On Wed, Aug 13, 2025 at 7:48 AM Jason Wang <jasow...@redhat.com> wrote:
>
> Following patch will introduce virtio mapping function to avoid
> abusing DMA API for device that doesn't do DMA. To ease the
> introduction, this patch rename "dma" to "map" for the current dma
> mapping helpers.
>
> Reviewed-by: Christoph Hellwig <h...@lst.de>
> Reviewed-by: Xuan Zhuo <xuanz...@linux.alibaba.com>
Reviewed-by: Eugenio Pérez <epere...@redhat.com>
> Signed-off-by: Jason Wang <jasow...@redhat.com>
> ---
> drivers/net/virtio_net.c | 28 ++++-----
> drivers/virtio/virtio_ring.c | 114 +++++++++++++++++------------------
> include/linux/virtio.h | 12 ++--
> 3 files changed, 77 insertions(+), 77 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 5d674eb9a0f2..929db41a579b 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -933,7 +933,7 @@ static void virtnet_rq_unmap(struct receive_queue *rq,
> void *buf, u32 len)
> if (dma->need_sync && len) {
> offset = buf - (head + sizeof(*dma));
>
> - virtqueue_dma_sync_single_range_for_cpu(rq->vq, dma->addr,
> + virtqueue_map_sync_single_range_for_cpu(rq->vq, dma->addr,
> offset, len,
> DMA_FROM_DEVICE);
> }
> @@ -941,8 +941,8 @@ static void virtnet_rq_unmap(struct receive_queue *rq,
> void *buf, u32 len)
> if (dma->ref)
> return;
>
> - virtqueue_dma_unmap_single_attrs(rq->vq, dma->addr, dma->len,
> - DMA_FROM_DEVICE,
> DMA_ATTR_SKIP_CPU_SYNC);
> + virtqueue_unmap_single_attrs(rq->vq, dma->addr, dma->len,
> + DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
> put_page(page);
> }
>
> @@ -1009,13 +1009,13 @@ static void *virtnet_rq_alloc(struct receive_queue
> *rq, u32 size, gfp_t gfp)
>
> dma->len = alloc_frag->size - sizeof(*dma);
>
> - addr = virtqueue_dma_map_single_attrs(rq->vq, dma + 1,
> - dma->len,
> DMA_FROM_DEVICE, 0);
> - if (virtqueue_dma_mapping_error(rq->vq, addr))
> + addr = virtqueue_map_single_attrs(rq->vq, dma + 1,
> + dma->len, DMA_FROM_DEVICE,
> 0);
> + if (virtqueue_map_mapping_error(rq->vq, addr))
> return NULL;
>
> dma->addr = addr;
> - dma->need_sync = virtqueue_dma_need_sync(rq->vq, addr);
> + dma->need_sync = virtqueue_map_need_sync(rq->vq, addr);
>
> /* Add a reference to dma to prevent the entire dma from
> * being released during error handling. This reference
> @@ -5921,9 +5921,9 @@ static int virtnet_xsk_pool_enable(struct net_device
> *dev,
> if (!rq->xsk_buffs)
> return -ENOMEM;
>
> - hdr_dma = virtqueue_dma_map_single_attrs(sq->vq, &xsk_hdr,
> vi->hdr_len,
> - DMA_TO_DEVICE, 0);
> - if (virtqueue_dma_mapping_error(sq->vq, hdr_dma)) {
> + hdr_dma = virtqueue_map_single_attrs(sq->vq, &xsk_hdr, vi->hdr_len,
> + DMA_TO_DEVICE, 0);
> + if (virtqueue_map_mapping_error(sq->vq, hdr_dma)) {
> err = -ENOMEM;
> goto err_free_buffs;
> }
> @@ -5952,8 +5952,8 @@ static int virtnet_xsk_pool_enable(struct net_device
> *dev,
> err_rq:
> xsk_pool_dma_unmap(pool, 0);
> err_xsk_map:
> - virtqueue_dma_unmap_single_attrs(rq->vq, hdr_dma, vi->hdr_len,
> - DMA_TO_DEVICE, 0);
> + virtqueue_unmap_single_attrs(rq->vq, hdr_dma, vi->hdr_len,
> + DMA_TO_DEVICE, 0);
> err_free_buffs:
> kvfree(rq->xsk_buffs);
> return err;
> @@ -5980,8 +5980,8 @@ static int virtnet_xsk_pool_disable(struct net_device
> *dev, u16 qid)
>
> xsk_pool_dma_unmap(pool, 0);
>
> - virtqueue_dma_unmap_single_attrs(sq->vq, sq->xsk_hdr_dma_addr,
> - vi->hdr_len, DMA_TO_DEVICE, 0);
> + virtqueue_unmap_single_attrs(sq->vq, sq->xsk_hdr_dma_addr,
> + vi->hdr_len, DMA_TO_DEVICE, 0);
> kvfree(rq->xsk_buffs);
>
> return err;
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 75e5f6336c8d..482a268af851 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -166,7 +166,7 @@ struct vring_virtqueue {
> bool packed_ring;
>
> /* Is DMA API used? */
> - bool use_dma_api;
> + bool use_map_api;
>
> /* Can we use weak barriers? */
> bool weak_barriers;
> @@ -268,7 +268,7 @@ static bool virtqueue_use_indirect(const struct
> vring_virtqueue *vq,
> * unconditionally on data path.
> */
>
> -static bool vring_use_dma_api(const struct virtio_device *vdev)
> +static bool vring_use_map_api(const struct virtio_device *vdev)
> {
> if (!virtio_has_dma_quirk(vdev))
> return true;
> @@ -291,14 +291,14 @@ static bool vring_use_dma_api(const struct
> virtio_device *vdev)
> static bool vring_need_unmap_buffer(const struct vring_virtqueue *vring,
> const struct vring_desc_extra *extra)
> {
> - return vring->use_dma_api && (extra->addr != DMA_MAPPING_ERROR);
> + return vring->use_map_api && (extra->addr != DMA_MAPPING_ERROR);
> }
>
> size_t virtio_max_dma_size(const struct virtio_device *vdev)
> {
> size_t max_segment_size = SIZE_MAX;
>
> - if (vring_use_dma_api(vdev))
> + if (vring_use_map_api(vdev))
> max_segment_size = dma_max_mapping_size(vdev->dev.parent);
>
> return max_segment_size;
> @@ -309,7 +309,7 @@ static void *vring_alloc_queue(struct virtio_device
> *vdev, size_t size,
> dma_addr_t *dma_handle, gfp_t flag,
> struct device *dma_dev)
> {
> - if (vring_use_dma_api(vdev)) {
> + if (vring_use_map_api(vdev)) {
> return dma_alloc_coherent(dma_dev, size,
> dma_handle, flag);
> } else {
> @@ -343,7 +343,7 @@ static void vring_free_queue(struct virtio_device *vdev,
> size_t size,
> void *queue, dma_addr_t dma_handle,
> struct device *dma_dev)
> {
> - if (vring_use_dma_api(vdev))
> + if (vring_use_map_api(vdev))
> dma_free_coherent(dma_dev, size, queue, dma_handle);
> else
> free_pages_exact(queue, PAGE_ALIGN(size));
> @@ -372,7 +372,7 @@ static int vring_map_one_sg(const struct vring_virtqueue
> *vq, struct scatterlist
>
> *len = sg->length;
>
> - if (!vq->use_dma_api) {
> + if (!vq->use_map_api) {
> /*
> * If DMA is not used, KMSAN doesn't know that the scatterlist
> * is initialized by the hardware. Explicitly check/unpoison
> it
> @@ -402,17 +402,17 @@ static dma_addr_t vring_map_single(const struct
> vring_virtqueue *vq,
> void *cpu_addr, size_t size,
> enum dma_data_direction direction)
> {
> - if (!vq->use_dma_api)
> + if (!vq->use_map_api)
> return (dma_addr_t)virt_to_phys(cpu_addr);
>
> - return virtqueue_dma_map_single_attrs(&vq->vq, cpu_addr,
> - size, direction, 0);
> + return virtqueue_map_single_attrs(&vq->vq, cpu_addr,
> + size, direction, 0);
> }
>
> static int vring_mapping_error(const struct vring_virtqueue *vq,
> dma_addr_t addr)
> {
> - if (!vq->use_dma_api)
> + if (!vq->use_map_api)
> return 0;
>
> return dma_mapping_error(vring_dma_dev(vq), addr);
> @@ -449,7 +449,7 @@ static unsigned int vring_unmap_one_split(const struct
> vring_virtqueue *vq,
> flags = extra->flags;
>
> if (flags & VRING_DESC_F_INDIRECT) {
> - if (!vq->use_dma_api)
> + if (!vq->use_map_api)
> goto out;
> } else if (!vring_need_unmap_buffer(vq, extra))
> goto out;
> @@ -782,7 +782,7 @@ static void detach_buf_split(struct vring_virtqueue *vq,
> unsigned int head,
>
> extra = (struct vring_desc_extra *)&indir_desc[num];
>
> - if (vq->use_dma_api) {
> + if (vq->use_map_api) {
> for (j = 0; j < num; j++)
> vring_unmap_one_split(vq, &extra[j]);
> }
> @@ -1150,7 +1150,7 @@ static struct virtqueue
> *__vring_new_virtqueue_split(unsigned int index,
> vq->broken = false;
> #endif
> vq->dma_dev = dma_dev;
> - vq->use_dma_api = vring_use_dma_api(vdev);
> + vq->use_map_api = vring_use_map_api(vdev);
>
> vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)
> &&
> !context;
> @@ -1266,7 +1266,7 @@ static void vring_unmap_extra_packed(const struct
> vring_virtqueue *vq,
> flags = extra->flags;
>
> if (flags & VRING_DESC_F_INDIRECT) {
> - if (!vq->use_dma_api)
> + if (!vq->use_map_api)
> return;
> } else if (!vring_need_unmap_buffer(vq, extra))
> return;
> @@ -1351,7 +1351,7 @@ static int virtqueue_add_indirect_packed(struct
> vring_virtqueue *vq,
> desc[i].addr = cpu_to_le64(addr);
> desc[i].len = cpu_to_le32(len);
>
> - if (unlikely(vq->use_dma_api)) {
> + if (unlikely(vq->use_map_api)) {
> extra[i].addr = premapped ? DMA_MAPPING_ERROR
> : addr;
> extra[i].len = len;
> extra[i].flags = n < out_sgs ? 0 :
> VRING_DESC_F_WRITE;
> @@ -1373,7 +1373,7 @@ static int virtqueue_add_indirect_packed(struct
> vring_virtqueue *vq,
> sizeof(struct vring_packed_desc));
> vq->packed.vring.desc[head].id = cpu_to_le16(id);
>
> - if (vq->use_dma_api) {
> + if (vq->use_map_api) {
> vq->packed.desc_extra[id].addr = addr;
> vq->packed.desc_extra[id].len = total_sg *
> sizeof(struct vring_packed_desc);
> @@ -1515,7 +1515,7 @@ static inline int virtqueue_add_packed(struct virtqueue
> *_vq,
> desc[i].len = cpu_to_le32(len);
> desc[i].id = cpu_to_le16(id);
>
> - if (unlikely(vq->use_dma_api)) {
> + if (unlikely(vq->use_map_api)) {
> vq->packed.desc_extra[curr].addr = premapped ?
> DMA_MAPPING_ERROR : addr;
> vq->packed.desc_extra[curr].len = len;
> @@ -1650,7 +1650,7 @@ static void detach_buf_packed(struct vring_virtqueue
> *vq,
> vq->free_head = id;
> vq->vq.num_free += state->num;
>
> - if (unlikely(vq->use_dma_api)) {
> + if (unlikely(vq->use_map_api)) {
> curr = id;
> for (i = 0; i < state->num; i++) {
> vring_unmap_extra_packed(vq,
> @@ -1668,7 +1668,7 @@ static void detach_buf_packed(struct vring_virtqueue
> *vq,
> if (!desc)
> return;
>
> - if (vq->use_dma_api) {
> + if (vq->use_map_api) {
> len = vq->packed.desc_extra[id].len;
> num = len / sizeof(struct vring_packed_desc);
>
> @@ -2121,7 +2121,7 @@ static struct virtqueue
> *__vring_new_virtqueue_packed(unsigned int index,
> #endif
> vq->packed_ring = true;
> vq->dma_dev = dma_dev;
> - vq->use_dma_api = vring_use_dma_api(vdev);
> + vq->use_map_api = vring_use_map_api(vdev);
>
> vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)
> &&
> !context;
> @@ -2433,7 +2433,7 @@ struct device *virtqueue_dma_dev(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> - if (vq->use_dma_api)
> + if (vq->use_map_api)
> return vring_dma_dev(vq);
> else
> return NULL;
> @@ -3122,7 +3122,7 @@ const struct vring *virtqueue_get_vring(const struct
> virtqueue *vq)
> EXPORT_SYMBOL_GPL(virtqueue_get_vring);
>
> /**
> - * virtqueue_dma_map_single_attrs - map DMA for _vq
> + * virtqueue_map_single_attrs - map DMA for _vq
> * @_vq: the struct virtqueue we're talking about.
> * @ptr: the pointer of the buffer to do dma
> * @size: the size of the buffer to do dma
> @@ -3132,16 +3132,16 @@ EXPORT_SYMBOL_GPL(virtqueue_get_vring);
> * The caller calls this to do dma mapping in advance. The DMA address can be
> * passed to this _vq when it is in pre-mapped mode.
> *
> - * return DMA address. Caller should check that by
> virtqueue_dma_mapping_error().
> + * return DMA address. Caller should check that by virtqueue_mapping_error().
> */
> -dma_addr_t virtqueue_dma_map_single_attrs(const struct virtqueue *_vq, void
> *ptr,
> - size_t size,
> - enum dma_data_direction dir,
> - unsigned long attrs)
> +dma_addr_t virtqueue_map_single_attrs(const struct virtqueue *_vq, void *ptr,
> + size_t size,
> + enum dma_data_direction dir,
> + unsigned long attrs)
> {
> const struct vring_virtqueue *vq = to_vvq(_vq);
>
> - if (!vq->use_dma_api) {
> + if (!vq->use_map_api) {
> kmsan_handle_dma(virt_to_page(ptr), offset_in_page(ptr),
> size, dir);
> return (dma_addr_t)virt_to_phys(ptr);
> }
> @@ -3154,85 +3154,85 @@ dma_addr_t virtqueue_dma_map_single_attrs(const
> struct virtqueue *_vq, void *ptr
> return dma_map_page_attrs(vring_dma_dev(vq), virt_to_page(ptr),
> offset_in_page(ptr), size, dir, attrs);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_dma_map_single_attrs);
> +EXPORT_SYMBOL_GPL(virtqueue_map_single_attrs);
>
> /**
> - * virtqueue_dma_unmap_single_attrs - unmap DMA for _vq
> + * virtqueue_unmap_single_attrs - unmap map for _vq
> * @_vq: the struct virtqueue we're talking about.
> * @addr: the dma address to unmap
> * @size: the size of the buffer
> * @dir: DMA direction
> * @attrs: DMA Attrs
> *
> - * Unmap the address that is mapped by the virtqueue_dma_map_* APIs.
> + * Unmap the address that is mapped by the virtqueue_map_* APIs.
> *
> */
> -void virtqueue_dma_unmap_single_attrs(const struct virtqueue *_vq,
> - dma_addr_t addr,
> - size_t size, enum dma_data_direction
> dir,
> - unsigned long attrs)
> +void virtqueue_unmap_single_attrs(const struct virtqueue *_vq,
> + dma_addr_t addr,
> + size_t size, enum dma_data_direction dir,
> + unsigned long attrs)
> {
> const struct vring_virtqueue *vq = to_vvq(_vq);
>
> - if (!vq->use_dma_api)
> + if (!vq->use_map_api)
> return;
>
> dma_unmap_page_attrs(vring_dma_dev(vq), addr, size, dir, attrs);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_dma_unmap_single_attrs);
> +EXPORT_SYMBOL_GPL(virtqueue_unmap_single_attrs);
>
> /**
> - * virtqueue_dma_mapping_error - check dma address
> + * virtqueue_map_mapping_error - check dma address
> * @_vq: the struct virtqueue we're talking about.
> * @addr: DMA address
> *
> * Returns 0 means dma valid. Other means invalid dma address.
> */
> -int virtqueue_dma_mapping_error(const struct virtqueue *_vq, dma_addr_t addr)
> +int virtqueue_map_mapping_error(const struct virtqueue *_vq, dma_addr_t addr)
> {
> const struct vring_virtqueue *vq = to_vvq(_vq);
>
> - if (!vq->use_dma_api)
> + if (!vq->use_map_api)
> return 0;
>
> return dma_mapping_error(vring_dma_dev(vq), addr);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_dma_mapping_error);
> +EXPORT_SYMBOL_GPL(virtqueue_map_mapping_error);
>
> /**
> - * virtqueue_dma_need_sync - check a dma address needs sync
> + * virtqueue_map_need_sync - check a dma address needs sync
> * @_vq: the struct virtqueue we're talking about.
> * @addr: DMA address
> *
> - * Check if the dma address mapped by the virtqueue_dma_map_* APIs needs to
> be
> + * Check if the dma address mapped by the virtqueue_map_* APIs needs to be
> * synchronized
> *
> * return bool
> */
> -bool virtqueue_dma_need_sync(const struct virtqueue *_vq, dma_addr_t addr)
> +bool virtqueue_map_need_sync(const struct virtqueue *_vq, dma_addr_t addr)
> {
> const struct vring_virtqueue *vq = to_vvq(_vq);
>
> - if (!vq->use_dma_api)
> + if (!vq->use_map_api)
> return false;
>
> return dma_need_sync(vring_dma_dev(vq), addr);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_dma_need_sync);
> +EXPORT_SYMBOL_GPL(virtqueue_map_need_sync);
>
> /**
> - * virtqueue_dma_sync_single_range_for_cpu - dma sync for cpu
> + * virtqueue_map_sync_single_range_for_cpu - map sync for cpu
> * @_vq: the struct virtqueue we're talking about.
> * @addr: DMA address
> * @offset: DMA address offset
> * @size: buf size for sync
> * @dir: DMA direction
> *
> - * Before calling this function, use virtqueue_dma_need_sync() to confirm
> that
> + * Before calling this function, use virtqueue_map_need_sync() to confirm
> that
> * the DMA address really needs to be synchronized
> *
> */
> -void virtqueue_dma_sync_single_range_for_cpu(const struct virtqueue *_vq,
> +void virtqueue_map_sync_single_range_for_cpu(const struct virtqueue *_vq,
> dma_addr_t addr,
> unsigned long offset, size_t
> size,
> enum dma_data_direction dir)
> @@ -3240,25 +3240,25 @@ void virtqueue_dma_sync_single_range_for_cpu(const
> struct virtqueue *_vq,
> const struct vring_virtqueue *vq = to_vvq(_vq);
> struct device *dev = vring_dma_dev(vq);
>
> - if (!vq->use_dma_api)
> + if (!vq->use_map_api)
> return;
>
> dma_sync_single_range_for_cpu(dev, addr, offset, size, dir);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_dma_sync_single_range_for_cpu);
> +EXPORT_SYMBOL_GPL(virtqueue_map_sync_single_range_for_cpu);
>
> /**
> - * virtqueue_dma_sync_single_range_for_device - dma sync for device
> + * virtqueue_map_sync_single_range_for_device - map sync for device
> * @_vq: the struct virtqueue we're talking about.
> * @addr: DMA address
> * @offset: DMA address offset
> * @size: buf size for sync
> * @dir: DMA direction
> *
> - * Before calling this function, use virtqueue_dma_need_sync() to confirm
> that
> + * Before calling this function, use virtqueue_map_need_sync() to confirm
> that
> * the DMA address really needs to be synchronized
> */
> -void virtqueue_dma_sync_single_range_for_device(const struct virtqueue *_vq,
> +void virtqueue_map_sync_single_range_for_device(const struct virtqueue *_vq,
> dma_addr_t addr,
> unsigned long offset, size_t
> size,
> enum dma_data_direction dir)
> @@ -3266,12 +3266,12 @@ void virtqueue_dma_sync_single_range_for_device(const
> struct virtqueue *_vq,
> const struct vring_virtqueue *vq = to_vvq(_vq);
> struct device *dev = vring_dma_dev(vq);
>
> - if (!vq->use_dma_api)
> + if (!vq->use_map_api)
> return;
>
> dma_sync_single_range_for_device(dev, addr, offset, size, dir);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_dma_sync_single_range_for_device);
> +EXPORT_SYMBOL_GPL(virtqueue_map_sync_single_range_for_device);
>
> MODULE_DESCRIPTION("Virtio ring implementation");
> MODULE_LICENSE("GPL");
> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> index cf8def717dfd..addbc209275a 100644
> --- a/include/linux/virtio.h
> +++ b/include/linux/virtio.h
> @@ -259,18 +259,18 @@ void unregister_virtio_driver(struct virtio_driver
> *drv);
> module_driver(__virtio_driver, register_virtio_driver, \
> unregister_virtio_driver)
>
> -dma_addr_t virtqueue_dma_map_single_attrs(const struct virtqueue *_vq, void
> *ptr, size_t size,
> +dma_addr_t virtqueue_map_single_attrs(const struct virtqueue *_vq, void
> *ptr, size_t size,
> enum dma_data_direction dir,
> unsigned long attrs);
> -void virtqueue_dma_unmap_single_attrs(const struct virtqueue *_vq,
> dma_addr_t addr,
> +void virtqueue_unmap_single_attrs(const struct virtqueue *_vq, dma_addr_t
> addr,
> size_t size, enum dma_data_direction
> dir,
> unsigned long attrs);
> -int virtqueue_dma_mapping_error(const struct virtqueue *_vq, dma_addr_t
> addr);
> +int virtqueue_map_mapping_error(const struct virtqueue *_vq, dma_addr_t
> addr);
>
> -bool virtqueue_dma_need_sync(const struct virtqueue *_vq, dma_addr_t addr);
> -void virtqueue_dma_sync_single_range_for_cpu(const struct virtqueue *_vq,
> dma_addr_t addr,
> +bool virtqueue_map_need_sync(const struct virtqueue *_vq, dma_addr_t addr);
> +void virtqueue_map_sync_single_range_for_cpu(const struct virtqueue *_vq,
> dma_addr_t addr,
> unsigned long offset, size_t
> size,
> enum dma_data_direction dir);
> -void virtqueue_dma_sync_single_range_for_device(const struct virtqueue *_vq,
> dma_addr_t addr,
> +void virtqueue_map_sync_single_range_for_device(const struct virtqueue *_vq,
> dma_addr_t addr,
> unsigned long offset, size_t
> size,
> enum dma_data_direction dir);
>
> --
> 2.31.1
>
