[PATCH V4 02/10] vhost-vdpa: classify one time request

[Jason Wang <jasowang@redhat.com>]

Vhost-vdpa uses one device multiqueue queue (pairs) model. So we need
to classify the one time request (e.g SET_OWNER) and make sure those
request were only called once per device.

This is used for multiqueue support.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20210907090322.1756-3-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/vhost-vdpa.c         | 52 ++++++++++++++++++++++++++++++----
 include/hw/virtio/vhost-vdpa.h |  1 +
 2 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 47d7a5a23d..edac4017da 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -279,6 +279,13 @@ static void vhost_vdpa_add_status(struct vhost_dev *dev, uint8_t status)
     vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &s);
 }
 
+static bool vhost_vdpa_one_time_request(struct vhost_dev *dev)
+{
+    struct vhost_vdpa *v = dev->opaque;
+
+    return v->index != 0;
+}
+
 static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
 {
     struct vhost_vdpa *v;
@@ -291,6 +298,10 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
     v->listener = vhost_vdpa_memory_listener;
     v->msg_type = VHOST_IOTLB_MSG_V2;
 
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
                                VIRTIO_CONFIG_S_DRIVER);
 
@@ -401,6 +412,10 @@ static int vhost_vdpa_memslots_limit(struct vhost_dev *dev)
 static int vhost_vdpa_set_mem_table(struct vhost_dev *dev,
                                     struct vhost_memory *mem)
 {
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     trace_vhost_vdpa_set_mem_table(dev, mem->nregions, mem->padding);
     if (trace_event_get_state_backends(TRACE_VHOST_VDPA_SET_MEM_TABLE) &&
         trace_event_get_state_backends(TRACE_VHOST_VDPA_DUMP_REGIONS)) {
@@ -424,6 +439,11 @@ static int vhost_vdpa_set_features(struct vhost_dev *dev,
                                    uint64_t features)
 {
     int ret;
+
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     trace_vhost_vdpa_set_features(dev, features);
     ret = vhost_vdpa_call(dev, VHOST_SET_FEATURES, &features);
     uint8_t status = 0;
@@ -448,9 +468,12 @@ static int vhost_vdpa_set_backend_cap(struct vhost_dev *dev)
     }
 
     features &= f;
-    r = vhost_vdpa_call(dev, VHOST_SET_BACKEND_FEATURES, &features);
-    if (r) {
-        return -EFAULT;
+
+    if (vhost_vdpa_one_time_request(dev)) {
+        r = vhost_vdpa_call(dev, VHOST_SET_BACKEND_FEATURES, &features);
+        if (r) {
+            return -EFAULT;
+        }
     }
 
     dev->backend_cap = features;
@@ -559,11 +582,21 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
 {
     struct vhost_vdpa *v = dev->opaque;
     trace_vhost_vdpa_dev_start(dev, started);
+
     if (started) {
-        uint8_t status = 0;
-        memory_listener_register(&v->listener, &address_space_memory);
         vhost_vdpa_host_notifiers_init(dev);
         vhost_vdpa_set_vring_ready(dev);
+    } else {
+        vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
+    }
+
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
+    if (started) {
+        uint8_t status = 0;
+        memory_listener_register(&v->listener, &address_space_memory);
         vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
         vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
 
@@ -572,7 +605,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
         vhost_vdpa_reset_device(dev);
         vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
                                    VIRTIO_CONFIG_S_DRIVER);
-        vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
         memory_listener_unregister(&v->listener);
 
         return 0;
@@ -582,6 +614,10 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
 static int vhost_vdpa_set_log_base(struct vhost_dev *dev, uint64_t base,
                                      struct vhost_log *log)
 {
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     trace_vhost_vdpa_set_log_base(dev, base, log->size, log->refcnt, log->fd,
                                   log->log);
     return vhost_vdpa_call(dev, VHOST_SET_LOG_BASE, &base);
@@ -647,6 +683,10 @@ static int vhost_vdpa_get_features(struct vhost_dev *dev,
 
 static int vhost_vdpa_set_owner(struct vhost_dev *dev)
 {
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     trace_vhost_vdpa_set_owner(dev);
     return vhost_vdpa_call(dev, VHOST_SET_OWNER, NULL);
 }
diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index a8963da2d9..6b9288fef8 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -21,6 +21,7 @@ typedef struct VhostVDPAHostNotifier {
 
 typedef struct vhost_vdpa {
     int device_fd;
+    int index;
     uint32_t msg_type;
     bool iotlb_batch_begin_sent;
     MemoryListener listener;
-- 
2.25.1