diff mbox series

[RFC,net-next,v6,01/14] af_vsock: generalize vsock_dgram_recvmsg() to all transports

Message ID 20240710212555.1617795-2-amery.hung@bytedance.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series virtio/vsock: support datagrams | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 816 this patch: 816
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 3 maintainers not CCed: eperezma@redhat.com virtualization@lists.linux.dev bcm-kernel-feedback-list@broadcom.com
netdev/build_clang success Errors and warnings before: 821 this patch: 821
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 821 this patch: 821
netdev/checkpatch fail ERROR: open brace '{' following function definitions go on the next line
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Amery Hung July 10, 2024, 9:25 p.m. UTC 
From: Bobby Eshleman <bobby.eshleman@bytedance.com>

This commit drops the transport->dgram_dequeue callback and makes
vsock_dgram_recvmsg() generic to all transports.

To make this possible, two transport-level changes are introduced:
- transport in the receiving path now stores the cid and port into
  the control buffer of an skb when populating an skb. The information
  later is used to initialize sockaddr_vm structure in recvmsg()
  without referencing vsk->transport.
- transport implementations set the skb->data pointer to the beginning
  of the payload prior to adding the skb to the socket's receive queue.
  That is, they must use skb_pull() before enqueuing. This is an
  agreement between the transport and the socket layer that skb->data
  always points to the beginning of the payload (and not, for example,
  the packet header).

Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
Signed-off-by: Amery Hung <amery.hung@bytedance.com>
---
 drivers/vhost/vsock.c                   |  1 -
 include/linux/virtio_vsock.h            |  5 ---
 include/net/af_vsock.h                  | 11 ++++-
 net/vmw_vsock/af_vsock.c                | 42 +++++++++++++++++-
 net/vmw_vsock/hyperv_transport.c        |  7 ---
 net/vmw_vsock/virtio_transport.c        |  1 -
 net/vmw_vsock/virtio_transport_common.c |  9 ----
 net/vmw_vsock/vmci_transport.c          | 59 +++----------------------
 net/vmw_vsock/vsock_loopback.c          |  1 -
 9 files changed, 55 insertions(+), 81 deletions(-)

Comments

Luigi Leonardi July 15, 2024, 8:02 a.m. UTC | #1 
Hi Amery, Bobby

> From: Bobby Eshleman <bobby.eshleman@bytedance.com>
>
> This commit drops the transport->dgram_dequeue callback and makes
> vsock_dgram_recvmsg() generic to all transports.
>
> To make this possible, two transport-level changes are introduced:
> - transport in the receiving path now stores the cid and port into
>   the control buffer of an skb when populating an skb. The information
>   later is used to initialize sockaddr_vm structure in recvmsg()
>   without referencing vsk->transport.
> - transport implementations set the skb->data pointer to the beginning
>   of the payload prior to adding the skb to the socket's receive queue.
>   That is, they must use skb_pull() before enqueuing. This is an
>   agreement between the transport and the socket layer that skb->data
>   always points to the beginning of the payload (and not, for example,
>   the packet header).
>
Like in the other patch, please use imperative in the commit message.
>
> Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
> Signed-off-by: Amery Hung <amery.hung@bytedance.com>
> ---
>  drivers/vhost/vsock.c                   |  1 -
>  include/linux/virtio_vsock.h            |  5 ---
>  include/net/af_vsock.h                  | 11 ++++-
>  net/vmw_vsock/af_vsock.c                | 42 +++++++++++++++++-
>  net/vmw_vsock/hyperv_transport.c        |  7 ---
>  net/vmw_vsock/virtio_transport.c        |  1 -
>  net/vmw_vsock/virtio_transport_common.c |  9 ----
>  net/vmw_vsock/vmci_transport.c          | 59 +++----------------------
>  net/vmw_vsock/vsock_loopback.c          |  1 -
>  9 files changed, 55 insertions(+), 81 deletions(-)
>
> diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
> index ec20ecff85c7..97fffa914e66 100644
> --- a/drivers/vhost/vsock.c
> +++ b/drivers/vhost/vsock.c
> @@ -419,7 +419,6 @@ static struct virtio_transport vhost_transport = {
>  		.cancel_pkt               = vhost_transport_cancel_pkt,
>
>  		.dgram_enqueue            = virtio_transport_dgram_enqueue,
> -		.dgram_dequeue            = virtio_transport_dgram_dequeue,
>  		.dgram_bind               = virtio_transport_dgram_bind,
>  		.dgram_allow              = virtio_transport_dgram_allow,
>
> diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
> index c82089dee0c8..8b56b8a19ddd 100644
> --- a/include/linux/virtio_vsock.h
> +++ b/include/linux/virtio_vsock.h
> @@ -177,11 +177,6 @@ virtio_transport_stream_dequeue(struct vsock_sock *vsk,
>  				size_t len,
>  				int type);
>  int
> -virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
> -			       struct msghdr *msg,
> -			       size_t len, int flags);
> -
> -int
>  virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
>  				   struct msghdr *msg,
>  				   size_t len);
> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
> index 535701efc1e5..7aa1f5f2b1a5 100644
> --- a/include/net/af_vsock.h
> +++ b/include/net/af_vsock.h
> @@ -120,8 +120,6 @@ struct vsock_transport {
>
>  	/* DGRAM. */
>  	int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *);
> -	int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
> -			     size_t len, int flags);
>  	int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
>  			     struct msghdr *, size_t len);
>  	bool (*dgram_allow)(u32 cid, u32 port);
> @@ -219,6 +217,15 @@ void vsock_for_each_connected_socket(struct vsock_transport *transport,
>  int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
>  bool vsock_find_cid(unsigned int cid);
>
> +struct vsock_skb_cb {
> +	unsigned int src_cid;
> +	unsigned int src_port;
> +};
> +
> +static inline struct vsock_skb_cb *vsock_skb_cb(struct sk_buff *skb) {
> +	return (struct vsock_skb_cb *)skb->cb;
> +};
> +
>

Running scripts/checkpatch.pl --strict --codespell on the patch shows this error:

 ERROR: open brace '{' following function definitions go on the next line
 #183: FILE: include/net/af_vsock.h:225:
 +static inline struct vsock_skb_cb *vsock_skb_cb(struct sk_buff *skb) {

 total: 1 errors, 0 warnings, 0 checks, 235 lines checked
>
>  /**** TAP ****/
>
>  struct vsock_tap {
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index 4b040285aa78..5e7d4d99ea2c 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -1273,11 +1273,15 @@ static int vsock_dgram_connect(struct socket *sock,
>  int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
>  			size_t len, int flags)
>  {
> +	struct vsock_skb_cb *vsock_cb;
>  #ifdef CONFIG_BPF_SYSCALL
>  	const struct proto *prot;
>  #endif
>  	struct vsock_sock *vsk;
> +	struct sk_buff *skb;
> +	size_t payload_len;
>  	struct sock *sk;
> +	int err;
>
>  	sk = sock->sk;
>  	vsk = vsock_sk(sk);
> @@ -1288,7 +1292,43 @@ int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
>  		return prot->recvmsg(sk, msg, len, flags, NULL);
>  #endif
>
> -	return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
> +	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
> +		return -EOPNOTSUPP;
> +
> +	if (unlikely(flags & MSG_ERRQUEUE))
> +		return sock_recv_errqueue(sk, msg, len, SOL_VSOCK, 0);
>
This if statement is always false!
>
> +
> +	/* Retrieve the head sk_buff from the socket's receive queue. */
> +	err = 0;
> +	skb = skb_recv_datagram(sk_vsock(vsk), flags, &err);
> +	if (!skb)
> +		return err;
> +
> +	payload_len = skb->len;
> +
nit: I'd remove this blank line.
> +	if (payload_len > len) {
> +		payload_len = len;
> +		msg->msg_flags |= MSG_TRUNC;
> +	}
> +
> +	/* Place the datagram payload in the user's iovec. */
> +	err = skb_copy_datagram_msg(skb, 0, msg, payload_len);
> +	if (err)
> +		goto out;
> +
> +	if (msg->msg_name) {
> +		/* Provide the address of the sender. */
> +		DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
> +
> +		vsock_cb = vsock_skb_cb(skb);
> +		vsock_addr_init(vm_addr, vsock_cb->src_cid, vsock_cb->src_port);
> +		msg->msg_namelen = sizeof(*vm_addr);
> +	}
> +	err = payload_len;
> +
> +out:
> +	skb_free_datagram(&vsk->sk, skb);
> +	return err;
>  }
>  EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
>
> diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
> index e2157e387217..326dd41ee2d5 100644
> --- a/net/vmw_vsock/hyperv_transport.c
> +++ b/net/vmw_vsock/hyperv_transport.c
> @@ -556,12 +556,6 @@ static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr)
>  	return -EOPNOTSUPP;
>  }
>
> -static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
> -			     size_t len, int flags)
> -{
> -	return -EOPNOTSUPP;
> -}
> -
>  static int hvs_dgram_enqueue(struct vsock_sock *vsk,
>  			     struct sockaddr_vm *remote, struct msghdr *msg,
>  			     size_t dgram_len)
> @@ -833,7 +827,6 @@ static struct vsock_transport hvs_transport = {
>  	.shutdown                 = hvs_shutdown,
>
>  	.dgram_bind               = hvs_dgram_bind,
> -	.dgram_dequeue            = hvs_dgram_dequeue,
>  	.dgram_enqueue            = hvs_dgram_enqueue,
>  	.dgram_allow              = hvs_dgram_allow,
>
> diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
> index 43d405298857..a8c97e95622a 100644
> --- a/net/vmw_vsock/virtio_transport.c
> +++ b/net/vmw_vsock/virtio_transport.c
> @@ -508,7 +508,6 @@ static struct virtio_transport virtio_transport = {
>  		.cancel_pkt               = virtio_transport_cancel_pkt,
>
>  		.dgram_bind               = virtio_transport_dgram_bind,
> -		.dgram_dequeue            = virtio_transport_dgram_dequeue,
>  		.dgram_enqueue            = virtio_transport_dgram_enqueue,
>  		.dgram_allow              = virtio_transport_dgram_allow,
>
> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> index 16ff976a86e3..4bf73d20c12a 100644
> --- a/net/vmw_vsock/virtio_transport_common.c
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -810,15 +810,6 @@ virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
>  }
>  EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue);
>
> -int
> -virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
> -			       struct msghdr *msg,
> -			       size_t len, int flags)
> -{
> -	return -EOPNOTSUPP;
> -}
> -EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
> -
>  s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
>  {
>  	struct virtio_vsock_sock *vvs = vsk->trans;
> diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
> index b370070194fa..b39df3ed8c8d 100644
> --- a/net/vmw_vsock/vmci_transport.c
> +++ b/net/vmw_vsock/vmci_transport.c
> @@ -610,6 +610,7 @@ vmci_transport_datagram_create_hnd(u32 resource_id,
>
>  static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
>  {
> +	struct vsock_skb_cb *vsock_cb;
>  	struct sock *sk;
>  	size_t size;
>  	struct sk_buff *skb;
> @@ -637,10 +638,14 @@ static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
>  	if (!skb)
>  		return VMCI_ERROR_NO_MEM;
>
> +	vsock_cb = vsock_skb_cb(skb);
> +	vsock_cb->src_cid = dg->src.context;
> +	vsock_cb->src_port = dg->src.resource;
>  	/* sk_receive_skb() will do a sock_put(), so hold here. */
>  	sock_hold(sk);
>  	skb_put(skb, size);
>  	memcpy(skb->data, dg, size);
> +	skb_pull(skb, VMCI_DG_HEADERSIZE);
>  	sk_receive_skb(sk, skb, 0);
>
>  	return VMCI_SUCCESS;
> @@ -1731,59 +1736,6 @@ static int vmci_transport_dgram_enqueue(
>  	return err - sizeof(*dg);
>  }
>
> -static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk,
> -					struct msghdr *msg, size_t len,
> -					int flags)
> -{
> -	int err;
> -	struct vmci_datagram *dg;
> -	size_t payload_len;
> -	struct sk_buff *skb;
> -
> -	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
> -		return -EOPNOTSUPP;
> -
> -	/* Retrieve the head sk_buff from the socket's receive queue. */
> -	err = 0;
> -	skb = skb_recv_datagram(&vsk->sk, flags, &err);
> -	if (!skb)
> -		return err;
> -
> -	dg = (struct vmci_datagram *)skb->data;
> -	if (!dg)
> -		/* err is 0, meaning we read zero bytes. */
> -		goto out;
> -
> -	payload_len = dg->payload_size;
> -	/* Ensure the sk_buff matches the payload size claimed in the packet. */
> -	if (payload_len != skb->len - sizeof(*dg)) {
> -		err = -EINVAL;
> -		goto out;
> -	}
> -
> -	if (payload_len > len) {
> -		payload_len = len;
> -		msg->msg_flags |= MSG_TRUNC;
> -	}
> -
> -	/* Place the datagram payload in the user's iovec. */
> -	err = skb_copy_datagram_msg(skb, sizeof(*dg), msg, payload_len);
> -	if (err)
> -		goto out;
> -
> -	if (msg->msg_name) {
> -		/* Provide the address of the sender. */
> -		DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
> -		vsock_addr_init(vm_addr, dg->src.context, dg->src.resource);
> -		msg->msg_namelen = sizeof(*vm_addr);
> -	}
> -	err = payload_len;
> -
> -out:
> -	skb_free_datagram(&vsk->sk, skb);
> -	return err;
> -}
> -
>  static bool vmci_transport_dgram_allow(u32 cid, u32 port)
>  {
>  	if (cid == VMADDR_CID_HYPERVISOR) {
> @@ -2040,7 +1992,6 @@ static struct vsock_transport vmci_transport = {
>  	.release = vmci_transport_release,
>  	.connect = vmci_transport_connect,
>  	.dgram_bind = vmci_transport_dgram_bind,
> -	.dgram_dequeue = vmci_transport_dgram_dequeue,
>  	.dgram_enqueue = vmci_transport_dgram_enqueue,
>  	.dgram_allow = vmci_transport_dgram_allow,
>  	.stream_dequeue = vmci_transport_stream_dequeue,
> diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
> index 6dea6119f5b2..11488887a5cc 100644
> --- a/net/vmw_vsock/vsock_loopback.c
> +++ b/net/vmw_vsock/vsock_loopback.c
> @@ -66,7 +66,6 @@ static struct virtio_transport loopback_transport = {
>  		.cancel_pkt               = vsock_loopback_cancel_pkt,
>
>  		.dgram_bind               = virtio_transport_dgram_bind,
> -		.dgram_dequeue            = virtio_transport_dgram_dequeue,
>  		.dgram_enqueue            = virtio_transport_dgram_enqueue,
>  		.dgram_allow              = virtio_transport_dgram_allow,
>
> --
> 2.20.1
>
>

Small changes :)
Rest LGTM!

Thanks,
Luigi
Amery Hung July 15, 2024, 11:39 p.m. UTC | #2 
On Mon, Jul 15, 2024 at 1:02 AM Luigi Leonardi
<luigi.leonardi@outlook.com> wrote:
>
> Hi Amery, Bobby
>
> > From: Bobby Eshleman <bobby.eshleman@bytedance.com>
> >
> > This commit drops the transport->dgram_dequeue callback and makes
> > vsock_dgram_recvmsg() generic to all transports.
> >
> > To make this possible, two transport-level changes are introduced:
> > - transport in the receiving path now stores the cid and port into
> >   the control buffer of an skb when populating an skb. The information
> >   later is used to initialize sockaddr_vm structure in recvmsg()
> >   without referencing vsk->transport.
> > - transport implementations set the skb->data pointer to the beginning
> >   of the payload prior to adding the skb to the socket's receive queue.
> >   That is, they must use skb_pull() before enqueuing. This is an
> >   agreement between the transport and the socket layer that skb->data
> >   always points to the beginning of the payload (and not, for example,
> >   the packet header).
> >
> Like in the other patch, please use imperative in the commit message.
> >
> > Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
> > Signed-off-by: Amery Hung <amery.hung@bytedance.com>
> > ---
> >  drivers/vhost/vsock.c                   |  1 -
> >  include/linux/virtio_vsock.h            |  5 ---
> >  include/net/af_vsock.h                  | 11 ++++-
> >  net/vmw_vsock/af_vsock.c                | 42 +++++++++++++++++-
> >  net/vmw_vsock/hyperv_transport.c        |  7 ---
> >  net/vmw_vsock/virtio_transport.c        |  1 -
> >  net/vmw_vsock/virtio_transport_common.c |  9 ----
> >  net/vmw_vsock/vmci_transport.c          | 59 +++----------------------
> >  net/vmw_vsock/vsock_loopback.c          |  1 -
> >  9 files changed, 55 insertions(+), 81 deletions(-)
> >
> > diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
> > index ec20ecff85c7..97fffa914e66 100644
> > --- a/drivers/vhost/vsock.c
> > +++ b/drivers/vhost/vsock.c
> > @@ -419,7 +419,6 @@ static struct virtio_transport vhost_transport = {
> >               .cancel_pkt               = vhost_transport_cancel_pkt,
> >
> >               .dgram_enqueue            = virtio_transport_dgram_enqueue,
> > -             .dgram_dequeue            = virtio_transport_dgram_dequeue,
> >               .dgram_bind               = virtio_transport_dgram_bind,
> >               .dgram_allow              = virtio_transport_dgram_allow,
> >
> > diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
> > index c82089dee0c8..8b56b8a19ddd 100644
> > --- a/include/linux/virtio_vsock.h
> > +++ b/include/linux/virtio_vsock.h
> > @@ -177,11 +177,6 @@ virtio_transport_stream_dequeue(struct vsock_sock *vsk,
> >                               size_t len,
> >                               int type);
> >  int
> > -virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
> > -                            struct msghdr *msg,
> > -                            size_t len, int flags);
> > -
> > -int
> >  virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
> >                                  struct msghdr *msg,
> >                                  size_t len);
> > diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
> > index 535701efc1e5..7aa1f5f2b1a5 100644
> > --- a/include/net/af_vsock.h
> > +++ b/include/net/af_vsock.h
> > @@ -120,8 +120,6 @@ struct vsock_transport {
> >
> >       /* DGRAM. */
> >       int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *);
> > -     int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
> > -                          size_t len, int flags);
> >       int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
> >                            struct msghdr *, size_t len);
> >       bool (*dgram_allow)(u32 cid, u32 port);
> > @@ -219,6 +217,15 @@ void vsock_for_each_connected_socket(struct vsock_transport *transport,
> >  int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
> >  bool vsock_find_cid(unsigned int cid);
> >
> > +struct vsock_skb_cb {
> > +     unsigned int src_cid;
> > +     unsigned int src_port;
> > +};
> > +
> > +static inline struct vsock_skb_cb *vsock_skb_cb(struct sk_buff *skb) {
> > +     return (struct vsock_skb_cb *)skb->cb;
> > +};
> > +
> >
>
> Running scripts/checkpatch.pl --strict --codespell on the patch shows this error:
>
>  ERROR: open brace '{' following function definitions go on the next line
>  #183: FILE: include/net/af_vsock.h:225:
>  +static inline struct vsock_skb_cb *vsock_skb_cb(struct sk_buff *skb) {
>
>  total: 1 errors, 0 warnings, 0 checks, 235 lines checked
> >
> >  /**** TAP ****/
> >
> >  struct vsock_tap {
> > diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> > index 4b040285aa78..5e7d4d99ea2c 100644
> > --- a/net/vmw_vsock/af_vsock.c
> > +++ b/net/vmw_vsock/af_vsock.c
> > @@ -1273,11 +1273,15 @@ static int vsock_dgram_connect(struct socket *sock,
> >  int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
> >                       size_t len, int flags)
> >  {
> > +     struct vsock_skb_cb *vsock_cb;
> >  #ifdef CONFIG_BPF_SYSCALL
> >       const struct proto *prot;
> >  #endif
> >       struct vsock_sock *vsk;
> > +     struct sk_buff *skb;
> > +     size_t payload_len;
> >       struct sock *sk;
> > +     int err;
> >
> >       sk = sock->sk;
> >       vsk = vsock_sk(sk);
> > @@ -1288,7 +1292,43 @@ int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
> >               return prot->recvmsg(sk, msg, len, flags, NULL);
> >  #endif
> >
> > -     return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
> > +     if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
> > +             return -EOPNOTSUPP;
> > +
> > +     if (unlikely(flags & MSG_ERRQUEUE))
> > +             return sock_recv_errqueue(sk, msg, len, SOL_VSOCK, 0);
> >
> This if statement is always false!
> >
> > +
> > +     /* Retrieve the head sk_buff from the socket's receive queue. */
> > +     err = 0;
> > +     skb = skb_recv_datagram(sk_vsock(vsk), flags, &err);
> > +     if (!skb)
> > +             return err;
> > +
> > +     payload_len = skb->len;
> > +
> nit: I'd remove this blank line.
> > +     if (payload_len > len) {
> > +             payload_len = len;
> > +             msg->msg_flags |= MSG_TRUNC;
> > +     }
> > +
> > +     /* Place the datagram payload in the user's iovec. */
> > +     err = skb_copy_datagram_msg(skb, 0, msg, payload_len);
> > +     if (err)
> > +             goto out;
> > +
> > +     if (msg->msg_name) {
> > +             /* Provide the address of the sender. */
> > +             DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
> > +
> > +             vsock_cb = vsock_skb_cb(skb);
> > +             vsock_addr_init(vm_addr, vsock_cb->src_cid, vsock_cb->src_port);
> > +             msg->msg_namelen = sizeof(*vm_addr);
> > +     }
> > +     err = payload_len;
> > +
> > +out:
> > +     skb_free_datagram(&vsk->sk, skb);
> > +     return err;
> >  }
> >  EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
> >
> > diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
> > index e2157e387217..326dd41ee2d5 100644
> > --- a/net/vmw_vsock/hyperv_transport.c
> > +++ b/net/vmw_vsock/hyperv_transport.c
> > @@ -556,12 +556,6 @@ static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr)
> >       return -EOPNOTSUPP;
> >  }
> >
> > -static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
> > -                          size_t len, int flags)
> > -{
> > -     return -EOPNOTSUPP;
> > -}
> > -
> >  static int hvs_dgram_enqueue(struct vsock_sock *vsk,
> >                            struct sockaddr_vm *remote, struct msghdr *msg,
> >                            size_t dgram_len)
> > @@ -833,7 +827,6 @@ static struct vsock_transport hvs_transport = {
> >       .shutdown                 = hvs_shutdown,
> >
> >       .dgram_bind               = hvs_dgram_bind,
> > -     .dgram_dequeue            = hvs_dgram_dequeue,
> >       .dgram_enqueue            = hvs_dgram_enqueue,
> >       .dgram_allow              = hvs_dgram_allow,
> >
> > diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
> > index 43d405298857..a8c97e95622a 100644
> > --- a/net/vmw_vsock/virtio_transport.c
> > +++ b/net/vmw_vsock/virtio_transport.c
> > @@ -508,7 +508,6 @@ static struct virtio_transport virtio_transport = {
> >               .cancel_pkt               = virtio_transport_cancel_pkt,
> >
> >               .dgram_bind               = virtio_transport_dgram_bind,
> > -             .dgram_dequeue            = virtio_transport_dgram_dequeue,
> >               .dgram_enqueue            = virtio_transport_dgram_enqueue,
> >               .dgram_allow              = virtio_transport_dgram_allow,
> >
> > diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> > index 16ff976a86e3..4bf73d20c12a 100644
> > --- a/net/vmw_vsock/virtio_transport_common.c
> > +++ b/net/vmw_vsock/virtio_transport_common.c
> > @@ -810,15 +810,6 @@ virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
> >  }
> >  EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue);
> >
> > -int
> > -virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
> > -                            struct msghdr *msg,
> > -                            size_t len, int flags)
> > -{
> > -     return -EOPNOTSUPP;
> > -}
> > -EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
> > -
> >  s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
> >  {
> >       struct virtio_vsock_sock *vvs = vsk->trans;
> > diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
> > index b370070194fa..b39df3ed8c8d 100644
> > --- a/net/vmw_vsock/vmci_transport.c
> > +++ b/net/vmw_vsock/vmci_transport.c
> > @@ -610,6 +610,7 @@ vmci_transport_datagram_create_hnd(u32 resource_id,
> >
> >  static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
> >  {
> > +     struct vsock_skb_cb *vsock_cb;
> >       struct sock *sk;
> >       size_t size;
> >       struct sk_buff *skb;
> > @@ -637,10 +638,14 @@ static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
> >       if (!skb)
> >               return VMCI_ERROR_NO_MEM;
> >
> > +     vsock_cb = vsock_skb_cb(skb);
> > +     vsock_cb->src_cid = dg->src.context;
> > +     vsock_cb->src_port = dg->src.resource;
> >       /* sk_receive_skb() will do a sock_put(), so hold here. */
> >       sock_hold(sk);
> >       skb_put(skb, size);
> >       memcpy(skb->data, dg, size);
> > +     skb_pull(skb, VMCI_DG_HEADERSIZE);
> >       sk_receive_skb(sk, skb, 0);
> >
> >       return VMCI_SUCCESS;
> > @@ -1731,59 +1736,6 @@ static int vmci_transport_dgram_enqueue(
> >       return err - sizeof(*dg);
> >  }
> >
> > -static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk,
> > -                                     struct msghdr *msg, size_t len,
> > -                                     int flags)
> > -{
> > -     int err;
> > -     struct vmci_datagram *dg;
> > -     size_t payload_len;
> > -     struct sk_buff *skb;
> > -
> > -     if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
> > -             return -EOPNOTSUPP;
> > -
> > -     /* Retrieve the head sk_buff from the socket's receive queue. */
> > -     err = 0;
> > -     skb = skb_recv_datagram(&vsk->sk, flags, &err);
> > -     if (!skb)
> > -             return err;
> > -
> > -     dg = (struct vmci_datagram *)skb->data;
> > -     if (!dg)
> > -             /* err is 0, meaning we read zero bytes. */
> > -             goto out;
> > -
> > -     payload_len = dg->payload_size;
> > -     /* Ensure the sk_buff matches the payload size claimed in the packet. */
> > -     if (payload_len != skb->len - sizeof(*dg)) {
> > -             err = -EINVAL;
> > -             goto out;
> > -     }
> > -
> > -     if (payload_len > len) {
> > -             payload_len = len;
> > -             msg->msg_flags |= MSG_TRUNC;
> > -     }
> > -
> > -     /* Place the datagram payload in the user's iovec. */
> > -     err = skb_copy_datagram_msg(skb, sizeof(*dg), msg, payload_len);
> > -     if (err)
> > -             goto out;
> > -
> > -     if (msg->msg_name) {
> > -             /* Provide the address of the sender. */
> > -             DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
> > -             vsock_addr_init(vm_addr, dg->src.context, dg->src.resource);
> > -             msg->msg_namelen = sizeof(*vm_addr);
> > -     }
> > -     err = payload_len;
> > -
> > -out:
> > -     skb_free_datagram(&vsk->sk, skb);
> > -     return err;
> > -}
> > -
> >  static bool vmci_transport_dgram_allow(u32 cid, u32 port)
> >  {
> >       if (cid == VMADDR_CID_HYPERVISOR) {
> > @@ -2040,7 +1992,6 @@ static struct vsock_transport vmci_transport = {
> >       .release = vmci_transport_release,
> >       .connect = vmci_transport_connect,
> >       .dgram_bind = vmci_transport_dgram_bind,
> > -     .dgram_dequeue = vmci_transport_dgram_dequeue,
> >       .dgram_enqueue = vmci_transport_dgram_enqueue,
> >       .dgram_allow = vmci_transport_dgram_allow,
> >       .stream_dequeue = vmci_transport_stream_dequeue,
> > diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
> > index 6dea6119f5b2..11488887a5cc 100644
> > --- a/net/vmw_vsock/vsock_loopback.c
> > +++ b/net/vmw_vsock/vsock_loopback.c
> > @@ -66,7 +66,6 @@ static struct virtio_transport loopback_transport = {
> >               .cancel_pkt               = vsock_loopback_cancel_pkt,
> >
> >               .dgram_bind               = virtio_transport_dgram_bind,
> > -             .dgram_dequeue            = virtio_transport_dgram_dequeue,
> >               .dgram_enqueue            = virtio_transport_dgram_enqueue,
> >               .dgram_allow              = virtio_transport_dgram_allow,
> >
> > --
> > 2.20.1
> >
> >
>
> Small changes :)
> Rest LGTM!
>

I will fix the two style issues.

Thank you,
Amery

> Thanks,
> Luigi
Arseniy Krasnov July 29, 2024, 7:25 p.m. UTC | #3 
> @@ -1273,11 +1273,15 @@ static int vsock_dgram_connect(struct socket *sock,
>  int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
>  			size_t len, int flags)
>  {
> +	struct vsock_skb_cb *vsock_cb;
>  #ifdef CONFIG_BPF_SYSCALL
>  	const struct proto *prot;
>  #endif
>  	struct vsock_sock *vsk;
> +	struct sk_buff *skb;
> +	size_t payload_len;
>  	struct sock *sk;
> +	int err;
>  
>  	sk = sock->sk;
>  	vsk = vsock_sk(sk);
> @@ -1288,7 +1292,43 @@ int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
>  		return prot->recvmsg(sk, msg, len, flags, NULL);
>  #endif
>  
> -	return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
> +	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
> +		return -EOPNOTSUPP;
> +
> +	if (unlikely(flags & MSG_ERRQUEUE))
> +		return sock_recv_errqueue(sk, msg, len, SOL_VSOCK, 0);
> +
> +	/* Retrieve the head sk_buff from the socket's receive queue. */
> +	err = 0;
> +	skb = skb_recv_datagram(sk_vsock(vsk), flags, &err);
> +	if (!skb)
> +		return err;
> +
> +	payload_len = skb->len;
> +
> +	if (payload_len > len) {
> +		payload_len = len;
> +		msg->msg_flags |= MSG_TRUNC;
> +	}
> +
> +	/* Place the datagram payload in the user's iovec. */
> +	err = skb_copy_datagram_msg(skb, 0, msg, payload_len);
> +	if (err)
> +		goto out;
> +
> +	if (msg->msg_name) {
> +		/* Provide the address of the sender. */
> +		DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
> +
> +		vsock_cb = vsock_skb_cb(skb);

May be we can declare 'vsock_cb' here ? Reducing its scope.

> +		vsock_addr_init(vm_addr, vsock_cb->src_cid, vsock_cb->src_port);
> +		msg->msg_namelen = sizeof(*vm_addr);
> +	}
> +	err = payload_len;
> +
> +out:
> +	skb_free_datagram(&vsk->sk, skb);
> +	return err;
>  }
>  EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
>  


> --- a/net/vmw_vsock/vmci_transport.c
> +++ b/net/vmw_vsock/vmci_transport.c
> @@ -610,6 +610,7 @@ vmci_transport_datagram_create_hnd(u32 resource_id,
>  
>  static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
>  {
> +	struct vsock_skb_cb *vsock_cb;
>  	struct sock *sk;
>  	size_t size;
>  	struct sk_buff *skb;
> @@ -637,10 +638,14 @@ static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
>  	if (!skb)
>  		return VMCI_ERROR_NO_MEM;
>  
> +	vsock_cb = vsock_skb_cb(skb);
> +	vsock_cb->src_cid = dg->src.context;
> +	vsock_cb->src_port = dg->src.resource;
>  	/* sk_receive_skb() will do a sock_put(), so hold here. */
>  	sock_hold(sk);
>  	skb_put(skb, size);
>  	memcpy(skb->data, dg, size);
> +	skb_pull(skb, VMCI_DG_HEADERSIZE);

Small suggestion: here we do:

1) skb_put(skb, size of entire datagram)
2) memcpy(entire datagram)
3) skb_pull(VMCI_DG_HEADERSIZE)

If we provide only data to the upper layer, we can do:
1) skb_put(dg->payload_size)
2) memcpy(dg->payload_size)

Also (I'm no expert in VMCI), i guess using dg->payload_size is safer
to know number of data bytes, instead of using VMCI_DG_HEADERSIZE.

WDYT?

>  	sk_receive_skb(sk, skb, 0);
>  
>  	return VMCI_SUCCESS;
> @@ -1731,59 +1736,6 @@ static int vmci_transport_dgram_enqueue(
>  	return err - sizeof(*dg);
>  }
>  

Thanks
diff mbox series

Patch

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index ec20ecff85c7..97fffa914e66 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -419,7 +419,6 @@  static struct virtio_transport vhost_transport = {
 		.cancel_pkt               = vhost_transport_cancel_pkt,
 
 		.dgram_enqueue            = virtio_transport_dgram_enqueue,
-		.dgram_dequeue            = virtio_transport_dgram_dequeue,
 		.dgram_bind               = virtio_transport_dgram_bind,
 		.dgram_allow              = virtio_transport_dgram_allow,
 
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index c82089dee0c8..8b56b8a19ddd 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -177,11 +177,6 @@  virtio_transport_stream_dequeue(struct vsock_sock *vsk,
 				size_t len,
 				int type);
 int
-virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
-			       struct msghdr *msg,
-			       size_t len, int flags);
-
-int
 virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
 				   struct msghdr *msg,
 				   size_t len);
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 535701efc1e5..7aa1f5f2b1a5 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -120,8 +120,6 @@  struct vsock_transport {
 
 	/* DGRAM. */
 	int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *);
-	int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
-			     size_t len, int flags);
 	int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
 			     struct msghdr *, size_t len);
 	bool (*dgram_allow)(u32 cid, u32 port);
@@ -219,6 +217,15 @@  void vsock_for_each_connected_socket(struct vsock_transport *transport,
 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
 bool vsock_find_cid(unsigned int cid);
 
+struct vsock_skb_cb {
+	unsigned int src_cid;
+	unsigned int src_port;
+};
+
+static inline struct vsock_skb_cb *vsock_skb_cb(struct sk_buff *skb) {
+	return (struct vsock_skb_cb *)skb->cb;
+};
+
 /**** TAP ****/
 
 struct vsock_tap {
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 4b040285aa78..5e7d4d99ea2c 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1273,11 +1273,15 @@  static int vsock_dgram_connect(struct socket *sock,
 int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
 			size_t len, int flags)
 {
+	struct vsock_skb_cb *vsock_cb;
 #ifdef CONFIG_BPF_SYSCALL
 	const struct proto *prot;
 #endif
 	struct vsock_sock *vsk;
+	struct sk_buff *skb;
+	size_t payload_len;
 	struct sock *sk;
+	int err;
 
 	sk = sock->sk;
 	vsk = vsock_sk(sk);
@@ -1288,7 +1292,43 @@  int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
 		return prot->recvmsg(sk, msg, len, flags, NULL);
 #endif
 
-	return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
+	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
+		return -EOPNOTSUPP;
+
+	if (unlikely(flags & MSG_ERRQUEUE))
+		return sock_recv_errqueue(sk, msg, len, SOL_VSOCK, 0);
+
+	/* Retrieve the head sk_buff from the socket's receive queue. */
+	err = 0;
+	skb = skb_recv_datagram(sk_vsock(vsk), flags, &err);
+	if (!skb)
+		return err;
+
+	payload_len = skb->len;
+
+	if (payload_len > len) {
+		payload_len = len;
+		msg->msg_flags |= MSG_TRUNC;
+	}
+
+	/* Place the datagram payload in the user's iovec. */
+	err = skb_copy_datagram_msg(skb, 0, msg, payload_len);
+	if (err)
+		goto out;
+
+	if (msg->msg_name) {
+		/* Provide the address of the sender. */
+		DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
+
+		vsock_cb = vsock_skb_cb(skb);
+		vsock_addr_init(vm_addr, vsock_cb->src_cid, vsock_cb->src_port);
+		msg->msg_namelen = sizeof(*vm_addr);
+	}
+	err = payload_len;
+
+out:
+	skb_free_datagram(&vsk->sk, skb);
+	return err;
 }
 EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
 
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index e2157e387217..326dd41ee2d5 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -556,12 +556,6 @@  static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr)
 	return -EOPNOTSUPP;
 }
 
-static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
-			     size_t len, int flags)
-{
-	return -EOPNOTSUPP;
-}
-
 static int hvs_dgram_enqueue(struct vsock_sock *vsk,
 			     struct sockaddr_vm *remote, struct msghdr *msg,
 			     size_t dgram_len)
@@ -833,7 +827,6 @@  static struct vsock_transport hvs_transport = {
 	.shutdown                 = hvs_shutdown,
 
 	.dgram_bind               = hvs_dgram_bind,
-	.dgram_dequeue            = hvs_dgram_dequeue,
 	.dgram_enqueue            = hvs_dgram_enqueue,
 	.dgram_allow              = hvs_dgram_allow,
 
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 43d405298857..a8c97e95622a 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -508,7 +508,6 @@  static struct virtio_transport virtio_transport = {
 		.cancel_pkt               = virtio_transport_cancel_pkt,
 
 		.dgram_bind               = virtio_transport_dgram_bind,
-		.dgram_dequeue            = virtio_transport_dgram_dequeue,
 		.dgram_enqueue            = virtio_transport_dgram_enqueue,
 		.dgram_allow              = virtio_transport_dgram_allow,
 
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 16ff976a86e3..4bf73d20c12a 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -810,15 +810,6 @@  virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
 }
 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue);
 
-int
-virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
-			       struct msghdr *msg,
-			       size_t len, int flags)
-{
-	return -EOPNOTSUPP;
-}
-EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
-
 s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
 {
 	struct virtio_vsock_sock *vvs = vsk->trans;
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index b370070194fa..b39df3ed8c8d 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -610,6 +610,7 @@  vmci_transport_datagram_create_hnd(u32 resource_id,
 
 static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
 {
+	struct vsock_skb_cb *vsock_cb;
 	struct sock *sk;
 	size_t size;
 	struct sk_buff *skb;
@@ -637,10 +638,14 @@  static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
 	if (!skb)
 		return VMCI_ERROR_NO_MEM;
 
+	vsock_cb = vsock_skb_cb(skb);
+	vsock_cb->src_cid = dg->src.context;
+	vsock_cb->src_port = dg->src.resource;
 	/* sk_receive_skb() will do a sock_put(), so hold here. */
 	sock_hold(sk);
 	skb_put(skb, size);
 	memcpy(skb->data, dg, size);
+	skb_pull(skb, VMCI_DG_HEADERSIZE);
 	sk_receive_skb(sk, skb, 0);
 
 	return VMCI_SUCCESS;
@@ -1731,59 +1736,6 @@  static int vmci_transport_dgram_enqueue(
 	return err - sizeof(*dg);
 }
 
-static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk,
-					struct msghdr *msg, size_t len,
-					int flags)
-{
-	int err;
-	struct vmci_datagram *dg;
-	size_t payload_len;
-	struct sk_buff *skb;
-
-	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
-		return -EOPNOTSUPP;
-
-	/* Retrieve the head sk_buff from the socket's receive queue. */
-	err = 0;
-	skb = skb_recv_datagram(&vsk->sk, flags, &err);
-	if (!skb)
-		return err;
-
-	dg = (struct vmci_datagram *)skb->data;
-	if (!dg)
-		/* err is 0, meaning we read zero bytes. */
-		goto out;
-
-	payload_len = dg->payload_size;
-	/* Ensure the sk_buff matches the payload size claimed in the packet. */
-	if (payload_len != skb->len - sizeof(*dg)) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	if (payload_len > len) {
-		payload_len = len;
-		msg->msg_flags |= MSG_TRUNC;
-	}
-
-	/* Place the datagram payload in the user's iovec. */
-	err = skb_copy_datagram_msg(skb, sizeof(*dg), msg, payload_len);
-	if (err)
-		goto out;
-
-	if (msg->msg_name) {
-		/* Provide the address of the sender. */
-		DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
-		vsock_addr_init(vm_addr, dg->src.context, dg->src.resource);
-		msg->msg_namelen = sizeof(*vm_addr);
-	}
-	err = payload_len;
-
-out:
-	skb_free_datagram(&vsk->sk, skb);
-	return err;
-}
-
 static bool vmci_transport_dgram_allow(u32 cid, u32 port)
 {
 	if (cid == VMADDR_CID_HYPERVISOR) {
@@ -2040,7 +1992,6 @@  static struct vsock_transport vmci_transport = {
 	.release = vmci_transport_release,
 	.connect = vmci_transport_connect,
 	.dgram_bind = vmci_transport_dgram_bind,
-	.dgram_dequeue = vmci_transport_dgram_dequeue,
 	.dgram_enqueue = vmci_transport_dgram_enqueue,
 	.dgram_allow = vmci_transport_dgram_allow,
 	.stream_dequeue = vmci_transport_stream_dequeue,
diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index 6dea6119f5b2..11488887a5cc 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c
@@ -66,7 +66,6 @@  static struct virtio_transport loopback_transport = {
 		.cancel_pkt               = vsock_loopback_cancel_pkt,
 
 		.dgram_bind               = virtio_transport_dgram_bind,
-		.dgram_dequeue            = virtio_transport_dgram_dequeue,
 		.dgram_enqueue            = virtio_transport_dgram_enqueue,
 		.dgram_allow              = virtio_transport_dgram_allow,