From: "Alex Bennée" <alex.bennee@linaro.org>
To: qemu-devel@nongnu.org
Cc: slp@redhat.com, mst@redhat.com, marcandre.lureau@redhat.com,
stefanha@redhat.com, mathieu.poirier@linaro.org,
viresh.kumar@linaro.org, mark.cave-ayland@ilande.co.uk,
jasowang@redhat.com, "Alex Bennée" <alex.bennee@linaro.org>
Subject: [PATCH v3 01/21] include/hw/virtio: more comment for VIRTIO_F_BAD_FEATURE
Date: Tue, 26 Jul 2022 20:21:30 +0100 [thread overview]
Message-ID: <20220726192150.2435175-2-alex.bennee@linaro.org> (raw)
In-Reply-To: <20220726192150.2435175-1-alex.bennee@linaro.org>
When debugging a new vhost user you may be surprised to see
VHOST_USER_F_PROTOCOL getting squashed in the maze of
backend_features, acked_features and guest_features. Expand the
description here to help the next poor soul trying to work through
this.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
v3
- s/vhost/vhost-user/
---
include/hw/virtio/virtio.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index db1c0ddf6b..9bb2485415 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -24,7 +24,12 @@
#include "qom/object.h"
#include "hw/virtio/vhost.h"
-/* A guest should never accept this. It implies negotiation is broken. */
+/*
+ * A guest should never accept this. It implies negotiation is broken
+ * between the driver frontend and the device. This bit is re-used for
+ * vhost-user to advertise VHOST_USER_F_PROTOCOL_FEATURES between QEMU
+ * and a vhost-user backend.
+ */
#define VIRTIO_F_BAD_FEATURE 30
#define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \
--
2.30.2
next prev parent reply other threads:[~2022-07-26 19:24 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-26 19:21 [PATCH v3 for 7.2 00/21] virtio-gpio and various virtio cleanups Alex Bennée
2022-07-26 19:21 ` Alex Bennée [this message]
2022-07-26 19:21 ` [PATCH v3 02/21] include/hw: document vhost_dev feature life-cycle Alex Bennée
2022-07-28 6:06 ` Jason Wang
2022-07-28 10:34 ` Alex Bennée
2022-07-26 19:21 ` [PATCH v3 03/21] hw/virtio: fix some coding style issues Alex Bennée
2022-07-28 6:07 ` Jason Wang
2022-07-26 19:21 ` [PATCH v3 04/21] hw/virtio: log potentially buggy guest drivers Alex Bennée
2022-07-28 6:09 ` Jason Wang
2022-07-26 19:21 ` [PATCH v3 05/21] block/vhost-user-blk-server: don't expose VHOST_USER_F_PROTOCOL_FEATURES Alex Bennée
2022-07-27 16:32 ` Kevin Wolf
2022-07-28 6:13 ` Jason Wang
2022-07-28 10:41 ` Alex Bennée
2022-07-26 19:21 ` [PATCH v3 06/21] hw/virtio: incorporate backend features in features Alex Bennée
2022-07-26 19:21 ` [PATCH v3 07/21] hw/virtio: gracefully handle unset vhost_dev vdev Alex Bennée
2022-07-26 19:21 ` [PATCH v3 08/21] hw/virtio: handle un-configured shutdown in virtio-pci Alex Bennée
2022-07-28 6:23 ` Jason Wang
2022-07-26 19:21 ` [PATCH v3 09/21] hw/virtio: fix vhost_user_read tracepoint Alex Bennée
2022-07-28 6:28 ` Jason Wang
2022-07-26 19:21 ` [PATCH v3 10/21] hw/virtio: add some vhost-user trace events Alex Bennée
2022-07-26 19:21 ` [PATCH v3 11/21] hw/virtio: add boilerplate for vhost-user-gpio device Alex Bennée
2022-07-26 19:21 ` [PATCH v3 12/21] hw/virtio: add vhost-user-gpio-pci boilerplate Alex Bennée
2022-07-26 19:21 ` [PATCH v3 13/21] tests/qtest: pass stdout/stderr down to subtests Alex Bennée
2022-07-26 19:21 ` [PATCH v3 14/21] tests/qtest: add a timeout for subprocess_run_one_test Alex Bennée
2022-07-27 6:24 ` Thomas Huth
2022-07-26 19:21 ` [PATCH v3 15/21] tests/qtest: use qos_printf instead of g_test_message Alex Bennée
2022-07-26 19:21 ` [PATCH v3 16/21] tests/qtest: catch unhandled vhost-user messages Alex Bennée
2022-07-26 19:21 ` [PATCH v3 17/21] tests/qtest: plain g_assert for VHOST_USER_F_PROTOCOL_FEATURES Alex Bennée
2022-07-26 19:21 ` [PATCH v3 18/21] tests/qtest: add assert to catch bad features Alex Bennée
2022-07-26 19:21 ` [PATCH v3 19/21] tests/qtest: implement stub for VHOST_USER_GET_CONFIG Alex Bennée
2022-07-26 19:21 ` [PATCH v3 20/21] tests/qtest: add a get_features op to vhost-user-test Alex Bennée
2022-07-26 19:21 ` [PATCH v3 21/21] tests/qtest: enable tests for virtio-gpio Alex Bennée
2022-07-26 19:46 ` [PATCH v3 for 7.2 00/21] virtio-gpio and various virtio cleanups Michael S. Tsirkin
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