vhost-user-blk: make it possible to disable write-zeroes/discard

It is useful to have the ability to disable these features for
compatibility with older VMs that don't have these implemented.

Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220906073111.353245-4-d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 2bba424..92bfe56 100644 (file)
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -259,8 +259,6 @@ static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
     virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
     virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH);
     virtio_add_feature(&features, VIRTIO_BLK_F_RO);
-    virtio_add_feature(&features, VIRTIO_BLK_F_DISCARD);
-    virtio_add_feature(&features, VIRTIO_BLK_F_WRITE_ZEROES);
 
     if (s->config_wce) {
         virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);
@@ -598,6 +596,10 @@ static Property vhost_user_blk_properties[] = {
                        VHOST_USER_BLK_AUTO_NUM_QUEUES),
     DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128),
     DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true),
+    DEFINE_PROP_BIT64("discard", VHostUserBlk, parent_obj.host_features,
+                      VIRTIO_BLK_F_DISCARD, true),
+    DEFINE_PROP_BIT64("write-zeroes", VHostUserBlk, parent_obj.host_features,
+                      VIRTIO_BLK_F_WRITE_ZEROES, true),
     DEFINE_PROP_END_OF_LIST(),
 };