virtio_pci: Revert "virtio_pci: support the arg sizes of find_vqs()"

This reverts commit cdb4480: the legacy
path is wrong and in fact can not support the proposed API since for a
legacy device we never communicate the vq size to the hypervisor.

Reported-by: Andres Freund <andres@anarazel.de>
Fixes: cdb4480 ("virtio_pci: support the arg sizes of find_vqs()")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20220816053602.173815-5-mst@redhat.com>

drivers/virtio/virtio_pci_common.c

@@ -174,7 +174,6 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
 static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned int index,
 				     void (*callback)(struct virtqueue *vq),
 				     const char *name,
-				     u32 size,
 				     bool ctx,
 				     u16 msix_vec)
 {
@@ -187,7 +186,7 @@ static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned int in
 	if (!info)
 		return ERR_PTR(-ENOMEM);
 
-	vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, size, ctx,
+	vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, ctx,
 			      msix_vec);
 	if (IS_ERR(vq))
 		goto out_info;
@@ -284,7 +283,7 @@ void vp_del_vqs(struct virtio_device *vdev)
 
 static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs,
 		struct virtqueue *vqs[], vq_callback_t *callbacks[],
-		const char * const names[], u32 sizes[], bool per_vq_vectors,
+		const char * const names[], bool per_vq_vectors,
 		const bool *ctx,
 		struct irq_affinity *desc)
 {
@@ -327,8 +326,8 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs,
 		else
 			msix_vec = VP_MSIX_VQ_VECTOR;
 		vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
-				     sizes ? sizes[i] : 0,
-				     ctx ? ctx[i] : false, msix_vec);
+				     ctx ? ctx[i] : false,
+				     msix_vec);
 		if (IS_ERR(vqs[i])) {
 			err = PTR_ERR(vqs[i]);
 			goto error_find;
@@ -358,7 +357,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs,
 
 static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs,
 		struct virtqueue *vqs[], vq_callback_t *callbacks[],
-		const char * const names[], u32 sizes[], const bool *ctx)
+		const char * const names[], const bool *ctx)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 	int i, err, queue_idx = 0;
@@ -380,7 +379,6 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs,
 			continue;
 		}
 		vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
-				     sizes ? sizes[i] : 0,
 				     ctx ? ctx[i] : false,
 				     VIRTIO_MSI_NO_VECTOR);
 		if (IS_ERR(vqs[i])) {
@@ -404,15 +402,15 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
 	int err;
 
 	/* Try MSI-X with one vector per queue. */
-	err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, sizes, true, ctx, desc);
+	err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, true, ctx, desc);
 	if (!err)
 		return 0;
 	/* Fallback: MSI-X with one vector for config, one shared for queues. */
-	err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, sizes, false, ctx, desc);
+	err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false, ctx, desc);
 	if (!err)
 		return 0;
 	/* Finally fall back to regular interrupts. */
-	return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, sizes, ctx);
+	return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx);
 }
 
 const char *vp_bus_name(struct virtio_device *vdev)

drivers/virtio/virtio_pci_common.h

@@ -80,7 +80,6 @@ struct virtio_pci_device {
 				      unsigned int idx,
 				      void (*callback)(struct virtqueue *vq),
 				      const char *name,
-				      u32 size,
 				      bool ctx,
 				      u16 msix_vec);
 	void (*del_vq)(struct virtio_pci_vq_info *info);

drivers/virtio/virtio_pci_legacy.c

@@ -112,7 +112,6 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
 				  unsigned int index,
 				  void (*callback)(struct virtqueue *vq),
 				  const char *name,
-				  u32 size,
 				  bool ctx,
 				  u16 msix_vec)
 {
@@ -126,13 +125,10 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
 	if (!num || vp_legacy_get_queue_enable(&vp_dev->ldev, index))
 		return ERR_PTR(-ENOENT);
 
-	if (!size || size > num)
-		size = num;
-
 	info->msix_vector = msix_vec;
 
 	/* create the vring */
-	vq = vring_create_virtqueue(index, size,
+	vq = vring_create_virtqueue(index, num,
 				    VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
 				    true, false, ctx,
 				    vp_notify, callback, name);

drivers/virtio/virtio_pci_modern.c

@@ -293,7 +293,6 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
 				  unsigned int index,
 				  void (*callback)(struct virtqueue *vq),
 				  const char *name,
-				  u32 size,
 				  bool ctx,
 				  u16 msix_vec)
 {
@@ -311,18 +310,15 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
 	if (!num || vp_modern_get_queue_enable(mdev, index))
 		return ERR_PTR(-ENOENT);
 
-	if (!size || size > num)
-		size = num;
-
-	if (size & (size - 1)) {
-		dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", size);
+	if (num & (num - 1)) {
+		dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num);
 		return ERR_PTR(-EINVAL);
 	}
 
 	info->msix_vector = msix_vec;
 
 	/* create the vring */
-	vq = vring_create_virtqueue(index, size,
+	vq = vring_create_virtqueue(index, num,
 				    SMP_CACHE_BYTES, &vp_dev->vdev,
 				    true, true, ctx,
 				    vp_notify, callback, name);