[RFC PATCH v1 12/16] virtio/vsock: add 'drop until EOR' logic
From: Arseny Krasnov <hidden>
Date: 2021-06-28 10:04:51
Also in:
kvm, lkml
Subsystem:
networking [general], the rest, virtio and vhost vsock driver, virtio core, vm sockets (af_vsock) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Stefan Hajnoczi, Stefano Garzarella, "Michael S. Tsirkin", Jason Wang, Eugenio Pérez
Data will copied only if 'drop until EOR' mode is disabled, also if EOR found, 'msg_ready' is set only if we don't have current message to drop. Signed-off-by: Arseny Krasnov <redacted> --- include/linux/virtio_vsock.h | 2 ++ net/vmw_vsock/virtio_transport_common.c | 23 +++++++++++++++++++---- 2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 7360ab7ea0af..18a50f64bf54 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h@@ -36,6 +36,7 @@ struct virtio_vsock_sock { u32 rx_bytes; u32 buf_alloc; struct list_head rx_queue; + bool drop_until_eor; }; struct virtio_vsock_pkt {
@@ -89,6 +90,7 @@ virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, struct msghdr *msg, int flags, bool *msg_ready); +void virtio_transport_seqpacket_drop(struct vsock_sock *vsk); s64 virtio_transport_stream_has_data(struct vsock_sock *vsk); s64 virtio_transport_stream_has_space(struct vsock_sock *vsk);
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 5a46c3f94e83..a8f74cc343e4 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c@@ -425,7 +425,7 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, pkt = list_first_entry(&vvs->rx_queue, struct virtio_vsock_pkt, list); pkt_len = (size_t)le32_to_cpu(pkt->hdr.len); - bytes_to_copy = min(user_buf_len, pkt_len); + bytes_to_copy = vvs->drop_until_eor ? 0 : min(user_buf_len, pkt_len); if (bytes_to_copy) { int err;
@@ -438,17 +438,22 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, spin_lock_bh(&vvs->rx_lock); - if (err) + if (err) { dequeued_len = err; - else + vvs->drop_until_eor = true; + } else { user_buf_len -= bytes_to_copy; + } } if (dequeued_len >= 0) dequeued_len += pkt_len; if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR) { - *msg_ready = true; + if (vvs->drop_until_eor) + vvs->drop_until_eor = false; + else + *msg_ready = true; } virtio_transport_dec_rx_pkt(vvs, pkt);
@@ -487,6 +492,16 @@ virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, } EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue); +void virtio_transport_seqpacket_drop(struct vsock_sock *vsk) +{ + struct virtio_vsock_sock *vvs = vsk->trans; + + spin_lock_bh(&vvs->rx_lock); + vvs->drop_until_eor = true; + spin_unlock_bh(&vvs->rx_lock); +} +EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_drop); + int virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk, struct msghdr *msg,
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2.25.1