The goal of this patch is to only request a sync (reply_ack,
or get_features) in set_mem_table only when necessary.
It should not be necessary the first time we set the table,
or when we add a new regions which hadn't been merged with an
existing ones.
Suggested-by: Michael S. Tsirkin <m...@redhat.com>
Cc: Prerna Saxena <prerna.sax...@nutanix.com>
Cc: Marc-André Lureau <marcandre.lur...@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
hw/virtio/vhost-user.c | 7 +++++++
hw/virtio/vhost.c | 10 ++++++++++
include/hw/virtio/vhost.h | 1 +
3 files changed, 18 insertions(+)
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 1a7d53c..ca41728 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -531,6 +531,11 @@ static int vhost_user_set_mem_table(struct vhost_dev *dev,
vhost_user_write(dev, &msg, fds, fd_num);
+ if (!dev->mem_changed_req_sync) {
+ /* The update only add regions, skip the sync */
+ return 0;
+ }
+
if (reply_supported) {
return process_message_reply(dev, msg.request);
} else {
@@ -541,6 +546,8 @@ static int vhost_user_set_mem_table(struct vhost_dev *dev,
vhost_user_get_features(dev, &features);
}
+ dev->mem_changed_req_sync = false;
+
return 0;
}
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 3d0c807..e653067 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -303,7 +303,11 @@ static void vhost_dev_assign_memory(struct vhost_dev *dev,
reg->guest_phys_addr = start_addr;
reg->userspace_addr = uaddr;
++to;
+ } else {
+ /* Existing mapping updated, sync is required */
+ dev->mem_changed_req_sync = true;
}
+
assert(to <= dev->mem->nregions + 1);
dev->mem->nregions = to;
}
@@ -533,6 +537,7 @@ static void vhost_set_memory(MemoryListener *listener,
} else {
/* Remove old mapping for this memory, if any. */
vhost_dev_unassign_memory(dev, start_addr, size);
+ dev->mem_changed_req_sync = true;
}
dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr);
dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr +
size - 1);
@@ -1126,6 +1131,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
hdev->log_enabled = false;
hdev->started = false;
hdev->memory_changed = false;
+ hdev->mem_changed_req_sync = false;
memory_listener_register(&hdev->memory_listener, &address_space_memory);
QLIST_INSERT_HEAD(&vhost_devices, hdev, entry);
return 0;
@@ -1301,6 +1307,10 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice
*vdev)
if (r < 0) {
goto fail_features;
}
+
+ /* First time the mem table is set, skip sync for completion */
+ hdev->mem_changed_req_sync = false;
+
r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem);
if (r < 0) {
VHOST_OPS_DEBUG("vhost_set_mem_table failed");
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index e433089..4bbf36a 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -55,6 +55,7 @@ struct vhost_dev {
uint64_t log_size;
Error *migration_blocker;
bool memory_changed;
+ bool mem_changed_req_sync;
hwaddr mem_changed_start_addr;
hwaddr mem_changed_end_addr;
const VhostOps *vhost_ops;
--
2.7.4
