Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull vhost,virtio,vdpa bugfixes from Michael Tsirkin:
"Misc fixes all over the place.

Revert of virtio used length validation series: the approach taken
does not seem to work, breaking too many guests in the process. We'll
need to do length validation using some other approach"

[ This merge also ends up reverting commit f7a36b03a732 ("vsock/virtio:
suppress used length validation"), which came in through the
networking tree in the meantime, and was part of that whole used
length validation series - Linus ]

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vdpa_sim: avoid putting an uninitialized iova_domain
vhost-vdpa: clean irqs before reseting vdpa device
virtio-blk: modify the value type of num in virtio_queue_rq()
vhost/vsock: cleanup removing `len` variable
vhost/vsock: fix incorrect used length reported to the guest
Revert "virtio_ring: validate used buffer length"
Revert "virtio-net: don't let virtio core to validate used length"
Revert "virtio-blk: don't let virtio core to validate used length"
Revert "virtio-scsi: don't let virtio core to validate used buffer length"

drivers/block/virtio_blk.c

···
 	struct request *req = bd->rq;
 	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
 	unsigned long flags;
-	unsigned int num;
+	int num;
 	int qid = hctx->queue_num;
 	bool notify = false;
 	blk_status_t status;
···
 	.feature_table_size		= ARRAY_SIZE(features),
 	.feature_table_legacy		= features_legacy,
 	.feature_table_size_legacy	= ARRAY_SIZE(features_legacy),
-	.suppress_used_validation	= true,
 	.driver.name			= KBUILD_MODNAME,
 	.driver.owner			= THIS_MODULE,
 	.id_table			= id_table,

drivers/net/virtio_net.c

···
 	.feature_table_size = ARRAY_SIZE(features),
 	.feature_table_legacy = features_legacy,
 	.feature_table_size_legacy = ARRAY_SIZE(features_legacy),
-	.suppress_used_validation = true,
 	.driver.name =	KBUILD_MODNAME,
 	.driver.owner =	THIS_MODULE,
 	.id_table =	id_table,

drivers/scsi/virtio_scsi.c

···
 static struct virtio_driver virtio_scsi_driver = {
 	.feature_table = features,
 	.feature_table_size = ARRAY_SIZE(features),
-	.suppress_used_validation = true,
 	.driver.name = KBUILD_MODNAME,
 	.driver.owner = THIS_MODULE,
 	.id_table = id_table,

drivers/vdpa/vdpa_sim/vdpa_sim.c

···
 		vringh_kiov_cleanup(&vdpasim->vqs[i].in_iov);
 	}
 
-	put_iova_domain(&vdpasim->iova);
-	iova_cache_put();
+	if (vdpa_get_dma_dev(vdpa)) {
+		put_iova_domain(&vdpasim->iova);
+		iova_cache_put();
+	}
+
 	kvfree(vdpasim->buffer);
 	if (vdpasim->iommu)
 		vhost_iotlb_free(vdpasim->iommu);

drivers/vhost/vdpa.c

···
 
 	mutex_lock(&d->mutex);
 	filep->private_data = NULL;
+	vhost_vdpa_clean_irq(v);
 	vhost_vdpa_reset(v);
 	vhost_dev_stop(&v->vdev);
 	vhost_vdpa_iotlb_free(v);
 	vhost_vdpa_free_domain(v);
 	vhost_vdpa_config_put(v);
-	vhost_vdpa_clean_irq(v);
 	vhost_dev_cleanup(&v->vdev);
 	kfree(v->vdev.vqs);
 	mutex_unlock(&d->mutex);

drivers/vhost/vsock.c

···
 
 	vhost_disable_notify(&vsock->dev, vq);
 	do {
-		u32 len;
-
 		if (!vhost_vsock_more_replies(vsock)) {
 			/* Stop tx until the device processes already
 			 * pending replies.  Leave tx virtqueue
···
 			continue;
 		}
 
-		len = pkt->len;
+		total_len += sizeof(pkt->hdr) + pkt->len;
 
 		/* Deliver to monitoring devices all received packets */
 		virtio_transport_deliver_tap_pkt(pkt);
···
 		else
 			virtio_transport_free_pkt(pkt);
 
-		len += sizeof(pkt->hdr);
-		vhost_add_used(vq, head, len);
-		total_len += len;
+		vhost_add_used(vq, head, 0);
 		added = true;
 	} while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
 

drivers/virtio/virtio_ring.c

···
 #include <linux/spinlock.h>
 #include <xen/xen.h>
 
-static bool force_used_validation = false;
-module_param(force_used_validation, bool, 0444);
-
 #ifdef DEBUG
 /* For development, we want to crash whenever the ring is screwed. */
 #define BAD_RING(_vq, fmt, args...)				\
···
 			size_t event_size_in_bytes;
 		} packed;
 	};
-
-	/* Per-descriptor in buffer length */
-	u32 *buflen;
 
 	/* How to notify other side. FIXME: commonalize hcalls! */
 	bool (*notify)(struct virtqueue *vq);
···
 	unsigned int i, n, avail, descs_used, prev, err_idx;
 	int head;
 	bool indirect;
-	u32 buflen = 0;
 
 	START_USE(vq);
 
···
 						     VRING_DESC_F_NEXT |
 						     VRING_DESC_F_WRITE,
 						     indirect);
-			buflen += sg->length;
 		}
 	}
 	/* Last one doesn't continue. */
···
 		vq->split.desc_state[head].indir_desc = desc;
 	else
 		vq->split.desc_state[head].indir_desc = ctx;
-
-	/* Store in buffer length if necessary */
-	if (vq->buflen)
-		vq->buflen[head] = buflen;
 
 	/* Put entry in available array (but don't update avail->idx until they
 	 * do sync). */
···
 	}
 	if (unlikely(!vq->split.desc_state[i].data)) {
 		BAD_RING(vq, "id %u is not a head!\n", i);
-		return NULL;
-	}
-	if (vq->buflen && unlikely(*len > vq->buflen[i])) {
-		BAD_RING(vq, "used len %d is larger than in buflen %u\n",
-			*len, vq->buflen[i]);
 		return NULL;
 	}
 
···
 	unsigned int i, n, err_idx;
 	u16 head, id;
 	dma_addr_t addr;
-	u32 buflen = 0;
 
 	head = vq->packed.next_avail_idx;
 	desc = alloc_indirect_packed(total_sg, gfp);
···
 			desc[i].addr = cpu_to_le64(addr);
 			desc[i].len = cpu_to_le32(sg->length);
 			i++;
-			if (n >= out_sgs)
-				buflen += sg->length;
 		}
 	}
 
···
 	vq->packed.desc_state[id].indir_desc = desc;
 	vq->packed.desc_state[id].last = id;
 
-	/* Store in buffer length if necessary */
-	if (vq->buflen)
-		vq->buflen[id] = buflen;
-
 	vq->num_added += 1;
 
 	pr_debug("Added buffer head %i to %p\n", head, vq);
···
 	__le16 head_flags, flags;
 	u16 head, id, prev, curr, avail_used_flags;
 	int err;
-	u32 buflen = 0;
 
 	START_USE(vq);
 
···
 					1 << VRING_PACKED_DESC_F_AVAIL |
 					1 << VRING_PACKED_DESC_F_USED;
 			}
-			if (n >= out_sgs)
-				buflen += sg->length;
 		}
 	}
 
···
 	vq->packed.desc_state[id].data = data;
 	vq->packed.desc_state[id].indir_desc = ctx;
 	vq->packed.desc_state[id].last = prev;
-
-	/* Store in buffer length if necessary */
-	if (vq->buflen)
-		vq->buflen[id] = buflen;
 
 	/*
 	 * A driver MUST NOT make the first descriptor in the list
···
 	}
 	if (unlikely(!vq->packed.desc_state[id].data)) {
 		BAD_RING(vq, "id %u is not a head!\n", id);
-		return NULL;
-	}
-	if (vq->buflen && unlikely(*len > vq->buflen[id])) {
-		BAD_RING(vq, "used len %d is larger than in buflen %u\n",
-			*len, vq->buflen[id]);
 		return NULL;
 	}
 
···
 	struct vring_virtqueue *vq;
 	struct vring_packed_desc *ring;
 	struct vring_packed_desc_event *driver, *device;
-	struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver);
 	dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
 	size_t ring_size_in_bytes, event_size_in_bytes;
 
···
 	if (!vq->packed.desc_extra)
 		goto err_desc_extra;
 
-	if (!drv->suppress_used_validation || force_used_validation) {
-		vq->buflen = kmalloc_array(num, sizeof(*vq->buflen),
-					   GFP_KERNEL);
-		if (!vq->buflen)
-			goto err_buflen;
-	} else {
-		vq->buflen = NULL;
-	}
-
 	/* No callback?  Tell other side not to bother us. */
 	if (!callback) {
 		vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
···
 	spin_unlock(&vdev->vqs_list_lock);
 	return &vq->vq;
 
-err_buflen:
-	kfree(vq->packed.desc_extra);
 err_desc_extra:
 	kfree(vq->packed.desc_state);
 err_desc_state:
···
 					void (*callback)(struct virtqueue *),
 					const char *name)
 {
-	struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver);
 	struct vring_virtqueue *vq;
 
 	if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
···
 	if (!vq->split.desc_extra)
 		goto err_extra;
 
-	if (!drv->suppress_used_validation || force_used_validation) {
-		vq->buflen = kmalloc_array(vring.num, sizeof(*vq->buflen),
-					   GFP_KERNEL);
-		if (!vq->buflen)
-			goto err_buflen;
-	} else {
-		vq->buflen = NULL;
-	}
-
 	/* Put everything in free lists. */
 	vq->free_head = 0;
 	memset(vq->split.desc_state, 0, vring.num *
···
 	spin_unlock(&vdev->vqs_list_lock);
 	return &vq->vq;
 
-err_buflen:
-	kfree(vq->split.desc_extra);
 err_extra:
 	kfree(vq->split.desc_state);
 err_state:

include/linux/virtio.h

···
  * @feature_table_size: number of entries in the feature table array.
  * @feature_table_legacy: same as feature_table but when working in legacy mode.
  * @feature_table_size_legacy: number of entries in feature table legacy array.
- * @suppress_used_validation: set to not have core validate used length
  * @probe: the function to call when a device is found.  Returns 0 or -errno.
  * @scan: optional function to call after successful probe; intended
  *    for virtio-scsi to invoke a scan.
···
 	unsigned int feature_table_size;
 	const unsigned int *feature_table_legacy;
 	unsigned int feature_table_size_legacy;
-	bool suppress_used_validation;
 	int (*validate)(struct virtio_device *dev);
 	int (*probe)(struct virtio_device *dev);
 	void (*scan)(struct virtio_device *dev);

net/vmw_vsock/virtio_transport.c

···
 static struct virtio_driver virtio_vsock_driver = {
 	.feature_table = features,
 	.feature_table_size = ARRAY_SIZE(features),
-	.suppress_used_validation = true,
 	.driver.name = KBUILD_MODNAME,
 	.driver.owner = THIS_MODULE,
 	.id_table = id_table,