virtio-ccw: Check indicators location.

If a guest neglected to register (secondary) indicators but still runs
with notifications enabled, we might end up writing to guest zero;
avoid this by checking for valid indicators and only writing to the
guest and generating an interrupt if indicators have been setup.

Cc: qemu-stable@nongnu.org
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This commit is contained in:
Cornelia Huck 2013-04-23 17:15:19 +02:00
parent 9953f8822c
commit 7c4869761d

View File

@ -742,10 +742,16 @@ static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
}
if (vector < VIRTIO_PCI_QUEUE_MAX) {
if (!dev->indicators) {
return;
}
indicators = ldq_phys(dev->indicators);
indicators |= 1ULL << vector;
stq_phys(dev->indicators, indicators);
} else {
if (!dev->indicators2) {
return;
}
vector = 0;
indicators = ldq_phys(dev->indicators2);
indicators |= 1ULL << vector;