X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=drivers%2Fnet%2Fvirtio_net.c;h=d75f8edf4fb370300d13bd22adcfe66e754fb5a2;hb=b399c46ea0070671f3abbe1915d26076101a42f2;hp=5d776447d9c33e2da56b622a2537536cf950ca0c;hpb=07b19808486054f356dbf3495a277f51af062b35;p=cascardo%2Flinux.git
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 5d776447d9c3..d75f8edf4fb3 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -13,8 +13,7 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * along with this program; if not, see .
*/
//#define DEBUG
#include
@@ -27,6 +26,7 @@
#include
#include
#include
+#include
static int napi_weight = NAPI_POLL_WEIGHT;
module_param(napi_weight, int, 0444);
@@ -37,11 +37,18 @@ module_param(gso, bool, 0444);
/* FIXME: MTU in config. */
#define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
-#define MERGE_BUFFER_LEN (ALIGN(GOOD_PACKET_LEN + \
- sizeof(struct virtio_net_hdr_mrg_rxbuf), \
- L1_CACHE_BYTES))
#define GOOD_COPY_LEN 128
+/* Weight used for the RX packet size EWMA. The average packet size is used to
+ * determine the packet buffer size when refilling RX rings. As the entire RX
+ * ring may be refilled at once, the weight is chosen so that the EWMA will be
+ * insensitive to short-term, transient changes in packet size.
+ */
+#define RECEIVE_AVG_WEIGHT 64
+
+/* Minimum alignment for mergeable packet buffers. */
+#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
+
#define VIRTNET_DRIVER_VERSION "1.0.0"
struct virtnet_stats {
@@ -73,12 +80,15 @@ struct receive_queue {
struct napi_struct napi;
- /* Number of input buffers, and max we've ever had. */
- unsigned int num, max;
-
/* Chain pages by the private ptr. */
struct page *pages;
+ /* Average packet length for mergeable receive buffers. */
+ struct ewma mrg_avg_pkt_len;
+
+ /* Page frag for packet buffer allocation. */
+ struct page_frag alloc_frag;
+
/* RX: fragments + linear part + virtio header */
struct scatterlist sg[MAX_SKB_FRAGS + 2];
@@ -127,11 +137,6 @@ struct virtnet_info {
/* Lock for config space updates */
struct mutex config_lock;
- /* Page_frag for GFP_KERNEL packet buffer allocation when we run
- * low on memory.
- */
- struct page_frag alloc_frag;
-
/* Does the affinity hint is set for virtqueues? */
bool affinity_hint_set;
@@ -222,6 +227,24 @@ static void skb_xmit_done(struct virtqueue *vq)
netif_wake_subqueue(vi->dev, vq2txq(vq));
}
+static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
+{
+ unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
+ return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
+}
+
+static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
+{
+ return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
+
+}
+
+static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
+{
+ unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
+ return (unsigned long)buf | (size - 1);
+}
+
/* Called from bottom half context */
static struct sk_buff *page_to_skb(struct receive_queue *rq,
struct page *page, unsigned int offset,
@@ -330,38 +353,34 @@ err:
static struct sk_buff *receive_mergeable(struct net_device *dev,
struct receive_queue *rq,
- void *buf,
+ unsigned long ctx,
unsigned int len)
{
+ void *buf = mergeable_ctx_to_buf_address(ctx);
struct skb_vnet_hdr *hdr = buf;
int num_buf = hdr->mhdr.num_buffers;
struct page *page = virt_to_head_page(buf);
int offset = buf - page_address(page);
- struct sk_buff *head_skb = page_to_skb(rq, page, offset, len,
- MERGE_BUFFER_LEN);
+ unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
+
+ struct sk_buff *head_skb = page_to_skb(rq, page, offset, len, truesize);
struct sk_buff *curr_skb = head_skb;
if (unlikely(!curr_skb))
goto err_skb;
-
while (--num_buf) {
int num_skb_frags;
- buf = virtqueue_get_buf(rq->vq, &len);
- if (unlikely(!buf)) {
+ ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
+ if (unlikely(!ctx)) {
pr_debug("%s: rx error: %d buffers out of %d missing\n",
dev->name, num_buf, hdr->mhdr.num_buffers);
dev->stats.rx_length_errors++;
goto err_buf;
}
- if (unlikely(len > MERGE_BUFFER_LEN)) {
- pr_debug("%s: rx error: merge buffer too long\n",
- dev->name);
- len = MERGE_BUFFER_LEN;
- }
+ buf = mergeable_ctx_to_buf_address(ctx);
page = virt_to_head_page(buf);
- --rq->num;
num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
@@ -377,37 +396,38 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
head_skb->truesize += nskb->truesize;
num_skb_frags = 0;
}
+ truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
if (curr_skb != head_skb) {
head_skb->data_len += len;
head_skb->len += len;
- head_skb->truesize += MERGE_BUFFER_LEN;
+ head_skb->truesize += truesize;
}
offset = buf - page_address(page);
if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
put_page(page);
skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
- len, MERGE_BUFFER_LEN);
+ len, truesize);
} else {
skb_add_rx_frag(curr_skb, num_skb_frags, page,
- offset, len, MERGE_BUFFER_LEN);
+ offset, len, truesize);
}
}
+ ewma_add(&rq->mrg_avg_pkt_len, head_skb->len);
return head_skb;
err_skb:
put_page(page);
while (--num_buf) {
- buf = virtqueue_get_buf(rq->vq, &len);
- if (unlikely(!buf)) {
+ ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
+ if (unlikely(!ctx)) {
pr_debug("%s: rx error: %d buffers missing\n",
dev->name, num_buf);
dev->stats.rx_length_errors++;
break;
}
- page = virt_to_head_page(buf);
+ page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
put_page(page);
- --rq->num;
}
err_buf:
dev->stats.rx_dropped++;
@@ -426,17 +446,20 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
pr_debug("%s: short packet %i\n", dev->name, len);
dev->stats.rx_length_errors++;
- if (vi->mergeable_rx_bufs)
- put_page(virt_to_head_page(buf));
- else if (vi->big_packets)
+ if (vi->mergeable_rx_bufs) {
+ unsigned long ctx = (unsigned long)buf;
+ void *base = mergeable_ctx_to_buf_address(ctx);
+ put_page(virt_to_head_page(base));
+ } else if (vi->big_packets) {
give_pages(rq, buf);
- else
+ } else {
dev_kfree_skb(buf);
+ }
return;
}
if (vi->mergeable_rx_bufs)
- skb = receive_mergeable(dev, rq, buf, len);
+ skb = receive_mergeable(dev, rq, (unsigned long)buf, len);
else if (vi->big_packets)
skb = receive_big(dev, rq, buf, len);
else
@@ -577,28 +600,45 @@ static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
return err;
}
+static unsigned int get_mergeable_buf_len(struct ewma *avg_pkt_len)
+{
+ const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+ unsigned int len;
+
+ len = hdr_len + clamp_t(unsigned int, ewma_read(avg_pkt_len),
+ GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
+ return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
+}
+
static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
{
- struct virtnet_info *vi = rq->vq->vdev->priv;
- char *buf = NULL;
+ struct page_frag *alloc_frag = &rq->alloc_frag;
+ char *buf;
+ unsigned long ctx;
int err;
+ unsigned int len, hole;
- if (gfp & __GFP_WAIT) {
- if (skb_page_frag_refill(MERGE_BUFFER_LEN, &vi->alloc_frag,
- gfp)) {
- buf = (char *)page_address(vi->alloc_frag.page) +
- vi->alloc_frag.offset;
- get_page(vi->alloc_frag.page);
- vi->alloc_frag.offset += MERGE_BUFFER_LEN;
- }
- } else {
- buf = netdev_alloc_frag(MERGE_BUFFER_LEN);
- }
- if (!buf)
+ len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
+ if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
return -ENOMEM;
- sg_init_one(rq->sg, buf, MERGE_BUFFER_LEN);
- err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, buf, gfp);
+ buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
+ ctx = mergeable_buf_to_ctx(buf, len);
+ get_page(alloc_frag->page);
+ alloc_frag->offset += len;
+ hole = alloc_frag->size - alloc_frag->offset;
+ if (hole < len) {
+ /* To avoid internal fragmentation, if there is very likely not
+ * enough space for another buffer, add the remaining space to
+ * the current buffer. This extra space is not included in
+ * the truesize stored in ctx.
+ */
+ len += hole;
+ alloc_frag->offset += hole;
+ }
+
+ sg_init_one(rq->sg, buf, len);
+ err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
if (err < 0)
put_page(virt_to_head_page(buf));
@@ -618,6 +658,7 @@ static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
int err;
bool oom;
+ gfp |= __GFP_COLD;
do {
if (vi->mergeable_rx_bufs)
err = add_recvbuf_mergeable(rq, gfp);
@@ -629,10 +670,7 @@ static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
oom = err == -ENOMEM;
if (err)
break;
- ++rq->num;
} while (rq->vq->num_free);
- if (unlikely(rq->num > rq->max))
- rq->max = rq->num;
if (unlikely(!virtqueue_kick(rq->vq)))
return false;
return !oom;
@@ -700,11 +738,10 @@ again:
while (received < budget &&
(buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
receive_buf(rq, buf, len);
- --rq->num;
received++;
}
- if (rq->num < rq->max / 2) {
+ if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
if (!try_fill_recv(rq, GFP_ATOMIC))
schedule_delayed_work(&vi->refill, 0);
}
@@ -874,16 +911,15 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
/*
* Send command via the control virtqueue and check status. Commands
* supported by the hypervisor, as indicated by feature bits, should
- * never fail unless improperly formated.
+ * never fail unless improperly formatted.
*/
static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
- struct scatterlist *out,
- struct scatterlist *in)
+ struct scatterlist *out)
{
struct scatterlist *sgs[4], hdr, stat;
struct virtio_net_ctrl_hdr ctrl;
virtio_net_ctrl_ack status = ~0;
- unsigned out_num = 0, in_num = 0, tmp;
+ unsigned out_num = 0, tmp;
/* Caller should know better */
BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
@@ -896,16 +932,13 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
if (out)
sgs[out_num++] = out;
- if (in)
- sgs[out_num + in_num++] = in;
/* Add return status. */
sg_init_one(&stat, &status, sizeof(status));
- sgs[out_num + in_num++] = &stat;
+ sgs[out_num] = &stat;
- BUG_ON(out_num + in_num > ARRAY_SIZE(sgs));
- BUG_ON(virtqueue_add_sgs(vi->cvq, sgs, out_num, in_num, vi, GFP_ATOMIC)
- < 0);
+ BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
+ BUG_ON(virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC) < 0);
if (unlikely(!virtqueue_kick(vi->cvq)))
return status == VIRTIO_NET_OK;
@@ -935,8 +968,7 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
sg_init_one(&sg, addr->sa_data, dev->addr_len);
if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
- VIRTIO_NET_CTRL_MAC_ADDR_SET,
- &sg, NULL)) {
+ VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
dev_warn(&vdev->dev,
"Failed to set mac address by vq command.\n");
return -EINVAL;
@@ -1009,7 +1041,7 @@ static void virtnet_ack_link_announce(struct virtnet_info *vi)
{
rtnl_lock();
if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
- VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL, NULL))
+ VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
rtnl_unlock();
}
@@ -1027,7 +1059,7 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
sg_init_one(&sg, &s, sizeof(s));
if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
- VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, NULL)) {
+ VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
queue_pairs);
return -EINVAL;
@@ -1067,7 +1099,7 @@ static void virtnet_set_rx_mode(struct net_device *dev)
void *buf;
int i;
- /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
+ /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
return;
@@ -1077,16 +1109,14 @@ static void virtnet_set_rx_mode(struct net_device *dev)
sg_init_one(sg, &promisc, sizeof(promisc));
if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
- VIRTIO_NET_CTRL_RX_PROMISC,
- sg, NULL))
+ VIRTIO_NET_CTRL_RX_PROMISC, sg))
dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
promisc ? "en" : "dis");
sg_init_one(sg, &allmulti, sizeof(allmulti));
if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
- VIRTIO_NET_CTRL_RX_ALLMULTI,
- sg, NULL))
+ VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
allmulti ? "en" : "dis");
@@ -1122,8 +1152,7 @@ static void virtnet_set_rx_mode(struct net_device *dev)
sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
- VIRTIO_NET_CTRL_MAC_TABLE_SET,
- sg, NULL))
+ VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
kfree(buf);
@@ -1138,7 +1167,7 @@ static int virtnet_vlan_rx_add_vid(struct net_device *dev,
sg_init_one(&sg, &vid, sizeof(vid));
if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
- VIRTIO_NET_CTRL_VLAN_ADD, &sg, NULL))
+ VIRTIO_NET_CTRL_VLAN_ADD, &sg))
dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
return 0;
}
@@ -1152,7 +1181,7 @@ static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
sg_init_one(&sg, &vid, sizeof(vid));
if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
- VIRTIO_NET_CTRL_VLAN_DEL, &sg, NULL))
+ VIRTIO_NET_CTRL_VLAN_DEL, &sg))
dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
return 0;
}
@@ -1386,6 +1415,14 @@ static void free_receive_bufs(struct virtnet_info *vi)
}
}
+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)
+ put_page(vi->rq[i].alloc_frag.page);
+}
+
static void free_unused_bufs(struct virtnet_info *vi)
{
void *buf;
@@ -1401,15 +1438,16 @@ static void free_unused_bufs(struct virtnet_info *vi)
struct virtqueue *vq = vi->rq[i].vq;
while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
- if (vi->mergeable_rx_bufs)
- put_page(virt_to_head_page(buf));
- else if (vi->big_packets)
+ if (vi->mergeable_rx_bufs) {
+ unsigned long ctx = (unsigned long)buf;
+ void *base = mergeable_ctx_to_buf_address(ctx);
+ put_page(virt_to_head_page(base));
+ } else if (vi->big_packets) {
give_pages(&vi->rq[i], buf);
- else
+ } else {
dev_kfree_skb(buf);
- --vi->rq[i].num;
+ }
}
- BUG_ON(vi->rq[i].num != 0);
}
}
@@ -1516,6 +1554,7 @@ static int virtnet_alloc_queues(struct virtnet_info *vi)
napi_weight);
sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
+ ewma_init(&vi->rq[i].mrg_avg_pkt_len, 1, RECEIVE_AVG_WEIGHT);
sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
}
@@ -1552,6 +1591,33 @@ err:
return ret;
}
+#ifdef CONFIG_SYSFS
+static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
+ struct rx_queue_attribute *attribute, char *buf)
+{
+ struct virtnet_info *vi = netdev_priv(queue->dev);
+ unsigned int queue_index = get_netdev_rx_queue_index(queue);
+ struct ewma *avg;
+
+ BUG_ON(queue_index >= vi->max_queue_pairs);
+ avg = &vi->rq[queue_index].mrg_avg_pkt_len;
+ return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
+}
+
+static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
+ __ATTR_RO(mergeable_rx_buffer_size);
+
+static struct attribute *virtio_net_mrg_rx_attrs[] = {
+ &mergeable_rx_buffer_size_attribute.attr,
+ NULL
+};
+
+static const struct attribute_group virtio_net_mrg_rx_group = {
+ .name = "virtio_net",
+ .attrs = virtio_net_mrg_rx_attrs
+};
+#endif
+
static int virtnet_probe(struct virtio_device *vdev)
{
int i, err;
@@ -1666,6 +1732,10 @@ static int virtnet_probe(struct virtio_device *vdev)
if (err)
goto free_stats;
+#ifdef CONFIG_SYSFS
+ if (vi->mergeable_rx_bufs)
+ dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
+#endif
netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
@@ -1680,7 +1750,8 @@ static int virtnet_probe(struct virtio_device *vdev)
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 (vi->rq[i].vq->num_free ==
+ virtqueue_get_vring_size(vi->rq[i].vq)) {
free_unused_bufs(vi);
err = -ENOMEM;
goto free_recv_bufs;
@@ -1714,9 +1785,8 @@ free_recv_bufs:
unregister_netdev(dev);
free_vqs:
cancel_delayed_work_sync(&vi->refill);
+ free_receive_page_frags(vi);
virtnet_del_vqs(vi);
- if (vi->alloc_frag.page)
- put_page(vi->alloc_frag.page);
free_stats:
free_percpu(vi->stats);
free:
@@ -1733,6 +1803,8 @@ static void remove_vq_common(struct virtnet_info *vi)
free_receive_bufs(vi);
+ free_receive_page_frags(vi);
+
virtnet_del_vqs(vi);
}
@@ -1750,8 +1822,6 @@ static void virtnet_remove(struct virtio_device *vdev)
unregister_netdev(vi->dev);
remove_vq_common(vi);
- if (vi->alloc_frag.page)
- put_page(vi->alloc_frag.page);
flush_work(&vi->config_work);