vdpa_sim: add supported_features field in vdpasim_dev_attr

Introduce a new VDPASIM_FEATURES macro with the generic features
supported by the vDPA simulator, and VDPASIM_NET_FEATURES macro with
vDPA-net features.

Add 'supported_features' field in vdpasim_dev_attr, to allow devices
to specify their features.
Co-developed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20201215144256.155342-9-sgarzare@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/vdpa_sim/vdpa_sim.c

@@ -59,12 +59,15 @@ struct vdpasim_virtqueue {
 #define VDPASIM_VQ_NUM 0x2
 #define VDPASIM_NAME "vdpasim-netdev"
 
-static u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
-			      (1ULL << VIRTIO_F_VERSION_1)  |
-			      (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
-			      (1ULL << VIRTIO_NET_F_MAC);
+#define VDPASIM_FEATURES	((1ULL << VIRTIO_F_ANY_LAYOUT) | \
+				 (1ULL << VIRTIO_F_VERSION_1)  | \
+				 (1ULL << VIRTIO_F_ACCESS_PLATFORM))
+
+#define VDPASIM_NET_FEATURES	(VDPASIM_FEATURES | \
+				 (1ULL << VIRTIO_NET_F_MAC))
 
 struct vdpasim_dev_attr {
+	u64 supported_features;
 	int nvqs;
 	u32 id;
 };
@@ -122,7 +125,7 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
 {
 	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 
-	vringh_init_iotlb(&vq->vring, vdpasim_features,
+	vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
 			  VDPASIM_QUEUE_MAX, false,
 			  (struct vring_desc *)(uintptr_t)vq->desc_addr,
 			  (struct vring_avail *)
@@ -131,7 +134,8 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
 			  (uintptr_t)vq->device_addr);
 }
 
-static void vdpasim_vq_reset(struct vdpasim_virtqueue *vq)
+static void vdpasim_vq_reset(struct vdpasim *vdpasim,
+			     struct vdpasim_virtqueue *vq)
 {
 	vq->ready = false;
 	vq->desc_addr = 0;
@@ -139,8 +143,8 @@ static void vdpasim_vq_reset(struct vdpasim_virtqueue *vq)
 	vq->device_addr = 0;
 	vq->cb = NULL;
 	vq->private = NULL;
-	vringh_init_iotlb(&vq->vring, vdpasim_features, VDPASIM_QUEUE_MAX,
-			  false, NULL, NULL, NULL);
+	vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
+			  VDPASIM_QUEUE_MAX, false, NULL, NULL, NULL);
 }
 
 static void vdpasim_reset(struct vdpasim *vdpasim)
@@ -148,7 +152,7 @@ static void vdpasim_reset(struct vdpasim *vdpasim)
 	int i;
 
 	for (i = 0; i < vdpasim->dev_attr.nvqs; i++)
-		vdpasim_vq_reset(&vdpasim->vqs[i]);
+		vdpasim_vq_reset(vdpasim, &vdpasim->vqs[i]);
 
 	spin_lock(&vdpasim->iommu_lock);
 	vhost_iotlb_reset(vdpasim->iommu);
@@ -508,7 +512,9 @@ static u32 vdpasim_get_vq_align(struct vdpa_device *vdpa)
 
 static u64 vdpasim_get_features(struct vdpa_device *vdpa)
 {
-	return vdpasim_features;
+	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+	return vdpasim->dev_attr.supported_features;
 }
 
 static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
@@ -520,7 +526,7 @@ static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
 	if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
 		return -EINVAL;
 
-	vdpasim->features = features & vdpasim_features;
+	vdpasim->features = features & vdpasim->dev_attr.supported_features;
 
 	/* We generally only know whether guest is using the legacy interface
 	 * here, so generally that's the earliest we can set config fields.
@@ -732,6 +738,7 @@ static int __init vdpasim_dev_init(void)
 	struct vdpasim_dev_attr dev_attr = {};
 
 	dev_attr.id = VIRTIO_ID_NET;
+	dev_attr.supported_features = VDPASIM_NET_FEATURES;
 	dev_attr.nvqs = VDPASIM_VQ_NUM;
 
 	vdpasim_dev = vdpasim_create(&dev_attr);