0, 0) == EMULATE_DONE;
}
static int emulate_on_interception(struct vcpu_svm *svm)
{
- if (emulate_instruction(&svm->vcpu, 0, 0, 0) != EMULATE_DONE)
- pr_unimpl(&svm->vcpu, "%s: failed\n", __func__);
- return 1;
+ return emulate_instruction(&svm->vcpu, 0, 0, 0) == EMULATE_DONE;
}
static int cr8_write_interception(struct vcpu_svm *svm)