KVM: x86: Fix x86_decode_insn() return when fetching insn bytes fails

Jump to the common error handling in x86_decode_insn() if
__do_insn_fetch_bytes() fails so that its error code is converted to the
appropriate return type.  Although the various helpers used by
x86_decode_insn() return X86EMUL_* values, x86_decode_insn() itself
returns EMULATION_FAILED or EMULATION_OK.

This doesn't cause a functional issue as the sole caller,
x86_emulate_instruction(), currently only cares about success vs.
failure, and success is indicated by '0' for both types
(X86EMUL_CONTINUE and EMULATION_OK).

Fixes: 285ca9e948fa ("KVM: emulate: speed up do_insn_fetch")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 718f7d9..6170ddf 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5144,7 +5144,7 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
        else {
                rc = __do_insn_fetch_bytes(ctxt, 1);
                if (rc != X86EMUL_CONTINUE)
-                       return rc;
+                       goto done;
        }
 
        switch (mode) {