KVM: X86: Propagate fetch faults

KVM currently ignores fetch faults in the instruction
emulator. With nested-npt we could have such faults. This
patch adds the code to handle these.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 2b08b78b6cab..aead72e141b4 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1198,6 +1198,9 @@ static int emulate_popf(struct x86_emulate_ctxt *ctxt,
         *(unsigned long *)dest =
                 (ctxt->eflags & ~change_mask) | (val & change_mask);
 
+        if (rc == X86EMUL_PROPAGATE_FAULT)
+                emulate_pf(ctxt);
+
         return rc;
 }
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0281d920e9ed..3101060033ae 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4247,6 +4247,9 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
                 vcpu->arch.emulate_ctxt.perm_ok = false;
 
                 r = x86_decode_insn(&vcpu->arch.emulate_ctxt);
+                if (r == X86EMUL_PROPAGATE_FAULT)
+                        goto done;
+
                 trace_kvm_emulate_insn_start(vcpu);
 
                 /* Only allow emulation of specific instructions on #UD
@@ -4305,6 +4308,7 @@ restart:
                 return handle_emulation_failure(vcpu);
         }
 
+done:
         if (vcpu->arch.emulate_ctxt.exception >= 0) {
                 inject_emulated_exception(vcpu);
                 r = EMULATE_DONE;