Re: [PATCH v2] vsock: replace virtio_vsock_pkt with sk_buff

From: Stefano Garzarella
Date: Fri Oct 14 2022 - 09:31:39 EST


On Wed, Oct 05, 2022 at 06:19:44PM -0700, Bobby Eshleman wrote:
This patch replaces the struct virtio_vsock_pkt with struct sk_buff.

Using sk_buff in vsock benefits it by a) allowing vsock to be extended
for socket-related features like sockmap, b) vsock may in the future
use other sk_buff-dependent kernel capabilities, and c) vsock shares
commonality with other socket types.

This patch is taken from the original series found here:
https://lore.kernel.org/all/cover.1660362668.git.bobby.eshleman@xxxxxxxxxxxxx/

Small-sized packet throughput improved by ~5% (from 18.53 Mb/s to 19.51
Mb/s). Tested using uperf, 16B payloads, 64 threads, 100s, averaged from
10 test runs (n=10). This improvement is likely due to packet merging.

Large-sized packet throughput decreases ~9% (from 27.25 Gb/s to 25.04
Gb/s). Tested using uperf, 64KB payloads, 64 threads, 100s, averaged
from 10 test runs (n=10).

Medium-sized packet throughput decreases ~5% (from 4.0 Gb/s to 3.81
Gb/s). Tested using uperf, 4k to 8k payload sizes picked randomly
according to normal distribution, 64 threads, 100s, averaged from 10
test runs (n=10).

All tests done in nested VMs (virtual host and virtual guest).

Signed-off-by: Bobby Eshleman <bobby.eshleman@xxxxxxxxxxxxx>
---
Changes in v2:
- Use alloc_skb() directly instead of sock_alloc_send_pskb() to minimize
uAPI changes.
- Do not marshal errors to -ENOMEM for non-virtio implementations.
- No longer a part of the original series
- Some code cleanup and refactoring
- Include performance stats

drivers/vhost/vsock.c | 215 +++++------
include/linux/virtio_vsock.h | 64 +++-
net/vmw_vsock/af_vsock.c | 1 +
net/vmw_vsock/virtio_transport.c | 206 +++++-----
net/vmw_vsock/virtio_transport_common.c | 483 ++++++++++++------------
net/vmw_vsock/vsock_loopback.c | 51 +--
6 files changed, 504 insertions(+), 516 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 368330417bde..6179e637602f 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -51,8 +51,7 @@ struct vhost_vsock {
struct hlist_node hash;

struct vhost_work send_pkt_work;
- spinlock_t send_pkt_list_lock;
- struct list_head send_pkt_list; /* host->guest pending packets */
+ struct sk_buff_head send_pkt_queue; /* host->guest pending packets */

atomic_t queued_replies;

@@ -108,7 +107,8 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
vhost_disable_notify(&vsock->dev, vq);

do {
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
+ struct virtio_vsock_hdr *hdr;

Reverse xmas tree is preferred in the net tree.
https://docs.kernel.org/process/maintainer-netdev.html?highlight=what+reverse+xmas+tree#what-is-reverse-xmas-tree

Please, check also in other places in this patch.

struct iov_iter iov_iter;
unsigned out, in;
size_t nbytes;
@@ -116,31 +116,22 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
int head;
u32 flags_to_restore = 0;

- spin_lock_bh(&vsock->send_pkt_list_lock);
- if (list_empty(&vsock->send_pkt_list)) {
- spin_unlock_bh(&vsock->send_pkt_list_lock);
+ skb = skb_dequeue(&vsock->send_pkt_queue);
+
+ if (!skb) {
vhost_enable_notify(&vsock->dev, vq);
break;
}

- pkt = list_first_entry(&vsock->send_pkt_list,
- struct virtio_vsock_pkt, list);
- list_del_init(&pkt->list);
- spin_unlock_bh(&vsock->send_pkt_list_lock);
-
head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
&out, &in, NULL, NULL);
if (head < 0) {
- spin_lock_bh(&vsock->send_pkt_list_lock);
- list_add(&pkt->list, &vsock->send_pkt_list);
- spin_unlock_bh(&vsock->send_pkt_list_lock);
+ skb_queue_head(&vsock->send_pkt_queue, skb);
break;
}

if (head == vq->num) {
- spin_lock_bh(&vsock->send_pkt_list_lock);
- list_add(&pkt->list, &vsock->send_pkt_list);
- spin_unlock_bh(&vsock->send_pkt_list_lock);
+ skb_queue_head(&vsock->send_pkt_queue, skb);

/* We cannot finish yet if more buffers snuck in while
* re-enabling notify.
@@ -153,26 +144,27 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
}

if (out) {
- virtio_transport_free_pkt(pkt);
+ kfree_skb(skb);
vq_err(vq, "Expected 0 output buffers, got %u\n", out);
break;
}

iov_len = iov_length(&vq->iov[out], in);
- if (iov_len < sizeof(pkt->hdr)) {
- virtio_transport_free_pkt(pkt);
+ if (iov_len < sizeof(*hdr)) {
+ kfree_skb(skb);
vq_err(vq, "Buffer len [%zu] too small\n", iov_len);
break;
}

iov_iter_init(&iov_iter, READ, &vq->iov[out], in, iov_len);
- payload_len = pkt->len - pkt->off;
+ payload_len = skb->len - vsock_metadata(skb)->off;

I guess the compiler will optimize, but what about store the metadata pointer in a variable?

+ hdr = vsock_hdr(skb);

/* If the packet is greater than the space available in the
* buffer, we split it using multiple buffers.
*/
- if (payload_len > iov_len - sizeof(pkt->hdr)) {
- payload_len = iov_len - sizeof(pkt->hdr);
+ if (payload_len > iov_len - sizeof(*hdr)) {
+ payload_len = iov_len - sizeof(*hdr);

/* As we are copying pieces of large packet's buffer to
* small rx buffers, headers of packets in rx queue are
@@ -185,31 +177,31 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
* bits set. After initialized header will be copied to
* rx buffer, these required bits will be restored.
*/
- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
- pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
+ hdr->flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
flags_to_restore |= VIRTIO_VSOCK_SEQ_EOM;

- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR) {
- pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR) {
+ hdr->flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
flags_to_restore |= VIRTIO_VSOCK_SEQ_EOR;
}
}
}

/* Set the correct length in the header */
- pkt->hdr.len = cpu_to_le32(payload_len);
+ hdr->len = cpu_to_le32(payload_len);

- nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
- if (nbytes != sizeof(pkt->hdr)) {
- virtio_transport_free_pkt(pkt);
+ nbytes = copy_to_iter(hdr, sizeof(*hdr), &iov_iter);
+ if (nbytes != sizeof(*hdr)) {
+ kfree_skb(skb);
vq_err(vq, "Faulted on copying pkt hdr\n");
break;
}

- nbytes = copy_to_iter(pkt->buf + pkt->off, payload_len,
+ nbytes = copy_to_iter(skb->data + vsock_metadata(skb)->off, payload_len,
&iov_iter);
if (nbytes != payload_len) {
- virtio_transport_free_pkt(pkt);
+ kfree_skb(skb);
vq_err(vq, "Faulted on copying pkt buf\n");
break;
}
@@ -217,31 +209,28 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
/* Deliver to monitoring devices all packets that we
* will transmit.
*/
- virtio_transport_deliver_tap_pkt(pkt);
+ virtio_transport_deliver_tap_pkt(skb);

- vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len);
+ vhost_add_used(vq, head, sizeof(*hdr) + payload_len);
added = true;

- pkt->off += payload_len;
+ vsock_metadata(skb)->off += payload_len;
total_len += payload_len;

/* If we didn't send all the payload we can requeue the packet
* to send it with the next available buffer.
*/
- if (pkt->off < pkt->len) {
- pkt->hdr.flags |= cpu_to_le32(flags_to_restore);
+ if (vsock_metadata(skb)->off < skb->len) {
+ hdr->flags |= cpu_to_le32(flags_to_restore);

- /* We are queueing the same virtio_vsock_pkt to handle
+ /* We are queueing the same skb to handle
* the remaining bytes, and we want to deliver it
* to monitoring devices in the next iteration.
*/
- pkt->tap_delivered = false;
-
- spin_lock_bh(&vsock->send_pkt_list_lock);
- list_add(&pkt->list, &vsock->send_pkt_list);
- spin_unlock_bh(&vsock->send_pkt_list_lock);
+ vsock_metadata(skb)->flags &= ~VIRTIO_VSOCK_METADATA_FLAGS_TAP_DELIVERED;
+ skb_queue_head(&vsock->send_pkt_queue, skb);
} else {
- if (pkt->reply) {
+ if (vsock_metadata(skb)->flags & VIRTIO_VSOCK_METADATA_FLAGS_REPLY) {
int val;

val = atomic_dec_return(&vsock->queued_replies);
@@ -253,7 +242,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
restart_tx = true;
}

- virtio_transport_free_pkt(pkt);
+ consume_skb(skb);
}
} while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
if (added)
@@ -278,28 +267,26 @@ static void vhost_transport_send_pkt_work(struct vhost_work *work)
}

static int
-vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
+vhost_transport_send_pkt(struct sk_buff *skb)
{
struct vhost_vsock *vsock;
- int len = pkt->len;
+ int len = skb->len;
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);

rcu_read_lock();

/* Find the vhost_vsock according to guest context id */
- vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
+ vsock = vhost_vsock_get(le64_to_cpu(hdr->dst_cid));
if (!vsock) {
rcu_read_unlock();
- virtio_transport_free_pkt(pkt);
+ kfree_skb(skb);
return -ENODEV;
}

- if (pkt->reply)
+ if (vsock_metadata(skb)->flags & VIRTIO_VSOCK_METADATA_FLAGS_REPLY)
atomic_inc(&vsock->queued_replies);

- spin_lock_bh(&vsock->send_pkt_list_lock);
- list_add_tail(&pkt->list, &vsock->send_pkt_list);
- spin_unlock_bh(&vsock->send_pkt_list_lock);
-
+ skb_queue_tail(&vsock->send_pkt_queue, skb);
vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);

rcu_read_unlock();
@@ -310,10 +297,8 @@ static int
vhost_transport_cancel_pkt(struct vsock_sock *vsk)
{
struct vhost_vsock *vsock;
- struct virtio_vsock_pkt *pkt, *n;
int cnt = 0;
int ret = -ENODEV;
- LIST_HEAD(freeme);

rcu_read_lock();

@@ -322,20 +307,7 @@ vhost_transport_cancel_pkt(struct vsock_sock *vsk)
if (!vsock)
goto out;

- spin_lock_bh(&vsock->send_pkt_list_lock);
- list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
- if (pkt->vsk != vsk)
- continue;
- list_move(&pkt->list, &freeme);
- }
- spin_unlock_bh(&vsock->send_pkt_list_lock);
-
- list_for_each_entry_safe(pkt, n, &freeme, list) {
- if (pkt->reply)
- cnt++;
- list_del(&pkt->list);
- virtio_transport_free_pkt(pkt);
- }
+ cnt = virtio_transport_purge_skbs(vsk, &vsock->send_pkt_queue);

if (cnt) {
struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
@@ -352,11 +324,12 @@ vhost_transport_cancel_pkt(struct vsock_sock *vsk)
return ret;
}

-static struct virtio_vsock_pkt *
-vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
+static struct sk_buff *
+vhost_vsock_alloc_skb(struct vhost_virtqueue *vq,
unsigned int out, unsigned int in)
{
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
+ struct virtio_vsock_hdr *hdr;
struct iov_iter iov_iter;
size_t nbytes;
size_t len;
@@ -366,50 +339,50 @@ vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
return NULL;
}

- pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
- if (!pkt)
+ len = iov_length(vq->iov, out);
+
+ /* len contains both payload and hdr, so only add additional space for metadata */
+ skb = alloc_skb(len + sizeof(struct virtio_vsock_metadata), GFP_KERNEL);
+ if (!skb)
return NULL;

- len = iov_length(vq->iov, out);
+ /* Only zero metadata, preserve the header */
+ memset(skb->head, 0, sizeof(struct virtio_vsock_metadata));
+ virtio_vsock_skb_reserve(skb);
iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);

- nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
- if (nbytes != sizeof(pkt->hdr)) {
+ hdr = vsock_hdr(skb);
+ nbytes = copy_from_iter(hdr, sizeof(*hdr), &iov_iter);
+ if (nbytes != sizeof(*hdr)) {
vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
- sizeof(pkt->hdr), nbytes);
- kfree(pkt);
+ sizeof(*hdr), nbytes);
+ kfree_skb(skb);
return NULL;
}

- pkt->len = le32_to_cpu(pkt->hdr.len);
+ len = le32_to_cpu(hdr->len);

/* No payload */
- if (!pkt->len)
- return pkt;
+ if (!len)
+ return skb;

/* The pkt is too big */
- if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
- kfree(pkt);
+ if (len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
+ kfree_skb(skb);
return NULL;
}

- pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
- if (!pkt->buf) {
- kfree(pkt);
- return NULL;
- }
+ virtio_vsock_skb_rx_put(skb);

- pkt->buf_len = pkt->len;
-
- nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
- if (nbytes != pkt->len) {
- vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
- pkt->len, nbytes);
- virtio_transport_free_pkt(pkt);
+ nbytes = copy_from_iter(skb->data, len, &iov_iter);
+ if (nbytes != len) {
+ vq_err(vq, "Expected %zu byte payload, got %zu bytes\n",
+ len, nbytes);
+ kfree_skb(skb);
return NULL;
}

- return pkt;
+ return skb;
}

/* Is there space left for replies to rx packets? */
@@ -496,7 +469,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
poll.work);
struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
dev);
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
int head, pkts = 0, total_len = 0;
unsigned int out, in;
bool added = false;
@@ -511,6 +484,9 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)

vhost_disable_notify(&vsock->dev, vq);
do {
+ struct virtio_vsock_hdr *hdr;
+ u32 len;
+
if (!vhost_vsock_more_replies(vsock)) {
/* Stop tx until the device processes already
* pending replies. Leave tx virtqueue
@@ -532,26 +508,29 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
break;
}

- pkt = vhost_vsock_alloc_pkt(vq, out, in);
- if (!pkt) {
- vq_err(vq, "Faulted on pkt\n");
+ skb = vhost_vsock_alloc_skb(vq, out, in);
+ if (!skb)
continue;
- }

- total_len += sizeof(pkt->hdr) + pkt->len;
+ len = skb->len;

/* Deliver to monitoring devices all received packets */
- virtio_transport_deliver_tap_pkt(pkt);
+ virtio_transport_deliver_tap_pkt(skb);
+
+ hdr = vsock_hdr(skb);

/* Only accept correctly addressed packets */
- if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid &&
- le64_to_cpu(pkt->hdr.dst_cid) ==
+ if (le64_to_cpu(hdr->src_cid) == vsock->guest_cid &&
+ le64_to_cpu(hdr->dst_cid) ==
vhost_transport_get_local_cid())
- virtio_transport_recv_pkt(&vhost_transport, pkt);
+ virtio_transport_recv_pkt(&vhost_transport, skb);
else
- virtio_transport_free_pkt(pkt);
+ kfree_skb(skb);
+

- vhost_add_used(vq, head, 0);
+ len += sizeof(*hdr);
+ vhost_add_used(vq, head, len);

Please don't use `len` in vhost_add_used(). We should pass the number of bytes written by the device. Take a look at https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=49d8c5ffad07ca014cfae72a1b9b8c52b6ad9cb8

Maybe we should document better vhost_add_used() to avoid future issue.

+ total_len += len;
added = true;
} while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));

@@ -693,8 +672,7 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
VHOST_VSOCK_WEIGHT, true, NULL);

file->private_data = vsock;
- spin_lock_init(&vsock->send_pkt_list_lock);
- INIT_LIST_HEAD(&vsock->send_pkt_list);
+ skb_queue_head_init(&vsock->send_pkt_queue);
vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
return 0;

@@ -760,16 +738,7 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
vhost_vsock_flush(vsock);
vhost_dev_stop(&vsock->dev);

- spin_lock_bh(&vsock->send_pkt_list_lock);
- while (!list_empty(&vsock->send_pkt_list)) {
- struct virtio_vsock_pkt *pkt;
-
- pkt = list_first_entry(&vsock->send_pkt_list,
- struct virtio_vsock_pkt, list);
- list_del_init(&pkt->list);
- virtio_transport_free_pkt(pkt);
- }
- spin_unlock_bh(&vsock->send_pkt_list_lock);
+ skb_queue_purge(&vsock->send_pkt_queue);

vhost_dev_cleanup(&vsock->dev);
kfree(vsock->dev.vqs);
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 35d7eedb5e8e..b1dff55c91a5 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -4,9 +4,47 @@

#include <uapi/linux/virtio_vsock.h>
#include <linux/socket.h>
+#include <vdso/bits.h>
#include <net/sock.h>
#include <net/af_vsock.h>

+/* Threshold for detecting small packets to copy */
+#define GOOD_COPY_LEN 128

Since we moved this in an header, I guess is better to add a prefix (e.g. VIRTIO_VSOCK_GOOD_COPY_LEN)

+
+enum virtio_vsock_metadata_flags {
+ VIRTIO_VSOCK_METADATA_FLAGS_REPLY = BIT(0),
+ VIRTIO_VSOCK_METADATA_FLAGS_TAP_DELIVERED = BIT(1),
+};
+
+/* Used only by the virtio/vhost vsock drivers, not related to protocol */
+struct virtio_vsock_metadata {
+ size_t off;
+ enum virtio_vsock_metadata_flags flags;
+};
+
+#define vsock_hdr(skb) \

For uniformity better virtio_vsock_get_hdr()

+ ((struct virtio_vsock_hdr *) \
+ ((void *)skb->head + sizeof(struct virtio_vsock_metadata)))
+
+#define vsock_metadata(skb) \

Ditto

+ ((struct virtio_vsock_metadata *)skb->head)
+
+#define VIRTIO_VSOCK_SKB_RESERVE_SIZE \
+ (sizeof(struct virtio_vsock_metadata) + sizeof(struct virtio_vsock_hdr))
+
+#define virtio_vsock_skb_reserve(skb) \
+ skb_reserve(skb, VIRTIO_VSOCK_SKB_RESERVE_SIZE)
+
+static inline void virtio_vsock_skb_rx_put(struct sk_buff *skb)
+{
+ u32 len;
+
+ len = le32_to_cpu(vsock_hdr(skb)->len);
+
+ if (len > 0)
+ skb_put(skb, len);
+}
+
#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 4)
#define VIRTIO_VSOCK_MAX_BUF_SIZE 0xFFFFFFFFUL
#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64)
@@ -35,23 +73,10 @@ struct virtio_vsock_sock {
u32 last_fwd_cnt;
u32 rx_bytes;
u32 buf_alloc;
- struct list_head rx_queue;
+ struct sk_buff_head rx_queue;
u32 msg_count;
};

-struct virtio_vsock_pkt {
- struct virtio_vsock_hdr hdr;
- struct list_head list;
- /* socket refcnt not held, only use for cancellation */
- struct vsock_sock *vsk;
- void *buf;
- u32 buf_len;
- u32 len;
- u32 off;
- bool reply;
- bool tap_delivered;
-};
-
struct virtio_vsock_pkt_info {
u32 remote_cid, remote_port;
struct vsock_sock *vsk;
@@ -68,7 +93,7 @@ struct virtio_transport {
struct vsock_transport transport;

/* Takes ownership of the packet */
- int (*send_pkt)(struct virtio_vsock_pkt *pkt);
+ int (*send_pkt)(struct sk_buff *skb);
};

ssize_t
@@ -149,11 +174,10 @@ virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
void virtio_transport_destruct(struct vsock_sock *vsk);

void virtio_transport_recv_pkt(struct virtio_transport *t,
- struct virtio_vsock_pkt *pkt);
-void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt);
-void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt);
+ struct sk_buff *skb);
+void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct sk_buff *skb);
u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 wanted);
void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit);
-void virtio_transport_deliver_tap_pkt(struct virtio_vsock_pkt *pkt);
-
+void virtio_transport_deliver_tap_pkt(struct sk_buff *skb);
+int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *queue);
#endif /* _LINUX_VIRTIO_VSOCK_H */
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index b4ee163154a6..de8a9b0ec3a0 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -748,6 +748,7 @@ static struct sock *__vsock_create(struct net *net,
vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);

+ sk->sk_allocation = GFP_KERNEL;

This will change also other transports, like VMCI that uses sk_buff for datagram. We should check that it is okay for them.

sk->sk_destruct = vsock_sk_destruct;
sk->sk_backlog_rcv = vsock_queue_rcv_skb;
sock_reset_flag(sk, SOCK_DONE);
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index ad64f403536a..ac8c7003835b 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -21,6 +21,11 @@
#include <linux/mutex.h>
#include <net/af_vsock.h>

+#define VIRTIO_VSOCK_MAX_RX_HDR_PAYLOAD_SIZE \
+ (VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE \
+ - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) \
+ - VIRTIO_VSOCK_SKB_RESERVE_SIZE)
+
static struct workqueue_struct *virtio_vsock_workqueue;
static struct virtio_vsock __rcu *the_virtio_vsock;
static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
@@ -42,8 +47,7 @@ struct virtio_vsock {
bool tx_run;

struct work_struct send_pkt_work;
- spinlock_t send_pkt_list_lock;
- struct list_head send_pkt_list;
+ struct sk_buff_head send_pkt_queue;

atomic_t queued_replies;

@@ -101,41 +105,32 @@ virtio_transport_send_pkt_work(struct work_struct *work)
vq = vsock->vqs[VSOCK_VQ_TX];

for (;;) {
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
struct scatterlist hdr, buf, *sgs[2];
int ret, in_sg = 0, out_sg = 0;
bool reply;

- spin_lock_bh(&vsock->send_pkt_list_lock);
- if (list_empty(&vsock->send_pkt_list)) {
- spin_unlock_bh(&vsock->send_pkt_list_lock);
- break;
- }
+ skb = skb_dequeue(&vsock->send_pkt_queue);

- pkt = list_first_entry(&vsock->send_pkt_list,
- struct virtio_vsock_pkt, list);
- list_del_init(&pkt->list);
- spin_unlock_bh(&vsock->send_pkt_list_lock);
-
- virtio_transport_deliver_tap_pkt(pkt);
+ if (!skb)
+ break;

- reply = pkt->reply;
+ virtio_transport_deliver_tap_pkt(skb);
+ reply = vsock_metadata(skb)->flags & VIRTIO_VSOCK_METADATA_FLAGS_REPLY;

- sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
+ sg_init_one(&hdr, vsock_hdr(skb), sizeof(*vsock_hdr(skb)));
sgs[out_sg++] = &hdr;
- if (pkt->buf) {
- sg_init_one(&buf, pkt->buf, pkt->len);
+ if (skb->len > 0) {
+ sg_init_one(&buf, skb->data, skb->len);
sgs[out_sg++] = &buf;
}

- ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL);
+ ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, GFP_KERNEL);
/* Usually this means that there is no more space available in
* the vq
*/
if (ret < 0) {
- spin_lock_bh(&vsock->send_pkt_list_lock);
- list_add(&pkt->list, &vsock->send_pkt_list);
- spin_unlock_bh(&vsock->send_pkt_list_lock);
+ skb_queue_head(&vsock->send_pkt_queue, skb);
break;
}

@@ -163,33 +158,83 @@ virtio_transport_send_pkt_work(struct work_struct *work)
queue_work(virtio_vsock_workqueue, &vsock->rx_work);
}

+static inline bool
+virtio_transport_skbs_can_merge(struct sk_buff *old, struct sk_buff *new)
+{
+ return (new->len < GOOD_COPY_LEN &&
+ skb_tailroom(old) >= new->len &&
+ vsock_hdr(new)->src_cid == vsock_hdr(old)->src_cid &&
+ vsock_hdr(new)->dst_cid == vsock_hdr(old)->dst_cid &&
+ vsock_hdr(new)->src_port == vsock_hdr(old)->src_port &&
+ vsock_hdr(new)->dst_port == vsock_hdr(old)->dst_port &&

For these first fields perhaps we can use a memcmp.

Can we use a pointer to store the header pointers?

+ vsock_hdr(new)->type == vsock_hdr(old)->type &&
+ vsock_hdr(new)->flags == vsock_hdr(old)->flags &&
+ le16_to_cpu(vsock_hdr(old)->op) == VIRTIO_VSOCK_OP_RW &&
+ le16_to_cpu(vsock_hdr(new)->op) == VIRTIO_VSOCK_OP_RW);
+}
+
+/* Add new sk_buff to queue.
+ *
+ * Merge the two most recent skbs together if possible.
+ */
+static void
+virtio_transport_add_to_queue(struct sk_buff_head *queue, struct sk_buff *new)
+{
+ struct sk_buff *old;
+
+ spin_lock_bh(&queue->lock);
+ if (skb_queue_empty_lockless(queue)) {
+ __skb_queue_tail(queue, new);
+ goto out;
+ }
+
+ old = skb_peek_tail(queue);
+
+ /* In order to reduce skb memory overhead, we merge new packets with
+ * older packets if they pass virtio_transport_skbs_can_merge().
+ */
+ if (!virtio_transport_skbs_can_merge(old, new)) {
+ __skb_queue_tail(queue, new);
+ goto out;
+ }
+
+ memcpy(skb_put(old, new->len), new->data, new->len);

This extra copy (and maybe also the call to can_merge) could be responsible for the perf drop. I understand why we have it, though, you could give it a try by avoiding merging and see what happens to performance.

Maybe we can split this patch and move change in a separate patch of the same series, and in the cover report the performance result incrementally with only the first patch applied and with first and second.

+ vsock_hdr(old)->len = cpu_to_le32(old->len);
+ vsock_hdr(old)->buf_alloc = vsock_hdr(new)->buf_alloc;
+ vsock_hdr(old)->fwd_cnt = vsock_hdr(new)->fwd_cnt;
+ dev_kfree_skb_any(new);
+
+out:
+ spin_unlock_bh(&queue->lock);
+}
+
static int
-virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
+virtio_transport_send_pkt(struct sk_buff *skb)
{
+ struct virtio_vsock_hdr *hdr;
struct virtio_vsock *vsock;
- int len = pkt->len;
+ int len = skb->len;
+
+ hdr = vsock_hdr(skb);

rcu_read_lock();
vsock = rcu_dereference(the_virtio_vsock);
if (!vsock) {
- virtio_transport_free_pkt(pkt);
+ kfree_skb(skb);
len = -ENODEV;
goto out_rcu;
}

- if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) {
- virtio_transport_free_pkt(pkt);
+ if (le64_to_cpu(hdr->dst_cid) == vsock->guest_cid) {
+ kfree_skb(skb);
len = -ENODEV;
goto out_rcu;
}

- if (pkt->reply)
+ if (vsock_metadata(skb)->flags & VIRTIO_VSOCK_METADATA_FLAGS_REPLY)
atomic_inc(&vsock->queued_replies);

- spin_lock_bh(&vsock->send_pkt_list_lock);
- list_add_tail(&pkt->list, &vsock->send_pkt_list);
- spin_unlock_bh(&vsock->send_pkt_list_lock);
-
+ virtio_transport_add_to_queue(&vsock->send_pkt_queue, skb);
queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);

out_rcu:
@@ -201,9 +246,7 @@ static int
virtio_transport_cancel_pkt(struct vsock_sock *vsk)
{
struct virtio_vsock *vsock;
- struct virtio_vsock_pkt *pkt, *n;
int cnt = 0, ret;
- LIST_HEAD(freeme);

rcu_read_lock();
vsock = rcu_dereference(the_virtio_vsock);
@@ -212,20 +255,7 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk)
goto out_rcu;
}

- spin_lock_bh(&vsock->send_pkt_list_lock);
- list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
- if (pkt->vsk != vsk)
- continue;
- list_move(&pkt->list, &freeme);
- }
- spin_unlock_bh(&vsock->send_pkt_list_lock);
-
- list_for_each_entry_safe(pkt, n, &freeme, list) {
- if (pkt->reply)
- cnt++;
- list_del(&pkt->list);
- virtio_transport_free_pkt(pkt);
- }
+ cnt = virtio_transport_purge_skbs(vsk, &vsock->send_pkt_queue);

if (cnt) {
struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
@@ -246,38 +276,32 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk)

static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
{
- int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
- struct virtio_vsock_pkt *pkt;
- struct scatterlist hdr, buf, *sgs[2];
+ struct scatterlist pkt, *sgs[1];
struct virtqueue *vq;
int ret;

vq = vsock->vqs[VSOCK_VQ_RX];

do {
- pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
- if (!pkt)
- break;
+ struct sk_buff *skb;
+ const size_t len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE -
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));

- pkt->buf = kmalloc(buf_len, GFP_KERNEL);
- if (!pkt->buf) {
- virtio_transport_free_pkt(pkt);
+ skb = alloc_skb(len, GFP_KERNEL);
+ if (!skb)
break;
- }

- pkt->buf_len = buf_len;
- pkt->len = buf_len;
+ memset(skb->head, 0, VIRTIO_VSOCK_SKB_RESERVE_SIZE);

- sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
- sgs[0] = &hdr;
+ sg_init_one(&pkt, vsock_hdr(skb), VIRTIO_VSOCK_MAX_RX_HDR_PAYLOAD_SIZE);
+ sgs[0] = &pkt;

- sg_init_one(&buf, pkt->buf, buf_len);
- sgs[1] = &buf;
- ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
- if (ret) {
- virtio_transport_free_pkt(pkt);
+ ret = virtqueue_add_sgs(vq, sgs, 0, 1, skb, GFP_KERNEL);
+ if (ret < 0) {
+ kfree_skb(skb);
break;
}
+
vsock->rx_buf_nr++;
} while (vq->num_free);
if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
@@ -299,12 +323,12 @@ static void virtio_transport_tx_work(struct work_struct *work)
goto out;

do {
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
unsigned int len;

virtqueue_disable_cb(vq);
- while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
- virtio_transport_free_pkt(pkt);
+ while ((skb = virtqueue_get_buf(vq, &len)) != NULL) {
+ consume_skb(skb);
added = true;
}
} while (!virtqueue_enable_cb(vq));
@@ -529,7 +553,7 @@ static void virtio_transport_rx_work(struct work_struct *work)
do {
virtqueue_disable_cb(vq);
for (;;) {
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
unsigned int len;

if (!virtio_transport_more_replies(vsock)) {
@@ -540,23 +564,23 @@ static void virtio_transport_rx_work(struct work_struct *work)
goto out;
}

- pkt = virtqueue_get_buf(vq, &len);
- if (!pkt) {
+ skb = virtqueue_get_buf(vq, &len);
+ if (!skb)
break;
- }

vsock->rx_buf_nr--;

/* Drop short/long packets */
- if (unlikely(len < sizeof(pkt->hdr) ||
- len > sizeof(pkt->hdr) + pkt->len)) {
- virtio_transport_free_pkt(pkt);
+ if (unlikely(len < sizeof(struct virtio_vsock_hdr) ||
+ len > VIRTIO_VSOCK_MAX_RX_HDR_PAYLOAD_SIZE)) {
+ kfree_skb(skb);
continue;
}

- pkt->len = len - sizeof(pkt->hdr);
- virtio_transport_deliver_tap_pkt(pkt);
- virtio_transport_recv_pkt(&virtio_transport, pkt);
+ virtio_vsock_skb_reserve(skb);
+ virtio_vsock_skb_rx_put(skb);
+ virtio_transport_deliver_tap_pkt(skb);
+ virtio_transport_recv_pkt(&virtio_transport, skb);
}
} while (!virtqueue_enable_cb(vq));

@@ -610,7 +634,7 @@ static int virtio_vsock_vqs_init(struct virtio_vsock *vsock)
static void virtio_vsock_vqs_del(struct virtio_vsock *vsock)
{
struct virtio_device *vdev = vsock->vdev;
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;

/* Reset all connected sockets when the VQs disappear */
vsock_for_each_connected_socket(&virtio_transport.transport,
@@ -637,23 +661,16 @@ static void virtio_vsock_vqs_del(struct virtio_vsock *vsock)
virtio_reset_device(vdev);

mutex_lock(&vsock->rx_lock);
- while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
- virtio_transport_free_pkt(pkt);
+ while ((skb = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
+ kfree_skb(skb);
mutex_unlock(&vsock->rx_lock);

mutex_lock(&vsock->tx_lock);
- while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
- virtio_transport_free_pkt(pkt);
+ while ((skb = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
+ kfree_skb(skb);
mutex_unlock(&vsock->tx_lock);

- spin_lock_bh(&vsock->send_pkt_list_lock);
- while (!list_empty(&vsock->send_pkt_list)) {
- pkt = list_first_entry(&vsock->send_pkt_list,
- struct virtio_vsock_pkt, list);
- list_del(&pkt->list);
- virtio_transport_free_pkt(pkt);
- }
- spin_unlock_bh(&vsock->send_pkt_list_lock);
+ skb_queue_purge(&vsock->send_pkt_queue);

/* Delete virtqueues and flush outstanding callbacks if any */
vdev->config->del_vqs(vdev);
@@ -690,8 +707,7 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
mutex_init(&vsock->tx_lock);
mutex_init(&vsock->rx_lock);
mutex_init(&vsock->event_lock);
- spin_lock_init(&vsock->send_pkt_list_lock);
- INIT_LIST_HEAD(&vsock->send_pkt_list);
+ skb_queue_head_init(&vsock->send_pkt_queue);
INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
INIT_WORK(&vsock->event_work, virtio_transport_event_work);
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index ec2c2afbf0d0..19678bd45c23 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -23,9 +23,6 @@
/* How long to wait for graceful shutdown of a connection */
#define VSOCK_CLOSE_TIMEOUT (8 * HZ)

-/* Threshold for detecting small packets to copy */
-#define GOOD_COPY_LEN 128
-
static const struct virtio_transport *
virtio_transport_get_ops(struct vsock_sock *vsk)
{
@@ -37,53 +34,64 @@ virtio_transport_get_ops(struct vsock_sock *vsk)
return container_of(t, struct virtio_transport, transport);
}

-static struct virtio_vsock_pkt *
-virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
+/* Returns a new packet on success, otherwise returns NULL.
+ *
+ * If NULL is returned, errp is set to a negative errno.
+ */
+static struct sk_buff *
+virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info,
size_t len,
u32 src_cid,
u32 src_port,
u32 dst_cid,
- u32 dst_port)
+ u32 dst_port,
+ int *errp)
{
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
+ struct virtio_vsock_hdr *hdr;
+ void *payload;
+ const size_t skb_len = VIRTIO_VSOCK_SKB_RESERVE_SIZE + len;
int err;

- pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
- if (!pkt)
+ skb = alloc_skb(skb_len, GFP_KERNEL);
+ if (!skb) {
+ *errp = -ENOMEM;
return NULL;
+ }

- pkt->hdr.type = cpu_to_le16(info->type);
- pkt->hdr.op = cpu_to_le16(info->op);
- pkt->hdr.src_cid = cpu_to_le64(src_cid);
- pkt->hdr.dst_cid = cpu_to_le64(dst_cid);
- pkt->hdr.src_port = cpu_to_le32(src_port);
- pkt->hdr.dst_port = cpu_to_le32(dst_port);
- pkt->hdr.flags = cpu_to_le32(info->flags);
- pkt->len = len;
- pkt->hdr.len = cpu_to_le32(len);
- pkt->reply = info->reply;
- pkt->vsk = info->vsk;
-
- if (info->msg && len > 0) {
- pkt->buf = kmalloc(len, GFP_KERNEL);
- if (!pkt->buf)
- goto out_pkt;
+ memset(skb->head, 0, VIRTIO_VSOCK_SKB_RESERVE_SIZE);
+ virtio_vsock_skb_reserve(skb);
+ payload = skb_put(skb, len);

- pkt->buf_len = len;
+ hdr = vsock_hdr(skb);
+ hdr->type = cpu_to_le16(info->type);
+ hdr->op = cpu_to_le16(info->op);
+ hdr->src_cid = cpu_to_le64(src_cid);
+ hdr->dst_cid = cpu_to_le64(dst_cid);
+ hdr->src_port = cpu_to_le32(src_port);
+ hdr->dst_port = cpu_to_le32(dst_port);
+ hdr->flags = cpu_to_le32(info->flags);
+ hdr->len = cpu_to_le32(len);

- err = memcpy_from_msg(pkt->buf, info->msg, len);
- if (err)
+ if (info->msg && len > 0) {
+ err = memcpy_from_msg(payload, info->msg, len);
+ if (err) {
+ *errp = -ENOMEM;
goto out;
+ }

if (msg_data_left(info->msg) == 0 &&
info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
- pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
+ hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);

if (info->msg->msg_flags & MSG_EOR)
- pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
+ hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
}
}

+ if (info->reply)
+ vsock_metadata(skb)->flags |= VIRTIO_VSOCK_METADATA_FLAGS_REPLY;
+
trace_virtio_transport_alloc_pkt(src_cid, src_port,
dst_cid, dst_port,
len,
@@ -91,85 +99,26 @@ virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
info->op,
info->flags);

- return pkt;
+ return skb;

out:
- kfree(pkt->buf);
-out_pkt:
- kfree(pkt);
+ kfree_skb(skb);
return NULL;
}

/* Packet capture */
static struct sk_buff *virtio_transport_build_skb(void *opaque)
{
- struct virtio_vsock_pkt *pkt = opaque;
- struct af_vsockmon_hdr *hdr;
- struct sk_buff *skb;
- size_t payload_len;
- void *payload_buf;
-
- /* A packet could be split to fit the RX buffer, so we can retrieve
- * the payload length from the header and the buffer pointer taking
- * care of the offset in the original packet.
- */
- payload_len = le32_to_cpu(pkt->hdr.len);
- payload_buf = pkt->buf + pkt->off;
-
- skb = alloc_skb(sizeof(*hdr) + sizeof(pkt->hdr) + payload_len,
- GFP_ATOMIC);
- if (!skb)
- return NULL;
-
- hdr = skb_put(skb, sizeof(*hdr));
-
- /* pkt->hdr is little-endian so no need to byteswap here */
- hdr->src_cid = pkt->hdr.src_cid;
- hdr->src_port = pkt->hdr.src_port;
- hdr->dst_cid = pkt->hdr.dst_cid;
- hdr->dst_port = pkt->hdr.dst_port;
-
- hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO);
- hdr->len = cpu_to_le16(sizeof(pkt->hdr));
- memset(hdr->reserved, 0, sizeof(hdr->reserved));
-
- switch (le16_to_cpu(pkt->hdr.op)) {
- case VIRTIO_VSOCK_OP_REQUEST:
- case VIRTIO_VSOCK_OP_RESPONSE:
- hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT);
- break;
- case VIRTIO_VSOCK_OP_RST:
- case VIRTIO_VSOCK_OP_SHUTDOWN:
- hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT);
- break;
- case VIRTIO_VSOCK_OP_RW:
- hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD);
- break;
- case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
- case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
- hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL);
- break;
- default:
- hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN);
- break;
- }
-
- skb_put_data(skb, &pkt->hdr, sizeof(pkt->hdr));
-
- if (payload_len) {
- skb_put_data(skb, payload_buf, payload_len);
- }
-
- return skb;
+ return skb_clone((struct sk_buff *)opaque, GFP_ATOMIC);
}

-void virtio_transport_deliver_tap_pkt(struct virtio_vsock_pkt *pkt)
+void virtio_transport_deliver_tap_pkt(struct sk_buff *skb)
{
- if (pkt->tap_delivered)
+ if (vsock_metadata(skb)->flags & VIRTIO_VSOCK_METADATA_FLAGS_TAP_DELIVERED)
return;

- vsock_deliver_tap(virtio_transport_build_skb, pkt);
- pkt->tap_delivered = true;
+ vsock_deliver_tap(virtio_transport_build_skb, skb);
+ vsock_metadata(skb)->flags |= VIRTIO_VSOCK_METADATA_FLAGS_TAP_DELIVERED;
}
EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);

@@ -192,8 +141,9 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
u32 src_cid, src_port, dst_cid, dst_port;
const struct virtio_transport *t_ops;
struct virtio_vsock_sock *vvs;
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
u32 pkt_len = info->pkt_len;
+ int err;

info->type = virtio_transport_get_type(sk_vsock(vsk));

@@ -224,42 +174,47 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
return pkt_len;

- pkt = virtio_transport_alloc_pkt(info, pkt_len,
+ skb = virtio_transport_alloc_skb(info, pkt_len,
src_cid, src_port,
- dst_cid, dst_port);
- if (!pkt) {
+ dst_cid, dst_port,
+ &err);
+ if (!skb) {
virtio_transport_put_credit(vvs, pkt_len);
- return -ENOMEM;
+ return err;
}

- virtio_transport_inc_tx_pkt(vvs, pkt);
+ virtio_transport_inc_tx_pkt(vvs, skb);
+
+ err = t_ops->send_pkt(skb);

- return t_ops->send_pkt(pkt);
+ return err < 0 ? -ENOMEM : err;
}

static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
- if (vvs->rx_bytes + pkt->len > vvs->buf_alloc)
+ if (vvs->rx_bytes + skb->len > vvs->buf_alloc)
return false;

- vvs->rx_bytes += pkt->len;
+ vvs->rx_bytes += skb->len;
return true;
}

static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
- vvs->rx_bytes -= pkt->len;
- vvs->fwd_cnt += pkt->len;
+ vvs->rx_bytes -= skb->len;
+ vvs->fwd_cnt += skb->len;
}

-void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
+void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct sk_buff *skb)
{
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);
+
spin_lock_bh(&vvs->rx_lock);
vvs->last_fwd_cnt = vvs->fwd_cnt;
- pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
- pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
+ hdr->fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
+ hdr->buf_alloc = cpu_to_le32(vvs->buf_alloc);
spin_unlock_bh(&vvs->rx_lock);
}
EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
@@ -303,29 +258,29 @@ virtio_transport_stream_do_peek(struct vsock_sock *vsk,
size_t len)
{
struct virtio_vsock_sock *vvs = vsk->trans;
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb, *tmp;
size_t bytes, total = 0, off;
int err = -EFAULT;

spin_lock_bh(&vvs->rx_lock);

- list_for_each_entry(pkt, &vvs->rx_queue, list) {
- off = pkt->off;
+ skb_queue_walk_safe(&vvs->rx_queue, skb, tmp) {
+ off = vsock_metadata(skb)->off;

if (total == len)
break;

- while (total < len && off < pkt->len) {
+ while (total < len && off < skb->len) {
bytes = len - total;
- if (bytes > pkt->len - off)
- bytes = pkt->len - off;
+ if (bytes > skb->len - off)
+ bytes = skb->len - off;

/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since memcpy_to_msg() may sleep.
*/
spin_unlock_bh(&vvs->rx_lock);

- err = memcpy_to_msg(msg, pkt->buf + off, bytes);
+ err = memcpy_to_msg(msg, skb->data + off, bytes);
if (err)
goto out;

@@ -352,37 +307,40 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
size_t len)
{
struct virtio_vsock_sock *vvs = vsk->trans;
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
size_t bytes, total = 0;
u32 free_space;
int err = -EFAULT;

spin_lock_bh(&vvs->rx_lock);
- while (total < len && !list_empty(&vvs->rx_queue)) {
- pkt = list_first_entry(&vvs->rx_queue,
- struct virtio_vsock_pkt, list);
+ while (total < len && !skb_queue_empty_lockless(&vvs->rx_queue)) {
+ skb = __skb_dequeue(&vvs->rx_queue);

bytes = len - total;
- if (bytes > pkt->len - pkt->off)
- bytes = pkt->len - pkt->off;
+ if (bytes > skb->len - vsock_metadata(skb)->off)
+ bytes = skb->len - vsock_metadata(skb)->off;

/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since memcpy_to_msg() may sleep.
*/
spin_unlock_bh(&vvs->rx_lock);

- err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
+ err = memcpy_to_msg(msg, skb->data + vsock_metadata(skb)->off, bytes);
if (err)
goto out;

spin_lock_bh(&vvs->rx_lock);

total += bytes;
- pkt->off += bytes;
- if (pkt->off == pkt->len) {
- virtio_transport_dec_rx_pkt(vvs, pkt);
- list_del(&pkt->list);
- virtio_transport_free_pkt(pkt);
+ vsock_metadata(skb)->off += bytes;
+
+ WARN_ON(vsock_metadata(skb)->off > skb->len);
^
Can this ever happen?

+
+ if (vsock_metadata(skb)->off == skb->len) {
+ virtio_transport_dec_rx_pkt(vvs, skb);
+ consume_skb(skb);
+ } else {
+ __skb_queue_head(&vvs->rx_queue, skb);
}
}

@@ -414,7 +372,7 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
int flags)
{
struct virtio_vsock_sock *vvs = vsk->trans;
- struct virtio_vsock_pkt *pkt;
+ struct sk_buff *skb;
int dequeued_len = 0;
size_t user_buf_len = msg_data_left(msg);
bool msg_ready = false;
@@ -426,14 +384,24 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
return 0;
}

+ if (skb_queue_empty_lockless(&vvs->rx_queue)) {
+ spin_unlock_bh(&vvs->rx_lock);
+ return 0;
+ }
+
while (!msg_ready) {
- pkt = list_first_entry(&vvs->rx_queue, struct virtio_vsock_pkt, list);
+ struct virtio_vsock_hdr *hdr;
+
+ skb = __skb_dequeue(&vvs->rx_queue);
+ if (!skb)
+ break;
+ hdr = vsock_hdr(skb);

if (dequeued_len >= 0) {
size_t pkt_len;
size_t bytes_to_copy;

- pkt_len = (size_t)le32_to_cpu(pkt->hdr.len);
+ pkt_len = (size_t)le32_to_cpu(hdr->len);
bytes_to_copy = min(user_buf_len, pkt_len);

if (bytes_to_copy) {
@@ -444,7 +412,7 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
*/
spin_unlock_bh(&vvs->rx_lock);

- err = memcpy_to_msg(msg, pkt->buf, bytes_to_copy);
+ err = memcpy_to_msg(msg, skb->data, bytes_to_copy);
if (err) {
/* Copy of message failed. Rest of
* fragments will be freed without copy.
@@ -461,17 +429,16 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
dequeued_len += pkt_len;
}

- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
msg_ready = true;
vvs->msg_count--;

- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR)
+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
msg->msg_flags |= MSG_EOR;
}

- virtio_transport_dec_rx_pkt(vvs, pkt);
- list_del(&pkt->list);
- virtio_transport_free_pkt(pkt);
+ virtio_transport_dec_rx_pkt(vvs, skb);
+ kfree_skb(skb);
}

spin_unlock_bh(&vvs->rx_lock);
@@ -609,7 +576,7 @@ int virtio_transport_do_socket_init(struct vsock_sock *vsk,

spin_lock_init(&vvs->rx_lock);
spin_lock_init(&vvs->tx_lock);
- INIT_LIST_HEAD(&vvs->rx_queue);
+ skb_queue_head_init(&vvs->rx_queue);

return 0;
}
@@ -809,16 +776,16 @@ void virtio_transport_destruct(struct vsock_sock *vsk)
EXPORT_SYMBOL_GPL(virtio_transport_destruct);

static int virtio_transport_reset(struct vsock_sock *vsk,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RST,
- .reply = !!pkt,
+ .reply = !!skb,
.vsk = vsk,
};

/* Send RST only if the original pkt is not a RST pkt */
- if (pkt && le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
+ if (skb && le16_to_cpu(vsock_hdr(skb)->op) == VIRTIO_VSOCK_OP_RST)
return 0;

return virtio_transport_send_pkt_info(vsk, &info);
@@ -828,29 +795,32 @@ static int virtio_transport_reset(struct vsock_sock *vsk,
* attempt was made to connect to a socket that does not exist.
*/
static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
- struct virtio_vsock_pkt *reply;
+ struct sk_buff *reply;
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RST,
- .type = le16_to_cpu(pkt->hdr.type),
+ .type = le16_to_cpu(hdr->type),
.reply = true,
};
+ int err;

/* Send RST only if the original pkt is not a RST pkt */
- if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
+ if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST)
return 0;

- reply = virtio_transport_alloc_pkt(&info, 0,
- le64_to_cpu(pkt->hdr.dst_cid),
- le32_to_cpu(pkt->hdr.dst_port),
- le64_to_cpu(pkt->hdr.src_cid),
- le32_to_cpu(pkt->hdr.src_port));
+ reply = virtio_transport_alloc_skb(&info, 0,
+ le64_to_cpu(hdr->dst_cid),
+ le32_to_cpu(hdr->dst_port),
+ le64_to_cpu(hdr->src_cid),
+ le32_to_cpu(hdr->src_port),
+ &err);
if (!reply)
- return -ENOMEM;
+ return err;

if (!t) {
- virtio_transport_free_pkt(reply);
+ kfree_skb(reply);
return -ENOTCONN;
}

@@ -861,16 +831,11 @@ static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
static void virtio_transport_remove_sock(struct vsock_sock *vsk)
{
struct virtio_vsock_sock *vvs = vsk->trans;
- struct virtio_vsock_pkt *pkt, *tmp;

/* We don't need to take rx_lock, as the socket is closing and we are
* removing it.
*/
- list_for_each_entry_safe(pkt, tmp, &vvs->rx_queue, list) {
- list_del(&pkt->list);
- virtio_transport_free_pkt(pkt);
- }
-
+ __skb_queue_purge(&vvs->rx_queue);
vsock_remove_sock(vsk);
}

@@ -984,13 +949,14 @@ EXPORT_SYMBOL_GPL(virtio_transport_release);

static int
virtio_transport_recv_connecting(struct sock *sk,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
struct vsock_sock *vsk = vsock_sk(sk);
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);
int err;
int skerr;

- switch (le16_to_cpu(pkt->hdr.op)) {
+ switch (le16_to_cpu(hdr->op)) {
case VIRTIO_VSOCK_OP_RESPONSE:
sk->sk_state = TCP_ESTABLISHED;
sk->sk_socket->state = SS_CONNECTED;
@@ -1011,7 +977,7 @@ virtio_transport_recv_connecting(struct sock *sk,
return 0;

destroy:
- virtio_transport_reset(vsk, pkt);
+ virtio_transport_reset(vsk, skb);
sk->sk_state = TCP_CLOSE;
sk->sk_err = skerr;
sk_error_report(sk);
@@ -1020,34 +986,38 @@ virtio_transport_recv_connecting(struct sock *sk,

static void
virtio_transport_recv_enqueue(struct vsock_sock *vsk,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
struct virtio_vsock_sock *vvs = vsk->trans;
+ struct virtio_vsock_hdr *hdr;
bool can_enqueue, free_pkt = false;
+ u32 len;

- pkt->len = le32_to_cpu(pkt->hdr.len);
- pkt->off = 0;
+ hdr = vsock_hdr(skb);
+ len = le32_to_cpu(hdr->len);
+ vsock_metadata(skb)->off = 0;

spin_lock_bh(&vvs->rx_lock);

- can_enqueue = virtio_transport_inc_rx_pkt(vvs, pkt);
+ can_enqueue = virtio_transport_inc_rx_pkt(vvs, skb);
if (!can_enqueue) {
free_pkt = true;
goto out;
}

- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM)
+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)
vvs->msg_count++;

/* Try to copy small packets into the buffer of last packet queued,
* to avoid wasting memory queueing the entire buffer with a small
* payload.
*/
- if (pkt->len <= GOOD_COPY_LEN && !list_empty(&vvs->rx_queue)) {
- struct virtio_vsock_pkt *last_pkt;
+ if (len <= GOOD_COPY_LEN && !skb_queue_empty_lockless(&vvs->rx_queue)) {
+ struct virtio_vsock_hdr *last_hdr;
+ struct sk_buff *last_skb;

- last_pkt = list_last_entry(&vvs->rx_queue,
- struct virtio_vsock_pkt, list);
+ last_skb = skb_peek_tail(&vvs->rx_queue);
+ last_hdr = vsock_hdr(last_skb);

/* If there is space in the last packet queued, we copy the
* new packet in its buffer. We avoid this if the last packet
@@ -1055,35 +1025,34 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
* delimiter of SEQPACKET message, so 'pkt' is the first packet
* of a new message.
*/
- if ((pkt->len <= last_pkt->buf_len - last_pkt->len) &&
- !(le32_to_cpu(last_pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM)) {
- memcpy(last_pkt->buf + last_pkt->len, pkt->buf,
- pkt->len);
- last_pkt->len += pkt->len;
+ if (skb->len < skb_tailroom(last_skb) &&
+ !(le32_to_cpu(last_hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)) {
+ memcpy(skb_put(last_skb, skb->len), skb->data, skb->len);
free_pkt = true;
- last_pkt->hdr.flags |= pkt->hdr.flags;
+ last_hdr->flags |= hdr->flags;
goto out;
}
}

- list_add_tail(&pkt->list, &vvs->rx_queue);
+ __skb_queue_tail(&vvs->rx_queue, skb);

out:
spin_unlock_bh(&vvs->rx_lock);
if (free_pkt)
- virtio_transport_free_pkt(pkt);
+ kfree_skb(skb);
}

static int
virtio_transport_recv_connected(struct sock *sk,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
struct vsock_sock *vsk = vsock_sk(sk);
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);
int err = 0;

- switch (le16_to_cpu(pkt->hdr.op)) {
+ switch (le16_to_cpu(hdr->op)) {
case VIRTIO_VSOCK_OP_RW:
- virtio_transport_recv_enqueue(vsk, pkt);
+ virtio_transport_recv_enqueue(vsk, skb);
sk->sk_data_ready(sk);
return err;
case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
@@ -1093,18 +1062,17 @@ virtio_transport_recv_connected(struct sock *sk,
sk->sk_write_space(sk);
break;
case VIRTIO_VSOCK_OP_SHUTDOWN:
- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
vsk->peer_shutdown |= RCV_SHUTDOWN;
- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
vsk->peer_shutdown |= SEND_SHUTDOWN;
if (vsk->peer_shutdown == SHUTDOWN_MASK &&
vsock_stream_has_data(vsk) <= 0 &&
!sock_flag(sk, SOCK_DONE)) {
(void)virtio_transport_reset(vsk, NULL);
-
virtio_transport_do_close(vsk, true);
}
- if (le32_to_cpu(pkt->hdr.flags))
+ if (le32_to_cpu(vsock_hdr(skb)->flags))
sk->sk_state_change(sk);
break;
case VIRTIO_VSOCK_OP_RST:
@@ -1115,28 +1083,30 @@ virtio_transport_recv_connected(struct sock *sk,
break;
}

- virtio_transport_free_pkt(pkt);
+ kfree_skb(skb);
return err;
}

static void
virtio_transport_recv_disconnecting(struct sock *sk,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
struct vsock_sock *vsk = vsock_sk(sk);
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);

- if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
+ if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST)
virtio_transport_do_close(vsk, true);
}

static int
virtio_transport_send_response(struct vsock_sock *vsk,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RESPONSE,
- .remote_cid = le64_to_cpu(pkt->hdr.src_cid),
- .remote_port = le32_to_cpu(pkt->hdr.src_port),
+ .remote_cid = le64_to_cpu(hdr->src_cid),
+ .remote_port = le32_to_cpu(hdr->src_port),
.reply = true,
.vsk = vsk,
};
@@ -1145,10 +1115,11 @@ virtio_transport_send_response(struct vsock_sock *vsk,
}

static bool virtio_transport_space_update(struct sock *sk,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
struct vsock_sock *vsk = vsock_sk(sk);
struct virtio_vsock_sock *vvs = vsk->trans;
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);
bool space_available;

/* Listener sockets are not associated with any transport, so we are
@@ -1161,8 +1132,8 @@ static bool virtio_transport_space_update(struct sock *sk,

/* buf_alloc and fwd_cnt is always included in the hdr */
spin_lock_bh(&vvs->tx_lock);
- vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
- vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
+ vvs->peer_buf_alloc = le32_to_cpu(hdr->buf_alloc);
+ vvs->peer_fwd_cnt = le32_to_cpu(hdr->fwd_cnt);
space_available = virtio_transport_has_space(vsk);
spin_unlock_bh(&vvs->tx_lock);
return space_available;
@@ -1170,27 +1141,28 @@ static bool virtio_transport_space_update(struct sock *sk,

/* Handle server socket */
static int
-virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
+virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
struct virtio_transport *t)
{
struct vsock_sock *vsk = vsock_sk(sk);
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);
struct vsock_sock *vchild;
struct sock *child;
int ret;

- if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
- virtio_transport_reset_no_sock(t, pkt);
+ if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) {
+ virtio_transport_reset_no_sock(t, skb);
return -EINVAL;
}

if (sk_acceptq_is_full(sk)) {
- virtio_transport_reset_no_sock(t, pkt);
+ virtio_transport_reset_no_sock(t, skb);
return -ENOMEM;
}

child = vsock_create_connected(sk);
if (!child) {
- virtio_transport_reset_no_sock(t, pkt);
+ virtio_transport_reset_no_sock(t, skb);
return -ENOMEM;
}

@@ -1201,10 +1173,10 @@ virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
child->sk_state = TCP_ESTABLISHED;

vchild = vsock_sk(child);
- vsock_addr_init(&vchild->local_addr, le64_to_cpu(pkt->hdr.dst_cid),
- le32_to_cpu(pkt->hdr.dst_port));
- vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
- le32_to_cpu(pkt->hdr.src_port));
+ vsock_addr_init(&vchild->local_addr, le64_to_cpu(hdr->dst_cid),
+ le32_to_cpu(hdr->dst_port));
+ vsock_addr_init(&vchild->remote_addr, le64_to_cpu(hdr->src_cid),
+ le32_to_cpu(hdr->src_port));

ret = vsock_assign_transport(vchild, vsk);
/* Transport assigned (looking at remote_addr) must be the same
@@ -1212,17 +1184,17 @@ virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
*/
if (ret || vchild->transport != &t->transport) {
release_sock(child);
- virtio_transport_reset_no_sock(t, pkt);
+ virtio_transport_reset_no_sock(t, skb);
sock_put(child);
return ret;
}

- if (virtio_transport_space_update(child, pkt))
+ if (virtio_transport_space_update(child, skb))
child->sk_write_space(child);

vsock_insert_connected(vchild);
vsock_enqueue_accept(sk, child);
- virtio_transport_send_response(vchild, pkt);
+ virtio_transport_send_response(vchild, skb);

release_sock(child);

@@ -1240,29 +1212,30 @@ static bool virtio_transport_valid_type(u16 type)
* lock.
*/
void virtio_transport_recv_pkt(struct virtio_transport *t,
- struct virtio_vsock_pkt *pkt)
+ struct sk_buff *skb)
{
struct sockaddr_vm src, dst;
struct vsock_sock *vsk;
struct sock *sk;
bool space_available;
+ struct virtio_vsock_hdr *hdr = vsock_hdr(skb);

- vsock_addr_init(&src, le64_to_cpu(pkt->hdr.src_cid),
- le32_to_cpu(pkt->hdr.src_port));
- vsock_addr_init(&dst, le64_to_cpu(pkt->hdr.dst_cid),
- le32_to_cpu(pkt->hdr.dst_port));
+ vsock_addr_init(&src, le64_to_cpu(hdr->src_cid),
+ le32_to_cpu(hdr->src_port));
+ vsock_addr_init(&dst, le64_to_cpu(hdr->dst_cid),
+ le32_to_cpu(hdr->dst_port));

trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
dst.svm_cid, dst.svm_port,
- le32_to_cpu(pkt->hdr.len),
- le16_to_cpu(pkt->hdr.type),
- le16_to_cpu(pkt->hdr.op),
- le32_to_cpu(pkt->hdr.flags),
- le32_to_cpu(pkt->hdr.buf_alloc),
- le32_to_cpu(pkt->hdr.fwd_cnt));
-
- if (!virtio_transport_valid_type(le16_to_cpu(pkt->hdr.type))) {
- (void)virtio_transport_reset_no_sock(t, pkt);
+ le32_to_cpu(hdr->len),
+ le16_to_cpu(hdr->type),
+ le16_to_cpu(hdr->op),
+ le32_to_cpu(hdr->flags),
+ le32_to_cpu(hdr->buf_alloc),
+ le32_to_cpu(hdr->fwd_cnt));
+
+ if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) {
+ (void)virtio_transport_reset_no_sock(t, skb);
goto free_pkt;
}

@@ -1273,13 +1246,13 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
if (!sk) {
sk = vsock_find_bound_socket(&dst);
if (!sk) {
- (void)virtio_transport_reset_no_sock(t, pkt);
+ (void)virtio_transport_reset_no_sock(t, skb);
goto free_pkt;
}
}

- if (virtio_transport_get_type(sk) != le16_to_cpu(pkt->hdr.type)) {
- (void)virtio_transport_reset_no_sock(t, pkt);
+ if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) {
+ (void)virtio_transport_reset_no_sock(t, skb);
sock_put(sk);
goto free_pkt;
}
@@ -1290,13 +1263,13 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,

/* Check if sk has been closed before lock_sock */
if (sock_flag(sk, SOCK_DONE)) {
- (void)virtio_transport_reset_no_sock(t, pkt);
+ (void)virtio_transport_reset_no_sock(t, skb);
release_sock(sk);
sock_put(sk);
goto free_pkt;
}

- space_available = virtio_transport_space_update(sk, pkt);
+ space_available = virtio_transport_space_update(sk, skb);

/* Update CID in case it has changed after a transport reset event */
if (vsk->local_addr.svm_cid != VMADDR_CID_ANY)
@@ -1307,23 +1280,23 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,

switch (sk->sk_state) {
case TCP_LISTEN:
- virtio_transport_recv_listen(sk, pkt, t);
- virtio_transport_free_pkt(pkt);
+ virtio_transport_recv_listen(sk, skb, t);
+ kfree_skb(skb);
break;
case TCP_SYN_SENT:
- virtio_transport_recv_connecting(sk, pkt);
- virtio_transport_free_pkt(pkt);
+ virtio_transport_recv_connecting(sk, skb);
+ kfree_skb(skb);
break;
case TCP_ESTABLISHED:
- virtio_transport_recv_connected(sk, pkt);
+ virtio_transport_recv_connected(sk, skb);
break;
case TCP_CLOSING:
- virtio_transport_recv_disconnecting(sk, pkt);
- virtio_transport_free_pkt(pkt);
+ virtio_transport_recv_disconnecting(sk, skb);
+ kfree_skb(skb);
break;
default:
- (void)virtio_transport_reset_no_sock(t, pkt);
- virtio_transport_free_pkt(pkt);
+ (void)virtio_transport_reset_no_sock(t, skb);
+ kfree_skb(skb);
break;
}

@@ -1336,16 +1309,42 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
return;

free_pkt:
- virtio_transport_free_pkt(pkt);
+ kfree(skb);
}
EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);

-void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
+/* Remove skbs found in a queue that have a vsk that matches.
+ *
+ * Each skb is freed.
+ *
+ * Returns the count of skbs that were reply packets.
+ */
+int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *queue)
{
- kfree(pkt->buf);
- kfree(pkt);
+ int cnt = 0;
+ struct sk_buff *skb, *tmp;
+ struct sk_buff_head freeme;
+
+ skb_queue_head_init(&freeme);
+
+ spin_lock_bh(&queue->lock);
+ skb_queue_walk_safe(queue, skb, tmp) {
+ if (vsock_sk(skb->sk) != vsk)
+ continue;
+
+ __skb_unlink(skb, queue);
+ skb_queue_tail(&freeme, skb);
+
+ if (vsock_metadata(skb)->flags & VIRTIO_VSOCK_METADATA_FLAGS_REPLY)
+ cnt++;
+ }
+ spin_unlock_bh(&queue->lock);
+
+ skb_queue_purge(&freeme);
+
+ return cnt;
}
-EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
+EXPORT_SYMBOL_GPL(virtio_transport_purge_skbs);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Asias He");
diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index 169a8cf65b39..792128e66869 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c
@@ -16,7 +16,7 @@ struct vsock_loopback {
struct workqueue_struct *workqueue;

spinlock_t pkt_list_lock; /* protects pkt_list */
- struct list_head pkt_list;
+ struct sk_buff_head pkt_queue;
struct work_struct pkt_work;
};

@@ -27,13 +27,13 @@ static u32 vsock_loopback_get_local_cid(void)
return VMADDR_CID_LOCAL;
}

-static int vsock_loopback_send_pkt(struct virtio_vsock_pkt *pkt)
+static int vsock_loopback_send_pkt(struct sk_buff *skb)
{
struct vsock_loopback *vsock = &the_vsock_loopback;
- int len = pkt->len;
+ int len = skb->len;

spin_lock_bh(&vsock->pkt_list_lock);
- list_add_tail(&pkt->list, &vsock->pkt_list);
+ skb_queue_tail(&vsock->pkt_queue, skb);
spin_unlock_bh(&vsock->pkt_list_lock);

queue_work(vsock->workqueue, &vsock->pkt_work);
@@ -44,21 +44,8 @@ static int vsock_loopback_send_pkt(struct virtio_vsock_pkt *pkt)
static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
{
struct vsock_loopback *vsock = &the_vsock_loopback;
- struct virtio_vsock_pkt *pkt, *n;
- LIST_HEAD(freeme);

- spin_lock_bh(&vsock->pkt_list_lock);
- list_for_each_entry_safe(pkt, n, &vsock->pkt_list, list) {
- if (pkt->vsk != vsk)
- continue;
- list_move(&pkt->list, &freeme);
- }
- spin_unlock_bh(&vsock->pkt_list_lock);
-
- list_for_each_entry_safe(pkt, n, &freeme, list) {
- list_del(&pkt->list);
- virtio_transport_free_pkt(pkt);
- }
+ virtio_transport_purge_skbs(vsk, &vsock->pkt_queue);

return 0;
}
@@ -121,20 +108,18 @@ static void vsock_loopback_work(struct work_struct *work)
{
struct vsock_loopback *vsock =
container_of(work, struct vsock_loopback, pkt_work);
- LIST_HEAD(pkts);
+ struct sk_buff_head pkts;
+ struct sk_buff *skb;
+
+ skb_queue_head_init(&pkts);

spin_lock_bh(&vsock->pkt_list_lock);
- list_splice_init(&vsock->pkt_list, &pkts);
+ skb_queue_splice_init(&vsock->pkt_queue, &pkts);
spin_unlock_bh(&vsock->pkt_list_lock);

- while (!list_empty(&pkts)) {
- struct virtio_vsock_pkt *pkt;
-
- pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list);
- list_del_init(&pkt->list);
-
- virtio_transport_deliver_tap_pkt(pkt);
- virtio_transport_recv_pkt(&loopback_transport, pkt);
+ while ((skb = skb_dequeue(&pkts))) {
+ virtio_transport_deliver_tap_pkt(skb);
+ virtio_transport_recv_pkt(&loopback_transport, skb);
}
}

@@ -148,7 +133,7 @@ static int __init vsock_loopback_init(void)
return -ENOMEM;

spin_lock_init(&vsock->pkt_list_lock);
- INIT_LIST_HEAD(&vsock->pkt_list);
+ skb_queue_head_init(&vsock->pkt_queue);
INIT_WORK(&vsock->pkt_work, vsock_loopback_work);

ret = vsock_core_register(&loopback_transport.transport,
@@ -166,19 +151,13 @@ static int __init vsock_loopback_init(void)
static void __exit vsock_loopback_exit(void)
{
struct vsock_loopback *vsock = &the_vsock_loopback;
- struct virtio_vsock_pkt *pkt;

vsock_core_unregister(&loopback_transport.transport);

flush_work(&vsock->pkt_work);

spin_lock_bh(&vsock->pkt_list_lock);
- while (!list_empty(&vsock->pkt_list)) {
- pkt = list_first_entry(&vsock->pkt_list,
- struct virtio_vsock_pkt, list);
- list_del(&pkt->list);
- virtio_transport_free_pkt(pkt);
- }
+ skb_queue_purge(&vsock->pkt_queue);
spin_unlock_bh(&vsock->pkt_list_lock);

destroy_workqueue(vsock->workqueue);
--
2.35.1


Not for this patch, but if we implement this change, it would be nice to have APIs that all transports can re-use. (Like we do in vsock_loopback which has nothing to do with virtio, but we had reused virtio_vsock_pkt for convenience)

Good job so far!

Thanks,
Stefano