virtio: VIRTIO_F_IOMMU_PLATFORM -> VIRTIO_F_ACCESS_PLATFORM

Rename the bit to match latest virtio spec.
Add a compat macro to avoid breaking existing userspace.

Signed-off-by: Michael S. Tsirkin <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>

arch/um/drivers/virtio_uml.c

···
 		}
 		break;
 	case VHOST_USER_SLAVE_IOTLB_MSG:
-		/* not supported - VIRTIO_F_IOMMU_PLATFORM */
+		/* not supported - VIRTIO_F_ACCESS_PLATFORM */
 	case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
 		/* not supported - VHOST_USER_PROTOCOL_F_HOST_NOTIFIER */
 	default:

drivers/vdpa/ifcvf/ifcvf_base.h

···
 		 (1ULL << VIRTIO_F_VERSION_1)			| \
 		 (1ULL << VIRTIO_NET_F_STATUS)			| \
 		 (1ULL << VIRTIO_F_ORDER_PLATFORM)		| \
-		 (1ULL << VIRTIO_F_IOMMU_PLATFORM)		| \
+		 (1ULL << VIRTIO_F_ACCESS_PLATFORM)		| \
 		 (1ULL << VIRTIO_NET_F_MRG_RXBUF))
 
 /* Only one queue pair for now. */

drivers/vdpa/vdpa_sim/vdpa_sim.c

···
 
 static u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
 			      (1ULL << VIRTIO_F_VERSION_1)  |
-			      (1ULL << VIRTIO_F_IOMMU_PLATFORM);
+			      (1ULL << VIRTIO_F_ACCESS_PLATFORM);
 
 /* State of each vdpasim device */
 struct vdpasim {
···
 	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 
 	/* DMA mapping must be done by driver */
-	if (!(features & (1ULL << VIRTIO_F_IOMMU_PLATFORM)))
+	if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
 		return -EINVAL;
 
 	vdpasim->features = features & vdpasim_features;

drivers/vhost/net.c

···
 	VHOST_NET_FEATURES = VHOST_FEATURES |
 			 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
 			 (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
-			 (1ULL << VIRTIO_F_IOMMU_PLATFORM)
+			 (1ULL << VIRTIO_F_ACCESS_PLATFORM)
 };
 
 enum {
···
 	    !vhost_log_access_ok(&n->dev))
 		goto out_unlock;
 
-	if ((features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) {
+	if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) {
 		if (vhost_init_device_iotlb(&n->dev, true))
 			goto out_unlock;
 	}

drivers/vhost/vdpa.c

···
 		(1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
 		(1ULL << VIRTIO_F_ANY_LAYOUT) |
 		(1ULL << VIRTIO_F_VERSION_1) |
-		(1ULL << VIRTIO_F_IOMMU_PLATFORM) |
+		(1ULL << VIRTIO_F_ACCESS_PLATFORM) |
 		(1ULL << VIRTIO_F_RING_PACKED) |
 		(1ULL << VIRTIO_F_ORDER_PLATFORM) |
 		(1ULL << VIRTIO_RING_F_INDIRECT_DESC) |

drivers/virtio/virtio_balloon.c

···
 	else if (!virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON))
 		__virtio_clear_bit(vdev, VIRTIO_BALLOON_F_REPORTING);
 
-	__virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM);
+	__virtio_clear_bit(vdev, VIRTIO_F_ACCESS_PLATFORM);
 	return 0;
 }
 

drivers/virtio/virtio_ring.c

···
 			break;
 		case VIRTIO_F_VERSION_1:
 			break;
-		case VIRTIO_F_IOMMU_PLATFORM:
+		case VIRTIO_F_ACCESS_PLATFORM:
 			break;
 		case VIRTIO_F_RING_PACKED:
 			break;

include/linux/virtio_config.h

···
 	 * Note the reverse polarity of the quirk feature (compared to most
 	 * other features), this is for compatibility with legacy systems.
 	 */
-	return !virtio_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
+	return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM);
 }
 
 static inline

include/uapi/linux/virtio_config.h

···
 #define VIRTIO_F_VERSION_1		32
 
 /*
- * If clear - device has the IOMMU bypass quirk feature.
- * If set - use platform tools to detect the IOMMU.
+ * If clear - device has the platform DMA (e.g. IOMMU) bypass quirk feature.
+ * If set - use platform DMA tools to access the memory.
  *
  * Note the reverse polarity (compared to most other features),
  * this is for compatibility with legacy systems.
  */
-#define VIRTIO_F_IOMMU_PLATFORM		33
+#define VIRTIO_F_ACCESS_PLATFORM	33
+#ifndef __KERNEL__
+/* Legacy name for VIRTIO_F_ACCESS_PLATFORM (for compatibility with old userspace) */
+#define VIRTIO_F_IOMMU_PLATFORM		VIRTIO_F_ACCESS_PLATFORM
+#endif /* __KERNEL__ */
 
 /* This feature indicates support for the packed virtqueue layout. */
 #define VIRTIO_F_RING_PACKED		34

tools/virtio/linux/virtio_config.h

···
 	 * Note the reverse polarity of the quirk feature (compared to most
 	 * other features), this is for compatibility with legacy systems.
 	 */
-	return !virtio_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
+	return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM);
 }
 
 static inline bool virtio_is_little_endian(struct virtio_device *vdev)