Re: [PATCH v5 06/22] virtio_ring: queue_reset: packed: support enable reset queue
From: Jason Wang <hidden>
Date: 2022-02-16 04:14:38
Also in:
bpf, virtualization
On Mon, Feb 14, 2022 at 4:14 PM Xuan Zhuo [off-list ref] wrote:
quoted hunk ↗ jump to hunk
The purpose of this patch is to make vring packed support re-enable reset vq. Based on whether the incoming vq passed by vring_setup_virtqueue() is NULL or not, distinguish whether it is a normal create virtqueue or re-enable a reset queue. When re-enable a reset queue, reuse the original callback, name, indirect. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/virtio/virtio_ring.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-)diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 4639e1643c78..20659f7ca582 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c@@ -1683,7 +1683,8 @@ static struct virtqueue *vring_create_virtqueue_packed( bool context, bool (*notify)(struct virtqueue *), void (*callback)(struct virtqueue *), - const char *name) + const char *name, + struct virtqueue *_vq) { struct vring_virtqueue *vq; struct vring_packed_desc *ring;@@ -1713,13 +1714,20 @@ static struct virtqueue *vring_create_virtqueue_packed( if (!device) goto err_device; - vq = kmalloc(sizeof(*vq), GFP_KERNEL); - if (!vq) - goto err_vq; + if (_vq) { + vq = to_vvq(_vq); + } else { + vq = kmalloc(sizeof(*vq), GFP_KERNEL); + if (!vq) + goto err_vq; + + vq->vq.callback = callback; + vq->vq.name = name; + vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && + !context; + }
The code looks tricky. Except for the memory we don't even need to touch any of the other attributes. I'd suggest splitting out the vring allocation into a dedicated helper that could be called by both vring_create_queue_XXX and the enable() logic (and in the enable logic we don't even need to relocate if size is not changed). Thanks
quoted hunk ↗ jump to hunk
- vq->vq.callback = callback; vq->vq.vdev = vdev; - vq->vq.name = name; vq->vq.num_free = num; vq->vq.index = index; vq->we_own_ring = true;@@ -1736,8 +1744,6 @@ static struct virtqueue *vring_create_virtqueue_packed( vq->last_add_time_valid = false; #endif - vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && - !context; vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))@@ -1778,7 +1784,7 @@ static struct virtqueue *vring_create_virtqueue_packed( goto err_desc_extra; /* No callback? Tell other side not to bother us. */ - if (!callback) { + if (!vq->vq.callback) { vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE; vq->packed.vring.driver->flags = cpu_to_le16(vq->packed.event_flags_shadow);@@ -1792,7 +1798,8 @@ static struct virtqueue *vring_create_virtqueue_packed( err_desc_extra: kfree(vq->packed.desc_state); err_desc_state: - kfree(vq); + if (!_vq) + kfree(vq); err_vq: vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr); err_device:@@ -2317,7 +2324,7 @@ struct virtqueue *vring_setup_virtqueue( if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) return vring_create_virtqueue_packed(index, num, vring_align, vdev, weak_barriers, may_reduce_num, - context, notify, callback, name); + context, notify, callback, name, vq); return vring_create_virtqueue_split(index, num, vring_align, vdev, weak_barriers, may_reduce_num, --2.31.0