Re: [RFC PATCH v4 12/17] vsock/loopback: support MSG_ZEROCOPY for transport

[Stefano Garzarella <sgarzare@redhat.com>]

On Sat, Jun 03, 2023 at 11:49:34PM +0300, Arseniy Krasnov wrote:
>Add 'msgzerocopy_allow()' callback for loopback transport.
>
>Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
>---
> net/vmw_vsock/vsock_loopback.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
>diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
>index 5c6360df1f31..a2e4aeda2d92 100644
>--- a/net/vmw_vsock/vsock_loopback.c
>+++ b/net/vmw_vsock/vsock_loopback.c
>@@ -47,6 +47,7 @@ static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
> }
>
> static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
>+static bool vsock_loopback_msgzerocopy_allow(void);

I don't know why we did this for `vsock_loopback_seqpacket_allow`, but
can we just put the implementation here?

>
> static struct virtio_transport loopback_transport = {
> 	.transport = {
>@@ -92,11 +93,18 @@ static struct virtio_transport loopback_transport = {
> 		.notify_buffer_size       = virtio_transport_notify_buffer_size,
>
> 		.read_skb = virtio_transport_read_skb,
>+
>+		.msgzerocopy_allow        = vsock_loopback_msgzerocopy_allow,

Ditto the moving.

> 	},
>
> 	.send_pkt = vsock_loopback_send_pkt,
> };
>
>+static bool vsock_loopback_msgzerocopy_allow(void)
>+{
>+	return true;
>+}
>+
> static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
> {
> 	return true;
>-- 
>2.25.1
>