diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index f75731396b7ef..ec20ecff85c7f 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -449,6 +449,7 @@ static struct virtio_transport vhost_transport = { .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, .notify_buffer_size = virtio_transport_notify_buffer_size, + .notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat, .read_skb = virtio_transport_read_skb, }, diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index ebb3ce63d64da..c82089dee0c83 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -256,4 +256,5 @@ void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit); void virtio_transport_deliver_tap_pkt(struct sk_buff *skb); int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *list); int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t read_actor); +int virtio_transport_notify_set_rcvlowat(struct vsock_sock *vsk, int val); #endif /* _LINUX_VIRTIO_VSOCK_H */ diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h index e302c0e804d0f..535701efc1e5c 100644 --- a/include/net/af_vsock.h +++ b/include/net/af_vsock.h @@ -137,7 +137,6 @@ struct vsock_transport { u64 (*stream_rcvhiwat)(struct vsock_sock *); bool (*stream_is_active)(struct vsock_sock *); bool (*stream_allow)(u32 cid, u32 port); - int (*set_rcvlowat)(struct vsock_sock *vsk, int val); /* SEQ_PACKET. */ ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, @@ -168,6 +167,7 @@ struct vsock_transport { struct vsock_transport_send_notify_data *); /* sk_lock held by the caller */ void (*notify_buffer_size)(struct vsock_sock *, u64 *); + int (*notify_set_rcvlowat)(struct vsock_sock *vsk, int val); /* Shutdown. */ int (*shutdown)(struct vsock_sock *, int); diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 816725af281f3..54ba7316f8085 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -2264,8 +2264,13 @@ static int vsock_set_rcvlowat(struct sock *sk, int val) transport = vsk->transport; - if (transport && transport->set_rcvlowat) - return transport->set_rcvlowat(vsk, val); + if (transport && transport->notify_set_rcvlowat) { + int err; + + err = transport->notify_set_rcvlowat(vsk, val); + if (err) + return err; + } WRITE_ONCE(sk->sk_rcvlowat, val ? : 1); return 0; diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c index 7cb1a9d2cdb4f..e2157e3872177 100644 --- a/net/vmw_vsock/hyperv_transport.c +++ b/net/vmw_vsock/hyperv_transport.c @@ -816,7 +816,7 @@ int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written, } static -int hvs_set_rcvlowat(struct vsock_sock *vsk, int val) +int hvs_notify_set_rcvlowat(struct vsock_sock *vsk, int val) { return -EOPNOTSUPP; } @@ -856,7 +856,7 @@ static struct vsock_transport hvs_transport = { .notify_send_pre_enqueue = hvs_notify_send_pre_enqueue, .notify_send_post_enqueue = hvs_notify_send_post_enqueue, - .set_rcvlowat = hvs_set_rcvlowat + .notify_set_rcvlowat = hvs_notify_set_rcvlowat }; static bool hvs_check_transport(struct vsock_sock *vsk) diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index af5bab1acee17..f495b9e5186b2 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -537,6 +537,7 @@ static struct virtio_transport virtio_transport = { .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, .notify_buffer_size = virtio_transport_notify_buffer_size, + .notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat, .read_skb = virtio_transport_read_skb, }, diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 6df246b532606..16ff976a86e3e 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -557,6 +557,8 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, struct virtio_vsock_sock *vvs = vsk->trans; size_t bytes, total = 0; struct sk_buff *skb; + u32 fwd_cnt_delta; + bool low_rx_bytes; int err = -EFAULT; u32 free_space; @@ -600,7 +602,10 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, } } - free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt); + fwd_cnt_delta = vvs->fwd_cnt - vvs->last_fwd_cnt; + free_space = vvs->buf_alloc - fwd_cnt_delta; + low_rx_bytes = (vvs->rx_bytes < + sock_rcvlowat(sk_vsock(vsk), 0, INT_MAX)); spin_unlock_bh(&vvs->rx_lock); @@ -610,9 +615,11 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, * too high causes extra messages. Too low causes transmitter * stalls. As stalls are in theory more expensive than extra * messages, we set the limit to a high value. TODO: experiment - * with different values. + * with different values. Also send credit update message when + * number of bytes in rx queue is not enough to wake up reader. */ - if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) + if (fwd_cnt_delta && + (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE || low_rx_bytes)) virtio_transport_send_credit_update(vsk); return total; @@ -1683,6 +1690,36 @@ int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_acto } EXPORT_SYMBOL_GPL(virtio_transport_read_skb); +int virtio_transport_notify_set_rcvlowat(struct vsock_sock *vsk, int val) +{ + struct virtio_vsock_sock *vvs = vsk->trans; + bool send_update; + + spin_lock_bh(&vvs->rx_lock); + + /* If number of available bytes is less than new SO_RCVLOWAT value, + * kick sender to send more data, because sender may sleep in its + * 'send()' syscall waiting for enough space at our side. Also + * don't send credit update when peer already knows actual value - + * such transmission will be useless. + */ + send_update = (vvs->rx_bytes < val) && + (vvs->fwd_cnt != vvs->last_fwd_cnt); + + spin_unlock_bh(&vvs->rx_lock); + + if (send_update) { + int err; + + err = virtio_transport_send_credit_update(vsk); + if (err < 0) + return err; + } + + return 0; +} +EXPORT_SYMBOL_GPL(virtio_transport_notify_set_rcvlowat); + MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Asias He"); MODULE_DESCRIPTION("common code for virtio vsock"); diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c index 0486401674117..6dea6119f5b28 100644 --- a/net/vmw_vsock/vsock_loopback.c +++ b/net/vmw_vsock/vsock_loopback.c @@ -96,6 +96,7 @@ static struct virtio_transport loopback_transport = { .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, .notify_buffer_size = virtio_transport_notify_buffer_size, + .notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat, .read_skb = virtio_transport_read_skb, }, diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c index 01fa816868bc4..66246d81d6549 100644 --- a/tools/testing/vsock/vsock_test.c +++ b/tools/testing/vsock/vsock_test.c @@ -1232,6 +1232,171 @@ static void test_double_bind_connect_client(const struct test_opts *opts) } } +#define RCVLOWAT_CREDIT_UPD_BUF_SIZE (1024 * 128) +/* This define is the same as in 'include/linux/virtio_vsock.h': + * it is used to decide when to send credit update message during + * reading from rx queue of a socket. Value and its usage in + * kernel is important for this test. + */ +#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64) + +static void test_stream_rcvlowat_def_cred_upd_client(const struct test_opts *opts) +{ + size_t buf_size; + void *buf; + int fd; + + fd = vsock_stream_connect(opts->peer_cid, 1234); + if (fd < 0) { + perror("connect"); + exit(EXIT_FAILURE); + } + + /* Send 1 byte more than peer's buffer size. */ + buf_size = RCVLOWAT_CREDIT_UPD_BUF_SIZE + 1; + + buf = malloc(buf_size); + if (!buf) { + perror("malloc"); + exit(EXIT_FAILURE); + } + + /* Wait until peer sets needed buffer size. */ + recv_byte(fd, 1, 0); + + if (send(fd, buf, buf_size, 0) != buf_size) { + perror("send failed"); + exit(EXIT_FAILURE); + } + + free(buf); + close(fd); +} + +static void test_stream_credit_update_test(const struct test_opts *opts, + bool low_rx_bytes_test) +{ + size_t recv_buf_size; + struct pollfd fds; + size_t buf_size; + void *buf; + int fd; + + fd = vsock_stream_accept(VMADDR_CID_ANY, 1234, NULL); + if (fd < 0) { + perror("accept"); + exit(EXIT_FAILURE); + } + + buf_size = RCVLOWAT_CREDIT_UPD_BUF_SIZE; + + if (setsockopt(fd, AF_VSOCK, SO_VM_SOCKETS_BUFFER_SIZE, + &buf_size, sizeof(buf_size))) { + perror("setsockopt(SO_VM_SOCKETS_BUFFER_SIZE)"); + exit(EXIT_FAILURE); + } + + if (low_rx_bytes_test) { + /* Set new SO_RCVLOWAT here. This enables sending credit + * update when number of bytes if our rx queue become < + * SO_RCVLOWAT value. + */ + recv_buf_size = 1 + VIRTIO_VSOCK_MAX_PKT_BUF_SIZE; + + if (setsockopt(fd, SOL_SOCKET, SO_RCVLOWAT, + &recv_buf_size, sizeof(recv_buf_size))) { + perror("setsockopt(SO_RCVLOWAT)"); + exit(EXIT_FAILURE); + } + } + + /* Send one dummy byte here, because 'setsockopt()' above also + * sends special packet which tells sender to update our buffer + * size. This 'send_byte()' will serialize such packet with data + * reads in a loop below. Sender starts transmission only when + * it receives this single byte. + */ + send_byte(fd, 1, 0); + + buf = malloc(buf_size); + if (!buf) { + perror("malloc"); + exit(EXIT_FAILURE); + } + + /* Wait until there will be 128KB of data in rx queue. */ + while (1) { + ssize_t res; + + res = recv(fd, buf, buf_size, MSG_PEEK); + if (res == buf_size) + break; + + if (res <= 0) { + fprintf(stderr, "unexpected 'recv()' return: %zi\n", res); + exit(EXIT_FAILURE); + } + } + + /* There is 128KB of data in the socket's rx queue, dequeue first + * 64KB, credit update is sent if 'low_rx_bytes_test' == true. + * Otherwise, credit update is sent in 'if (!low_rx_bytes_test)'. + */ + recv_buf_size = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE; + recv_buf(fd, buf, recv_buf_size, 0, recv_buf_size); + + if (!low_rx_bytes_test) { + recv_buf_size++; + + /* Updating SO_RCVLOWAT will send credit update. */ + if (setsockopt(fd, SOL_SOCKET, SO_RCVLOWAT, + &recv_buf_size, sizeof(recv_buf_size))) { + perror("setsockopt(SO_RCVLOWAT)"); + exit(EXIT_FAILURE); + } + } + + fds.fd = fd; + fds.events = POLLIN | POLLRDNORM | POLLERR | + POLLRDHUP | POLLHUP; + + /* This 'poll()' will return once we receive last byte + * sent by client. + */ + if (poll(&fds, 1, -1) < 0) { + perror("poll"); + exit(EXIT_FAILURE); + } + + if (fds.revents & POLLERR) { + fprintf(stderr, "'poll()' error\n"); + exit(EXIT_FAILURE); + } + + if (fds.revents & (POLLIN | POLLRDNORM)) { + recv_buf(fd, buf, recv_buf_size, MSG_DONTWAIT, recv_buf_size); + } else { + /* These flags must be set, as there is at + * least 64KB of data ready to read. + */ + fprintf(stderr, "POLLIN | POLLRDNORM expected\n"); + exit(EXIT_FAILURE); + } + + free(buf); + close(fd); +} + +static void test_stream_cred_upd_on_low_rx_bytes(const struct test_opts *opts) +{ + test_stream_credit_update_test(opts, true); +} + +static void test_stream_cred_upd_on_set_rcvlowat(const struct test_opts *opts) +{ + test_stream_credit_update_test(opts, false); +} + static struct test_case test_cases[] = { { .name = "SOCK_STREAM connection reset", @@ -1342,6 +1507,16 @@ static struct test_case test_cases[] = { .run_client = test_double_bind_connect_client, .run_server = test_double_bind_connect_server, }, + { + .name = "SOCK_STREAM virtio credit update + SO_RCVLOWAT", + .run_client = test_stream_rcvlowat_def_cred_upd_client, + .run_server = test_stream_cred_upd_on_set_rcvlowat, + }, + { + .name = "SOCK_STREAM virtio credit update + low rx_bytes", + .run_client = test_stream_rcvlowat_def_cred_upd_client, + .run_server = test_stream_cred_upd_on_low_rx_bytes, + }, {}, };