* Re: [PATCH RFC net-next v2 1/3] vsock: support sockmap
[not found] ` <20230118-support-vsock-sockmap-connectible-v2-1-58ffafde0965@bytedance.com>
@ 2023-02-16 10:11 ` Stefano Garzarella
0 siblings, 0 replies; 5+ messages in thread
From: Stefano Garzarella @ 2023-02-16 10:11 UTC (permalink / raw)
To: Bobby Eshleman
Cc: Bobby Eshleman, hdanton, cong.wang, kvm, Michael S. Tsirkin,
Alexei Starovoitov, virtualization, Song Liu, Eric Dumazet,
Stanislav Fomichev, linux-kselftest, Shuah Khan, Mykola Lysenko,
jakub, Daniel Borkmann, John Fastabend, Andrii Nakryiko,
Yonghong Song, Paolo Abeni, KP Singh, Stefan Hajnoczi,
Jakub Kicinski, Hao Luo, netdev, linux-kernel, Jiri Olsa, bpf,
Martin KaFai Lau, David S. Miller
On Mon, Jan 30, 2023 at 08:35:12PM -0800, Bobby Eshleman wrote:
>This patch adds sockmap support for vsock sockets. It is intended to be
>usable by all transports, but only the virtio transport is implemented.
>
>Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
>---
> drivers/vhost/vsock.c | 1 +
> include/linux/virtio_vsock.h | 1 +
> include/net/af_vsock.h | 17 ++++
> net/vmw_vsock/Makefile | 1 +
> net/vmw_vsock/af_vsock.c | 55 ++++++++--
> net/vmw_vsock/virtio_transport.c | 2 +
> net/vmw_vsock/virtio_transport_common.c | 24 +++++
> net/vmw_vsock/vsock_bpf.c | 175 ++++++++++++++++++++++++++++++++
> net/vmw_vsock/vsock_loopback.c | 2 +
> 9 files changed, 272 insertions(+), 6 deletions(-)
>
>diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
>index 1f3b89c885cc..3c6dc036b904 100644
>--- a/drivers/vhost/vsock.c
>+++ b/drivers/vhost/vsock.c
>@@ -439,6 +439,7 @@ static struct virtio_transport vhost_transport = {
> .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
> .notify_buffer_size = virtio_transport_notify_buffer_size,
>
>+ .read_skb = virtio_transport_read_skb,
> },
>
> .send_pkt = vhost_transport_send_pkt,
>diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
>index 3f9c16611306..c58453699ee9 100644
>--- a/include/linux/virtio_vsock.h
>+++ b/include/linux/virtio_vsock.h
>@@ -245,4 +245,5 @@ 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 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);
> #endif /* _LINUX_VIRTIO_VSOCK_H */
>diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
>index 568a87c5e0d0..a73f5fbd296a 100644
>--- a/include/net/af_vsock.h
>+++ b/include/net/af_vsock.h
>@@ -75,6 +75,7 @@ struct vsock_sock {
> void *trans;
> };
>
>+s64 vsock_connectible_has_data(struct vsock_sock *vsk);
> s64 vsock_stream_has_data(struct vsock_sock *vsk);
> s64 vsock_stream_has_space(struct vsock_sock *vsk);
> struct sock *vsock_create_connected(struct sock *parent);
>@@ -173,6 +174,9 @@ struct vsock_transport {
>
> /* Addressing. */
> u32 (*get_local_cid)(void);
>+
>+ /* Read a single skb */
>+ int (*read_skb)(struct vsock_sock *, skb_read_actor_t);
> };
>
> /**** CORE ****/
>@@ -225,5 +229,18 @@ int vsock_init_tap(void);
> int vsock_add_tap(struct vsock_tap *vt);
> int vsock_remove_tap(struct vsock_tap *vt);
> void vsock_deliver_tap(struct sk_buff *build_skb(void *opaque), void *opaque);
>+int vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
>+ int flags);
>+int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
>+ size_t len, int flags);
checkpatch complains: "CHECK: Alignment should match open parenthesis"
>+
>+#ifdef CONFIG_BPF_SYSCALL
>+extern struct proto vsock_proto;
>+int vsock_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
>+void __init vsock_bpf_build_proto(void);
>+#else
>+static inline void __init vsock_bpf_build_proto(void)
>+{}
>+#endif
>
> #endif /* __AF_VSOCK_H__ */
>diff --git a/net/vmw_vsock/Makefile b/net/vmw_vsock/Makefile
>index 6a943ec95c4a..5da74c4a9f1d 100644
>--- a/net/vmw_vsock/Makefile
>+++ b/net/vmw_vsock/Makefile
>@@ -8,6 +8,7 @@ obj-$(CONFIG_HYPERV_VSOCKETS) += hv_sock.o
> obj-$(CONFIG_VSOCKETS_LOOPBACK) += vsock_loopback.o
>
> vsock-y += af_vsock.o af_vsock_tap.o vsock_addr.o
>+vsock-$(CONFIG_BPF_SYSCALL) += vsock_bpf.o
>
> vsock_diag-y += diag.o
>
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index 19aea7cba26e..f2cc04fb8b13 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -116,10 +116,13 @@ static void vsock_sk_destruct(struct sock *sk);
> static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
>
> /* Protocol family. */
>-static struct proto vsock_proto = {
>+struct proto vsock_proto = {
> .name = "AF_VSOCK",
> .owner = THIS_MODULE,
> .obj_size = sizeof(struct vsock_sock),
>+#ifdef CONFIG_BPF_SYSCALL
>+ .psock_update_sk_prot = vsock_bpf_update_proto,
>+#endif
> };
>
> /* The default peer timeout indicates how long we will wait for a peer response
>@@ -865,7 +868,7 @@ s64 vsock_stream_has_data(struct vsock_sock *vsk)
> }
> EXPORT_SYMBOL_GPL(vsock_stream_has_data);
>
>-static s64 vsock_connectible_has_data(struct vsock_sock *vsk)
>+s64 vsock_connectible_has_data(struct vsock_sock *vsk)
> {
> struct sock *sk = sk_vsock(vsk);
>
>@@ -874,6 +877,7 @@ static s64 vsock_connectible_has_data(struct vsock_sock *vsk)
> else
> return vsock_stream_has_data(vsk);
> }
>+EXPORT_SYMBOL_GPL(vsock_connectible_has_data);
>
> s64 vsock_stream_has_space(struct vsock_sock *vsk)
> {
>@@ -1131,6 +1135,13 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock,
> return mask;
> }
>
>+static int vsock_read_skb(struct sock *sk, skb_read_actor_t read_actor)
>+{
>+ struct vsock_sock *vsk = vsock_sk(sk);
>+
>+ return vsk->transport->read_skb(vsk, read_actor);
>+}
>+
> static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
> size_t len)
> {
>@@ -1241,19 +1252,34 @@ static int vsock_dgram_connect(struct socket *sock,
>
> memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
> sock->state = SS_CONNECTED;
>+ sk->sk_state = TCP_ESTABLISHED;
>
> out:
> release_sock(sk);
> return err;
> }
>
>-static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
>- size_t len, int flags)
>+int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
>+ size_t len, int flags)
> {
>- struct vsock_sock *vsk = vsock_sk(sock->sk);
>+#ifdef CONFIG_BPF_SYSCALL
>+ const struct proto *prot;
>+#endif
>+ struct vsock_sock *vsk;
>+ struct sock *sk;
>+
>+ sk = sock->sk;
>+ vsk = vsock_sk(sk);
>+
>+#ifdef CONFIG_BPF_SYSCALL
>+ prot = READ_ONCE(sk->sk_prot);
>+ if (prot != &vsock_proto)
>+ return prot->recvmsg(sk, msg, len, flags, NULL);
>+#endif
>
> return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
> }
>+EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
>
> static const struct proto_ops vsock_dgram_ops = {
> .family = PF_VSOCK,
>@@ -1272,6 +1298,7 @@ static const struct proto_ops vsock_dgram_ops = {
> .recvmsg = vsock_dgram_recvmsg,
> .mmap = sock_no_mmap,
> .sendpage = sock_no_sendpage,
>+ .read_skb = vsock_read_skb,
> };
>
> static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
>@@ -2086,13 +2113,16 @@ static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
> return err;
> }
>
>-static int
>+int
> vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> int flags)
> {
> struct sock *sk;
> struct vsock_sock *vsk;
> const struct vsock_transport *transport;
>+#ifdef CONFIG_BPF_SYSCALL
>+ const struct proto *prot;
>+#endif
> int err;
>
> sk = sock->sk;
>@@ -2139,6 +2169,14 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> goto out;
> }
>
>+#ifdef CONFIG_BPF_SYSCALL
>+ prot = READ_ONCE(sk->sk_prot);
>+ if (prot != &vsock_proto) {
>+ release_sock(sk);
>+ return prot->recvmsg(sk, msg, len, flags, NULL);
>+ }
>+#endif
>+
> if (sk->sk_type == SOCK_STREAM)
> err = __vsock_stream_recvmsg(sk, msg, len, flags);
> else
>@@ -2148,6 +2186,7 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> release_sock(sk);
> return err;
> }
>+EXPORT_SYMBOL_GPL(vsock_connectible_recvmsg);
>
> static int vsock_set_rcvlowat(struct sock *sk, int val)
> {
>@@ -2188,6 +2227,7 @@ static const struct proto_ops vsock_stream_ops = {
> .mmap = sock_no_mmap,
> .sendpage = sock_no_sendpage,
> .set_rcvlowat = vsock_set_rcvlowat,
>+ .read_skb = vsock_read_skb,
> };
>
> static const struct proto_ops vsock_seqpacket_ops = {
>@@ -2209,6 +2249,7 @@ static const struct proto_ops vsock_seqpacket_ops = {
> .recvmsg = vsock_connectible_recvmsg,
> .mmap = sock_no_mmap,
> .sendpage = sock_no_sendpage,
>+ .read_skb = vsock_read_skb,
> };
>
> static int vsock_create(struct net *net, struct socket *sock,
>@@ -2348,6 +2389,8 @@ static int __init vsock_init(void)
> goto err_unregister_proto;
> }
>
>+ vsock_bpf_build_proto();
>+
> return 0;
>
> err_unregister_proto:
>diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
>index 28b5a8e8e094..e95df847176b 100644
>--- a/net/vmw_vsock/virtio_transport.c
>+++ b/net/vmw_vsock/virtio_transport.c
>@@ -457,6 +457,8 @@ 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,
>+
>+ .read_skb = virtio_transport_read_skb,
> },
>
> .send_pkt = virtio_transport_send_pkt,
>diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>index a1581c77cf84..82bdaf61ee02 100644
>--- a/net/vmw_vsock/virtio_transport_common.c
>+++ b/net/vmw_vsock/virtio_transport_common.c
>@@ -1388,6 +1388,30 @@ int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *queue)
> }
> EXPORT_SYMBOL_GPL(virtio_transport_purge_skbs);
>
>+int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_actor)
>+{
>+ struct virtio_vsock_sock *vvs = vsk->trans;
>+ struct sock *sk = sk_vsock(vsk);
>+ struct sk_buff *skb;
>+ int off = 0;
>+ int copied;
>+ int err;
>+
>+ spin_lock_bh(&vvs->rx_lock);
>+ /* Use __skb_recv_datagram() for race-free handling of the receive. It
>+ * works for types other than dgrams. */
Checkpatch:
WARNING: Block comments use a trailing */ on a separate line
Since we also use this convention in the other comments in this file,
I would follow it.
>+ skb = __skb_recv_datagram(sk, &vvs->rx_queue, MSG_DONTWAIT, &off, &err);
>+ spin_unlock_bh(&vvs->rx_lock);
>+
>+ if (!skb)
>+ return err;
>+
>+ copied = recv_actor(sk, skb);
>+ kfree_skb(skb);
>+ return copied;
>+}
>+EXPORT_SYMBOL_GPL(virtio_transport_read_skb);
>+
> MODULE_LICENSE("GPL v2");
> MODULE_AUTHOR("Asias He");
> MODULE_DESCRIPTION("common code for virtio vsock");
>diff --git a/net/vmw_vsock/vsock_bpf.c b/net/vmw_vsock/vsock_bpf.c
>new file mode 100644
>index 000000000000..ee92a1f42031
>--- /dev/null
>+++ b/net/vmw_vsock/vsock_bpf.c
>@@ -0,0 +1,175 @@
>+// SPDX-License-Identifier: GPL-2.0
>+/* Copyright (c) 2022 Bobby Eshleman <bobby.eshleman@bytedance.com>
>+ *
>+ * Based off of net/unix/unix_bpf.c
>+ */
>+
>+#include <linux/bpf.h>
>+#include <linux/module.h>
>+#include <linux/skmsg.h>
>+#include <linux/socket.h>
>+#include <linux/wait.h>
>+#include <net/af_vsock.h>
>+#include <net/sock.h>
>+
>+#define vsock_sk_has_data(__sk, __psock) \
>+ ({ !skb_queue_empty(&__sk->sk_receive_queue) || \
>+ !skb_queue_empty(&__psock->ingress_skb) || \
>+ !list_empty(&__psock->ingress_msg); \
>+ })
Some suggestions from checkpatch that I would fix:
CHECK: Macro argument '__sk' may be better as '(__sk)' to avoid precedence issues
CHECK: Macro argument '__psock' may be better as '(__psock)' to avoid precedence issues
>+
>+static struct proto *vsock_prot_saved __read_mostly;
>+static DEFINE_SPINLOCK(vsock_prot_lock);
>+static struct proto vsock_bpf_prot;
>+
>+static bool vsock_has_data(struct sock *sk, struct sk_psock *psock)
>+{
>+ struct vsock_sock *vsk = vsock_sk(sk);
>+ s64 ret;
>+
>+ ret = vsock_connectible_has_data(vsk);
>+ if (ret > 0)
>+ return true;
>+
>+ return vsock_sk_has_data(sk, psock);
>+}
>+
>+static int vsock_msg_wait_data(struct sock *sk, struct sk_psock *psock, long timeo)
IIUC now this function returns 0 when there isn't data and 1 when there
is data, maybe better to change the return type to bool.
>+{
>+ int ret = 0;
>+
>+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
>+
>+ if (sk->sk_shutdown & RCV_SHUTDOWN)
>+ return 1;
>+
>+ if (!timeo)
>+ return ret;
>+
>+ add_wait_queue(sk_sleep(sk), &wait);
>+ sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
>+ ret = vsock_has_data(sk, psock);
>+ if (!ret) {
>+ wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
>+ ret = vsock_has_data(sk, psock);
>+ }
>+ sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
>+ remove_wait_queue(sk_sleep(sk), &wait);
>+ return ret;
>+}
>+
>+static int __vsock_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags)
>+{
>+ struct socket *sock = sk->sk_socket;
>+ int err;
>+
>+ if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)
>+ err = vsock_connectible_recvmsg(sock, msg, len, flags);
>+ else if (sk->sk_type == SOCK_DGRAM)
>+ err = vsock_dgram_recvmsg(sock, msg, len, flags);
>+ else
>+ err = -EPROTOTYPE;
>+
>+ return err;
>+}
>+
>+static int vsock_bpf_recvmsg(struct sock *sk, struct msghdr *msg,
>+ size_t len, int flags, int *addr_len)
>+{
>+ struct sk_psock *psock;
>+ int copied;
>+
>+ psock = sk_psock_get(sk);
>+ lock_sock(sk);
>+ if (unlikely(!psock)) {
>+ release_sock(sk);
I'm not sure we need the lock to check psock, so can we move this
block before the lock_sock?
>+ return __vsock_recvmsg(sk, msg, len, flags);
>+ }
>+
>+ if (vsock_has_data(sk, psock) && sk_psock_queue_empty(psock)) {
>+ release_sock(sk);
>+ sk_psock_put(sk, psock);
>+ return __vsock_recvmsg(sk, msg, len, flags);
>+ }
>+
>+msg_bytes_ready:
I saw that this code is also in unix_bpf.c and tcp_bpf.c, so I guess
it's acceptable, but I would have avoided using a label to go back.
I prefer a to use goto only for centralized exiting of functions.
One possible refactoring (not tested):
copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
while (!copied) {
long timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
if (!vsock_msg_wait_data(sk, psock, timeo)) {
copied = -EAGAIN;
break;
}
if (sk_psock_queue_empty(psock)) {
release_sock(sk);
sk_psock_put(sk, psock);
return __vsock_recvmsg(sk, msg, len, flags);
}
copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
}
...
I'm not sure why we need to call release_sock() and sk_psock_put()
before __vsock_recvmsg(). If it is not needed we can simplify more the
previous code.
The rest LGTM.
Thanks,
Stefano
>+ copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
>+ if (!copied) {
>+ long timeo;
>+ int data;
>+
>+ timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
>+ data = vsock_msg_wait_data(sk, psock, timeo);
>+ if (data) {
>+ if (!sk_psock_queue_empty(psock))
>+ goto msg_bytes_ready;
>+ release_sock(sk);
>+ sk_psock_put(sk, psock);
>+ return __vsock_recvmsg(sk, msg, len, flags);
>+ }
>+ copied = -EAGAIN;
>+ }
>+ release_sock(sk);
>+ sk_psock_put(sk, psock);
>+
>+ return copied;
>+}
>+
>+/* Copy of original proto with updated sock_map methods */
>+static struct proto vsock_bpf_prot = {
>+ .close = sock_map_close,
>+ .recvmsg = vsock_bpf_recvmsg,
>+ .sock_is_readable = sk_msg_is_readable,
>+ .unhash = sock_map_unhash,
>+};
>+
>+static void vsock_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
>+{
>+ *prot = *base;
>+ prot->close = sock_map_close;
>+ prot->recvmsg = vsock_bpf_recvmsg;
>+ prot->sock_is_readable = sk_msg_is_readable;
>+}
>+
>+static void vsock_bpf_check_needs_rebuild(struct proto *ops)
>+{
>+ /* Paired with the smp_store_release() below. */
>+ if (unlikely(ops != smp_load_acquire(&vsock_prot_saved))) {
>+ spin_lock_bh(&vsock_prot_lock);
>+ if (likely(ops != vsock_prot_saved)) {
>+ vsock_bpf_rebuild_protos(&vsock_bpf_prot, ops);
>+ /* Make sure proto function pointers are updated before publishing the
>+ * pointer to the struct.
>+ */
>+ smp_store_release(&vsock_prot_saved, ops);
>+ }
>+ spin_unlock_bh(&vsock_prot_lock);
>+ }
>+}
>+
>+int vsock_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
>+{
>+ struct vsock_sock *vsk;
>+
>+ if (restore) {
>+ sk->sk_write_space = psock->saved_write_space;
>+ sock_replace_proto(sk, psock->sk_proto);
>+ return 0;
>+ }
>+
>+ vsk = vsock_sk(sk);
>+ if (!vsk->transport)
>+ return -ENODEV;
>+
>+ if (!vsk->transport->read_skb)
>+ return -EOPNOTSUPP;
>+
>+ vsock_bpf_check_needs_rebuild(psock->sk_proto);
>+ sock_replace_proto(sk, &vsock_bpf_prot);
>+ return 0;
>+}
>+
>+void __init vsock_bpf_build_proto(void)
>+{
>+ vsock_bpf_rebuild_protos(&vsock_bpf_prot, &vsock_proto);
>+}
>diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
>index 671e03240fc5..40753b661c13 100644
>--- a/net/vmw_vsock/vsock_loopback.c
>+++ b/net/vmw_vsock/vsock_loopback.c
>@@ -94,6 +94,8 @@ 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,
>+
>+ .read_skb = virtio_transport_read_skb,
> },
>
> .send_pkt = vsock_loopback_send_pkt,
>
>--
>2.35.1
>
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