search for: vring_avail_idx

On Thu, Feb 09, 2017 at 04:48:53PM +0100, Paolo Bonzini wrote: > > > On 08/02/2017 20:59, Michael S. Tsirkin wrote: > > We couldn't decide what's better for everyone in 1.0 days and I doubt > > we'll be able to now, but yes, benchmarking is needed to make > > sire it's required. Very easy to remove or not to use/support in > > drivers/devices

On Thu, Feb 09, 2017 at 04:48:53PM +0100, Paolo Bonzini wrote: > > > On 08/02/2017 20:59, Michael S. Tsirkin wrote: > > We couldn't decide what's better for everyone in 1.0 days and I doubt > > we'll be able to now, but yes, benchmarking is needed to make > > sire it's required. Very easy to remove or not to use/support in > > drivers/devices

...ought originally there's a reason 1.0 rings had to be powers of two > but now I don't see why. OK, we can make it a feature flag later if we > want to. The reason is that it allows indices to be free running. This is an example of QEMU code that requires that: nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; /* Check it isn't doing strange things with descriptor numbers. */ if (nheads > vdev->vq[i].vring.num) { error_report("VQ %d size 0x%x Guest index 0x%x " &q...

...wrap-around */ if (unlikely(nheads < 0)) { nheads += N_qsize; } if (nheads < 0 || nheads > vdev->vq[i].vring.num) { error_report(...); return -1; } This can only catch bugs if N > 1 > This is an > example of QEMU code that requires that: > > nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; > /* Check it isn't doing strange things with descriptor numbers. */ > if (nheads > vdev->vq[i].vring.num) { > error_report("VQ %d size 0x%x Guest index 0x%x " >...

...wrap-around */ if (unlikely(nheads < 0)) { nheads += N_qsize; } if (nheads < 0 || nheads > vdev->vq[i].vring.num) { error_report(...); return -1; } This can only catch bugs if N > 1 > This is an > example of QEMU code that requires that: > > nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; > /* Check it isn't doing strange things with descriptor numbers. */ > if (nheads > vdev->vq[i].vring.num) { > error_report("VQ %d size 0x%x Guest index 0x%x " >...

...int16_t val) void virtio_queue_set_notification(VirtQueue *vq, int enable) { vq->notification = enable; - if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) { + if (virtio_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { vring_avail_event(vq, vring_avail_idx(vq)); } else if (enable) { vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); @@ -468,7 +468,7 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem) max = vq->vring.num; i = head = virtqueue_get_head(vq, vq->last_avail_idx++); - if (vdev->guest_featu...

...int16_t val) void virtio_queue_set_notification(VirtQueue *vq, int enable) { vq->notification = enable; - if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) { + if (virtio_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { vring_avail_event(vq, vring_avail_idx(vq)); } else if (enable) { vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); @@ -468,7 +468,7 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem) max = vq->vring.num; i = head = virtqueue_get_head(vq, vq->last_avail_idx++); - if (vdev->guest_featu...

OK, here's a patch that implements the virtio spec update that I sent earlier. It supercedes the PUBLISH_USED_IDX patches I sent out earlier. Support is added in both userspace and vhost-net. If you see issues or are just curious, you can turn the new feature off. For example: -global virtio-net-pci.event_idx=on -global virtio-blk-pci.event_idx=off Also, it's possible to try both

OK, here's a patch that implements the virtio spec update that I sent earlier. It supercedes the PUBLISH_USED_IDX patches I sent out earlier. Support is added in both userspace and vhost-net. If you see issues or are just curious, you can turn the new feature off. For example: -global virtio-net-pci.event_idx=on -global virtio-blk-pci.event_idx=off Also, it's possible to try both

...irtio_queue_set_notification(VirtQueue *vq, int enable) { vq->notification = enable; - if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) { + if (vq->vdev->guest_features[0] & (1 << VIRTIO_RING_F_EVENT_IDX)) { vring_avail_event(vq, vring_avail_idx(vq)); } else if (enable) { vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); @@ -468,7 +468,7 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem) max = vq->vring.num; i = head = virtqueue_get_head(vq, vq->last_avail_idx++); - if (vdev->guest_featu...

...irtio_queue_set_notification(VirtQueue *vq, int enable) { vq->notification = enable; - if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) { + if (vq->vdev->guest_features[0] & (1 << VIRTIO_RING_F_EVENT_IDX)) { vring_avail_event(vq, vring_avail_idx(vq)); } else if (enable) { vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); @@ -468,7 +468,7 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem) max = vq->vring.num; i = head = virtqueue_get_head(vq, vq->last_avail_idx++); - if (vdev->guest_featu...

On Tue, 2 Dec 2014 21:03:45 +0200 "Michael S. Tsirkin" <mst at redhat.com> wrote: > On Tue, Dec 02, 2014 at 04:41:36PM +0100, Cornelia Huck wrote: > > void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) > > { > > + /* > > + * For virtio-1 devices, the number of buffers may only be > > + * updated if the ring addresses have

On Tue, 2 Dec 2014 21:03:45 +0200 "Michael S. Tsirkin" <mst at redhat.com> wrote: > On Tue, Dec 02, 2014 at 04:41:36PM +0100, Cornelia Huck wrote: > > void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) > > { > > + /* > > + * For virtio-1 devices, the number of buffers may only be > > + * updated if the ring addresses have

...nconsistent with Host index 0x%x", @@ -1084,7 +1099,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } for (i = 0; i < num; i++) { - if (vdev->vq[i].pa) { + if (vdev->vq[i].vring.desc) { uint16_t nheads; nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; /* Check it isn't doing strange things with descriptor numbers. */ diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 68c40db..b63ced3 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virti...

...nconsistent with Host index 0x%x", @@ -1084,7 +1099,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } for (i = 0; i < num; i++) { - if (vdev->vq[i].pa) { + if (vdev->vq[i].vring.desc) { uint16_t nheads; nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; /* Check it isn't doing strange things with descriptor numbers. */ diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 68c40db..b63ced3 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virti...

...nconsistent with Host index 0x%x", @@ -1084,7 +1098,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } for (i = 0; i < num; i++) { - if (vdev->vq[i].pa) { + if (vdev->vq[i].vring.desc) { uint16_t nheads; nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; /* Check it isn't doing strange things with descriptor numbers. */ diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 68c40db..b63ced3 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virti...

...nconsistent with Host index 0x%x", @@ -1084,7 +1098,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } for (i = 0; i < num; i++) { - if (vdev->vq[i].pa) { + if (vdev->vq[i].vring.desc) { uint16_t nheads; nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; /* Check it isn't doing strange things with descriptor numbers. */ diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 68c40db..b63ced3 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virti...

...nconsistent with Host index 0x%x", @@ -1084,7 +1107,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } for (i = 0; i < num; i++) { - if (vdev->vq[i].pa) { + if (vdev->vq[i].vring.desc) { uint16_t nheads; nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; /* Check it isn't doing strange things with descriptor numbers. */ diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 68c40db..80ee313 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virti...

...nconsistent with Host index 0x%x", @@ -1084,7 +1107,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } for (i = 0; i < num; i++) { - if (vdev->vq[i].pa) { + if (vdev->vq[i].vring.desc) { uint16_t nheads; nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; /* Check it isn't doing strange things with descriptor numbers. */ diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 68c40db..80ee313 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virti...

...irtio_queue_set_notification(VirtQueue *vq, int enable) { vq->notification = enable; - if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) { + if (vq->vdev->guest_features[0] & (1 << VIRTIO_RING_F_EVENT_IDX)) { vring_avail_event(vq, vring_avail_idx(vq)); } else if (enable) { vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); @@ -468,7 +468,7 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem) max = vq->vring.num; i = head = virtqueue_get_head(vq, vq->last_avail_idx++); - if (vdev->guest_featu...