diff mbox

Fix kernel pio emulation mistake

Message ID 9832F13BD22FB94A829F798DA4A828050196AF5598@pdsmsx503.ccr.corp.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dong, Eddie March 19, 2009, 7:06 a.m. UTC
Kernel pio emulation return value is mistakenly checked, fortuantely it is not hit yet for normal OS bootup :(


Signed-off-by: Eddie Dong <Eddie.dong@linux.intel.com>



commit 98d3dc8b67ba0bc7f494de3ade8f2b5cfcadaeb4
Author: root <root@eddie-wb.localdomain>
Date:   Thu Mar 19 15:44:39 2009 +0800

    fix a bug when kernel PIO is emulated.

Comments

Avi Kivity March 19, 2009, 9:35 a.m. UTC | #1
Dong, Eddie wrote:
> Kernel pio emulation return value is mistakenly checked, fortuantely it is not hit yet for normal OS bootup :(
>
>
> diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
> index ca91749..0edd2e7 100644
> --- a/arch/x86/kvm/x86_emulate.c
> +++ b/arch/x86/kvm/x86_emulate.c
> @@ -1838,7 +1838,7 @@ special_insn:
>  		io_dir_in = 0;
>  	do_io:	if (kvm_emulate_pio(ctxt->vcpu, NULL, io_dir_in,
>  				   (c->d & ByteOp) ? 1 : c->op_bytes,
> -				   port) != 0) {
> +				   port) == 0) {
>  			c->eip = saved_eip;
>  			goto cannot_emulate;
>  		}

kvm_emulate_pio() returns 1 when emulation is complete, and 0 when 
emulation needs further processing in userspace.  So I think in both 
cases cannot_emulate is the wrong answer.  I think 'in' emulation gets 
it right.
diff mbox

Patch

diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index ca91749..0edd2e7 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -1838,7 +1838,7 @@  special_insn:
 		io_dir_in = 0;
 	do_io:	if (kvm_emulate_pio(ctxt->vcpu, NULL, io_dir_in,
 				   (c->d & ByteOp) ? 1 : c->op_bytes,
-				   port) != 0) {
+				   port) == 0) {
 			c->eip = saved_eip;
 			goto cannot_emulate;
 		}