From 4d191cfdc7de958d06f821173f721c56bc131620 Mon Sep 17 00:00:00 2001
From: Jason Wang <jasowang@redhat.com>
Date: Wed, 20 Oct 2021 12:55:52 +0800
Subject: [PATCH] vhost-vdpa: classify one time request

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: <20211020045600.16082-3-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         | 53 +++++++++++++++++++++++++++++++++++++-----
 include/hw/virtio/vhost-vdpa.h |  1 +
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 47c48f4ba8..ceb53613ba 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -319,6 +319,13 @@ static void vhost_vdpa_get_iova_range(struct vhost_vdpa *v)
                                     v->iova_range.last);
 }
 
+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;
@@ -332,6 +339,11 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
     v->msg_type = VHOST_IOTLB_MSG_V2;
 
     vhost_vdpa_get_iova_range(v);
+
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
                                VIRTIO_CONFIG_S_DRIVER);
 
@@ -442,6 +454,10 @@ 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)) {
@@ -465,6 +481,11 @@ 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;
@@ -489,9 +510,12 @@ 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;
@@ -600,11 +624,21 @@ 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);
 
@@ -613,7 +647,6 @@ 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;
@@ -623,6 +656,10 @@ 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);
@@ -688,6 +725,10 @@ 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 c288cf7ecb..3ce79a646d 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -22,6 +22,7 @@ typedef struct VhostVDPAHostNotifier {
 
 typedef struct vhost_vdpa {
     int device_fd;
+    int index;
     uint32_t msg_type;
     bool iotlb_batch_begin_sent;
     MemoryListener listener;
-- 
2.11.4.GIT