x86: svm: use kvm_fast_pio_in()

Commit Message

Joel Schopp Feb. 28, 2015, 12:01 a.m. UTC

From: David Kaplan <[e-mail]>

We can make the in instruction go faster the same way the out instruction is
already.

Signed-off-by: David Kaplan <[e-mail]>
[extracted from larger unlrelated patch, forward ported, tested]
Signed-off-by: Joel Schopp <[e-mail]>
---
 arch/x86/kvm/svm.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)


--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d319e0c..f8c906b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1899,7 +1899,7 @@  static int io_interception(struct vcpu_svm *svm)
 	++svm->vcpu.stat.io_exits;
 	string = (io_info & SVM_IOIO_STR_MASK) != 0;
 	in = (io_info & SVM_IOIO_TYPE_MASK) != 0;
-	if (string || in)
+	if (string)
 		return emulate_instruction(vcpu, 0) == EMULATE_DONE;
 
 	port = io_info >> 16;
@@ -1907,6 +1907,8 @@  static int io_interception(struct vcpu_svm *svm)
 	svm->next_rip = svm->vmcb->control.exit_info_2;
 	skip_emulated_instruction(&svm->vcpu);
 
+	if (in)
+		return kvm_fast_pio_in(vcpu, size, port);
 	return kvm_fast_pio_out(vcpu, size, port);
 }