virtio: add feature checking helpers

Add a helper function for checking whether a bit is set in the guest
features for a vdev as well as one that works on a feature bit set.

Convert code that open-coded this: It cleans up the code and makes it
easier to extend the guest feature bits.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Cornelia Huck 2014-12-11 14:25:06 +01:00 committed by Michael S. Tsirkin
parent 0cd09c3a6c
commit ef546f1275
8 changed files with 42 additions and 31 deletions

View file

@ -105,7 +105,7 @@ void vring_teardown(Vring *vring, VirtIODevice *vdev, int n)
/* Disable guest->host notifies */
void vring_disable_notification(VirtIODevice *vdev, Vring *vring)
{
if (!(vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX))) {
if (!virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
vring_set_used_flags(vdev, vring, VRING_USED_F_NO_NOTIFY);
}
}
@ -116,7 +116,7 @@ void vring_disable_notification(VirtIODevice *vdev, Vring *vring)
*/
bool vring_enable_notification(VirtIODevice *vdev, Vring *vring)
{
if (vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) {
if (virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
vring_avail_event(&vring->vr) = vring->vr.avail->idx;
} else {
vring_clear_used_flags(vdev, vring, VRING_USED_F_NO_NOTIFY);
@ -135,12 +135,12 @@ bool vring_should_notify(VirtIODevice *vdev, Vring *vring)
* interrupts. */
smp_mb();
if ((vdev->guest_features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) &&
if (virtio_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) &&
unlikely(!vring_more_avail(vdev, vring))) {
return true;
}
if (!(vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX))) {
if (!virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
return !(vring_get_avail_flags(vdev, vring) &
VRING_AVAIL_F_NO_INTERRUPT);
}
@ -401,7 +401,7 @@ int vring_pop(VirtIODevice *vdev, Vring *vring,
/* On success, increment avail index. */
vring->last_avail_idx++;
if (vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) {
if (virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
vring_avail_event(&vring->vr) = vring->last_avail_idx;
}