From b37e95507e1bd77c25ce8dae947cdfdb0d5b3308 Mon Sep 17 00:00:00 2001 From: Xuan Ding Date: Tue, 28 Jul 2020 01:33:47 +0000 Subject: [PATCH] doc: add vhost multi-queue reconnection issue This patch added known issue for vhost multi-queue reconnection with virtio-net/virtio-pmd. Signed-off-by: Xuan Ding Reviewed-by: Maxime Coquelin --- doc/guides/rel_notes/known_issues.rst | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/doc/guides/rel_notes/known_issues.rst b/doc/guides/rel_notes/known_issues.rst index de0782136d..5fb7f834f8 100644 --- a/doc/guides/rel_notes/known_issues.rst +++ b/doc/guides/rel_notes/known_issues.rst @@ -888,3 +888,24 @@ Unsuitable IOVA mode may be picked as the default **Driver/Module**: ALL. + +Vhost multi-queue reconnection failed with QEMU version >= 4.2.0 +---------------------------------------------------------------- + +**Description** + It's a QEMU regression bug (bad commit: c6beefd674ff). QEMU only saves + acked features for one vhost-net when vhost quits. When vhost reconnects + to virtio-net/virtio-pmd in multi-queue situations, the features been + set multiple times are not consistent. + +**Implication** + Vhost cannot reconnect back to virtio-net/virtio-pmd normally. + +**Resolution/Workaround**: + It is possible to filter the incorrect acked features at vhost-user side. + +**Affected Environment/Platform**: + ALL. + +**Driver/Module**: + Virtual Device Poll Mode Driver (PMD). -- 2.20.1