patches for DPDK stable branches
 help / color / mirror / Atom feed
From: Kevin Traynor <>
Cc: Kevin Traynor <>,
Subject: [dpdk-stable] [PATCH 18.11] vhost: remove zero-copy and client mode restriction
Date: Wed,  1 Jul 2020 14:52:50 +0100	[thread overview]
Message-ID: <> (raw)

Commits [1] were backported as fixes from the latest DPDK release
to the stable branches. They are detecting if vhost-user client and
zero-copy are being used together. As this can be problematic in
some cases, this combination was being rejected by those patches.

It might be ok to deprecate this combination in latest DPDK,
but for stable releases we should not remove the functionality
as it may be in use with earlier releases from the same stable branch.

In fact, we know that this functionality is used at least in OVS in
multiple releases/active branches.

This patch removes the restriction of zero-copy and client mode
and adds a warning for the user.

commit 81e025d7ed6a
("vhost: prevent zero-copy with incompatible client mode")

commit 0309429b1988
("vhost: fix zero-copy server mode")

Signed-off-by: Kevin Traynor <>
 lib/librte_vhost/socket.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index 4819d31737..6f7142be23 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -891,10 +891,8 @@ rte_vhost_driver_register(const char *path, uint64_t flags)
 	if (vsocket->dequeue_zero_copy) {
-		if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
-			"error: zero copy is incompatible with vhost client mode\n");
-			ret = -1;
-			goto out_mutex;
-		}
+		if ((flags & RTE_VHOST_USER_CLIENT) != 0)
+			"zero copy may be incompatible with vhost client mode\n");
 		vsocket->supported_features &= ~(1ULL << VIRTIO_F_IN_ORDER);
 		vsocket->features &= ~(1ULL << VIRTIO_F_IN_ORDER);

             reply	other threads:[~2020-07-01 13:53 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-01 13:52 Kevin Traynor [this message]
2020-07-01 15:09 ` Luca Boccassi
2020-07-02 11:57   ` Kevin Traynor

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).