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

From: David Hildenbrand
Date: Thu Jun 25 2020 - 02:50:27 EST


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