581512a6dc
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> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| af_vsock.c | ||
| af_vsock_tap.c | ||
| diag.c | ||
| hyperv_transport.c | ||
| virtio_transport.c | ||
| virtio_transport_common.c | ||
| vmci_transport.c | ||
| vmci_transport.h | ||
| vmci_transport_notify.c | ||
| vmci_transport_notify.h | ||
| vmci_transport_notify_qstate.c | ||
| vsock_addr.c | ||
| vsock_bpf.c | ||
| vsock_loopback.c | ||