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SubjectRe: [Qemu-devel] [net-next RFC PATCH 7/7] virtio-net changes
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On Fri, 2011-08-12 at 09:55 +0800, Jason Wang wrote:
> From: Krishna Kumar <krkumar2@in.ibm.com>
>
> Implement mq virtio-net driver.
>
> Though struct virtio_net_config changes, it works with the old
> qemu since the last element is not accessed unless qemu sets
> VIRTIO_NET_F_MULTIQUEUE.
>
> Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---

Could these changes be documented to virtio-spec as well?

> drivers/net/virtio_net.c | 578 +++++++++++++++++++++++++++++++-------------
> include/linux/virtio_net.h | 3
> 2 files changed, 411 insertions(+), 170 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 0c7321c..03a199d 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -49,16 +49,48 @@ struct virtnet_stats {
> u64 rx_packets;
> };
>
> -struct virtnet_info {
> - struct virtio_device *vdev;
> - struct virtqueue *rvq, *svq, *cvq;
> - struct net_device *dev;
> +/* Internal representation of a send virtqueue */
> +struct send_queue {
> + /* Virtqueue associated with this send _queue */
> + struct virtqueue *svq;
> +
> + /* TX: fragments + linear part + virtio header */
> + struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
> +};
> +
> +/* Internal representation of a receive virtqueue */
> +struct receive_queue {
> + /* Virtqueue associated with this receive_queue */
> + struct virtqueue *rvq;
> +
> + /* Back pointer to the virtnet_info */
> + struct virtnet_info *vi;
> +
> struct napi_struct napi;
> - unsigned int status;
>
> /* Number of input buffers, and max we've ever had. */
> unsigned int num, max;
>
> + /* Work struct for refilling if we run low on memory. */
> + struct delayed_work refill;
> +
> + /* Chain pages by the private ptr. */
> + struct page *pages;
> +
> + /* RX: fragments + linear part + virtio header */
> + struct scatterlist rx_sg[MAX_SKB_FRAGS + 2];
> +};
> +
> +struct virtnet_info {
> + struct send_queue **sq;
> + struct receive_queue **rq;
> +
> + int numtxqs; /* # of rxqs/txqs */
> + struct virtio_device *vdev;
> + struct virtqueue *cvq;
> + struct net_device *dev;
> + unsigned int status;
> +
> /* I like... big packets and I cannot lie! */
> bool big_packets;
>
> @@ -67,16 +99,6 @@ struct virtnet_info {
>
> /* Active statistics */
> struct virtnet_stats __percpu *stats;
> -
> - /* Work struct for refilling if we run low on memory. */
> - struct delayed_work refill;
> -
> - /* Chain pages by the private ptr. */
> - struct page *pages;
> -
> - /* fragments + linear part + virtio header */
> - struct scatterlist rx_sg[MAX_SKB_FRAGS + 2];
> - struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
> };
>
> struct skb_vnet_hdr {
> @@ -106,22 +128,22 @@ static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
> * private is used to chain pages for big packets, put the whole
> * most recent used list in the beginning for reuse
> */
> -static void give_pages(struct virtnet_info *vi, struct page *page)
> +static void give_pages(struct receive_queue *rq, struct page *page)
> {
> struct page *end;
>
> /* Find end of list, sew whole thing into vi->pages. */
> for (end = page; end->private; end = (struct page *)end->private);
> - end->private = (unsigned long)vi->pages;
> - vi->pages = page;
> + end->private = (unsigned long)rq->pages;
> + rq->pages = page;
> }
>
> -static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
> +static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
> {
> - struct page *p = vi->pages;
> + struct page *p = rq->pages;
>
> if (p) {
> - vi->pages = (struct page *)p->private;
> + rq->pages = (struct page *)p->private;
> /* clear private here, it is used to chain pages */
> p->private = 0;
> } else
> @@ -132,12 +154,13 @@ static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
> static void skb_xmit_done(struct virtqueue *svq)
> {
> struct virtnet_info *vi = svq->vdev->priv;
> + int qnum = svq->queue_index / 2; /* RX/TX vqs are allocated in pairs */
>
> /* Suppress further interrupts. */
> virtqueue_disable_cb(svq);
>
> /* We were probably waiting for more output buffers. */
> - netif_wake_queue(vi->dev);
> + netif_wake_subqueue(vi->dev, qnum);
> }
>
> static void set_skb_frag(struct sk_buff *skb, struct page *page,
> @@ -157,9 +180,10 @@ static void set_skb_frag(struct sk_buff *skb, struct page *page,
> *len -= f->size;
> }
>
> -static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> +static struct sk_buff *page_to_skb(struct receive_queue *rq,
> struct page *page, unsigned int len)
> {
> + struct virtnet_info *vi = rq->vi;
> struct sk_buff *skb;
> struct skb_vnet_hdr *hdr;
> unsigned int copy, hdr_len, offset;
> @@ -202,12 +226,12 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> }
>
> if (page)
> - give_pages(vi, page);
> + give_pages(rq, page);
>
> return skb;
> }
>
> -static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
> +static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb)
> {
> struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
> struct page *page;
> @@ -221,7 +245,8 @@ static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
> skb->dev->stats.rx_length_errors++;
> return -EINVAL;
> }
> - page = virtqueue_get_buf(vi->rvq, &len);
> +
> + page = virtqueue_get_buf(rq->rvq, &len);
> if (!page) {
> pr_debug("%s: rx error: %d buffers missing\n",
> skb->dev->name, hdr->mhdr.num_buffers);
> @@ -234,13 +259,14 @@ static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
>
> set_skb_frag(skb, page, 0, &len);
>
> - --vi->num;
> + --rq->num;
> }
> return 0;
> }
>
> -static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
> +static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
> {
> + struct net_device *dev = rq->vi->dev;
> struct virtnet_info *vi = netdev_priv(dev);
> struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);
> struct sk_buff *skb;
> @@ -251,7 +277,7 @@ static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
> pr_debug("%s: short packet %i\n", dev->name, len);
> dev->stats.rx_length_errors++;
> if (vi->mergeable_rx_bufs || vi->big_packets)
> - give_pages(vi, buf);
> + give_pages(rq, buf);
> else
> dev_kfree_skb(buf);
> return;
> @@ -263,14 +289,14 @@ static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
> skb_trim(skb, len);
> } else {
> page = buf;
> - skb = page_to_skb(vi, page, len);
> + skb = page_to_skb(rq, page, len);
> if (unlikely(!skb)) {
> dev->stats.rx_dropped++;
> - give_pages(vi, page);
> + give_pages(rq, page);
> return;
> }
> if (vi->mergeable_rx_bufs)
> - if (receive_mergeable(vi, skb)) {
> + if (receive_mergeable(rq, skb)) {
> dev_kfree_skb(skb);
> return;
> }
> @@ -341,184 +367,200 @@ frame_err:
> dev_kfree_skb(skb);
> }
>
> -static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
> +static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
> {
> struct sk_buff *skb;
> struct skb_vnet_hdr *hdr;
> int err;
>
> - skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN);
> + skb = netdev_alloc_skb_ip_align(rq->vi->dev, MAX_PACKET_LEN);
> if (unlikely(!skb))
> return -ENOMEM;
>
> skb_put(skb, MAX_PACKET_LEN);
>
> hdr = skb_vnet_hdr(skb);
> - sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr);
> + sg_set_buf(rq->rx_sg, &hdr->hdr, sizeof hdr->hdr);
>
> - skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len);
> + skb_to_sgvec(skb, rq->rx_sg + 1, 0, skb->len);
>
> - err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 2, skb, gfp);
> + err = virtqueue_add_buf_gfp(rq->rvq, rq->rx_sg, 0, 2, skb, gfp);
> if (err < 0)
> dev_kfree_skb(skb);
>
> return err;
> }
>
> -static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
> +static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
> {
> struct page *first, *list = NULL;
> char *p;
> int i, err, offset;
>
> - /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */
> + /* page in rq->rx_sg[MAX_SKB_FRAGS + 1] is list tail */
> for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
> - first = get_a_page(vi, gfp);
> + first = get_a_page(rq, gfp);
> if (!first) {
> if (list)
> - give_pages(vi, list);
> + give_pages(rq, list);
> return -ENOMEM;
> }
> - sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE);
> + sg_set_buf(&rq->rx_sg[i], page_address(first), PAGE_SIZE);
>
> /* chain new page in list head to match sg */
> first->private = (unsigned long)list;
> list = first;
> }
>
> - first = get_a_page(vi, gfp);
> + first = get_a_page(rq, gfp);
> if (!first) {
> - give_pages(vi, list);
> + give_pages(rq, list);
> return -ENOMEM;
> }
> p = page_address(first);
>
> - /* vi->rx_sg[0], vi->rx_sg[1] share the same page */
> - /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */
> - sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr));
> + /* rq->rx_sg[0], rq->rx_sg[1] share the same page */
> + /* a separated rq->rx_sg[0] for virtio_net_hdr only due to QEMU bug */
> + sg_set_buf(&rq->rx_sg[0], p, sizeof(struct virtio_net_hdr));
>
> - /* vi->rx_sg[1] for data packet, from offset */
> + /* rq->rx_sg[1] for data packet, from offset */
> offset = sizeof(struct padded_vnet_hdr);
> - sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset);
> + sg_set_buf(&rq->rx_sg[1], p + offset, PAGE_SIZE - offset);
>
> /* chain first in list head */
> first->private = (unsigned long)list;
> - err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2,
> + err = virtqueue_add_buf_gfp(rq->rvq, rq->rx_sg, 0, MAX_SKB_FRAGS + 2,
> first, gfp);
> if (err < 0)
> - give_pages(vi, first);
> + give_pages(rq, first);
>
> return err;
> }
>
> -static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
> +static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
> {
> struct page *page;
> int err;
>
> - page = get_a_page(vi, gfp);
> + page = get_a_page(rq, gfp);
> if (!page)
> return -ENOMEM;
>
> - sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE);
> + sg_init_one(rq->rx_sg, page_address(page), PAGE_SIZE);
>
> - err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 1, page, gfp);
> + err = virtqueue_add_buf_gfp(rq->rvq, rq->rx_sg, 0, 1, page, gfp);
> if (err < 0)
> - give_pages(vi, page);
> + give_pages(rq, page);
>
> return err;
> }
>
> /* Returns false if we couldn't fill entirely (OOM). */
> -static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
> +static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
> {
> + struct virtnet_info *vi = rq->vi;
> int err;
> bool oom;
>
> do {
> if (vi->mergeable_rx_bufs)
> - err = add_recvbuf_mergeable(vi, gfp);
> + err = add_recvbuf_mergeable(rq, gfp);
> else if (vi->big_packets)
> - err = add_recvbuf_big(vi, gfp);
> + err = add_recvbuf_big(rq, gfp);
> else
> - err = add_recvbuf_small(vi, gfp);
> + err = add_recvbuf_small(rq, gfp);
>
> oom = err == -ENOMEM;
> if (err < 0)
> break;
> - ++vi->num;
> + ++rq->num;
> } while (err > 0);
> - if (unlikely(vi->num > vi->max))
> - vi->max = vi->num;
> - virtqueue_kick(vi->rvq);
> + if (unlikely(rq->num > rq->max))
> + rq->max = rq->num;
> + virtqueue_kick(rq->rvq);
> return !oom;
> }
>
> static void skb_recv_done(struct virtqueue *rvq)
> {
> + int qnum = rvq->queue_index / 2; /* RX/TX vqs are allocated in pairs */
> struct virtnet_info *vi = rvq->vdev->priv;
> + struct napi_struct *napi = &vi->rq[qnum]->napi;
> +
> /* Schedule NAPI, Suppress further interrupts if successful. */
> - if (napi_schedule_prep(&vi->napi)) {
> + if (napi_schedule_prep(napi)) {
> virtqueue_disable_cb(rvq);
> - __napi_schedule(&vi->napi);
> + __napi_schedule(napi);
> }
> }
>
> -static void virtnet_napi_enable(struct virtnet_info *vi)
> +static void virtnet_napi_enable(struct receive_queue *rq)
> {
> - napi_enable(&vi->napi);
> + napi_enable(&rq->napi);
>
> /* If all buffers were filled by other side before we napi_enabled, we
> * won't get another interrupt, so process any outstanding packets
> * now. virtnet_poll wants re-enable the queue, so we disable here.
> * We synchronize against interrupts via NAPI_STATE_SCHED */
> - if (napi_schedule_prep(&vi->napi)) {
> - virtqueue_disable_cb(vi->rvq);
> - __napi_schedule(&vi->napi);
> + if (napi_schedule_prep(&rq->napi)) {
> + virtqueue_disable_cb(rq->rvq);
> + __napi_schedule(&rq->napi);
> }
> }
>
> +static void virtnet_napi_enable_all_queues(struct virtnet_info *vi)
> +{
> + int i;
> +
> + for (i = 0; i < vi->numtxqs; i++)
> + virtnet_napi_enable(vi->rq[i]);
> +}
> +
> static void refill_work(struct work_struct *work)
> {
> - struct virtnet_info *vi;
> + struct napi_struct *napi;
> + struct receive_queue *rq;
> bool still_empty;
>
> - vi = container_of(work, struct virtnet_info, refill.work);
> - napi_disable(&vi->napi);
> - still_empty = !try_fill_recv(vi, GFP_KERNEL);
> - virtnet_napi_enable(vi);
> + rq = container_of(work, struct receive_queue, refill.work);
> + napi = &rq->napi;
> +
> + napi_disable(napi);
> + still_empty = !try_fill_recv(rq, GFP_KERNEL);
> + virtnet_napi_enable(rq);
>
> /* In theory, this can happen: if we don't get any buffers in
> * we will *never* try to fill again. */
> if (still_empty)
> - schedule_delayed_work(&vi->refill, HZ/2);
> + schedule_delayed_work(&rq->refill, HZ/2);
> }
>
> static int virtnet_poll(struct napi_struct *napi, int budget)
> {
> - struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
> + struct receive_queue *rq = container_of(napi, struct receive_queue,
> + napi);
> void *buf;
> unsigned int len, received = 0;
>
> again:
> while (received < budget &&
> - (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) {
> - receive_buf(vi->dev, buf, len);
> - --vi->num;
> + (buf = virtqueue_get_buf(rq->rvq, &len)) != NULL) {
> + receive_buf(rq, buf, len);
> + --rq->num;
> received++;
> }
>
> - if (vi->num < vi->max / 2) {
> - if (!try_fill_recv(vi, GFP_ATOMIC))
> - schedule_delayed_work(&vi->refill, 0);
> + if (rq->num < rq->max / 2) {
> + if (!try_fill_recv(rq, GFP_ATOMIC))
> + schedule_delayed_work(&rq->refill, 0);
> }
>
> /* Out of packets? */
> if (received < budget) {
> napi_complete(napi);
> - if (unlikely(!virtqueue_enable_cb(vi->rvq)) &&
> + if (unlikely(!virtqueue_enable_cb(rq->rvq)) &&
> napi_schedule_prep(napi)) {
> - virtqueue_disable_cb(vi->rvq);
> + virtqueue_disable_cb(rq->rvq);
> __napi_schedule(napi);
> goto again;
> }
> @@ -527,13 +569,14 @@ again:
> return received;
> }
>
> -static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
> +static unsigned int free_old_xmit_skbs(struct virtnet_info *vi,
> + struct virtqueue *svq)
> {
> struct sk_buff *skb;
> unsigned int len, tot_sgs = 0;
> struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);
>
> - while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
> + while ((skb = virtqueue_get_buf(svq, &len)) != NULL) {
> pr_debug("Sent skb %p\n", skb);
>
> u64_stats_update_begin(&stats->syncp);
> @@ -547,7 +590,8 @@ static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
> return tot_sgs;
> }
>
> -static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
> +static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb,
> + struct virtqueue *svq, struct scatterlist *tx_sg)
> {
> struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
> const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
> @@ -585,12 +629,12 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
>
> /* Encode metadata header at front. */
> if (vi->mergeable_rx_bufs)
> - sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
> + sg_set_buf(tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
> else
> - sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
> + sg_set_buf(tx_sg, &hdr->hdr, sizeof hdr->hdr);
>
> - hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1;
> - return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg,
> + hdr->num_sg = skb_to_sgvec(skb, tx_sg + 1, 0, skb->len) + 1;
> + return virtqueue_add_buf(svq, tx_sg, hdr->num_sg,
> 0, skb);
> }
>
> @@ -598,31 +642,34 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
> {
> struct virtnet_info *vi = netdev_priv(dev);
> int capacity;
> + int qnum = skb_get_queue_mapping(skb);
> + struct virtqueue *svq = vi->sq[qnum]->svq;
>
> /* Free up any pending old buffers before queueing new ones. */
> - free_old_xmit_skbs(vi);
> + free_old_xmit_skbs(vi, svq);
>
> /* Try to transmit */
> - capacity = xmit_skb(vi, skb);
> + capacity = xmit_skb(vi, skb, svq, vi->sq[qnum]->tx_sg);
>
> /* This can happen with OOM and indirect buffers. */
> if (unlikely(capacity < 0)) {
> if (net_ratelimit()) {
> if (likely(capacity == -ENOMEM)) {
> dev_warn(&dev->dev,
> - "TX queue failure: out of memory\n");
> + "TXQ (%d) failure: out of memory\n",
> + qnum);
> } else {
> dev->stats.tx_fifo_errors++;
> dev_warn(&dev->dev,
> - "Unexpected TX queue failure: %d\n",
> - capacity);
> + "Unexpected TXQ (%d) failure: %d\n",
> + qnum, capacity);
> }
> }
> dev->stats.tx_dropped++;
> kfree_skb(skb);
> return NETDEV_TX_OK;
> }
> - virtqueue_kick(vi->svq);
> + virtqueue_kick(svq);
>
> /* Don't wait up for transmitted skbs to be freed. */
> skb_orphan(skb);
> @@ -631,13 +678,13 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
> /* Apparently nice girls don't return TX_BUSY; stop the queue
> * before it gets out of hand. Naturally, this wastes entries. */
> if (capacity < 2+MAX_SKB_FRAGS) {
> - netif_stop_queue(dev);
> - if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
> + netif_stop_subqueue(dev, qnum);
> + if (unlikely(!virtqueue_enable_cb_delayed(svq))) {
> /* More just got used, free them then recheck. */
> - capacity += free_old_xmit_skbs(vi);
> + capacity += free_old_xmit_skbs(vi, svq);
> if (capacity >= 2+MAX_SKB_FRAGS) {
> - netif_start_queue(dev);
> - virtqueue_disable_cb(vi->svq);
> + netif_start_subqueue(dev, qnum);
> + virtqueue_disable_cb(svq);
> }
> }
> }
> @@ -700,8 +747,10 @@ static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
> static void virtnet_netpoll(struct net_device *dev)
> {
> struct virtnet_info *vi = netdev_priv(dev);
> + int i;
>
> - napi_schedule(&vi->napi);
> + for (i = 0; i < vi->numtxqs; i++)
> + napi_schedule(&vi->rq[i]->napi);
> }
> #endif
>
> @@ -709,7 +758,7 @@ static int virtnet_open(struct net_device *dev)
> {
> struct virtnet_info *vi = netdev_priv(dev);
>
> - virtnet_napi_enable(vi);
> + virtnet_napi_enable_all_queues(vi);
> return 0;
> }
>
> @@ -761,8 +810,10 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
> static int virtnet_close(struct net_device *dev)
> {
> struct virtnet_info *vi = netdev_priv(dev);
> + int i;
>
> - napi_disable(&vi->napi);
> + for (i = 0; i < vi->numtxqs; i++)
> + napi_disable(&vi->rq[i]->napi);
>
> return 0;
> }
> @@ -919,10 +970,10 @@ static void virtnet_update_status(struct virtnet_info *vi)
>
> if (vi->status & VIRTIO_NET_S_LINK_UP) {
> netif_carrier_on(vi->dev);
> - netif_wake_queue(vi->dev);
> + netif_tx_wake_all_queues(vi->dev);
> } else {
> netif_carrier_off(vi->dev);
> - netif_stop_queue(vi->dev);
> + netif_tx_stop_all_queues(vi->dev);
> }
> }
>
> @@ -933,18 +984,222 @@ static void virtnet_config_changed(struct virtio_device *vdev)
> virtnet_update_status(vi);
> }
>
> +static void free_receive_bufs(struct virtnet_info *vi)
> +{
> + int i;
> +
> + for (i = 0; i < vi->numtxqs; i++) {
> + BUG_ON(vi->rq[i] == NULL);
> + while (vi->rq[i]->pages)
> + __free_pages(get_a_page(vi->rq[i], GFP_KERNEL), 0);
> + }
> +}
> +
> +/* Free memory allocated for send and receive queues */
> +static void free_rq_sq(struct virtnet_info *vi)
> +{
> + int i;
> +
> + if (vi->rq) {
> + for (i = 0; i < vi->numtxqs; i++)
> + kfree(vi->rq[i]);
> + kfree(vi->rq);
> + }
> +
> + if (vi->sq) {
> + for (i = 0; i < vi->numtxqs; i++)
> + kfree(vi->sq[i]);
> + kfree(vi->sq);
> + }
> +}
> +
> +static void free_unused_bufs(struct virtnet_info *vi)
> +{
> + void *buf;
> + int i;
> +
> + for (i = 0; i < vi->numtxqs; i++) {
> + struct virtqueue *svq = vi->sq[i]->svq;
> +
> + while (1) {
> + buf = virtqueue_detach_unused_buf(svq);
> + if (!buf)
> + break;
> + dev_kfree_skb(buf);
> + }
> + }
> +
> + for (i = 0; i < vi->numtxqs; i++) {
> + struct virtqueue *rvq = vi->rq[i]->rvq;
> +
> + while (1) {
> + buf = virtqueue_detach_unused_buf(rvq);
> + if (!buf)
> + break;
> + if (vi->mergeable_rx_bufs || vi->big_packets)
> + give_pages(vi->rq[i], buf);
> + else
> + dev_kfree_skb(buf);
> + --vi->rq[i]->num;
> + }
> + BUG_ON(vi->rq[i]->num != 0);
> + }
> +}
> +
> +#define MAX_DEVICE_NAME 16
> +static int initialize_vqs(struct virtnet_info *vi, int numtxqs)
> +{
> + vq_callback_t **callbacks;
> + struct virtqueue **vqs;
> + int i, err = -ENOMEM;
> + int totalvqs;
> + char **names;
> +
> + /* Allocate receive queues */
> + vi->rq = kcalloc(numtxqs, sizeof(*vi->rq), GFP_KERNEL);
> + if (!vi->rq)
> + goto out;
> + for (i = 0; i < numtxqs; i++) {
> + vi->rq[i] = kzalloc(sizeof(*vi->rq[i]), GFP_KERNEL);
> + if (!vi->rq[i])
> + goto out;
> + }
> +
> + /* Allocate send queues */
> + vi->sq = kcalloc(numtxqs, sizeof(*vi->sq), GFP_KERNEL);
> + if (!vi->sq)
> + goto out;
> + for (i = 0; i < numtxqs; i++) {
> + vi->sq[i] = kzalloc(sizeof(*vi->sq[i]), GFP_KERNEL);
> + if (!vi->sq[i])
> + goto out;
> + }
> +
> + /* setup initial receive and send queue parameters */
> + for (i = 0; i < numtxqs; i++) {
> + vi->rq[i]->vi = vi;
> + vi->rq[i]->pages = NULL;
> + INIT_DELAYED_WORK(&vi->rq[i]->refill, refill_work);
> + netif_napi_add(vi->dev, &vi->rq[i]->napi, virtnet_poll,
> + napi_weight);
> +
> + sg_init_table(vi->rq[i]->rx_sg, ARRAY_SIZE(vi->rq[i]->rx_sg));
> + sg_init_table(vi->sq[i]->tx_sg, ARRAY_SIZE(vi->sq[i]->tx_sg));
> + }
> +
> + /*
> + * We expect 1 RX virtqueue followed by 1 TX virtqueues, followed
> + * by the same 'numtxqs-1' times, and optionally one control virtqueue.
> + */
> + totalvqs = numtxqs * 2 +
> + virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
> +
> + /* Allocate space for find_vqs parameters */
> + vqs = kmalloc(totalvqs * sizeof(*vqs), GFP_KERNEL);
> + callbacks = kmalloc(totalvqs * sizeof(*callbacks), GFP_KERNEL);
> + names = kzalloc(totalvqs * sizeof(*names), GFP_KERNEL);
> + if (!vqs || !callbacks || !names)
> + goto free_params;
> +
> +#if 1
> + /* Allocate/initialize parameters for recv/send virtqueues */
> + for (i = 0; i < numtxqs * 2; i++) {
> + names[i] = kmalloc(MAX_DEVICE_NAME * sizeof(*names[i]),
> + GFP_KERNEL);
> + if (!names[i])
> + goto free_params;
> +
> + if (!(i & 1)) { /* RX */
> + callbacks[i] = skb_recv_done;
> + sprintf(names[i], "input.%d", i / 2);
> + } else {
> + callbacks[i] = skb_xmit_done;
> + sprintf(names[i], "output.%d", i / 2);
> + }
> + }
> +
> + /* Parameters for control virtqueue, if any */
> + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
> + callbacks[i] = NULL;
> + names[i] = "control";
> + }
> +#else
> + /* Allocate/initialize parameters for recv virtqueues */
> + for (i = 0; i < numtxqs * 2; i += 2) {
> + callbacks[i] = skb_recv_done;
> + names[i] = kmalloc(MAX_DEVICE_NAME * sizeof(*names[i]),
> + GFP_KERNEL);
> + if (!names[i])
> + goto free_params;
> + sprintf(names[i], "input.%d", i / 2);
> + }
> +
> + /* Allocate/initialize parameters for send virtqueues */
> + for (i = 1; i < numtxqs * 2; i += 2) {
> + callbacks[i] = skb_xmit_done;
> + names[i] = kmalloc(MAX_DEVICE_NAME * sizeof(*names[i]),
> + GFP_KERNEL);
> + if (!names[i])
> + goto free_params;
> + sprintf(names[i], "output.%d", i / 2);
> + }
> +
> + /* Parameters for control virtqueue, if any */
> + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
> + callbacks[i - 1] = NULL;
> + names[i - 1] = "control";
> + }
> +#endif
> +
> + err = vi->vdev->config->find_vqs(vi->vdev, totalvqs, vqs, callbacks,
> + (const char **)names);
> + if (err)
> + goto free_params;
> +
> + /* Assign the allocated vqs alternatively for RX/TX */
> + for (i = 0; i < numtxqs * 2; i += 2) {
> + vi->rq[i/2]->rvq = vqs[i];
> + vi->sq[i/2]->svq = vqs[i + 1];
> + }
> +
> + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ))
> + vi->cvq = vqs[i];
> +
> +free_params:
> + if (names) {
> + for (i = 0; i < numtxqs * 2; i++)
> + kfree(names[i]);
> + kfree(names);
> + }
> +
> + kfree(callbacks);
> + kfree(vqs);
> +
> +out:
> + if (err)
> + free_rq_sq(vi);
> +
> + return err;
> +}
> +
> static int virtnet_probe(struct virtio_device *vdev)
> {
> - int err;
> + int i, err;
> + u16 numtxqs;
> + u16 num_queue_pairs = 2;
> struct net_device *dev;
> struct virtnet_info *vi;
> - struct virtqueue *vqs[3];
> - vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
> - const char *names[] = { "input", "output", "control" };
> - int nvqs;
> +
> + /* Find if host supports MULTIQUEUE */
> + err = virtio_config_val(vdev, VIRTIO_NET_F_MULTIQUEUE,
> + offsetof(struct virtio_net_config,
> + num_queue_pairs), &num_queue_pairs);
> + numtxqs = num_queue_pairs / 2;
> + if (!numtxqs)
> + numtxqs = 1;
>
> /* Allocate ourselves a network device with room for our info */
> - dev = alloc_etherdev(sizeof(struct virtnet_info));
> + dev = alloc_etherdev_mq(sizeof(struct virtnet_info), numtxqs);
> if (!dev)
> return -ENOMEM;
>
> @@ -991,19 +1246,14 @@ static int virtnet_probe(struct virtio_device *vdev)
>
> /* Set up our device-specific information */
> vi = netdev_priv(dev);
> - netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
> vi->dev = dev;
> vi->vdev = vdev;
> vdev->priv = vi;
> - vi->pages = NULL;
> vi->stats = alloc_percpu(struct virtnet_stats);
> err = -ENOMEM;
> if (vi->stats == NULL)
> goto free;
> -
> - INIT_DELAYED_WORK(&vi->refill, refill_work);
> - sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
> - sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
> + vi->numtxqs = numtxqs;
>
> /* If we can receive ANY GSO packets, we must allocate large ones. */
> if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
> @@ -1014,23 +1264,14 @@ static int virtnet_probe(struct virtio_device *vdev)
> if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
> vi->mergeable_rx_bufs = true;
>
> - /* We expect two virtqueues, receive then send,
> - * and optionally control. */
> - nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
> -
> - err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
> + /* Initialize our rx/tx queue parameters, and invoke find_vqs */
> + err = initialize_vqs(vi, numtxqs);
> if (err)
> goto free_stats;
>
> - vi->rvq = vqs[0];
> - vi->svq = vqs[1];
> -
> - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
> - vi->cvq = vqs[2];
> -
> - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
> - dev->features |= NETIF_F_HW_VLAN_FILTER;
> - }
> + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) &&
> + virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
> + dev->features |= NETIF_F_HW_VLAN_FILTER;
>
> err = register_netdev(dev);
> if (err) {
> @@ -1039,14 +1280,21 @@ static int virtnet_probe(struct virtio_device *vdev)
> }
>
> /* Last of all, set up some receive buffers. */
> - try_fill_recv(vi, GFP_KERNEL);
> -
> - /* If we didn't even get one input buffer, we're useless. */
> - if (vi->num == 0) {
> - err = -ENOMEM;
> - goto unregister;
> + for (i = 0; i < numtxqs; i++) {
> + try_fill_recv(vi->rq[i], GFP_KERNEL);
> +
> + /* If we didn't even get one input buffer, we're useless. */
> + if (vi->rq[i]->num == 0) {
> + if (i)
> + free_unused_bufs(vi);
> + err = -ENOMEM;
> + goto free_recv_bufs;
> + }
> }
>
> + dev_info(&dev->dev, "(virtio-net) Allocated %d RX & TX vq's\n",
> + numtxqs);
> +
> /* Assume link up if device can't report link status,
> otherwise get link status from config. */
> if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
> @@ -1057,61 +1305,51 @@ static int virtnet_probe(struct virtio_device *vdev)
> netif_carrier_on(dev);
> }
>
> - pr_debug("virtnet: registered device %s\n", dev->name);
> + pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
> + dev->name, numtxqs);
> return 0;
>
> -unregister:
> +free_recv_bufs:
> + free_receive_bufs(vi);
> unregister_netdev(dev);
> - cancel_delayed_work_sync(&vi->refill);
> +
> free_vqs:
> + for (i = 0; i < numtxqs; i++)
> + cancel_delayed_work_sync(&vi->rq[i]->refill);
> vdev->config->del_vqs(vdev);
> + free_rq_sq(vi);
> +
> free_stats:
> free_percpu(vi->stats);
> +
> free:
> free_netdev(dev);
> return err;
> }
>
> -static void free_unused_bufs(struct virtnet_info *vi)
> -{
> - void *buf;
> - while (1) {
> - buf = virtqueue_detach_unused_buf(vi->svq);
> - if (!buf)
> - break;
> - dev_kfree_skb(buf);
> - }
> - while (1) {
> - buf = virtqueue_detach_unused_buf(vi->rvq);
> - if (!buf)
> - break;
> - if (vi->mergeable_rx_bufs || vi->big_packets)
> - give_pages(vi, buf);
> - else
> - dev_kfree_skb(buf);
> - --vi->num;
> - }
> - BUG_ON(vi->num != 0);
> -}
> -
> static void __devexit virtnet_remove(struct virtio_device *vdev)
> {
> struct virtnet_info *vi = vdev->priv;
> + int i;
>
> /* Stop all the virtqueues. */
> vdev->config->reset(vdev);
>
>
> unregister_netdev(vi->dev);
> - cancel_delayed_work_sync(&vi->refill);
> +
> + for (i = 0; i < vi->numtxqs; i++)
> + cancel_delayed_work_sync(&vi->rq[i]->refill);
>
> /* Free unused buffers in both send and recv, if any. */
> free_unused_bufs(vi);
>
> vdev->config->del_vqs(vi->vdev);
>
> - while (vi->pages)
> - __free_pages(get_a_page(vi, GFP_KERNEL), 0);
> + free_receive_bufs(vi);
> +
> + /* Free memory for send and receive queues */
> + free_rq_sq(vi);
>
> free_percpu(vi->stats);
> free_netdev(vi->dev);
> @@ -1129,7 +1367,7 @@ static unsigned int features[] = {
> VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
> VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
> VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
> - VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
> + VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, VIRTIO_NET_F_MULTIQUEUE,
> };
>
> static struct virtio_driver virtio_net_driver = {
> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
> index 970d5a2..fa85ac3 100644
> --- a/include/linux/virtio_net.h
> +++ b/include/linux/virtio_net.h
> @@ -49,6 +49,7 @@
> #define VIRTIO_NET_F_CTRL_RX 18 /* Control channel RX mode support */
> #define VIRTIO_NET_F_CTRL_VLAN 19 /* Control channel VLAN filtering */
> #define VIRTIO_NET_F_CTRL_RX_EXTRA 20 /* Extra RX mode control support */
> +#define VIRTIO_NET_F_MULTIQUEUE 21 /* Device supports multiple TXQ/RXQ */
>
> #define VIRTIO_NET_S_LINK_UP 1 /* Link is up */
>
> @@ -57,6 +58,8 @@ struct virtio_net_config {
> __u8 mac[6];
> /* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */
> __u16 status;
> + /* total number of RX/TX queues */
> + __u16 num_queue_pairs;
> } __attribute__((packed));
>
> /* This is the first element of the scatter-gather list. If you don't
>
>

--

Sasha.



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