[RFC PATCH 1/7] virtio-ring: maintain next in extra state for packed virtqueue
From: Jason Wang <jasowang@redhat.com>
Date: 2021-04-21 03:21:57
Also in:
kvm, lkml
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
This patch moves next from vring_desc_state_packed to vring_desc_desc_extra_packed. This makes it simpler to let extra state to be reused by split virtqueue. Signed-off-by: Jason Wang <jasowang@redhat.com> --- drivers/virtio/virtio_ring.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 71e16b53e9c1..e1e9ed42e637 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c@@ -74,7 +74,6 @@ struct vring_desc_state_packed { void *data; /* Data for callback. */ struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ u16 num; /* Descriptor list length. */ - u16 next; /* The next desc state in a list. */ u16 last; /* The last desc state in a list. */ };
@@ -82,6 +81,7 @@ struct vring_desc_extra_packed { dma_addr_t addr; /* Buffer DMA addr. */ u32 len; /* Buffer length. */ u16 flags; /* Descriptor flags. */ + u16 next; /* The next desc state in a list. */ }; struct vring_virtqueue {
@@ -1061,7 +1061,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, 1 << VRING_PACKED_DESC_F_USED; } vq->packed.next_avail_idx = n; - vq->free_head = vq->packed.desc_state[id].next; + vq->free_head = vq->packed.desc_extra[id].next; /* Store token and indirect buffer state. */ vq->packed.desc_state[id].num = 1;
@@ -1169,7 +1169,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, le16_to_cpu(flags); } prev = curr; - curr = vq->packed.desc_state[curr].next; + curr = vq->packed.desc_extra[curr].next; if ((unlikely(++i >= vq->packed.vring.num))) { i = 0;
@@ -1290,7 +1290,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, /* Clear data ptr. */ state->data = NULL; - vq->packed.desc_state[state->last].next = vq->free_head; + vq->packed.desc_extra[state->last].next = vq->free_head; vq->free_head = id; vq->vq.num_free += state->num;
@@ -1299,7 +1299,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, for (i = 0; i < state->num; i++) { vring_unmap_state_packed(vq, &vq->packed.desc_extra[curr]); - curr = vq->packed.desc_state[curr].next; + curr = vq->packed.desc_extra[curr].next; } }
@@ -1649,8 +1649,6 @@ static struct virtqueue *vring_create_virtqueue_packed( /* Put everything in free lists. */ vq->free_head = 0; - for (i = 0; i < num-1; i++) - vq->packed.desc_state[i].next = i + 1; vq->packed.desc_extra = kmalloc_array(num, sizeof(struct vring_desc_extra_packed),
@@ -1661,6 +1659,9 @@ static struct virtqueue *vring_create_virtqueue_packed( memset(vq->packed.desc_extra, 0, num * sizeof(struct vring_desc_extra_packed)); + for (i = 0; i < num - 1; i++) + vq->packed.desc_extra[i].next = i + 1; + /* No callback? Tell other side not to bother us. */ if (!callback) { vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
--
2.25.1
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