[PATCH vhost v3 13/19] virtio_net: set premapped mode by find_vqs()

Xuan Zhuo
2024-02-29T07:21:09Z

Now, the virtio core can set the premapped mode by find_vqs().
If the premapped can be enabled, the dma array will not be
allocated. So virtio-net use the api of find_vqs to enable the
premapped.

Judge the premapped mode by the vq->premapped instead of saving
local variable.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/net/virtio_net.c | 57 +++++++++++++++++------------------
include/linux/virtio_config.h | 16 ++--------
2 files changed, 29 insertions(+), 44 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d7ce4a1011ea..140b2c155650 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -208,9 +208,6 @@ struct receive_queue {

/* Record the last dma info to free after new pages is allocated. */
struct virtnet_rq_dma *last_dma;
-
- /* Do dma by self */
- bool do_dma;
};

/* This structure can contain rss message with maximum settings for indirection table and keysize
@@ -657,7 +654,7 @@ static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx)
void *buf;

buf = virtqueue_get_buf_ctx(rq->vq, len, ctx);
- if (buf && rq->do_dma)
+ if (buf && rq->vq->premapped)
virtnet_rq_unmap(rq, buf, *len);

return buf;
@@ -670,7 +667,7 @@ static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len)
u32 offset;
void *head;

- if (!rq->do_dma) {
+ if (!rq->vq->premapped) {
sg_init_one(rq->sg, buf, len);
return;
}
@@ -700,7 +697,7 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp)

head = page_address(alloc_frag->page);

- if (rq->do_dma) {
+ if (rq->vq->premapped) {
dma = head;

/* new pages */
@@ -746,22 +743,6 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp)
return buf;
}

-static void virtnet_rq_set_premapped(struct virtnet_info *vi)
-{
- int i;
-
- /* disable for big mode */
- if (!vi->mergeable_rx_bufs && vi->big_packets)
- return;
-
- for (i = 0; i < vi->max_queue_pairs; i++) {
- if (virtqueue_set_dma_premapped(vi->rq[i].vq))
- continue;
-
- vi->rq[i].do_dma = true;
- }
-}
-
static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
{
struct virtnet_info *vi = vq->vdev->priv;
@@ -770,7 +751,7 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)

rq = &vi->rq[i];

- if (rq->do_dma)
+ if (rq->vq->premapped)
virtnet_rq_unmap(rq, buf, 0);

virtnet_rq_free_buf(vi, rq, buf);
@@ -1865,7 +1846,7 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,

err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
if (err < 0) {
- if (rq->do_dma)
+ if (rq->vq->premapped)
virtnet_rq_unmap(rq, buf, 0);
put_page(virt_to_head_page(buf));
}
@@ -1980,7 +1961,7 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi,
ctx = mergeable_len_to_ctx(len + room, headroom);
err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
if (err < 0) {
- if (rq->do_dma)
+ if (rq->vq->premapped)
virtnet_rq_unmap(rq, buf, 0);
put_page(virt_to_head_page(buf));
}
@@ -4229,7 +4210,7 @@ static void free_receive_page_frags(struct virtnet_info *vi)
int i;
for (i = 0; i < vi->max_queue_pairs; i++)
if (vi->rq[i].alloc_frag.page) {
- if (vi->rq[i].do_dma && vi->rq[i].last_dma)
+ if (vi->rq[i].vq->premapped && vi->rq[i].last_dma)
virtnet_rq_unmap(&vi->rq[i], vi->rq[i].last_dma, 0);
put_page(vi->rq[i].alloc_frag.page);
}
@@ -4293,11 +4274,13 @@ static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqu

static int virtnet_find_vqs(struct virtnet_info *vi)
{
+ struct virtio_vq_config cfg = {};
vq_callback_t **callbacks;
struct virtqueue **vqs;
const char **names;
int ret = -ENOMEM;
int total_vqs;
+ bool *premapped;
bool *ctx;
u16 i;

@@ -4322,8 +4305,13 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
goto err_ctx;
+
+ premapped = kcalloc(total_vqs, sizeof(*premapped), GFP_KERNEL);
+ if (!ctx)
+ goto err_premapped;
} else {
ctx = NULL;
+ premapped = NULL;
}

/* Parameters for control virtqueue, if any */
@@ -4342,10 +4330,19 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
names[txq2vq(i)] = vi->sq[i].name;
if (ctx)
ctx[rxq2vq(i)] = true;
+
+ if (premapped)
+ premapped[rxq2vq(i)] = true;
}

- ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
- names, ctx, NULL);
+ cfg.nvqs = total_vqs;
+ cfg.vqs = vqs;
+ cfg.callbacks = callbacks;
+ cfg.names = names;
+ cfg.ctx = ctx;
+ cfg.premapped = premapped;
+
+ ret = virtio_find_vqs_cfg(vi->vdev, &cfg);
if (ret)
goto err_find;

@@ -4365,6 +4362,8 @@ static int virtnet_find_vqs(struct virtnet_info *vi)

err_find:
+ kfree(premapped);
+err_premapped:
kfree(ctx);
err_ctx:
kfree(names);
@@ -4437,8 +4436,6 @@ static int init_vqs(struct virtnet_info *vi)
if (ret)
goto err_free;

- virtnet_rq_set_premapped(vi);
-
cpus_read_lock();
virtnet_set_affinity(vi);
cpus_read_unlock();
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index f1f62e57f395..e40509fef5fe 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -260,21 +260,9 @@ int virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
}

static inline
-int virtio_find_vqs_ctx(struct virtio_device *vdev, unsigned nvqs,
- struct virtqueue *vqs[], vq_callback_t *callbacks[],
- const char * const names[], const bool *ctx,
- struct irq_affinity *desc)
+int virtio_find_vqs_cfg(struct virtio_device *vdev, struct virtio_vq_config *cfg)
{
- struct virtio_vq_config cfg = {};
-
- cfg.nvqs = nvqs;
- cfg.vqs = vqs;
- cfg.callbacks = callbacks;
- cfg.names = (const char **)names;
- cfg.ctx = ctx;
- cfg.desc = desc;
-
- return vdev->config->find_vqs(vdev, &cfg);
+ return vdev->config->find_vqs(vdev, cfg);
}

/**
--
2.32.0.3.g01195cf9f