Re: [External] Re: [RFC v1 3/6] vhost/vsock: add support for vhost dgram.
From: Jiang Wang . <hidden>
Date: 2021-06-21 17:32:49
Also in:
kvm, lkml, netdev
On Fri, Jun 18, 2021 at 3:14 AM Stefano Garzarella [off-list ref] wrote:
We should use le16_to_cpu when accessing pkt->hdr fields.
OK. Will do.
On Wed, Jun 09, 2021 at 11:24:55PM +0000, Jiang Wang wrote:quoted
This patch supports dgram on vhost side, including tx and rx. The vhost send packets asynchronously. Signed-off-by: Jiang Wang <redacted> --- drivers/vhost/vsock.c | 199 +++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 173 insertions(+), 26 deletions(-)diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 81d064601093..d366463be6d4 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c@@ -28,7 +28,10 @@ * small pkts. */#define VHOST_VSOCK_PKT_WEIGHT 256 +#define VHOST_VSOCK_DGRM_MAX_PENDING_PKT 128 +/* Max wait time in busy poll in microseconds */ +#define VHOST_VSOCK_BUSY_POLL_TIMEOUT 20 enum { VHOST_VSOCK_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_F_ACCESS_PLATFORM) |@@ -45,7 +48,7 @@ static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8);struct vhost_vsock { struct vhost_dev dev; - struct vhost_virtqueue vqs[2]; + struct vhost_virtqueue vqs[4]; /* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */ struct hlist_node hash;@@ -54,6 +57,11 @@ struct vhost_vsock { spinlock_t send_pkt_list_lock; struct list_head send_pkt_list; /* host->guest pending packets */ + spinlock_t dgram_send_pkt_list_lock; + struct list_head dgram_send_pkt_list; /* host->guest pending packets */ + struct vhost_work dgram_send_pkt_work; + int dgram_used; /*pending packets to be send */ + atomic_t queued_replies; u32 guest_cid;@@ -90,10 +98,22 @@ static voidvhost_transport_do_send_pkt(struct vhost_vsock *vsock, struct vhost_virtqueue *vq) { - struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX]; + struct vhost_virtqueue *tx_vq; int pkts = 0, total_len = 0; bool added = false; bool restart_tx = false; + spinlock_t *lock; + struct list_head *send_pkt_list; + + if (vq == &vsock->vqs[VSOCK_VQ_RX]) { + tx_vq = &vsock->vqs[VSOCK_VQ_TX]; + lock = &vsock->send_pkt_list_lock; + send_pkt_list = &vsock->send_pkt_list; + } else { + tx_vq = &vsock->vqs[VSOCK_VQ_DGRAM_TX]; + lock = &vsock->dgram_send_pkt_list_lock; + send_pkt_list = &vsock->dgram_send_pkt_list; + } mutex_lock(&vq->mutex);@@ -113,36 +133,48 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, size_t nbytes; size_t iov_len, payload_len; int head; + bool is_dgram = false; - spin_lock_bh(&vsock->send_pkt_list_lock); - if (list_empty(&vsock->send_pkt_list)) { - spin_unlock_bh(&vsock->send_pkt_list_lock); + spin_lock_bh(lock); + if (list_empty(send_pkt_list)) { + spin_unlock_bh(lock); vhost_enable_notify(&vsock->dev, vq); break; } - pkt = list_first_entry(&vsock->send_pkt_list, + pkt = list_first_entry(send_pkt_list, struct virtio_vsock_pkt, list); list_del_init(&pkt->list); - spin_unlock_bh(&vsock->send_pkt_list_lock); + spin_unlock_bh(lock); + + if (pkt->hdr.type == VIRTIO_VSOCK_TYPE_DGRAM)^ le16_to_cpu(pkt->hdr.type)quoted
+ is_dgram = true; 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); + spin_lock_bh(lock); + list_add(&pkt->list, send_pkt_list); + spin_unlock_bh(lock); 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); + if (is_dgram) { + virtio_transport_free_pkt(pkt); + vq_err(vq, "Dgram virtqueue is full!"); + spin_lock_bh(lock); + vsock->dgram_used--; + spin_unlock_bh(lock); + break; + } + spin_lock_bh(lock); + list_add(&pkt->list, send_pkt_list); + spin_unlock_bh(lock); /* We cannot finish yet if more buffers snuck in while - * re-enabling notify. - */ + * re-enabling notify. + */ if (unlikely(vhost_enable_notify(&vsock->dev, vq))) { vhost_disable_notify(&vsock->dev, vq); continue;@@ -153,6 +185,12 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, if (out) { virtio_transport_free_pkt(pkt); vq_err(vq, "Expected 0 output buffers, got %u\n", out); + if (is_dgram) { + spin_lock_bh(lock); + vsock->dgram_used--; + spin_unlock_bh(lock); + } + break; }@@ -160,6 +198,18 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, if (iov_len < sizeof(pkt->hdr)) { virtio_transport_free_pkt(pkt); vq_err(vq, "Buffer len [%zu] too small\n", iov_len); + if (is_dgram) { + spin_lock_bh(lock); + vsock->dgram_used--; + spin_unlock_bh(lock); + } + break; + } + + if (iov_len < pkt->len - pkt->off && + vq == &vsock->vqs[VSOCK_VQ_DGRAM_RX]) { + virtio_transport_free_pkt(pkt); + vq_err(vq, "Buffer len [%zu] too small for dgram\n", iov_len); break; }@@ -179,6 +229,11 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, if (nbytes != sizeof(pkt->hdr)) { virtio_transport_free_pkt(pkt); vq_err(vq, "Faulted on copying pkt hdr\n"); + if (is_dgram) { + spin_lock_bh(lock); + vsock->dgram_used--; + spin_unlock_bh(lock); + } break; }@@ -204,16 +259,17 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, /* 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) { + if ((pkt->off < pkt->len) + && (vq == &vsock->vqs[VSOCK_VQ_RX])) { /* We are queueing the same virtio_vsock_pkt 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); + spin_lock_bh(lock); + list_add(&pkt->list, send_pkt_list); + spin_unlock_bh(lock); } else { if (pkt->reply) { int val;@@ -228,6 +284,11 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, } virtio_transport_free_pkt(pkt); + if (is_dgram) { + spin_lock_bh(lock); + vsock->dgram_used--; + spin_unlock_bh(lock); + } } } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); if (added)@@ -251,11 +312,25 @@ static void vhost_transport_send_pkt_work(struct vhost_work *work) vhost_transport_do_send_pkt(vsock, vq);} +static void vhost_transport_dgram_send_pkt_work(struct vhost_work *work) +{ + struct vhost_virtqueue *vq; + struct vhost_vsock *vsock; + + vsock = container_of(work, struct vhost_vsock, dgram_send_pkt_work); + vq = &vsock->vqs[VSOCK_VQ_DGRAM_RX]; + + vhost_transport_do_send_pkt(vsock, vq); +} + static int vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt) { struct vhost_vsock *vsock; int len = pkt->len; + spinlock_t *lock; + struct list_head *send_pkt_list; + struct vhost_work *work; rcu_read_lock();@@ -267,14 +342,38 @@ vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt) return -ENODEV; } + if (pkt->hdr.type == VIRTIO_VSOCK_TYPE_STREAM) {^ le16_to_cpu(pkt->hdr.type)quoted
+ lock = &vsock->send_pkt_list_lock; + send_pkt_list = &vsock->send_pkt_list; + work = &vsock->send_pkt_work; + } else if (pkt->hdr.type == VIRTIO_VSOCK_TYPE_DGRAM) {^ le16_to_cpu(pkt->hdr.type)quoted
+ lock = &vsock->dgram_send_pkt_list_lock; + send_pkt_list = &vsock->dgram_send_pkt_list; + work = &vsock->dgram_send_pkt_work; + } else { + rcu_read_unlock(); + virtio_transport_free_pkt(pkt); + return -EINVAL; + } + + if (pkt->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); + spin_lock_bh(lock); + if (pkt->hdr.type == VIRTIO_VSOCK_TYPE_DGRAM) {^ le16_to_cpu(pkt->hdr.type)quoted
+ if (vsock->dgram_used == VHOST_VSOCK_DGRM_MAX_PENDING_PKT) + len = -ENOMEM; + else { + vsock->dgram_used++; + list_add_tail(&pkt->list, send_pkt_list); + } + } else + list_add_tail(&pkt->list, send_pkt_list); - vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); + spin_unlock_bh(lock); + + vhost_work_queue(&vsock->dev, work); rcu_read_unlock(); return len;@@ -355,7 +454,8 @@ vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq, return NULL; } - if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM) + if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM + || le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_DGRAM) pkt->len = le32_to_cpu(pkt->hdr.len); /* No payload */@@ -442,6 +542,18 @@ static struct virtio_transport vhost_transport = { .send_pkt = vhost_transport_send_pkt,}; +static inline unsigned long busy_clock(void) +{ + return local_clock() >> 10; +} + +static bool vhost_can_busy_poll(unsigned long endtime) +{ + return likely(!need_resched() && !time_after(busy_clock(), endtime) && + !signal_pending(current)); +} + + static void vhost_vsock_handle_tx_kick(struct vhost_work *work) { struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,@@ -452,6 +564,8 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) int head, pkts = 0, total_len = 0; unsigned int out, in; bool added = false; + unsigned long busyloop_timeout = VHOST_VSOCK_BUSY_POLL_TIMEOUT; + unsigned long endtime; mutex_lock(&vq->mutex);@@ -461,11 +575,14 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) if (!vq_meta_prefetch(vq)) goto out; + endtime = busy_clock() + busyloop_timeout; vhost_disable_notify(&vsock->dev, vq); + preempt_disable(); do { u32 len; - if (!vhost_vsock_more_replies(vsock)) { + if (vq == &vsock->vqs[VSOCK_VQ_TX] + && !vhost_vsock_more_replies(vsock)) { /* Stop tx until the device processes already * pending replies. Leave tx virtqueue * callbacks disabled.@@ -479,6 +596,11 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) break; if (head == vq->num) { + if (vhost_can_busy_poll(endtime)) { + cpu_relax(); + continue; + } + if (unlikely(vhost_enable_notify(&vsock->dev, vq))) { vhost_disable_notify(&vsock->dev, vq); continue;@@ -510,6 +632,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) total_len += len; added = true; } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); + preempt_enable();no_more_replies: if (added)@@ -565,6 +688,7 @@ static int vhost_vsock_start(struct vhost_vsock *vsock) * let's kick the send worker to send them. */ vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); + vhost_work_queue(&vsock->dev, &vsock->dgram_send_pkt_work); mutex_unlock(&vsock->dev.mutex); return 0;@@ -639,8 +763,14 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file) vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX]; vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX]; + vqs[VSOCK_VQ_DGRAM_TX] = &vsock->vqs[VSOCK_VQ_DGRAM_TX]; + vqs[VSOCK_VQ_DGRAM_RX] = &vsock->vqs[VSOCK_VQ_DGRAM_RX]; vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick; vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick; + vsock->vqs[VSOCK_VQ_DGRAM_TX].handle_kick = + vhost_vsock_handle_tx_kick; + vsock->vqs[VSOCK_VQ_DGRAM_RX].handle_kick = + vhost_vsock_handle_rx_kick; vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs), UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,@@ -650,6 +780,11 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file) spin_lock_init(&vsock->send_pkt_list_lock); INIT_LIST_HEAD(&vsock->send_pkt_list); vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work); + spin_lock_init(&vsock->dgram_send_pkt_list_lock); + INIT_LIST_HEAD(&vsock->dgram_send_pkt_list); + vhost_work_init(&vsock->dgram_send_pkt_work, + vhost_transport_dgram_send_pkt_work); + return 0;out:@@ -665,6 +800,7 @@ static void vhost_vsock_flush(struct vhost_vsock *vsock) if (vsock->vqs[i].handle_kick) vhost_poll_flush(&vsock->vqs[i].poll); vhost_work_flush(&vsock->dev, &vsock->send_pkt_work); + vhost_work_flush(&vsock->dev, &vsock->dgram_send_pkt_work);} static void vhost_vsock_reset_orphans(struct sock *sk)@@ -724,6 +860,17 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file) } spin_unlock_bh(&vsock->send_pkt_list_lock); + spin_lock_bh(&vsock->dgram_send_pkt_list_lock); + while (!list_empty(&vsock->dgram_send_pkt_list)) { + struct virtio_vsock_pkt *pkt; + + pkt = list_first_entry(&vsock->dgram_send_pkt_list, + struct virtio_vsock_pkt, list); + list_del_init(&pkt->list); + virtio_transport_free_pkt(pkt); + } + spin_unlock_bh(&vsock->dgram_send_pkt_list_lock); + vhost_dev_cleanup(&vsock->dev); kfree(vsock->dev.vqs); vhost_vsock_free(vsock);@@ -906,7 +1053,7 @@ static int __init vhost_vsock_init(void) int ret; ret = vsock_core_register(&vhost_transport.transport, - VSOCK_TRANSPORT_F_H2G); + VSOCK_TRANSPORT_F_H2G | VSOCK_TRANSPORT_F_DGRAM); if (ret < 0) return ret; return misc_register(&vhost_vsock_misc); --2.11.0
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