linux/net/vmw_vsock
Arseniy Krasnov 581512a6dc vsock/virtio: MSG_ZEROCOPY flag support
This adds handling of MSG_ZEROCOPY flag on transmission path:

1) If this flag is set and zerocopy transmission is possible (enabled
   in socket options and transport allows zerocopy), then non-linear
   skb will be created and filled with the pages of user's buffer.
   Pages of user's buffer are locked in memory by 'get_user_pages()'.
2) Replaces way of skb owning: instead of 'skb_set_owner_sk_safe()' it
   calls 'skb_set_owner_w()'. Reason of this change is that
   '__zerocopy_sg_from_iter()' increments 'sk_wmem_alloc' of socket, so
   to decrease this field correctly, proper skb destructor is needed:
   'sock_wfree()'. This destructor is set by 'skb_set_owner_w()'.
3) Adds new callback to 'struct virtio_transport': 'can_msgzerocopy'.
   If this callback is set, then transport needs extra check to be able
   to send provided number of buffers in zerocopy mode. Currently, the
   only transport that needs this callback set is virtio, because this
   transport adds new buffers to the virtio queue and we need to check,
   that number of these buffers is less than size of the queue (it is
   required by virtio spec). vhost and loopback transports don't need
   this check.

Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-09-21 12:34:00 +02:00
..
af_vsock_tap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
af_vsock.c vsock: send SIGPIPE on write to shutdowned socket 2023-09-14 08:19:55 +02:00
diag.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 321 2019-06-05 17:37:05 +02:00
hyperv_transport.c Drivers: hv: Make remove callback of hyperv driver void returned 2023-01-17 13:41:27 +00:00
Kconfig vsock: add vsock_loopback transport 2019-12-11 15:01:23 -08:00
Makefile vsock: support sockmap 2023-03-29 08:19:38 +01:00
virtio_transport_common.c vsock/virtio: MSG_ZEROCOPY flag support 2023-09-21 12:34:00 +02:00
virtio_transport.c vsock/virtio: MSG_ZEROCOPY flag support 2023-09-21 12:34:00 +02:00
vmci_transport_notify_qstate.c vmci/vsock: check SO_RCVLOWAT before wake up reader 2022-08-23 10:43:12 +02:00
vmci_transport_notify.c vmci/vsock: check SO_RCVLOWAT before wake up reader 2022-08-23 10:43:12 +02:00
vmci_transport_notify.h vsock: remove include/linux/vm_sockets.h file 2019-11-14 18:12:17 -08:00
vmci_transport.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-04-06 12:01:20 -07:00
vmci_transport.h vsock: Remove unused function declarations 2023-07-31 14:41:08 -07:00
vsock_addr.c vsock_addr: Check for supported flag values 2020-12-14 19:33:39 -08:00
vsock_bpf.c vsock: support sockmap 2023-03-29 08:19:38 +01:00
vsock_loopback.c vsock/loopback: don't disable irqs for queue access 2023-04-14 11:04:04 +01:00