Guest receive mergeable rx buffer, it can merge
scatter rx buffer into a big buffer and then copy
to user space.
In addition, it also use iovec to replace buf in struct
virtio_vsock_pkt, keep tx and rx consistency. The only
difference is now tx still uses a segment of continuous
physical memory to implement.
Signed-off-by: Yiwen Jiang <jiangyi...@huawei.com>
---
drivers/vhost/vsock.c | 31 +++++++---
include/linux/virtio_vsock.h | 6 +-
net/vmw_vsock/virtio_transport.c | 105 ++++++++++++++++++++++++++++----
net/vmw_vsock/virtio_transport_common.c | 59 ++++++++++++++----
4 files changed, 166 insertions(+), 35 deletions(-)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index dc52b0f..c7ab0dd 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -179,6 +179,8 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
size_t nbytes;
size_t len;
s16 headcount;
+ size_t remain_len;
+ int i;
spin_lock_bh(&vsock->send_pkt_list_lock);
if (list_empty(&vsock->send_pkt_list)) {
@@ -221,11 +223,19 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
break;
}
- nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter);
- if (nbytes != pkt->len) {
- virtio_transport_free_pkt(pkt);
- vq_err(vq, "Faulted on copying pkt buf\n");
- break;
+ remain_len = pkt->len;
+ for (i = 0; i < pkt->nr_vecs; i++) {
+ int tmp_len;
+
+ tmp_len = min(remain_len, pkt->vec[i].iov_len);
+ nbytes = copy_to_iter(pkt->vec[i].iov_base, tmp_len,
&iov_iter);
+ if (nbytes != tmp_len) {
+ virtio_transport_free_pkt(pkt);
+ vq_err(vq, "Faulted on copying pkt buf\n");
+ break;
+ }
+
+ remain_len -= tmp_len;
}
vhost_add_used_n(vq, vq->heads, headcount);
@@ -341,6 +351,7 @@ static void vhost_transport_send_pkt_work(struct vhost_work
*work)
struct iov_iter iov_iter;
size_t nbytes;
size_t len;
+ void *buf;
if (in != 0) {
vq_err(vq, "Expected 0 input buffers, got %u\n", in);
@@ -375,13 +386,17 @@ static void vhost_transport_send_pkt_work(struct
vhost_work *work)
return NULL;
}
- pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
- if (!pkt->buf) {
+ buf = kmalloc(pkt->len, GFP_KERNEL);
+ if (!buf) {
kfree(pkt);
return NULL;
}
- nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
+ pkt->vec[0].iov_base = buf;
+ pkt->vec[0].iov_len = pkt->len;
+ pkt->nr_vecs = 1;
+
+ nbytes = copy_from_iter(buf, pkt->len, &iov_iter);
if (nbytes != pkt->len) {
vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
pkt->len, nbytes);
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index da9e1fe..734eeed 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -13,6 +13,8 @@
#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)
+/* virtio_vsock_pkt + max_pkt_len(default MAX_PKT_BUF_SIZE) */
+#define VIRTIO_VSOCK_MAX_VEC_NUM ((VIRTIO_VSOCK_MAX_PKT_BUF_SIZE / PAGE_SIZE)
+ 1)
/* Virtio-vsock feature */
#define VIRTIO_VSOCK_F_MRG_RXBUF 0 /* Host can merge receive buffers. */
@@ -55,10 +57,12 @@ struct virtio_vsock_pkt {
struct list_head list;
/* socket refcnt not held, only use for cancellation */
struct vsock_sock *vsk;
- void *buf;
+ struct kvec vec[VIRTIO_VSOCK_MAX_VEC_NUM];
+ int nr_vecs;
u32 len;
u32 off;
bool reply;
+ bool mergeable;
};
struct virtio_vsock_pkt_info {
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index c4a465c..148b58a 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -155,8 +155,10 @@ static int virtio_transport_send_pkt_loopback(struct
virtio_vsock *vsock,
sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
sgs[out_sg++] = &hdr;
- if (pkt->buf) {
- sg_init_one(&buf, pkt->buf, pkt->len);
+ if (pkt->len) {
+ /* Currently only support a segment of memory in tx */
+ BUG_ON(pkt->vec[0].iov_len != pkt->len);
+ sg_init_one(&buf, pkt->vec[0].iov_base,
pkt->vec[0].iov_len);
sgs[out_sg++] = &buf;
}
@@ -304,23 +306,28 @@ static int fill_old_rx_buff(struct virtqueue *vq)
struct virtio_vsock_pkt *pkt;
struct scatterlist hdr, buf, *sgs[2];
int ret;
+ void *pkt_buf;
pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt)
return -ENOMEM;
- pkt->buf = kmalloc(buf_len, GFP_KERNEL);
- if (!pkt->buf) {
+ pkt_buf = kmalloc(buf_len, GFP_KERNEL);
+ if (!pkt_buf) {
virtio_transport_free_pkt(pkt);
return -ENOMEM;
}
+ pkt->vec[0].iov_base = pkt_buf;
+ pkt->vec[0].iov_len = buf_len;
+ pkt->nr_vecs = 1;
+
pkt->len = buf_len;
sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
sgs[0] = &hdr;
- sg_init_one(&buf, pkt->buf, buf_len);
+ sg_init_one(&buf, pkt->vec[0].iov_base, buf_len);
sgs[1] = &buf;
ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
if (ret)
@@ -388,11 +395,78 @@ static bool virtio_transport_more_replies(struct
virtio_vsock *vsock)
return val < virtqueue_get_vring_size(vq);
}
+static struct virtio_vsock_pkt *receive_mergeable(struct virtqueue *vq,
+ struct virtio_vsock *vsock, unsigned int *total_len)
+{
+ struct virtio_vsock_pkt *pkt;
+ u16 num_buf;
+ void *buf;
+ unsigned int len;
+ size_t vsock_hlen = sizeof(struct virtio_vsock_pkt);
+
+ buf = virtqueue_get_buf(vq, &len);
+ if (!buf)
+ return NULL;
+
+ *total_len = len;
+ vsock->rx_buf_nr--;
+
+ if (unlikely(len < vsock_hlen)) {
+ put_page(virt_to_head_page(buf));
+ return NULL;
+ }
+
+ pkt = buf;
+ num_buf = le16_to_cpu(pkt->mrg_rxbuf_hdr.num_buffers);
+ if (!num_buf || num_buf > VIRTIO_VSOCK_MAX_VEC_NUM) {
+ put_page(virt_to_head_page(buf));
+ return NULL;
+ }
+
+ /* Initialize pkt residual structure */
+ memset(&pkt->work, 0, vsock_hlen - sizeof(struct virtio_vsock_hdr) -
+ sizeof(struct virtio_vsock_mrg_rxbuf_hdr));
+
+ pkt->mergeable = true;
+ pkt->len = le32_to_cpu(pkt->hdr.len);
+ if (!pkt->len)
+ return pkt;
+
+ len -= vsock_hlen;
+ if (len) {
+ pkt->vec[pkt->nr_vecs].iov_base = buf + vsock_hlen;
+ pkt->vec[pkt->nr_vecs].iov_len = len;
+ /* Shared page with pkt, so get page in advance */
+ get_page(virt_to_head_page(buf));
+ pkt->nr_vecs++;
+ }
+
+ while (--num_buf) {
+ buf = virtqueue_get_buf(vq, &len);
+ if (!buf)
+ goto err;
+
+ *total_len += len;
+ vsock->rx_buf_nr--;
+
+ pkt->vec[pkt->nr_vecs].iov_base = buf;
+ pkt->vec[pkt->nr_vecs].iov_len = len;
+ pkt->nr_vecs++;
+ }
+
+ return pkt;
+err:
+ virtio_transport_free_pkt(pkt);
+ return NULL;
+}
+
static void virtio_transport_rx_work(struct work_struct *work)
{
struct virtio_vsock *vsock =
container_of(work, struct virtio_vsock, rx_work);
struct virtqueue *vq;
+ size_t vsock_hlen = vsock->mergeable ? sizeof(struct virtio_vsock_pkt) :
+ sizeof(struct virtio_vsock_hdr);
vq = vsock->vqs[VSOCK_VQ_RX];
@@ -412,21 +486,26 @@ static void virtio_transport_rx_work(struct work_struct
*work)
goto out;
}
- pkt = virtqueue_get_buf(vq, &len);
- if (!pkt) {
- break;
- }
+ if (likely(vsock->mergeable)) {
+ pkt = receive_mergeable(vq, vsock, &len);
+ if (!pkt)
+ break;
+ } else {
+ pkt = virtqueue_get_buf(vq, &len);
+ if (!pkt)
+ break;
- vsock->rx_buf_nr--;
+ vsock->rx_buf_nr--;
+ }
/* Drop short/long packets */
- if (unlikely(len < sizeof(pkt->hdr) ||
- len > sizeof(pkt->hdr) + pkt->len)) {
+ if (unlikely(len < vsock_hlen ||
+ len > vsock_hlen + pkt->len)) {
virtio_transport_free_pkt(pkt);
continue;
}
- pkt->len = len - sizeof(pkt->hdr);
+ pkt->len = len - vsock_hlen;
virtio_transport_deliver_tap_pkt(pkt);
virtio_transport_recv_pkt(pkt);
}
diff --git a/net/vmw_vsock/virtio_transport_common.c
b/net/vmw_vsock/virtio_transport_common.c
index 3ae3a33..123a8b6 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -44,6 +44,7 @@ static const struct virtio_transport
*virtio_transport_get_ops(void)
{
struct virtio_vsock_pkt *pkt;
int err;
+ void *buf = NULL;
pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt)
@@ -62,12 +63,16 @@ static const struct virtio_transport
*virtio_transport_get_ops(void)
pkt->vsk = info->vsk;
if (info->msg && len > 0) {
- pkt->buf = kmalloc(len, GFP_KERNEL);
- if (!pkt->buf)
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
goto out_pkt;
- err = memcpy_from_msg(pkt->buf, info->msg, len);
+ err = memcpy_from_msg(buf, info->msg, len);
if (err)
goto out;
+
+ pkt->vec[0].iov_base = buf;
+ pkt->vec[0].iov_len = len;
+ pkt->nr_vecs = 1;
}
trace_virtio_transport_alloc_pkt(src_cid, src_port,
@@ -80,7 +85,7 @@ static const struct virtio_transport
*virtio_transport_get_ops(void)
return pkt;
out:
- kfree(pkt->buf);
+ kfree(buf);
out_pkt:
kfree(pkt);
return NULL;
@@ -92,6 +97,7 @@ 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;
+ int i;
skb = alloc_skb(sizeof(*hdr) + sizeof(pkt->hdr) + pkt->len,
GFP_ATOMIC);
@@ -134,7 +140,8 @@ static struct sk_buff *virtio_transport_build_skb(void
*opaque)
skb_put_data(skb, &pkt->hdr, sizeof(pkt->hdr));
if (pkt->len) {
- skb_put_data(skb, pkt->buf, pkt->len);
+ for (i = 0; i < pkt->nr_vecs; i++)
+ skb_put_data(skb, pkt->vec[i].iov_base,
pkt->vec[i].iov_len);
}
return skb;
@@ -260,6 +267,9 @@ static int virtio_transport_send_credit_update(struct
vsock_sock *vsk,
spin_lock_bh(&vvs->rx_lock);
while (total < len && !list_empty(&vvs->rx_queue)) {
+ size_t copy_bytes, last_vec_total = 0, vec_off;
+ int i;
+
pkt = list_first_entry(&vvs->rx_queue,
struct virtio_vsock_pkt, list);
@@ -272,14 +282,28 @@ static int virtio_transport_send_credit_update(struct
vsock_sock *vsk,
*/
spin_unlock_bh(&vvs->rx_lock);
- err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
- if (err)
- goto out;
+ for (i = 0; i < pkt->nr_vecs; i++) {
+ if (pkt->off > last_vec_total + pkt->vec[i].iov_len) {
+ last_vec_total += pkt->vec[i].iov_len;
+ continue;
+ }
+
+ vec_off = pkt->off - last_vec_total;
+ copy_bytes = min(pkt->vec[i].iov_len - vec_off, bytes);
+ err = memcpy_to_msg(msg, pkt->vec[i].iov_base + vec_off,
+ copy_bytes);
+ if (err)
+ goto out;
+
+ bytes -= copy_bytes;
+ pkt->off += copy_bytes;
+ total += copy_bytes;
+ last_vec_total += pkt->vec[i].iov_len;
+ if (!bytes)
+ break;
+ }
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);
@@ -1050,8 +1074,17 @@ void virtio_transport_recv_pkt(struct virtio_vsock_pkt
*pkt)
void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
{
- kfree(pkt->buf);
- kfree(pkt);
+ int i;
+
+ if (pkt->mergeable) {
+ for (i = 0; i < pkt->nr_vecs; i++)
+ put_page(virt_to_head_page(pkt->vec[i].iov_base));
+ put_page(virt_to_head_page((void *)pkt));
+ } else {
+ for (i = 0; i < pkt->nr_vecs; i++)
+ kfree(pkt->vec[i].iov_base);
+ kfree(pkt);
+ }
}
EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
--
1.8.3.1
