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On Wed, Nov 23, 2022 at 10:07:49PM -0800, Bobby Eshleman wrote:

This commit changes virtio/vsock to use sk_buff instead of
virtio_vsock_pkt. Beyond better conforming to other net code, using
sk_buff allows vsock to use sk_buff-dependent features in the future
(such as sockmap) and improves throughput.

This patch introduces the following performance changes:

Tool/Config: uperf w/ 64 threads, SOCK_STREAM
Test Runs: 5, mean of results
Before: commit 95ec6bce2a0b ("Merge branch 'net-ipa-more-endpoints'")

Test: 64KB, g2h
Before: 21.63 Gb/s
After: 25.59 Gb/s (+18%)

Test: 16B, g2h
Before: 11.86 Mb/s
After: 17.41 Mb/s (+46%)

Test: 64KB, h2g
Before: 2.15 Gb/s
After: 3.6 Gb/s (+67%)

Test: 16B, h2g
Before: 14.38 Mb/s
After: 18.43 Mb/s (+28%)

Signed-off-by: Bobby Eshleman <redacted>
---

The patch LGTM. I run several tests (iperf3, vsock_test,
vsock_diag_test, vhost-user-vsock, tcpdump) and IMO we are okay.

I found the following problems that I would like to report:

- vhost-user-vsock [1] is failing, but it is not an issue of this patch,
   but a spec violation in the rust-vmm/vm-virtio/virtio-vsock crate as I
   reported here [2]. We will fix it there, this patch is fine, indeed
   trying a guest with the new layout (1 descriptor for both header and
   data) with vhost-vsock in Linux 6.0, everything works perfectly.

- the new "SOCK_SEQPACKET msg bounds" [3] reworked by Arseniy fails
   intermittently with this patch.

   Using the tests currently in the kernel tree everything is fine, so
   I don't understand if it's a problem in the new test or in this
   patch. I've looked at the code again and don't seem to see any
   criticisms.

   @Arseniy @Bobby can you take a look?

   I'll try to take a closer look too, and before I give my R-b I'd like
   to make sure it's a problem in the test and not in this patch.

   This is what I have (some times, not always) with both host and guest
   with this patch and the series of [3] applied:

   host$ ./vsock_test --control-host=192.168.133.3 --control-port=12345 \
                      --mode=client --peer-cid=4
   Control socket connected to 192.168.133.3:12345.
   0 - SOCK_STREAM connection reset...ok
   1 - SOCK_STREAM bind only...ok
   2 - SOCK_STREAM client close...ok
   3 - SOCK_STREAM server close...ok
   4 - SOCK_STREAM multiple connections...ok
   5 - SOCK_STREAM MSG_PEEK...ok
   6 - SOCK_SEQPACKET msg bounds...ok
   7 - SOCK_SEQPACKET MSG_TRUNC flag...recv: Connection reset by peer

   guest$ ./vsock_test --control-port=12345 --mode=server --peer-cid=2
   Control socket listening on 0.0.0.0:12345
   Control socket connection accepted...
   0 - SOCK_STREAM connection reset...ok
   1 - SOCK_STREAM bind only...ok
   2 - SOCK_STREAM client close...ok
   3 - SOCK_STREAM server close...ok
   4 - SOCK_STREAM multiple connections...ok
   5 - SOCK_STREAM MSG_PEEK...ok
   6 - SOCK_SEQPACKET msg bounds...Message bounds broken

Thanks,
Stefano

[1] https://github.com/rust-vmm/vhost-device/tree/main/crates/vsock
[2] https://github.com/rust-vmm/vm-virtio/issues/204
[3] https://lore.kernel.org/lkml/c991dffd-1dbc-e1d1-b682-a3c71f6ce51c@sberdevices.ru/ (local)