From f20d2752980c144c82649eb18746ef0c29f508dd Mon Sep 17 00:00:00 2001
From: Jes Sorensen <jes@sgi.com>
Date: Tue, 20 May 2008 13:13:50 +0200
Subject: [PATCH] KVM: ia64: fix zero extending for mmio ld1/2/4 emulation in
KVM
Only copy in the data actually requested by the instruction emulation
and zero pad the destination register first. This avoids the problem
where emulated mmio access got garbled data from ld2.acq instructions
in the vga console driver.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Acked-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---
arch/ia64/kvm/mmio.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/ia64/kvm/mmio.c b/arch/ia64/kvm/mmio.c
index 351bf70da463..7f1a858bc69f 100644
--- a/arch/ia64/kvm/mmio.c
+++ b/arch/ia64/kvm/mmio.c
@@ -159,7 +159,8 @@ static void mmio_access(struct kvm_vcpu *vcpu, u64 src_pa, u64 *dest,
if (p->u.ioreq.state == STATE_IORESP_READY) {
if (dir == IOREQ_READ)
- *dest = p->u.ioreq.data;
+ /* it's necessary to ensure zero extending */
+ *dest = p->u.ioreq.data & (~0UL >> (64-(s*8)));
} else
panic_vm(vcpu);
out: