Don''t clear upper 32 bits on 8- and 16-bit PIO reads.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Index: 2007-04-27/xen/arch/x86/hvm/io.c
==================================================================---
2007-04-27.orig/xen/arch/x86/hvm/io.c 2007-04-16 09:26:34.000000000 +0200
+++ 2007-04-27/xen/arch/x86/hvm/io.c 2007-05-09 18:00:08.000000000 +0200
@@ -418,11 +418,10 @@ static inline void set_eflags_PF(int siz
static void hvm_pio_assist(struct cpu_user_regs *regs, ioreq_t *p,
struct hvm_io_op *pio_opp)
{
- unsigned long old_eax;
- int sign = p->df ? -1 : 1;
-
if ( p->data_is_ptr || (pio_opp->flags & OVERLAP) )
{
+ int sign = p->df ? -1 : 1;
+
if ( pio_opp->flags & REPZ )
regs->ecx -= p->count;
@@ -459,14 +458,15 @@ static void hvm_pio_assist(struct cpu_us
}
else if ( p->dir == IOREQ_READ )
{
- old_eax = regs->eax;
+ unsigned long old_eax = regs->eax;
+
switch ( p->size )
{
case 1:
- regs->eax = (old_eax & 0xffffff00) | (p->data &
0xff);
+ regs->eax = (old_eax & ~0xff) | (p->data & 0xff);
break;
case 2:
- regs->eax = (old_eax & 0xffff0000) | (p->data &
0xffff);
+ regs->eax = (old_eax & ~0xffff) | (p->data & 0xffff);
break;
case 4:
regs->eax = (p->data & 0xffffffff);
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel