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authorJulian Stecklina <js@alien8.de>2011-11-23 13:54:30 +0100
committerAvi Kivity <avi@redhat.com>2011-12-27 11:17:44 +0200
commitd77fe6354d5b67f4d4eb62a47621da2b3ee3539e (patch)
tree4c399e8125d69d128c200807eb517dd7c20b277b /virt/kvm/ioapic.c
parent60f9a9ef5492cae66aca2ad9873360161320d5af (diff)
KVM: Allow aligned byte and word writes to IOAPIC registers.
This fixes byte accesses to IOAPIC_REG_SELECT as mandated by at least the ICH10 and Intel Series 5 chipset specs. It also makes ioapic_mmio_write consistent with ioapic_mmio_read, which also allows byte and word accesses. Signed-off-by: Julian Stecklina <js@alien8.de> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt/kvm/ioapic.c')
-rw-r--r--virt/kvm/ioapic.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 3eed61eb486..71e2253edee 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -332,9 +332,18 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
(void*)addr, len, val);
ASSERT(!(addr & 0xf)); /* check alignment */
- if (len == 4 || len == 8)
+ switch (len) {
+ case 8:
+ case 4:
data = *(u32 *) val;
- else {
+ break;
+ case 2:
+ data = *(u16 *) val;
+ break;
+ case 1:
+ data = *(u8 *) val;
+ break;
+ default:
printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
return 0;
}
@@ -343,7 +352,7 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
spin_lock(&ioapic->lock);
switch (addr) {
case IOAPIC_REG_SELECT:
- ioapic->ioregsel = data;
+ ioapic->ioregsel = data & 0xFF; /* 8-bit register */
break;
case IOAPIC_REG_WINDOW: