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[PULL 46/56] libvhost-user: advertise vring features
From: |
Michael S. Tsirkin |
Subject: |
[PULL 46/56] libvhost-user: advertise vring features |
Date: |
Wed, 10 Jun 2020 00:28:16 -0400 |
From: Stefan Hajnoczi <stefanha@redhat.com>
libvhost-user implements several vring features without advertising
them. There is no way for the vhost-user master to detect support for
these features.
Things more or less work today because QEMU assumes the vhost-user
backend always implements certain feature bits like
VIRTIO_RING_F_EVENT_IDX. This is not documented anywhere.
This patch explicitly advertises features implemented in libvhost-user
so that the vhost-user master does not need to make undocumented
assumptions.
Feature bits that libvhost-user now advertises can be removed from
vhost-user-blk.c. Devices should not be responsible for advertising
vring feature bits, that is libvhost-user's job.
Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200529161338.456017-1-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
contrib/libvhost-user/libvhost-user.c | 10 ++++++++++
contrib/vhost-user-blk/vhost-user-blk.c | 4 +---
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/contrib/libvhost-user/libvhost-user.c
b/contrib/libvhost-user/libvhost-user.c
index b1e607298c..d315db1396 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -498,6 +498,16 @@ static bool
vu_get_features_exec(VuDev *dev, VhostUserMsg *vmsg)
{
vmsg->payload.u64 =
+ /*
+ * The following VIRTIO feature bits are supported by our virtqueue
+ * implementation:
+ */
+ 1ULL << VIRTIO_F_NOTIFY_ON_EMPTY |
+ 1ULL << VIRTIO_RING_F_INDIRECT_DESC |
+ 1ULL << VIRTIO_RING_F_EVENT_IDX |
+ 1ULL << VIRTIO_F_VERSION_1 |
+
+ /* vhost-user feature bits */
1ULL << VHOST_F_LOG_ALL |
1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
diff --git a/contrib/vhost-user-blk/vhost-user-blk.c
b/contrib/vhost-user-blk/vhost-user-blk.c
index 6fd91c7e99..25eccd02b5 100644
--- a/contrib/vhost-user-blk/vhost-user-blk.c
+++ b/contrib/vhost-user-blk/vhost-user-blk.c
@@ -382,9 +382,7 @@ vub_get_features(VuDev *dev)
1ull << VIRTIO_BLK_F_DISCARD |
1ull << VIRTIO_BLK_F_WRITE_ZEROES |
#endif
- 1ull << VIRTIO_BLK_F_CONFIG_WCE |
- 1ull << VIRTIO_F_VERSION_1 |
- 1ull << VHOST_USER_F_PROTOCOL_FEATURES;
+ 1ull << VIRTIO_BLK_F_CONFIG_WCE;
if (vdev_blk->enable_ro) {
features |= 1ull << VIRTIO_BLK_F_RO;
--
MST
- [PULL 35/56] vhost-user-blk: delay vhost_user_blk_disconnect, (continued)
- [PULL 35/56] vhost-user-blk: delay vhost_user_blk_disconnect, Michael S. Tsirkin, 2020/06/10
- [PULL 34/56] char-socket: return -1 in case of disconnect during tcp_chr_write, Michael S. Tsirkin, 2020/06/10
- [PULL 36/56] Add helper to populate vhost-user message regions, Michael S. Tsirkin, 2020/06/10
- [PULL 38/56] Add VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS, Michael S. Tsirkin, 2020/06/10
- [PULL 39/56] Transmit vhost-user memory regions individually, Michael S. Tsirkin, 2020/06/10
- [PULL 40/56] Lift max memory slots limit imposed by vhost-user, Michael S. Tsirkin, 2020/06/10
- [PULL 41/56] Refactor out libvhost-user fault generation logic, Michael S. Tsirkin, 2020/06/10
- [PULL 42/56] Support ram slot configuration in libvhost-user, Michael S. Tsirkin, 2020/06/10
- [PULL 44/56] Support individual region unmap in libvhost-user, Michael S. Tsirkin, 2020/06/10
- [PULL 45/56] Lift max ram slots limit in libvhost-user, Michael S. Tsirkin, 2020/06/10
- [PULL 46/56] libvhost-user: advertise vring features,
Michael S. Tsirkin <=
- [PULL 47/56] hw/pci: Fix crash when running QEMU with "-nic model=rocker", Michael S. Tsirkin, 2020/06/10
- [PULL 48/56] vhost-vsock: add vhost-vsock-common abstraction, Michael S. Tsirkin, 2020/06/10
- [PULL 50/56] virtio: add vhost-user-vsock-pci device, Michael S. Tsirkin, 2020/06/10
- [PULL 55/56] acpi: ged: rename event memory region, Michael S. Tsirkin, 2020/06/10
- [PULL 56/56] Fix parameter type in vhost migration log path, Michael S. Tsirkin, 2020/06/10
- [PULL 03/56] hw/acpi/nvdimm: add a helper to augment SRAT generation, Michael S. Tsirkin, 2020/06/10
- [PULL 30/56] hw/pci-host/prep: Correct RAVEN bus bridge memory region size, Michael S. Tsirkin, 2020/06/10
- [PULL 04/56] tests/acpi: update expected SRAT files, Michael S. Tsirkin, 2020/06/10
- [PULL 11/56] acpi: move aml builder code for parallel device, Michael S. Tsirkin, 2020/06/10
- [PULL 05/56] qtest: allow DSDT acpi table changes, Michael S. Tsirkin, 2020/06/10