Re: [PATCH v2 1/2] virtio: VIRTIO_F_IOMMU_PLATFORM -> VIRTIO_F_ACCESS_PLATFORM

[David Hildenbrand]

On 25.06.20 01:21, Michael S. Tsirkin wrote:
> Rename the bit to match latest virtio spec.
> Add a compat macro to avoid breaking existing userspace.
> 
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
>  arch/um/drivers/virtio_uml.c       |  2 +-
>  drivers/vdpa/ifcvf/ifcvf_base.h    |  2 +-
>  drivers/vdpa/vdpa_sim/vdpa_sim.c   |  4 ++--
>  drivers/vhost/net.c                |  4 ++--
>  drivers/vhost/vdpa.c               |  2 +-
>  drivers/virtio/virtio_balloon.c    |  2 +-
>  drivers/virtio/virtio_ring.c       |  2 +-
>  include/linux/virtio_config.h      |  2 +-
>  include/uapi/linux/virtio_config.h | 10 +++++++---
>  tools/virtio/linux/virtio_config.h |  2 +-
>  10 files changed, 18 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c
> index 351aee52aca6..a6c4bb6c2c01 100644
> --- a/arch/um/drivers/virtio_uml.c
> +++ b/arch/um/drivers/virtio_uml.c
> @@ -385,7 +385,7 @@ static irqreturn_t vu_req_interrupt(int irq, void *data)
>  		}
>  		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:
> diff --git a/drivers/vdpa/ifcvf/ifcvf_base.h b/drivers/vdpa/ifcvf/ifcvf_base.h
> index f4554412e607..24af422b5a3e 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_base.h
> +++ b/drivers/vdpa/ifcvf/ifcvf_base.h
> @@ -29,7 +29,7 @@
>  		 (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. */
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index c7334cc65bb2..a9bc5e0fb353 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -55,7 +55,7 @@ struct vdpasim_virtqueue {
>  
>  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 {
> @@ -450,7 +450,7 @@ static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
>  	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;
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index e992decfec53..8e0921d3805d 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -73,7 +73,7 @@ enum {
>  	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 {
> @@ -1653,7 +1653,7 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
>  	    !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;
>  	}
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index a54b60d6623f..18869a35d408 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -31,7 +31,7 @@ enum {
>  		(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) |
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index 1f157d2f4952..fc7301406540 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -1120,7 +1120,7 @@ static int virtballoon_validate(struct virtio_device *vdev)
>  	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;
>  }
>  
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 58b96baa8d48..a1a5c2a91426 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -2225,7 +2225,7 @@ void vring_transport_features(struct virtio_device *vdev)
>  			break;
>  		case VIRTIO_F_VERSION_1:
>  			break;
> -		case VIRTIO_F_IOMMU_PLATFORM:
> +		case VIRTIO_F_ACCESS_PLATFORM:
>  			break;
>  		case VIRTIO_F_RING_PACKED:
>  			break;
> diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
> index bb4cc4910750..f2cc2a0df174 100644
> --- a/include/linux/virtio_config.h
> +++ b/include/linux/virtio_config.h
> @@ -171,7 +171,7 @@ static inline bool virtio_has_iommu_quirk(const struct virtio_device *vdev)
>  	 * 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
> diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h
> index ff8e7dc9d4dd..b5eda06f0d57 100644
> --- a/include/uapi/linux/virtio_config.h
> +++ b/include/uapi/linux/virtio_config.h
> @@ -67,13 +67,17 @@
>  #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
> diff --git a/tools/virtio/linux/virtio_config.h b/tools/virtio/linux/virtio_config.h
> index dbf14c1e2188..f99ae42668e0 100644
> --- a/tools/virtio/linux/virtio_config.h
> +++ b/tools/virtio/linux/virtio_config.h
> @@ -51,7 +51,7 @@ static inline bool virtio_has_iommu_quirk(const struct virtio_device *vdev)
>  	 * 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)
> 

Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>

-- 
Thanks,

David / dhildenb