Hi all:
This series is an update version of multiqueue virtio-net driver based on
Krishna Kumar's work to let virtio-net use multiple rx/tx queues to do the
packets reception and transmission. Please review and comments.
A protype implementation of qemu-kvm support could by found in
git://github.com/jasowang/qemu-kvm-mq.git. To start a guest with two queues, you
could specify the queues parameters to both tap and virtio-net like:
./qemu-kvm -netdev tap,queues=2,... -device virtio-net-pci,queues=2,...
then enable the multiqueue through ethtool by:
ethtool -L eth0 combined 2
Changes from RFC v7:
Addressing Rusty's comments:
- align the implementation (location of cvq) to v5.
- fix the style issue.
- use a global refill instead of per-vq one.
- check the VIRTIO_NET_F_RFS before calling virtnet_set_queues()
Addresing Michael's comments
- rename the curr_queue_pairs in virtnet_probe() to max_queue_pairs
- validate the number of queue pairs supported by the device against
VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MIN and VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MAX.
- don't crash when failing to change the number of virtqueues
- don't set the affinity hint when onle single queue is used or there's
too much
virtqueues
- add a TODO of handling cpu hotplug
- allow user to set the nubmer of queue pairs between 1 and max_queue_pairs
Changes from RFC v6:
- Align the implementation with the RFC spec update v5
- Addressing Rusty's comments:
* split the patches
* rename to max_queue_pairs and curr_queue_pairs
* remove the useless status
* fix the hibernation bug
- Addressing Ben's comments:
* check other parameters in ethtool_set_queues
Changes from RFC v5:
- Align the implementation with the RFC spec update v4
- Switch the mode between single mode and multiqueue mode without reset
- Remove the 256 limitation of queues
- Use helpers to do the mapping between virtqueues and tx/rx queues
- Use commbined channels instead of separated rx/tx queus when do the queue
number configuartion
- Other coding style comments from Michael
Changes from RFC v4:
- Add ability to negotiate the number of queues through control virtqueue
- Ethtool -{L|l} support and default the tx/rx queue number to 1
- Expose the API to set irq affinity instead of irq itself
Changes from RFC v3:
- Rebase to the net-next
- Let queue 2 to be the control virtqueue to obey the spec
- Prodives irq affinity
- Choose txq based on processor id
Reference:
- Virtio spec RFC: http://patchwork.ozlabs.org/patch/201303/
- RFC V7:https://lkml.org/lkml/2012/11/27/177
- RFC V6: https://lkml.org/lkml/2012/10/30/127
- RFC V5: http://lwn.net/Articles/505388/
- RFC V4: https://lkml.org/lkml/2012/6/25/120
- RFC V2: http://lwn.net/Articles/467283/
Perf Numbers:
Will do some basic test and post as a reply to this mail.
Jason Wang (3):
virtio-net: separate fields of sending/receiving queue from
virtnet_info
virtio_net: multiqueue support
virtio-net: change the number of queues through ethtool
drivers/net/virtio_net.c | 723 ++++++++++++++++++++++++++++-----------
include/uapi/linux/virtio_net.h | 16 +
2 files changed, 546 insertions(+), 193 deletions(-)
Jason Wang
2012-Dec-04 11:07 UTC
[PATCH net-next 1/3] virtio-net: separate fields of sending/receiving queue from virtnet_info
To support multiqueue transmitq/receiveq, the first step is to separate queue
related structure from virtnet_info. This patch introduce send_queue and
receive_queue structure and use the pointer to them as the parameter in
functions handling sending/receiving.
Signed-off-by: Krishna Kumar <krkumar2 at in.ibm.com>
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/net/virtio_net.c | 271 +++++++++++++++++++++++++---------------------
1 files changed, 149 insertions(+), 122 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 8262232..266f712 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -51,16 +51,40 @@ 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 *vq;
+
+ /* TX: fragments + linear part + virtio header */
+ struct scatterlist sg[MAX_SKB_FRAGS + 2];
+};
+
+/* Internal representation of a receive virtqueue */
+struct receive_queue {
+ /* Virtqueue associated with this receive_queue */
+ struct virtqueue *vq;
+
struct napi_struct napi;
- unsigned int status;
/* Number of input buffers, and max we've ever had. */
unsigned int num, max;
+ /* Chain pages by the private ptr. */
+ struct page *pages;
+
+ /* RX: fragments + linear part + virtio header */
+ struct scatterlist sg[MAX_SKB_FRAGS + 2];
+};
+
+struct virtnet_info {
+ struct virtio_device *vdev;
+ struct virtqueue *cvq;
+ struct net_device *dev;
+ struct send_queue sq;
+ struct receive_queue rq;
+ unsigned int status;
+
/* I like... big packets and I cannot lie! */
bool big_packets;
@@ -81,13 +105,6 @@ struct virtnet_info {
/* Lock for config space updates */
struct mutex config_lock;
-
- /* 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 {
@@ -117,22 +134,22 @@ 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. */
+ /* Find end of list, sew whole thing into vi->rq.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
@@ -140,12 +157,12 @@ static struct page *get_a_page(struct virtnet_info *vi,
gfp_t gfp_mask)
return p;
}
-static void skb_xmit_done(struct virtqueue *svq)
+static void skb_xmit_done(struct virtqueue *vq)
{
- struct virtnet_info *vi = svq->vdev->priv;
+ struct virtnet_info *vi = vq->vdev->priv;
/* Suppress further interrupts. */
- virtqueue_disable_cb(svq);
+ virtqueue_disable_cb(vq);
/* We were probably waiting for more output buffers. */
netif_wake_queue(vi->dev);
@@ -167,9 +184,10 @@ static void set_skb_frag(struct sk_buff *skb, struct page
*page,
}
/* Called from bottom half context */
-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->vq->vdev->priv;
struct sk_buff *skb;
struct skb_vnet_hdr *hdr;
unsigned int copy, hdr_len, offset;
@@ -224,12 +242,12 @@ 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;
@@ -243,7 +261,7 @@ 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->vq, &len);
if (!page) {
pr_debug("%s: rx error: %d buffers missing\n",
skb->dev->name, hdr->mhdr.num_buffers);
@@ -256,14 +274,15 @@ 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 virtnet_info *vi = netdev_priv(dev);
+ struct virtnet_info *vi = rq->vq->vdev->priv;
+ struct net_device *dev = vi->dev;
struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
struct sk_buff *skb;
struct page *page;
@@ -273,7 +292,7 @@ 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;
@@ -285,14 +304,14 @@ 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;
}
@@ -359,8 +378,9 @@ 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 virtnet_info *vi = rq->vq->vdev->priv;
struct sk_buff *skb;
struct skb_vnet_hdr *hdr;
int err;
@@ -372,77 +392,77 @@ static int add_recvbuf_small(struct virtnet_info *vi,
gfp_t gfp)
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->sg, &hdr->hdr, sizeof hdr->hdr);
- skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len);
+ skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
- err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 2, skb, gfp);
+ err = virtqueue_add_buf(rq->vq, rq->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->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->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->sg[0], rq->sg[1] share the same page */
+ /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
+ sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
- /* vi->rx_sg[1] for data packet, from offset */
+ /* rq->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->sg[1], p + offset, PAGE_SIZE - offset);
/* chain first in list head */
first->private = (unsigned long)list;
- err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2,
+ err = virtqueue_add_buf(rq->vq, rq->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->sg, page_address(page), PAGE_SIZE);
- err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 1, page, gfp);
+ err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp);
if (err < 0)
- give_pages(vi, page);
+ give_pages(rq, page);
return err;
}
@@ -454,65 +474,68 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi,
gfp_t gfp)
* before we're receiving packets, or from refill_work which is
* careful to disable receiving (using napi_disable).
*/
-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->vq->vdev->priv;
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->vq);
return !oom;
}
static void skb_recv_done(struct virtqueue *rvq)
{
struct virtnet_info *vi = rvq->vdev->priv;
+ struct receive_queue *rq = &vi->rq;
+
/* Schedule NAPI, Suppress further interrupts if successful. */
- if (napi_schedule_prep(&vi->napi)) {
+ if (napi_schedule_prep(&rq->napi)) {
virtqueue_disable_cb(rvq);
- __napi_schedule(&vi->napi);
+ __napi_schedule(&rq->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);
+ if (napi_schedule_prep(&rq->napi)) {
+ virtqueue_disable_cb(rq->vq);
local_bh_disable();
- __napi_schedule(&vi->napi);
+ __napi_schedule(&rq->napi);
local_bh_enable();
}
}
static void refill_work(struct work_struct *work)
{
- struct virtnet_info *vi;
+ struct virtnet_info *vi + container_of(work, struct virtnet_info,
refill.work);
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);
+ napi_disable(&vi->rq.napi);
+ still_empty = !try_fill_recv(&vi->rq, GFP_KERNEL);
+ virtnet_napi_enable(&vi->rq);
/* In theory, this can happen: if we don't get any buffers in
* we will *never* try to fill again. */
@@ -522,29 +545,31 @@ static void refill_work(struct work_struct *work)
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);
+ struct virtnet_info *vi = rq->vq->vdev->priv;
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->vq, &len)) != NULL) {
+ receive_buf(rq, buf, len);
+ --rq->num;
received++;
}
- if (vi->num < vi->max / 2) {
- if (!try_fill_recv(vi, GFP_ATOMIC))
+ if (rq->num < rq->max / 2) {
+ if (!try_fill_recv(rq, GFP_ATOMIC))
schedule_delayed_work(&vi->refill, 0);
}
/* Out of packets? */
if (received < budget) {
napi_complete(napi);
- if (unlikely(!virtqueue_enable_cb(vi->rvq)) &&
+ if (unlikely(!virtqueue_enable_cb(rq->vq)) &&
napi_schedule_prep(napi)) {
- virtqueue_disable_cb(vi->rvq);
+ virtqueue_disable_cb(rq->vq);
__napi_schedule(napi);
goto again;
}
@@ -553,13 +578,14 @@ again:
return received;
}
-static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
+static unsigned int free_old_xmit_skbs(struct send_queue *sq)
{
struct sk_buff *skb;
unsigned int len, tot_sgs = 0;
+ struct virtnet_info *vi = sq->vq->vdev->priv;
struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
- while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
+ while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
pr_debug("Sent skb %p\n", skb);
u64_stats_update_begin(&stats->tx_syncp);
@@ -573,10 +599,11 @@ 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 send_queue *sq, struct sk_buff *skb)
{
struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
+ struct virtnet_info *vi = sq->vq->vdev->priv;
pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
@@ -611,25 +638,26 @@ 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(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
else
- sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
+ sg_set_buf(sq->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, sq->sg + 1, 0, skb->len) + 1;
+ return virtqueue_add_buf(sq->vq, sq->sg, hdr->num_sg,
0, skb, GFP_ATOMIC);
}
static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
+ struct send_queue *sq = &vi->sq;
int capacity;
/* Free up any pending old buffers before queueing new ones. */
- free_old_xmit_skbs(vi);
+ free_old_xmit_skbs(sq);
/* Try to transmit */
- capacity = xmit_skb(vi, skb);
+ capacity = xmit_skb(sq, skb);
/* This can happen with OOM and indirect buffers. */
if (unlikely(capacity < 0)) {
@@ -648,7 +676,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct
net_device *dev)
kfree_skb(skb);
return NETDEV_TX_OK;
}
- virtqueue_kick(vi->svq);
+ virtqueue_kick(sq->vq);
/* Don't wait up for transmitted skbs to be freed. */
skb_orphan(skb);
@@ -658,12 +686,12 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct
net_device *dev)
* 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))) {
+ if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
/* More just got used, free them then recheck. */
- capacity += free_old_xmit_skbs(vi);
+ capacity += free_old_xmit_skbs(sq);
if (capacity >= 2+MAX_SKB_FRAGS) {
netif_start_queue(dev);
- virtqueue_disable_cb(vi->svq);
+ virtqueue_disable_cb(sq->vq);
}
}
}
@@ -731,7 +759,7 @@ static void virtnet_netpoll(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
- napi_schedule(&vi->napi);
+ napi_schedule(&vi->rq.napi);
}
#endif
@@ -740,10 +768,10 @@ static int virtnet_open(struct net_device *dev)
struct virtnet_info *vi = netdev_priv(dev);
/* Make sure we have some buffers: if oom use wq. */
- if (!try_fill_recv(vi, GFP_KERNEL))
+ if (!try_fill_recv(&vi->rq, GFP_KERNEL))
schedule_delayed_work(&vi->refill, 0);
- virtnet_napi_enable(vi);
+ virtnet_napi_enable(&vi->rq);
return 0;
}
@@ -808,7 +836,7 @@ static int virtnet_close(struct net_device *dev)
/* Make sure refill_work doesn't re-enable napi! */
cancel_delayed_work_sync(&vi->refill);
- napi_disable(&vi->napi);
+ napi_disable(&vi->rq.napi);
return 0;
}
@@ -920,11 +948,10 @@ static void virtnet_get_ringparam(struct net_device *dev,
{
struct virtnet_info *vi = netdev_priv(dev);
- ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq);
- ring->tx_max_pending = virtqueue_get_vring_size(vi->svq);
+ ring->rx_max_pending = virtqueue_get_vring_size(vi->rq.vq);
+ ring->tx_max_pending = virtqueue_get_vring_size(vi->sq.vq);
ring->rx_pending = ring->rx_max_pending;
ring->tx_pending = ring->tx_max_pending;
-
}
@@ -1034,8 +1061,8 @@ static int init_vqs(struct virtnet_info *vi)
if (err)
return err;
- vi->rvq = vqs[0];
- vi->svq = vqs[1];
+ vi->rq.vq = vqs[0];
+ vi->sq.vq = vqs[1];
if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
vi->cvq = vqs[2];
@@ -1100,11 +1127,11 @@ 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);
+ netif_napi_add(dev, &vi->rq.napi, virtnet_poll, napi_weight);
vi->dev = dev;
vi->vdev = vdev;
vdev->priv = vi;
- vi->pages = NULL;
+ vi->rq.pages = NULL;
vi->stats = alloc_percpu(struct virtnet_stats);
err = -ENOMEM;
if (vi->stats == NULL)
@@ -1114,8 +1141,8 @@ static int virtnet_probe(struct virtio_device *vdev)
mutex_init(&vi->config_lock);
vi->config_enable = true;
INIT_WORK(&vi->config_work, virtnet_config_changed_work);
- sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
- sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
+ sg_init_table(vi->rq.sg, ARRAY_SIZE(vi->rq.sg));
+ sg_init_table(vi->sq.sg, ARRAY_SIZE(vi->sq.sg));
/* If we can receive ANY GSO packets, we must allocate large ones. */
if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
@@ -1137,10 +1164,10 @@ static int virtnet_probe(struct virtio_device *vdev)
}
/* Last of all, set up some receive buffers. */
- try_fill_recv(vi, GFP_KERNEL);
+ try_fill_recv(&vi->rq, GFP_KERNEL);
/* If we didn't even get one input buffer, we're useless. */
- if (vi->num == 0) {
+ if (vi->rq.num == 0) {
err = -ENOMEM;
goto unregister;
}
@@ -1173,22 +1200,22 @@ static void free_unused_bufs(struct virtnet_info *vi)
{
void *buf;
while (1) {
- buf = virtqueue_detach_unused_buf(vi->svq);
+ buf = virtqueue_detach_unused_buf(vi->sq.vq);
if (!buf)
break;
dev_kfree_skb(buf);
}
while (1) {
- buf = virtqueue_detach_unused_buf(vi->rvq);
+ buf = virtqueue_detach_unused_buf(vi->rq.vq);
if (!buf)
break;
if (vi->mergeable_rx_bufs || vi->big_packets)
- give_pages(vi, buf);
+ give_pages(&vi->rq, buf);
else
dev_kfree_skb(buf);
- --vi->num;
+ --vi->rq.num;
}
- BUG_ON(vi->num != 0);
+ BUG_ON(vi->rq.num != 0);
}
static void remove_vq_common(struct virtnet_info *vi)
@@ -1200,8 +1227,8 @@ static void remove_vq_common(struct virtnet_info *vi)
vi->vdev->config->del_vqs(vi->vdev);
- while (vi->pages)
- __free_pages(get_a_page(vi, GFP_KERNEL), 0);
+ while (vi->rq.pages)
+ __free_pages(get_a_page(&vi->rq, GFP_KERNEL), 0);
}
static void __devexit virtnet_remove(struct virtio_device *vdev)
@@ -1237,7 +1264,7 @@ static int virtnet_freeze(struct virtio_device *vdev)
cancel_delayed_work_sync(&vi->refill);
if (netif_running(vi->dev))
- napi_disable(&vi->napi);
+ napi_disable(&vi->rq.napi);
remove_vq_common(vi);
@@ -1256,11 +1283,11 @@ static int virtnet_restore(struct virtio_device *vdev)
return err;
if (netif_running(vi->dev))
- virtnet_napi_enable(vi);
+ virtnet_napi_enable(&vi->rq);
netif_device_attach(vi->dev);
- if (!try_fill_recv(vi, GFP_KERNEL))
+ if (!try_fill_recv(&vi->rq, GFP_KERNEL))
schedule_delayed_work(&vi->refill, 0);
mutex_lock(&vi->config_lock);
--
1.7.1
This addes multiqueue support to virtio_net driver. In multiple queue modes, the
driver expects the number of queue paris is equal to the number of vcpus. To
eliminate the contention bettwen vcpus and virtqueues, per-cpu virtqueue pairs
were implemented through:
- select the txq based on the smp processor id.
- smp affinity hint were set to the vcpu that owns the queue pairs.
Signed-off-by: Krishna Kumar <krkumar2 at in.ibm.com>
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/net/virtio_net.c | 472 ++++++++++++++++++++++++++++++---------
include/uapi/linux/virtio_net.h | 16 ++
2 files changed, 385 insertions(+), 103 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 266f712..912f5b2 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -81,16 +81,25 @@ struct virtnet_info {
struct virtio_device *vdev;
struct virtqueue *cvq;
struct net_device *dev;
- struct send_queue sq;
- struct receive_queue rq;
+ struct send_queue *sq;
+ struct receive_queue *rq;
unsigned int status;
+ /* Max # of queue pairs supported by the device */
+ u16 max_queue_pairs;
+
+ /* # of queue pairs currently used by the driver */
+ u16 curr_queue_pairs;
+
/* I like... big packets and I cannot lie! */
bool big_packets;
/* Host will merge rx buffers for big packets (shake it! shake it!) */
bool mergeable_rx_bufs;
+ /* Has control virtqueue */
+ bool has_cvq;
+
/* enable config space updates */
bool config_enable;
@@ -125,6 +134,32 @@ struct padded_vnet_hdr {
char padding[6];
};
+static const struct ethtool_ops virtnet_ethtool_ops;
+
+
+/* Converting between virtqueue no. and kernel tx/rx queue no.
+ * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
+ */
+static int vq2txq(struct virtqueue *vq)
+{
+ return (virtqueue_get_queue_index(vq) - 1) / 2;
+}
+
+static int txq2vq(int txq)
+{
+ return txq * 2 + 1;
+}
+
+static int vq2rxq(struct virtqueue *vq)
+{
+ return virtqueue_get_queue_index(vq) / 2;
+}
+
+static int rxq2vq(int rxq)
+{
+ return rxq * 2;
+}
+
static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
{
return (struct skb_vnet_hdr *)skb->cb;
@@ -165,7 +200,7 @@ static void skb_xmit_done(struct virtqueue *vq)
virtqueue_disable_cb(vq);
/* We were probably waiting for more output buffers. */
- netif_wake_queue(vi->dev);
+ netif_wake_subqueue(vi->dev, vq2txq(vq));
}
static void set_skb_frag(struct sk_buff *skb, struct page *page,
@@ -502,7 +537,7 @@ static bool try_fill_recv(struct receive_queue *rq, gfp_t
gfp)
static void skb_recv_done(struct virtqueue *rvq)
{
struct virtnet_info *vi = rvq->vdev->priv;
- struct receive_queue *rq = &vi->rq;
+ struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
/* Schedule NAPI, Suppress further interrupts if successful. */
if (napi_schedule_prep(&rq->napi)) {
@@ -532,15 +567,21 @@ static void refill_work(struct work_struct *work)
struct virtnet_info *vi container_of(work, struct virtnet_info,
refill.work);
bool still_empty;
+ int i;
+
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ struct receive_queue *rq = &vi->rq[i];
- napi_disable(&vi->rq.napi);
- still_empty = !try_fill_recv(&vi->rq, GFP_KERNEL);
- virtnet_napi_enable(&vi->rq);
+ napi_disable(&rq->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);
+ /* 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);
+ }
}
static int virtnet_poll(struct napi_struct *napi, int budget)
@@ -650,7 +691,8 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff
*skb)
static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
- struct send_queue *sq = &vi->sq;
+ int qnum = skb_get_queue_mapping(skb);
+ struct send_queue *sq = &vi->sq[qnum];
int capacity;
/* Free up any pending old buffers before queueing new ones. */
@@ -664,13 +706,14 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct
net_device *dev)
if (likely(capacity == -ENOMEM)) {
if (net_ratelimit())
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++;
if (net_ratelimit())
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);
@@ -685,12 +728,12 @@ 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);
+ netif_stop_subqueue(dev, qnum);
if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
/* More just got used, free them then recheck. */
capacity += free_old_xmit_skbs(sq);
if (capacity >= 2+MAX_SKB_FRAGS) {
- netif_start_queue(dev);
+ netif_start_subqueue(dev, qnum);
virtqueue_disable_cb(sq->vq);
}
}
@@ -758,23 +801,13 @@ 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->rq.napi);
+ for (i = 0; i < vi->curr_queue_pairs; i++)
+ napi_schedule(&vi->rq[i].napi);
}
#endif
-static int virtnet_open(struct net_device *dev)
-{
- struct virtnet_info *vi = netdev_priv(dev);
-
- /* Make sure we have some buffers: if oom use wq. */
- if (!try_fill_recv(&vi->rq, GFP_KERNEL))
- schedule_delayed_work(&vi->refill, 0);
-
- virtnet_napi_enable(&vi->rq);
- return 0;
-}
-
/*
* Send command via the control virtqueue and check status. Commands
* supported by the hypervisor, as indicated by feature bits, should
@@ -830,13 +863,51 @@ static void virtnet_ack_link_announce(struct virtnet_info
*vi)
rtnl_unlock();
}
+/* Caller check the support of cvq and multiqueue. */
+static int virtnet_set_queues(struct virtnet_info *vi)
+{
+ struct scatterlist sg;
+ struct virtio_net_ctrl_rfs s;
+ struct net_device *dev = vi->dev;
+
+ s.virtqueue_pairs = vi->curr_queue_pairs;
+ sg_init_one(&sg, &s, sizeof(s));
+
+ if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RFS,
+ VIRTIO_NET_CTRL_RFS_VQ_PAIRS_SET, &sg, 1, 0)){
+ dev_warn(&dev->dev, "Fail to set num of queue pairs to
%d\n",
+ vi->curr_queue_pairs);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int virtnet_open(struct net_device *dev)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ int i;
+
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ /* Make sure we have some buffers: if oom use wq. */
+ if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
+ schedule_delayed_work(&vi->refill, 0);
+ virtnet_napi_enable(&vi->rq[i]);
+ }
+
+ return 0;
+}
+
static int virtnet_close(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
+ int i;
/* Make sure refill_work doesn't re-enable napi! */
cancel_delayed_work_sync(&vi->refill);
- napi_disable(&vi->rq.napi);
+
+ for (i = 0; i < vi->max_queue_pairs; i++)
+ napi_disable(&vi->rq[i].napi);
return 0;
}
@@ -948,8 +1019,8 @@ static void virtnet_get_ringparam(struct net_device *dev,
{
struct virtnet_info *vi = netdev_priv(dev);
- ring->rx_max_pending = virtqueue_get_vring_size(vi->rq.vq);
- ring->tx_max_pending = virtqueue_get_vring_size(vi->sq.vq);
+ ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
+ ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
ring->rx_pending = ring->rx_max_pending;
ring->tx_pending = ring->tx_max_pending;
}
@@ -967,12 +1038,6 @@ static void virtnet_get_drvinfo(struct net_device *dev,
}
-static const struct ethtool_ops virtnet_ethtool_ops = {
- .get_drvinfo = virtnet_get_drvinfo,
- .get_link = ethtool_op_get_link,
- .get_ringparam = virtnet_get_ringparam,
-};
-
#define MIN_MTU 68
#define MAX_MTU 65535
@@ -984,6 +1049,21 @@ static int virtnet_change_mtu(struct net_device *dev, int
new_mtu)
return 0;
}
+/* To avoid contending a lock hold by a vcpu who would exit to host, select the
+ * txq based on the processor id.
+ * TODO: handle cpu hotplug.
+ */
+static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb)
+{
+ int txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) :
+ smp_processor_id();
+
+ while (unlikely(txq >= dev->real_num_tx_queues))
+ txq -= dev->real_num_tx_queues;
+
+ return txq;
+}
+
static const struct net_device_ops virtnet_netdev = {
.ndo_open = virtnet_open,
.ndo_stop = virtnet_close,
@@ -995,6 +1075,7 @@ static const struct net_device_ops virtnet_netdev = {
.ndo_get_stats64 = virtnet_stats,
.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
+ .ndo_select_queue = virtnet_select_queue,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = virtnet_netpoll,
#endif
@@ -1030,10 +1111,10 @@ static void virtnet_config_changed_work(struct
work_struct *work)
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);
}
done:
mutex_unlock(&vi->config_lock);
@@ -1046,41 +1127,219 @@ static void virtnet_config_changed(struct virtio_device
*vdev)
schedule_work(&vi->config_work);
}
-static int init_vqs(struct virtnet_info *vi)
+static void free_receive_bufs(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, err;
+ int i;
- /* We expect two virtqueues, receive then send,
- * and optionally control. */
- nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ while (vi->rq[i].pages)
+ __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
+ }
+}
- err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks,
names);
- if (err)
- return err;
+/* Free memory allocated for send and receive queues */
+static void virtnet_free_queues(struct virtnet_info *vi)
+{
+ kfree(vi->rq);
+ vi->rq = NULL;
+ kfree(vi->sq);
+ vi->sq = NULL;
+}
+
+static void free_unused_bufs(struct virtnet_info *vi)
+{
+ void *buf;
+ int i;
+
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ struct virtqueue *vq = vi->sq[i].vq;
+ while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
+ dev_kfree_skb(buf);
+ }
+
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ struct virtqueue *vq = vi->rq[i].vq;
+
+ while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
+ 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);
+ }
+}
+
+static void virtnet_set_affinity(struct virtnet_info *vi, bool set)
+{
+ int i;
+
+ /* Don't set the affinity hint when in single queue mode or we have too
+ * much online cpus.
+ */
+ if (vi->curr_queue_pairs == 1 ||
+ vi->max_queue_pairs > num_online_cpus())
+ set = false;
+
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ int cpu = set ? i : -1;
+ virtqueue_set_affinity(vi->rq[i].vq, cpu);
+ virtqueue_set_affinity(vi->sq[i].vq, cpu);
+ }
+}
+
+static void virtnet_del_vqs(struct virtnet_info *vi)
+{
+ struct virtio_device *vdev = vi->vdev;
+
+ virtnet_set_affinity(vi, false);
+
+ vdev->config->del_vqs(vdev);
- vi->rq.vq = vqs[0];
- vi->sq.vq = vqs[1];
+ virtnet_free_queues(vi);
+}
- if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
- vi->cvq = vqs[2];
+static int virtnet_find_vqs(struct virtnet_info *vi)
+{
+ vq_callback_t **callbacks;
+ struct virtqueue **vqs;
+ int ret = -ENOMEM;
+ int i, total_vqs;
+ char **names;
+
+ /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followd by
+ * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
+ * possible control vq.
+ */
+ total_vqs = vi->max_queue_pairs * 2 +
+ virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
+
+ /* Allocate space for find_vqs parameters */
+ vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
+ callbacks = kzalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
+ if (!vqs || !callbacks)
+ goto err_mem;
+ names = kzalloc(total_vqs * sizeof(*names), GFP_KERNEL);
+ if (!names)
+ goto err_mem;
+
+ /* Parameters for control virtqueue, if any */
+ if (vi->has_cvq) {
+ callbacks[total_vqs - 1] = NULL;
+ names[total_vqs - 1] = kasprintf(GFP_KERNEL, "control");
+ }
+ /* Allocate/initialize parameters for send/receive virtqueues */
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ callbacks[rxq2vq(i)] = skb_recv_done;
+ callbacks[txq2vq(i)] = skb_xmit_done;
+ names[rxq2vq(i)] = kasprintf(GFP_KERNEL, "input.%d", i);
+ names[txq2vq(i)] = kasprintf(GFP_KERNEL, "output.%d", i);
+ }
+
+ ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs,
callbacks,
+ (const char **)names);
+ if (ret)
+ goto err_names;
+
+ if (vi->has_cvq) {
+ vi->cvq = vqs[total_vqs - 1];
if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
}
+
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ vi->rq[i].vq = vqs[rxq2vq(i)];
+ vi->sq[i].vq = vqs[txq2vq(i)];
+ }
+
+ kfree(callbacks);
+ kfree(vqs);
+
+ return 0;
+
+err_names:
+ for (i = 0; i < total_vqs * 2; i++)
+ kfree(names[i]);
+ kfree(names);
+
+err_mem:
+ kfree(callbacks);
+ kfree(vqs);
+
+ return ret;
+}
+
+static int virtnet_alloc_queues(struct virtnet_info *vi)
+{
+ int i;
+
+ vi->sq = kzalloc(sizeof(vi->sq[0]) * vi->max_queue_pairs,
GFP_KERNEL);
+ vi->rq = kzalloc(sizeof(vi->rq[0]) * vi->max_queue_pairs,
GFP_KERNEL);
+ if (!vi->rq || !vi->sq)
+ goto err;
+
+ INIT_DELAYED_WORK(&vi->refill, refill_work);
+ /* setup initial receive and send queue parameters */
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ vi->rq[i].pages = NULL;
+ netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
+ napi_weight);
+
+ sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
+ sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
+ }
+
+
+ return 0;
+
+err:
+ virtnet_free_queues(vi);
+ return -ENOMEM;
+}
+
+static int init_vqs(struct virtnet_info *vi)
+{
+ int ret;
+
+ /* Allocate send & receive queues */
+ ret = virtnet_alloc_queues(vi);
+ if (ret)
+ goto err;
+
+ ret = virtnet_find_vqs(vi);
+ if (ret)
+ goto err_free;
+
+ virtnet_set_affinity(vi, true);
return 0;
+
+err_free:
+ virtnet_free_queues(vi);
+err:
+ return ret;
}
static int virtnet_probe(struct virtio_device *vdev)
{
- int err;
+ int i, err;
struct net_device *dev;
struct virtnet_info *vi;
+ u16 max_queue_pairs;
+
+ /* Find if host supports multiqueue virtio_net device */
+ err = virtio_config_val(vdev, VIRTIO_NET_F_RFS,
+ offsetof(struct virtio_net_config,
+ max_virtqueue_pairs), &max_queue_pairs);
+
+ /* We need at least 2 queue's */
+ if (err || max_queue_pairs < VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MIN ||
+ max_queue_pairs > VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MAX)
+ max_queue_pairs = 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), max_queue_pairs);
if (!dev)
return -ENOMEM;
@@ -1127,22 +1386,17 @@ static int virtnet_probe(struct virtio_device *vdev)
/* Set up our device-specific information */
vi = netdev_priv(dev);
- netif_napi_add(dev, &vi->rq.napi, virtnet_poll, napi_weight);
vi->dev = dev;
vi->vdev = vdev;
vdev->priv = vi;
- vi->rq.pages = NULL;
vi->stats = alloc_percpu(struct virtnet_stats);
err = -ENOMEM;
if (vi->stats == NULL)
goto free;
- INIT_DELAYED_WORK(&vi->refill, refill_work);
mutex_init(&vi->config_lock);
vi->config_enable = true;
INIT_WORK(&vi->config_work, virtnet_config_changed_work);
- sg_init_table(vi->rq.sg, ARRAY_SIZE(vi->rq.sg));
- sg_init_table(vi->sq.sg, ARRAY_SIZE(vi->sq.sg));
/* If we can receive ANY GSO packets, we must allocate large ones. */
if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
@@ -1153,10 +1407,21 @@ static int virtnet_probe(struct virtio_device *vdev)
if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
vi->mergeable_rx_bufs = true;
+ if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
+ vi->has_cvq = true;
+
+ /* Use single tx/rx queue pair as default */
+ vi->curr_queue_pairs = 1;
+ vi->max_queue_pairs = max_queue_pairs;
+
+ /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
err = init_vqs(vi);
if (err)
goto free_stats;
+ netif_set_real_num_tx_queues(dev, 1);
+ netif_set_real_num_rx_queues(dev, 1);
+
err = register_netdev(dev);
if (err) {
pr_debug("virtio_net: registering device failed\n");
@@ -1164,12 +1429,15 @@ static int virtnet_probe(struct virtio_device *vdev)
}
/* Last of all, set up some receive buffers. */
- try_fill_recv(&vi->rq, GFP_KERNEL);
-
- /* If we didn't even get one input buffer, we're useless. */
- if (vi->rq.num == 0) {
- err = -ENOMEM;
- goto unregister;
+ for (i = 0; i < vi->max_queue_pairs; 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) {
+ free_unused_bufs(vi);
+ err = -ENOMEM;
+ goto free_recv_bufs;
+ }
}
/* Assume link up if device can't report link status,
@@ -1182,13 +1450,19 @@ 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, max_queue_pairs);
+
return 0;
-unregister:
+free_recv_bufs:
+ free_receive_bufs(vi);
unregister_netdev(dev);
+
free_vqs:
- vdev->config->del_vqs(vdev);
+ cancel_delayed_work_sync(&vi->refill);
+ virtnet_del_vqs(vi);
+
free_stats:
free_percpu(vi->stats);
free:
@@ -1196,28 +1470,6 @@ free:
return err;
}
-static void free_unused_bufs(struct virtnet_info *vi)
-{
- void *buf;
- while (1) {
- buf = virtqueue_detach_unused_buf(vi->sq.vq);
- if (!buf)
- break;
- dev_kfree_skb(buf);
- }
- while (1) {
- buf = virtqueue_detach_unused_buf(vi->rq.vq);
- if (!buf)
- break;
- if (vi->mergeable_rx_bufs || vi->big_packets)
- give_pages(&vi->rq, buf);
- else
- dev_kfree_skb(buf);
- --vi->rq.num;
- }
- BUG_ON(vi->rq.num != 0);
-}
-
static void remove_vq_common(struct virtnet_info *vi)
{
vi->vdev->config->reset(vi->vdev);
@@ -1225,10 +1477,9 @@ static void remove_vq_common(struct virtnet_info *vi)
/* Free unused buffers in both send and recv, if any. */
free_unused_bufs(vi);
- vi->vdev->config->del_vqs(vi->vdev);
+ free_receive_bufs(vi);
- while (vi->rq.pages)
- __free_pages(get_a_page(&vi->rq, GFP_KERNEL), 0);
+ virtnet_del_vqs(vi);
}
static void __devexit virtnet_remove(struct virtio_device *vdev)
@@ -1254,6 +1505,7 @@ static void __devexit virtnet_remove(struct virtio_device
*vdev)
static int virtnet_freeze(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
+ int i;
/* Prevent config work handler from accessing the device */
mutex_lock(&vi->config_lock);
@@ -1264,7 +1516,10 @@ static int virtnet_freeze(struct virtio_device *vdev)
cancel_delayed_work_sync(&vi->refill);
if (netif_running(vi->dev))
- napi_disable(&vi->rq.napi);
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ napi_disable(&vi->rq[i].napi);
+ netif_napi_del(&vi->rq[i].napi);
+ }
remove_vq_common(vi);
@@ -1276,24 +1531,29 @@ static int virtnet_freeze(struct virtio_device *vdev)
static int virtnet_restore(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
- int err;
+ int err, i;
err = init_vqs(vi);
if (err)
return err;
if (netif_running(vi->dev))
- virtnet_napi_enable(&vi->rq);
+ for (i = 0; i < vi->max_queue_pairs; i++)
+ virtnet_napi_enable(&vi->rq[i]);
netif_device_attach(vi->dev);
- if (!try_fill_recv(&vi->rq, GFP_KERNEL))
- schedule_delayed_work(&vi->refill, 0);
+ for (i = 0; i < vi->max_queue_pairs; i++)
+ if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
+ schedule_delayed_work(&vi->refill, 0);
mutex_lock(&vi->config_lock);
vi->config_enable = true;
mutex_unlock(&vi->config_lock);
+ if (vi->has_cvq && virtio_has_feature(vi->vdev,
VIRTIO_NET_F_RFS))
+ virtnet_set_queues(vi);
+
return 0;
}
#endif
@@ -1311,7 +1571,7 @@ static unsigned int features[] = {
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_GUEST_ANNOUNCE,
+ VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_RFS,
};
static struct virtio_driver virtio_net_driver = {
@@ -1329,6 +1589,12 @@ static struct virtio_driver virtio_net_driver = {
#endif
};
+static const struct ethtool_ops virtnet_ethtool_ops = {
+ .get_drvinfo = virtnet_get_drvinfo,
+ .get_link = ethtool_op_get_link,
+ .get_ringparam = virtnet_get_ringparam,
+};
+
static int __init init(void)
{
return register_virtio_driver(&virtio_net_driver);
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 2470f54..6056cec 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -51,6 +51,7 @@
#define VIRTIO_NET_F_CTRL_RX_EXTRA 20 /* Extra RX mode control support */
#define VIRTIO_NET_F_GUEST_ANNOUNCE 21 /* Guest can announce device on the
* network */
+#define VIRTIO_NET_F_RFS 22 /* Device supports multiple TXQ/RXQ */
#define VIRTIO_NET_S_LINK_UP 1 /* Link is up */
#define VIRTIO_NET_S_ANNOUNCE 2 /* Announcement is needed */
@@ -60,6 +61,8 @@ 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 max_virtqueue_pairs;
} __attribute__((packed));
/* This is the first element of the scatter-gather list. If you don't
@@ -166,4 +169,17 @@ struct virtio_net_ctrl_mac {
#define VIRTIO_NET_CTRL_ANNOUNCE 3
#define VIRTIO_NET_CTRL_ANNOUNCE_ACK 0
+/*
+ * Control multiqueue
+ *
+ */
+struct virtio_net_ctrl_rfs {
+ u16 virtqueue_pairs;
+};
+
+#define VIRTIO_NET_CTRL_RFS 4
+ #define VIRTIO_NET_CTRL_RFS_VQ_PAIRS_SET 0
+ #define VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MIN 1
+ #define VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MAX 0x8000
+
#endif /* _LINUX_VIRTIO_NET_H */
--
1.7.1
Jason Wang
2012-Dec-04 11:07 UTC
[PATCH net-next 3/3] virtio-net: change the number of queues through ethtool
This patch implement the ethtool_{set|get}_channels method of ethool to allow
user to change the number of queues dymaically when the device is running. This
would let the user to configure it on demand.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/net/virtio_net.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 44 insertions(+), 0 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 912f5b2..b9f9887 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1589,10 +1589,54 @@ static struct virtio_driver virtio_net_driver = {
#endif
};
+/* TODO: Eliminate OOO packets during switching */
+static int virtnet_set_channels(struct net_device *dev,
+ struct ethtool_channels *channels)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ u16 queue_pairs = channels->combined_count;
+ u16 old_queue_pairs = vi->curr_queue_pairs;
+
+ /* We don't support separate rx/tx channels.
+ * We don't allow setting 'other' channels.
+ */
+ if (channels->rx_count || channels->tx_count ||
channels->other_count)
+ return -EINVAL;
+
+ if (queue_pairs > vi->max_queue_pairs)
+ return -EINVAL;
+
+ vi->curr_queue_pairs = queue_pairs;
+ if (virtnet_set_queues(vi) == 0) {
+ netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
+ netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
+
+ virtnet_set_affinity(vi, true);
+ } else
+ vi->curr_queue_pairs = old_queue_pairs;
+
+ return 0;
+}
+
+static void virtnet_get_channels(struct net_device *dev,
+ struct ethtool_channels *channels)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+
+ channels->combined_count = vi->curr_queue_pairs;
+ channels->max_combined = vi->max_queue_pairs;
+ channels->max_other = 0;
+ channels->rx_count = 0;
+ channels->tx_count = 0;
+ channels->other_count = 0;
+}
+
static const struct ethtool_ops virtnet_ethtool_ops = {
.get_drvinfo = virtnet_get_drvinfo,
.get_link = ethtool_op_get_link,
.get_ringparam = virtnet_get_ringparam,
+ .set_channels = virtnet_set_channels,
+ .get_channels = virtnet_get_channels,
};
static int __init init(void)
--
1.7.1