KVM: x86 emulator: Let compiler know insn_fetch() rarely fails
Fetching the instruction which was to be executed by the guest cannot
fail normally. So compiler should always predict that it will succeed.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d4cc8af..191bc9b 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -672,11 +672,11 @@
size = min(15UL - cur_size,
PAGE_SIZE - offset_in_page(ctxt->_eip));
rc = __linearize(ctxt, addr, size, false, true, &linear);
- if (rc != X86EMUL_CONTINUE)
+ if (unlikely(rc != X86EMUL_CONTINUE))
return rc;
rc = ctxt->ops->fetch(ctxt, linear, fc->data + cur_size,
size, &ctxt->exception);
- if (rc != X86EMUL_CONTINUE)
+ if (unlikely(rc != X86EMUL_CONTINUE))
return rc;
fc->end += size;
}
@@ -691,7 +691,7 @@
int rc;
/* x86 instructions are limited to 15 bytes. */
- if (ctxt->_eip + size - ctxt->eip > 15)
+ if (unlikely(ctxt->_eip + size - ctxt->eip > 15))
return X86EMUL_UNHANDLEABLE;
while (size--) {
rc = do_insn_fetch_byte(ctxt, dest++);