* [PATCH V6 0/9] Refine virtio mapping API
@ 2025-08-21 6:46 Jason Wang
2025-08-21 6:46 ` [PATCH V6 1/9] virtio_ring: constify virtqueue pointer for DMA helpers Jason Wang
` (10 more replies)
0 siblings, 11 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma; +Cc: virtualization, linux-kernel, hch
Hi all:
Virtio used to be coupled with DMA API. This works fine for the device
that do real DMA but not the others. For example, VDUSE nees to craft
with DMA API in order to let the virtio-vdpa driver to work.
This series tries to solve this issue by introducing the mapping API
in the virtio core. So transport like vDPA can implement their own
mapping logic without the need to hack with DMA API. The mapping API
are abstracted with a new map operations in order to be re-used by
transprot or device. So device like VDUSE can implement its own
mapping loigc.
For device that uses DMA (for example PCI device), the virtio core
will still call DMA API directly without the need of implementing map
ops per device/transport.
Please review.
Changes since V5:
- Rename mapping_token to virtio_map
- Do not use opaque void * pointer, just use a forward decalration of
vduse_iova_domain
- Remove unused variable and typo fixes
Changes since V4:
- Rename map_token to mapping_token
- Introduce a union container for opaque token as well as the DMA
device so we won't lose the type safety
- Do not try to set DMA mask for VDUSE device
- Introduce a new mapper_error op for API completeness
Changes since V3:
- Fix build error of PDS vDPA driver
Changes since V2:
- Drop VDUSE dependenct for HAS_DMA and ARCH_HAS_DMA_OPS
Changes since V1:
- Fix build error of mlx5_vdpa driver
Jason Wang (9):
virtio_ring: constify virtqueue pointer for DMA helpers
virtio_ring: switch to use dma_{map|unmap}_page()
virtio: rename dma helpers
virtio: introduce virtio_map container union
virtio_ring: rename dma_handle to map_handle
virtio: introduce map ops in virtio core
vdpa: support virtio_map
vdpa: introduce map ops
vduse: switch to use virtio map API instead of DMA API
drivers/net/virtio_net.c | 28 +-
drivers/vdpa/Kconfig | 8 +-
drivers/vdpa/alibaba/eni_vdpa.c | 5 +-
drivers/vdpa/ifcvf/ifcvf_main.c | 5 +-
drivers/vdpa/mlx5/core/mr.c | 4 +-
drivers/vdpa/mlx5/net/mlx5_vnet.c | 15 +-
drivers/vdpa/octeon_ep/octep_vdpa_main.c | 6 +-
drivers/vdpa/pds/vdpa_dev.c | 5 +-
drivers/vdpa/solidrun/snet_main.c | 8 +-
drivers/vdpa/vdpa.c | 5 +-
drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 +-
drivers/vdpa/vdpa_user/iova_domain.c | 2 +-
drivers/vdpa/vdpa_user/iova_domain.h | 2 +-
drivers/vdpa/vdpa_user/vduse_dev.c | 79 ++--
drivers/vdpa/virtio_pci/vp_vdpa.c | 5 +-
drivers/vhost/vdpa.c | 6 +-
drivers/virtio/virtio_ring.c | 459 ++++++++++++++---------
drivers/virtio/virtio_vdpa.c | 20 +-
include/linux/vdpa.h | 25 +-
include/linux/virtio.h | 46 ++-
include/linux/virtio_config.h | 72 ++++
include/linux/virtio_ring.h | 7 +-
22 files changed, 531 insertions(+), 285 deletions(-)
--
2.31.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH V6 1/9] virtio_ring: constify virtqueue pointer for DMA helpers
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
@ 2025-08-21 6:46 ` Jason Wang
2025-08-21 6:46 ` [PATCH V6 2/9] virtio_ring: switch to use dma_{map|unmap}_page() Jason Wang
` (9 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma
Cc: virtualization, linux-kernel, hch, Christoph Hellwig
This patch consities virtqueue point for DMA helpers.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Reviewed-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/virtio/virtio_ring.c | 25 +++++++++++++------------
include/linux/virtio.h | 12 ++++++------
2 files changed, 19 insertions(+), 18 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index f5062061c408..103bad8cffff 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -3149,12 +3149,12 @@ EXPORT_SYMBOL_GPL(virtqueue_get_vring);
*
* return DMA address. Caller should check that by virtqueue_dma_mapping_error().
*/
-dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr,
+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)
{
- struct vring_virtqueue *vq = to_vvq(_vq);
+ const struct vring_virtqueue *vq = to_vvq(_vq);
if (!vq->use_dma_api) {
kmsan_handle_dma(virt_to_page(ptr), offset_in_page(ptr), size, dir);
@@ -3176,11 +3176,12 @@ EXPORT_SYMBOL_GPL(virtqueue_dma_map_single_attrs);
* Unmap the address that is mapped by the virtqueue_dma_map_* APIs.
*
*/
-void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
+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)
{
- struct vring_virtqueue *vq = to_vvq(_vq);
+ const struct vring_virtqueue *vq = to_vvq(_vq);
if (!vq->use_dma_api)
return;
@@ -3196,9 +3197,9 @@ EXPORT_SYMBOL_GPL(virtqueue_dma_unmap_single_attrs);
*
* Returns 0 means dma valid. Other means invalid dma address.
*/
-int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr)
+int virtqueue_dma_mapping_error(const struct virtqueue *_vq, dma_addr_t addr)
{
- struct vring_virtqueue *vq = to_vvq(_vq);
+ const struct vring_virtqueue *vq = to_vvq(_vq);
if (!vq->use_dma_api)
return 0;
@@ -3217,9 +3218,9 @@ EXPORT_SYMBOL_GPL(virtqueue_dma_mapping_error);
*
* return bool
*/
-bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr)
+bool virtqueue_dma_need_sync(const struct virtqueue *_vq, dma_addr_t addr)
{
- struct vring_virtqueue *vq = to_vvq(_vq);
+ const struct vring_virtqueue *vq = to_vvq(_vq);
if (!vq->use_dma_api)
return false;
@@ -3240,12 +3241,12 @@ EXPORT_SYMBOL_GPL(virtqueue_dma_need_sync);
* the DMA address really needs to be synchronized
*
*/
-void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq,
+void virtqueue_dma_sync_single_range_for_cpu(const struct virtqueue *_vq,
dma_addr_t addr,
unsigned long offset, size_t size,
enum dma_data_direction dir)
{
- struct vring_virtqueue *vq = to_vvq(_vq);
+ const struct vring_virtqueue *vq = to_vvq(_vq);
struct device *dev = vring_dma_dev(vq);
if (!vq->use_dma_api)
@@ -3266,12 +3267,12 @@ EXPORT_SYMBOL_GPL(virtqueue_dma_sync_single_range_for_cpu);
* Before calling this function, use virtqueue_dma_need_sync() to confirm that
* the DMA address really needs to be synchronized
*/
-void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq,
+void virtqueue_dma_sync_single_range_for_device(const struct virtqueue *_vq,
dma_addr_t addr,
unsigned long offset, size_t size,
enum dma_data_direction dir)
{
- struct vring_virtqueue *vq = to_vvq(_vq);
+ const struct vring_virtqueue *vq = to_vvq(_vq);
struct device *dev = vring_dma_dev(vq);
if (!vq->use_dma_api)
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index db31fc6f4f1f..eab71a440fba 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -262,18 +262,18 @@ 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(struct virtqueue *_vq, void *ptr, size_t size,
+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);
-void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
+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);
-int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
+int virtqueue_dma_mapping_error(const struct virtqueue *_vq, dma_addr_t addr);
-bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
-void virtqueue_dma_sync_single_range_for_cpu(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,
unsigned long offset, size_t size,
enum dma_data_direction dir);
-void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr,
+void virtqueue_dma_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
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH V6 2/9] virtio_ring: switch to use dma_{map|unmap}_page()
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
2025-08-21 6:46 ` [PATCH V6 1/9] virtio_ring: constify virtqueue pointer for DMA helpers Jason Wang
@ 2025-08-21 6:46 ` Jason Wang
2025-08-21 6:46 ` [PATCH V6 3/9] virtio: rename dma helpers Jason Wang
` (8 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma
Cc: virtualization, linux-kernel, hch, Christoph Hellwig
This patch switches to use dma_{map|unmap}_page() to reduce the
coverage of DMA operations. This would help for the following rework
on the virtio map operations.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/virtio/virtio_ring.c | 55 +++++++++++++++---------------------
1 file changed, 23 insertions(+), 32 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 103bad8cffff..75e5f6336c8d 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -405,8 +405,8 @@ static dma_addr_t vring_map_single(const struct vring_virtqueue *vq,
if (!vq->use_dma_api)
return (dma_addr_t)virt_to_phys(cpu_addr);
- return dma_map_single(vring_dma_dev(vq),
- cpu_addr, size, direction);
+ return virtqueue_dma_map_single_attrs(&vq->vq, cpu_addr,
+ size, direction, 0);
}
static int vring_mapping_error(const struct vring_virtqueue *vq,
@@ -451,22 +451,14 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq,
if (flags & VRING_DESC_F_INDIRECT) {
if (!vq->use_dma_api)
goto out;
+ } else if (!vring_need_unmap_buffer(vq, extra))
+ goto out;
- dma_unmap_single(vring_dma_dev(vq),
- extra->addr,
- extra->len,
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
- } else {
- if (!vring_need_unmap_buffer(vq, extra))
- goto out;
-
- dma_unmap_page(vring_dma_dev(vq),
- extra->addr,
- extra->len,
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
- }
+ dma_unmap_page(vring_dma_dev(vq),
+ extra->addr,
+ extra->len,
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
out:
return extra->next;
@@ -1276,20 +1268,13 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq,
if (flags & VRING_DESC_F_INDIRECT) {
if (!vq->use_dma_api)
return;
+ } else if (!vring_need_unmap_buffer(vq, extra))
+ return;
- dma_unmap_single(vring_dma_dev(vq),
- extra->addr, extra->len,
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
- } else {
- if (!vring_need_unmap_buffer(vq, extra))
- return;
-
- dma_unmap_page(vring_dma_dev(vq),
- extra->addr, extra->len,
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
- }
+ dma_unmap_page(vring_dma_dev(vq),
+ extra->addr, extra->len,
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
@@ -3161,7 +3146,13 @@ dma_addr_t virtqueue_dma_map_single_attrs(const struct virtqueue *_vq, void *ptr
return (dma_addr_t)virt_to_phys(ptr);
}
- return dma_map_single_attrs(vring_dma_dev(vq), ptr, size, dir, attrs);
+ /* DMA must never operate on areas that might be remapped. */
+ if (dev_WARN_ONCE(&_vq->vdev->dev, is_vmalloc_addr(ptr),
+ "rejecting DMA map of vmalloc memory\n"))
+ return DMA_MAPPING_ERROR;
+
+ 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);
@@ -3186,7 +3177,7 @@ void virtqueue_dma_unmap_single_attrs(const struct virtqueue *_vq,
if (!vq->use_dma_api)
return;
- dma_unmap_single_attrs(vring_dma_dev(vq), addr, size, dir, attrs);
+ dma_unmap_page_attrs(vring_dma_dev(vq), addr, size, dir, attrs);
}
EXPORT_SYMBOL_GPL(virtqueue_dma_unmap_single_attrs);
--
2.31.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH V6 3/9] virtio: rename dma helpers
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
2025-08-21 6:46 ` [PATCH V6 1/9] virtio_ring: constify virtqueue pointer for DMA helpers Jason Wang
2025-08-21 6:46 ` [PATCH V6 2/9] virtio_ring: switch to use dma_{map|unmap}_page() Jason Wang
@ 2025-08-21 6:46 ` Jason Wang
2025-08-21 6:46 ` [PATCH V6 4/9] virtio: introduce virtio_map container union Jason Wang
` (7 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma
Cc: virtualization, linux-kernel, hch, Christoph Hellwig
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 <hch@lst.de>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Jason Wang <jasowang@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 975bdc5dab84..31bd32bdecaf 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -962,7 +962,7 @@ 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);
}
@@ -970,8 +970,8 @@ 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);
}
@@ -1038,13 +1038,13 @@ 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
@@ -5952,9 +5952,9 @@ 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;
}
@@ -5983,8 +5983,8 @@ 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;
@@ -6011,8 +6011,8 @@ 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 eab71a440fba..576e08bd7697 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -262,18 +262,18 @@ 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
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH V6 4/9] virtio: introduce virtio_map container union
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
` (2 preceding siblings ...)
2025-08-21 6:46 ` [PATCH V6 3/9] virtio: rename dma helpers Jason Wang
@ 2025-08-21 6:46 ` Jason Wang
2025-08-21 6:46 ` [PATCH V6 5/9] virtio_ring: rename dma_handle to map_handle Jason Wang
` (6 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma; +Cc: virtualization, linux-kernel, hch
Following patch will introduce the mapping operations for virtio
device. In order to achieve this, besides the dma device, virtio core
needs to support a transport or device specific mapping metadata as well.
So this patch introduces a union container of a dma device. The idea
is the allow the transport layer to pass device specific mapping
metadata which will be used as a parameter for the virtio mapping
operations. For the transport or device that is using DMA, dma device
is still being used.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/virtio/virtio_ring.c | 104 ++++++++++++++++++-----------------
drivers/virtio/virtio_vdpa.c | 6 +-
include/linux/virtio.h | 5 ++
include/linux/virtio_ring.h | 7 ++-
4 files changed, 66 insertions(+), 56 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 482a268af851..cda9bc2121bf 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -210,8 +210,7 @@ struct vring_virtqueue {
/* DMA, allocation, and size information */
bool we_own_ring;
- /* Device used for doing DMA */
- struct device *dma_dev;
+ union virtio_map map;
#ifdef DEBUG
/* They're supposed to lock for us. */
@@ -307,10 +306,10 @@ EXPORT_SYMBOL_GPL(virtio_max_dma_size);
static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
- struct device *dma_dev)
+ union virtio_map map)
{
if (vring_use_map_api(vdev)) {
- return dma_alloc_coherent(dma_dev, size,
+ return dma_alloc_coherent(map.dma_dev, size,
dma_handle, flag);
} else {
void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag);
@@ -341,10 +340,10 @@ static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
static void vring_free_queue(struct virtio_device *vdev, size_t size,
void *queue, dma_addr_t dma_handle,
- struct device *dma_dev)
+ union virtio_map map)
{
if (vring_use_map_api(vdev))
- dma_free_coherent(dma_dev, size, queue, dma_handle);
+ dma_free_coherent(map.dma_dev, size, queue, dma_handle);
else
free_pages_exact(queue, PAGE_ALIGN(size));
}
@@ -356,7 +355,7 @@ static void vring_free_queue(struct virtio_device *vdev, size_t size,
*/
static struct device *vring_dma_dev(const struct vring_virtqueue *vq)
{
- return vq->dma_dev;
+ return vq->map.dma_dev;
}
/* Map one sg entry. */
@@ -1056,12 +1055,13 @@ static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_spl
}
static void vring_free_split(struct vring_virtqueue_split *vring_split,
- struct virtio_device *vdev, struct device *dma_dev)
+ struct virtio_device *vdev,
+ union virtio_map map)
{
vring_free_queue(vdev, vring_split->queue_size_in_bytes,
vring_split->vring.desc,
vring_split->queue_dma_addr,
- dma_dev);
+ map);
kfree(vring_split->desc_state);
kfree(vring_split->desc_extra);
@@ -1072,7 +1072,7 @@ static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split,
u32 num,
unsigned int vring_align,
bool may_reduce_num,
- struct device *dma_dev)
+ union virtio_map map)
{
void *queue = NULL;
dma_addr_t dma_addr;
@@ -1088,7 +1088,7 @@ static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split,
queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
&dma_addr,
GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
- dma_dev);
+ map);
if (queue)
break;
if (!may_reduce_num)
@@ -1102,7 +1102,7 @@ static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split,
/* Try to get a single page. You are my only hope! */
queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
&dma_addr, GFP_KERNEL | __GFP_ZERO,
- dma_dev);
+ map);
}
if (!queue)
return -ENOMEM;
@@ -1126,7 +1126,7 @@ static struct virtqueue *__vring_new_virtqueue_split(unsigned int index,
bool (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
const char *name,
- struct device *dma_dev)
+ union virtio_map map)
{
struct vring_virtqueue *vq;
int err;
@@ -1149,7 +1149,7 @@ static struct virtqueue *__vring_new_virtqueue_split(unsigned int index,
#else
vq->broken = false;
#endif
- vq->dma_dev = dma_dev;
+ vq->map = map;
vq->use_map_api = vring_use_map_api(vdev);
vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
@@ -1187,21 +1187,21 @@ static struct virtqueue *vring_create_virtqueue_split(
bool (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
const char *name,
- struct device *dma_dev)
+ union virtio_map map)
{
struct vring_virtqueue_split vring_split = {};
struct virtqueue *vq;
int err;
err = vring_alloc_queue_split(&vring_split, vdev, num, vring_align,
- may_reduce_num, dma_dev);
+ may_reduce_num, map);
if (err)
return NULL;
vq = __vring_new_virtqueue_split(index, &vring_split, vdev, weak_barriers,
- context, notify, callback, name, dma_dev);
+ context, notify, callback, name, map);
if (!vq) {
- vring_free_split(&vring_split, vdev, dma_dev);
+ vring_free_split(&vring_split, vdev, map);
return NULL;
}
@@ -1220,7 +1220,7 @@ static int virtqueue_resize_split(struct virtqueue *_vq, u32 num)
err = vring_alloc_queue_split(&vring_split, vdev, num,
vq->split.vring_align,
vq->split.may_reduce_num,
- vring_dma_dev(vq));
+ vq->map);
if (err)
goto err;
@@ -1238,7 +1238,7 @@ static int virtqueue_resize_split(struct virtqueue *_vq, u32 num)
return 0;
err_state_extra:
- vring_free_split(&vring_split, vdev, vring_dma_dev(vq));
+ vring_free_split(&vring_split, vdev, vq->map);
err:
virtqueue_reinit_split(vq);
return -ENOMEM;
@@ -1947,25 +1947,25 @@ static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num)
static void vring_free_packed(struct vring_virtqueue_packed *vring_packed,
struct virtio_device *vdev,
- struct device *dma_dev)
+ union virtio_map map)
{
if (vring_packed->vring.desc)
vring_free_queue(vdev, vring_packed->ring_size_in_bytes,
vring_packed->vring.desc,
vring_packed->ring_dma_addr,
- dma_dev);
+ map);
if (vring_packed->vring.driver)
vring_free_queue(vdev, vring_packed->event_size_in_bytes,
vring_packed->vring.driver,
vring_packed->driver_event_dma_addr,
- dma_dev);
+ map);
if (vring_packed->vring.device)
vring_free_queue(vdev, vring_packed->event_size_in_bytes,
vring_packed->vring.device,
vring_packed->device_event_dma_addr,
- dma_dev);
+ map);
kfree(vring_packed->desc_state);
kfree(vring_packed->desc_extra);
@@ -1973,7 +1973,7 @@ static void vring_free_packed(struct vring_virtqueue_packed *vring_packed,
static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
struct virtio_device *vdev,
- u32 num, struct device *dma_dev)
+ u32 num, union virtio_map map)
{
struct vring_packed_desc *ring;
struct vring_packed_desc_event *driver, *device;
@@ -1985,7 +1985,7 @@ static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
ring = vring_alloc_queue(vdev, ring_size_in_bytes,
&ring_dma_addr,
GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
- dma_dev);
+ map);
if (!ring)
goto err;
@@ -1998,7 +1998,7 @@ static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
driver = vring_alloc_queue(vdev, event_size_in_bytes,
&driver_event_dma_addr,
GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
- dma_dev);
+ map);
if (!driver)
goto err;
@@ -2009,7 +2009,7 @@ static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
device = vring_alloc_queue(vdev, event_size_in_bytes,
&device_event_dma_addr,
GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
- dma_dev);
+ map);
if (!device)
goto err;
@@ -2021,7 +2021,7 @@ static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
return 0;
err:
- vring_free_packed(vring_packed, vdev, dma_dev);
+ vring_free_packed(vring_packed, vdev, map);
return -ENOMEM;
}
@@ -2097,7 +2097,7 @@ static struct virtqueue *__vring_new_virtqueue_packed(unsigned int index,
bool (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
const char *name,
- struct device *dma_dev)
+ union virtio_map map)
{
struct vring_virtqueue *vq;
int err;
@@ -2120,7 +2120,7 @@ static struct virtqueue *__vring_new_virtqueue_packed(unsigned int index,
vq->broken = false;
#endif
vq->packed_ring = true;
- vq->dma_dev = dma_dev;
+ vq->map = map;
vq->use_map_api = vring_use_map_api(vdev);
vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
@@ -2158,18 +2158,18 @@ static struct virtqueue *vring_create_virtqueue_packed(
bool (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
const char *name,
- struct device *dma_dev)
+ union virtio_map map)
{
struct vring_virtqueue_packed vring_packed = {};
struct virtqueue *vq;
- if (vring_alloc_queue_packed(&vring_packed, vdev, num, dma_dev))
+ if (vring_alloc_queue_packed(&vring_packed, vdev, num, map))
return NULL;
vq = __vring_new_virtqueue_packed(index, &vring_packed, vdev, weak_barriers,
- context, notify, callback, name, dma_dev);
+ context, notify, callback, name, map);
if (!vq) {
- vring_free_packed(&vring_packed, vdev, dma_dev);
+ vring_free_packed(&vring_packed, vdev, map);
return NULL;
}
@@ -2185,7 +2185,7 @@ static int virtqueue_resize_packed(struct virtqueue *_vq, u32 num)
struct virtio_device *vdev = _vq->vdev;
int err;
- if (vring_alloc_queue_packed(&vring_packed, vdev, num, vring_dma_dev(vq)))
+ if (vring_alloc_queue_packed(&vring_packed, vdev, num, vq->map))
goto err_ring;
err = vring_alloc_state_extra_packed(&vring_packed);
@@ -2202,7 +2202,7 @@ static int virtqueue_resize_packed(struct virtqueue *_vq, u32 num)
return 0;
err_state_extra:
- vring_free_packed(&vring_packed, vdev, vring_dma_dev(vq));
+ vring_free_packed(&vring_packed, vdev, vq->map);
err_ring:
virtqueue_reinit_packed(vq);
return -ENOMEM;
@@ -2434,7 +2434,7 @@ struct device *virtqueue_dma_dev(struct virtqueue *_vq)
struct vring_virtqueue *vq = to_vvq(_vq);
if (vq->use_map_api)
- return vring_dma_dev(vq);
+ return vq->map.dma_dev;
else
return NULL;
}
@@ -2719,19 +2719,20 @@ struct virtqueue *vring_create_virtqueue(
void (*callback)(struct virtqueue *),
const char *name)
{
+ union virtio_map map = {.dma_dev = vdev->dev.parent};
if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
return vring_create_virtqueue_packed(index, num, vring_align,
vdev, weak_barriers, may_reduce_num,
- context, notify, callback, name, vdev->dev.parent);
+ context, notify, callback, name, map);
return vring_create_virtqueue_split(index, num, vring_align,
vdev, weak_barriers, may_reduce_num,
- context, notify, callback, name, vdev->dev.parent);
+ context, notify, callback, name, map);
}
EXPORT_SYMBOL_GPL(vring_create_virtqueue);
-struct virtqueue *vring_create_virtqueue_dma(
+struct virtqueue *vring_create_virtqueue_map(
unsigned int index,
unsigned int num,
unsigned int vring_align,
@@ -2742,19 +2743,19 @@ struct virtqueue *vring_create_virtqueue_dma(
bool (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
const char *name,
- struct device *dma_dev)
+ union virtio_map map)
{
if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
return vring_create_virtqueue_packed(index, num, vring_align,
vdev, weak_barriers, may_reduce_num,
- context, notify, callback, name, dma_dev);
+ context, notify, callback, name, map);
return vring_create_virtqueue_split(index, num, vring_align,
vdev, weak_barriers, may_reduce_num,
- context, notify, callback, name, dma_dev);
+ context, notify, callback, name, map);
}
-EXPORT_SYMBOL_GPL(vring_create_virtqueue_dma);
+EXPORT_SYMBOL_GPL(vring_create_virtqueue_map);
/**
* virtqueue_resize - resize the vring of vq
@@ -2865,6 +2866,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
const char *name)
{
struct vring_virtqueue_split vring_split = {};
+ union virtio_map map = {.dma_dev = vdev->dev.parent};
if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
struct vring_virtqueue_packed vring_packed = {};
@@ -2874,13 +2876,13 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
return __vring_new_virtqueue_packed(index, &vring_packed,
vdev, weak_barriers,
context, notify, callback,
- name, vdev->dev.parent);
+ name, map);
}
vring_init(&vring_split.vring, num, pages, vring_align);
return __vring_new_virtqueue_split(index, &vring_split, vdev, weak_barriers,
context, notify, callback, name,
- vdev->dev.parent);
+ map);
}
EXPORT_SYMBOL_GPL(vring_new_virtqueue);
@@ -2894,19 +2896,19 @@ static void vring_free(struct virtqueue *_vq)
vq->packed.ring_size_in_bytes,
vq->packed.vring.desc,
vq->packed.ring_dma_addr,
- vring_dma_dev(vq));
+ vq->map);
vring_free_queue(vq->vq.vdev,
vq->packed.event_size_in_bytes,
vq->packed.vring.driver,
vq->packed.driver_event_dma_addr,
- vring_dma_dev(vq));
+ vq->map);
vring_free_queue(vq->vq.vdev,
vq->packed.event_size_in_bytes,
vq->packed.vring.device,
vq->packed.device_event_dma_addr,
- vring_dma_dev(vq));
+ vq->map);
kfree(vq->packed.desc_state);
kfree(vq->packed.desc_extra);
@@ -2915,7 +2917,7 @@ static void vring_free(struct virtqueue *_vq)
vq->split.queue_size_in_bytes,
vq->split.vring.desc,
vq->split.queue_dma_addr,
- vring_dma_dev(vq));
+ vq->map);
}
}
if (!vq->packed_ring) {
diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
index 657b07a60788..dc557aa7c825 100644
--- a/drivers/virtio/virtio_vdpa.c
+++ b/drivers/virtio/virtio_vdpa.c
@@ -139,6 +139,7 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
struct vdpa_callback cb;
struct virtqueue *vq;
u64 desc_addr, driver_addr, device_addr;
+ union virtio_map map = {0};
/* Assume split virtqueue, switch to packed if necessary */
struct vdpa_vq_state state = {0};
u32 align, max_num, min_num = 1;
@@ -185,9 +186,10 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
dma_dev = ops->get_vq_dma_dev(vdpa, index);
else
dma_dev = vdpa_get_dma_dev(vdpa);
- vq = vring_create_virtqueue_dma(index, max_num, align, vdev,
+ map.dma_dev = dma_dev;
+ vq = vring_create_virtqueue_map(index, max_num, align, vdev,
true, may_reduce_num, ctx,
- notify, callback, name, dma_dev);
+ notify, callback, name, map);
if (!vq) {
err = -ENOMEM;
goto error_new_virtqueue;
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 576e08bd7697..b4ba1a99e5ab 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -41,6 +41,11 @@ struct virtqueue {
void *priv;
};
+union virtio_map {
+ /* Device that performs DMA */
+ struct device *dma_dev;
+};
+
int virtqueue_add_outbuf(struct virtqueue *vq,
struct scatterlist sg[], unsigned int num,
void *data,
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index 9b33df741b63..c97a12c1cda3 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -3,6 +3,7 @@
#define _LINUX_VIRTIO_RING_H
#include <asm/barrier.h>
+#include <linux/virtio.h>
#include <linux/irqreturn.h>
#include <uapi/linux/virtio_ring.h>
@@ -79,9 +80,9 @@ struct virtqueue *vring_create_virtqueue(unsigned int index,
/*
* Creates a virtqueue and allocates the descriptor ring with per
- * virtqueue DMA device.
+ * virtqueue mapping operations.
*/
-struct virtqueue *vring_create_virtqueue_dma(unsigned int index,
+struct virtqueue *vring_create_virtqueue_map(unsigned int index,
unsigned int num,
unsigned int vring_align,
struct virtio_device *vdev,
@@ -91,7 +92,7 @@ struct virtqueue *vring_create_virtqueue_dma(unsigned int index,
bool (*notify)(struct virtqueue *vq),
void (*callback)(struct virtqueue *vq),
const char *name,
- struct device *dma_dev);
+ union virtio_map map);
/*
* Creates a virtqueue with a standard layout but a caller-allocated
--
2.31.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH V6 5/9] virtio_ring: rename dma_handle to map_handle
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
` (3 preceding siblings ...)
2025-08-21 6:46 ` [PATCH V6 4/9] virtio: introduce virtio_map container union Jason Wang
@ 2025-08-21 6:46 ` Jason Wang
2025-08-21 6:46 ` [PATCH V6 6/9] virtio: introduce map ops in virtio core Jason Wang
` (5 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma
Cc: virtualization, linux-kernel, hch, Christoph Hellwig
Following patch will introduce virtio map opreations which means the
address is not necessarily used for DMA. Let's rename the dma_handle
to map_handle first.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/virtio/virtio_ring.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index cda9bc2121bf..46515b017ccb 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -305,18 +305,18 @@ size_t virtio_max_dma_size(const struct virtio_device *vdev)
EXPORT_SYMBOL_GPL(virtio_max_dma_size);
static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
- dma_addr_t *dma_handle, gfp_t flag,
+ dma_addr_t *map_handle, gfp_t flag,
union virtio_map map)
{
if (vring_use_map_api(vdev)) {
return dma_alloc_coherent(map.dma_dev, size,
- dma_handle, flag);
+ map_handle, flag);
} else {
void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag);
if (queue) {
phys_addr_t phys_addr = virt_to_phys(queue);
- *dma_handle = (dma_addr_t)phys_addr;
+ *map_handle = (dma_addr_t)phys_addr;
/*
* Sanity check: make sure we dind't truncate
@@ -329,7 +329,7 @@ static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
* warning and abort if we end up with an
* unrepresentable address.
*/
- if (WARN_ON_ONCE(*dma_handle != phys_addr)) {
+ if (WARN_ON_ONCE(*map_handle != phys_addr)) {
free_pages_exact(queue, PAGE_ALIGN(size));
return NULL;
}
@@ -339,11 +339,11 @@ static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
}
static void vring_free_queue(struct virtio_device *vdev, size_t size,
- void *queue, dma_addr_t dma_handle,
+ void *queue, dma_addr_t map_handle,
union virtio_map map)
{
if (vring_use_map_api(vdev))
- dma_free_coherent(map.dma_dev, size, queue, dma_handle);
+ dma_free_coherent(map.dma_dev, size, queue, map_handle);
else
free_pages_exact(queue, PAGE_ALIGN(size));
}
--
2.31.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH V6 6/9] virtio: introduce map ops in virtio core
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
` (4 preceding siblings ...)
2025-08-21 6:46 ` [PATCH V6 5/9] virtio_ring: rename dma_handle to map_handle Jason Wang
@ 2025-08-21 6:46 ` Jason Wang
2025-08-21 6:46 ` [PATCH V6 7/9] vdpa: support virtio_map Jason Wang
` (4 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma; +Cc: virtualization, linux-kernel, hch
This patch introduces map operations for virtio device. Virtio use to
use DMA API which is not necessarily the case since some devices
doesn't do DMA. Instead of using tricks and abusing DMA API, let's
simply abstract the current mapping logic into a virtio specific
mapping operations. For the device or transport that doesn't do DMA,
they can implement their own mapping logic without the need to trick
DMA core. In this case the mapping metadata is opaque to the virtio
core that will be passed back to the transport or device specific map
operations. For other devices, DMA API will still be used, so map
token will still be the dma device to minimize the changeset and
performance impact.
The mapping operations are abstracted as a independent structure
instead of reusing virtio_config_ops. This allows the transport can
simply reuse the structure for lower layers like vDPA.
A set of new mapping helpers were introduced for the device that want
to do mapping by themselves.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/virtio/virtio_ring.c | 211 +++++++++++++++++++++++++++-------
drivers/virtio/virtio_vdpa.c | 3 +
include/linux/virtio.h | 25 ++++
include/linux/virtio_config.h | 72 ++++++++++++
4 files changed, 269 insertions(+), 42 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 46515b017ccb..f91a432b3e53 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -297,8 +297,14 @@ size_t virtio_max_dma_size(const struct virtio_device *vdev)
{
size_t max_segment_size = SIZE_MAX;
- if (vring_use_map_api(vdev))
- max_segment_size = dma_max_mapping_size(vdev->dev.parent);
+ if (vring_use_map_api(vdev)) {
+ if (vdev->map) {
+ max_segment_size =
+ vdev->map->max_mapping_size(vdev->vmap);
+ } else
+ max_segment_size =
+ dma_max_mapping_size(vdev->dev.parent);
+ }
return max_segment_size;
}
@@ -309,8 +315,8 @@ static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
union virtio_map map)
{
if (vring_use_map_api(vdev)) {
- return dma_alloc_coherent(map.dma_dev, size,
- map_handle, flag);
+ return virtqueue_map_alloc_coherent(vdev, map, size,
+ map_handle, flag);
} else {
void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag);
@@ -343,7 +349,8 @@ static void vring_free_queue(struct virtio_device *vdev, size_t size,
union virtio_map map)
{
if (vring_use_map_api(vdev))
- dma_free_coherent(map.dma_dev, size, queue, map_handle);
+ virtqueue_map_free_coherent(vdev, map, size,
+ queue, map_handle);
else
free_pages_exact(queue, PAGE_ALIGN(size));
}
@@ -358,6 +365,20 @@ static struct device *vring_dma_dev(const struct vring_virtqueue *vq)
return vq->map.dma_dev;
}
+static int vring_mapping_error(const struct vring_virtqueue *vq,
+ dma_addr_t addr)
+{
+ struct virtio_device *vdev = vq->vq.vdev;
+
+ if (!vq->use_map_api)
+ return 0;
+
+ if (vdev->map)
+ return vdev->map->mapping_error(vq->map, addr);
+ else
+ return dma_mapping_error(vring_dma_dev(vq), addr);
+}
+
/* Map one sg entry. */
static int vring_map_one_sg(const struct vring_virtqueue *vq, struct scatterlist *sg,
enum dma_data_direction direction, dma_addr_t *addr,
@@ -387,11 +408,11 @@ static int vring_map_one_sg(const struct vring_virtqueue *vq, struct scatterlist
* the way it expects (we don't guarantee that the scatterlist
* will exist for the lifetime of the mapping).
*/
- *addr = dma_map_page(vring_dma_dev(vq),
- sg_page(sg), sg->offset, sg->length,
- direction);
+ *addr = virtqueue_map_page_attrs(&vq->vq, sg_page(sg),
+ sg->offset, sg->length,
+ direction, 0);
- if (dma_mapping_error(vring_dma_dev(vq), *addr))
+ if (vring_mapping_error(vq, *addr))
return -ENOMEM;
return 0;
@@ -408,15 +429,6 @@ static dma_addr_t vring_map_single(const struct vring_virtqueue *vq,
size, direction, 0);
}
-static int vring_mapping_error(const struct vring_virtqueue *vq,
- dma_addr_t addr)
-{
- if (!vq->use_map_api)
- return 0;
-
- return dma_mapping_error(vring_dma_dev(vq), addr);
-}
-
static void virtqueue_init(struct vring_virtqueue *vq, u32 num)
{
vq->vq.num_free = num;
@@ -453,11 +465,12 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq,
} else if (!vring_need_unmap_buffer(vq, extra))
goto out;
- dma_unmap_page(vring_dma_dev(vq),
- extra->addr,
- extra->len,
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
+ virtqueue_unmap_page_attrs(&vq->vq,
+ extra->addr,
+ extra->len,
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE,
+ 0);
out:
return extra->next;
@@ -1271,10 +1284,11 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq,
} else if (!vring_need_unmap_buffer(vq, extra))
return;
- dma_unmap_page(vring_dma_dev(vq),
- extra->addr, extra->len,
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
+ virtqueue_unmap_page_attrs(&vq->vq,
+ extra->addr, extra->len,
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE,
+ 0);
}
static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
@@ -2433,7 +2447,7 @@ struct device *virtqueue_dma_dev(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
- if (vq->use_map_api)
+ if (vq->use_map_api && !_vq->vdev->map)
return vq->map.dma_dev;
else
return NULL;
@@ -3123,6 +3137,107 @@ const struct vring *virtqueue_get_vring(const struct virtqueue *vq)
}
EXPORT_SYMBOL_GPL(virtqueue_get_vring);
+/**
+ * virtqueue_map_alloc_coherent - alloc coherent mapping
+ * @vdev: the virtio device we are talking to
+ * @map: metadata for performing mapping
+ * @size: the size of the buffer
+ * @map_handle: the pointer to the mapped address
+ * @gfp: allocation flag (GFP_XXX)
+ *
+ * return virtual address or NULL on error
+ */
+void *virtqueue_map_alloc_coherent(struct virtio_device *vdev,
+ union virtio_map map,
+ size_t size, dma_addr_t *map_handle,
+ gfp_t gfp)
+{
+ if (vdev->map)
+ return vdev->map->alloc(map, size,
+ map_handle, gfp);
+ else
+ return dma_alloc_coherent(map.dma_dev, size,
+ map_handle, gfp);
+}
+EXPORT_SYMBOL_GPL(virtqueue_map_alloc_coherent);
+
+/**
+ * virtqueue_map_free_coherent - free coherent mapping
+ * @vdev: the virtio device we are talking to
+ * @map: metadata for performing mapping
+ * @size: the size of the buffer
+ * @map_handle: the mapped address that needs to be freed
+ *
+ */
+void virtqueue_map_free_coherent(struct virtio_device *vdev,
+ union virtio_map map, size_t size, void *vaddr,
+ dma_addr_t map_handle)
+{
+ if (vdev->map)
+ vdev->map->free(map, size, vaddr,
+ map_handle, 0);
+ else
+ dma_free_coherent(map.dma_dev, size, vaddr, map_handle);
+}
+EXPORT_SYMBOL_GPL(virtqueue_map_free_coherent);
+
+/**
+ * virtqueue_map_page_attrs - map a page to the device
+ * @_vq: the virtqueue we are talking to
+ * @page: the page that will be mapped by the device
+ * @offset: the offset in the page for a buffer
+ * @size: the buffer size
+ * @dir: mapping direction
+ * @attrs: mapping attributes
+ *
+ * Returns mapped address. Caller should check that by virtqueue_mapping_error().
+ */
+dma_addr_t virtqueue_map_page_attrs(const struct virtqueue *_vq,
+ struct page *page,
+ unsigned long offset,
+ size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ const struct vring_virtqueue *vq = to_vvq(_vq);
+ struct virtio_device *vdev = _vq->vdev;
+
+ if (vdev->map)
+ return vdev->map->map_page(vq->map,
+ page, offset, size,
+ dir, attrs);
+
+ return dma_map_page_attrs(vring_dma_dev(vq),
+ page, offset, size,
+ dir, attrs);
+}
+EXPORT_SYMBOL_GPL(virtqueue_map_page_attrs);
+
+/**
+ * virtqueue_unmap_page_attrs - map a page to the device
+ * @_vq: the virtqueue we are talking to
+ * @map_handle: the mapped address
+ * @size: the buffer size
+ * @dir: mapping direction
+ * @attrs: unmapping attributes
+ */
+void virtqueue_unmap_page_attrs(const struct virtqueue *_vq,
+ dma_addr_t map_handle,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ const struct vring_virtqueue *vq = to_vvq(_vq);
+ struct virtio_device *vdev = _vq->vdev;
+
+ if (vdev->map)
+ vdev->map->unmap_page(vq->map,
+ map_handle, size, dir, attrs);
+ else
+ dma_unmap_page_attrs(vring_dma_dev(vq), map_handle,
+ size, dir, attrs);
+}
+EXPORT_SYMBOL_GPL(virtqueue_unmap_page_attrs);
+
/**
* virtqueue_map_single_attrs - map DMA for _vq
* @_vq: the struct virtqueue we're talking about.
@@ -3134,7 +3249,7 @@ 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_mapping_error().
+ * return mapped address. Caller should check that by virtqueue_mapping_error().
*/
dma_addr_t virtqueue_map_single_attrs(const struct virtqueue *_vq, void *ptr,
size_t size,
@@ -3153,8 +3268,8 @@ dma_addr_t virtqueue_map_single_attrs(const struct virtqueue *_vq, void *ptr,
"rejecting DMA map of vmalloc memory\n"))
return DMA_MAPPING_ERROR;
- return dma_map_page_attrs(vring_dma_dev(vq), virt_to_page(ptr),
- offset_in_page(ptr), size, dir, attrs);
+ return virtqueue_map_page_attrs(&vq->vq, virt_to_page(ptr),
+ offset_in_page(ptr), size, dir, attrs);
}
EXPORT_SYMBOL_GPL(virtqueue_map_single_attrs);
@@ -3179,12 +3294,12 @@ void virtqueue_unmap_single_attrs(const struct virtqueue *_vq,
if (!vq->use_map_api)
return;
- dma_unmap_page_attrs(vring_dma_dev(vq), addr, size, dir, attrs);
+ virtqueue_unmap_page_attrs(_vq, addr, size, dir, attrs);
}
EXPORT_SYMBOL_GPL(virtqueue_unmap_single_attrs);
/**
- * virtqueue_map_mapping_error - check dma address
+ * virtqueue_mapping_error - check dma address
* @_vq: the struct virtqueue we're talking about.
* @addr: DMA address
*
@@ -3194,10 +3309,7 @@ int virtqueue_map_mapping_error(const struct virtqueue *_vq, dma_addr_t addr)
{
const struct vring_virtqueue *vq = to_vvq(_vq);
- if (!vq->use_map_api)
- return 0;
-
- return dma_mapping_error(vring_dma_dev(vq), addr);
+ return vring_mapping_error(vq, addr);
}
EXPORT_SYMBOL_GPL(virtqueue_map_mapping_error);
@@ -3214,11 +3326,15 @@ EXPORT_SYMBOL_GPL(virtqueue_map_mapping_error);
bool virtqueue_map_need_sync(const struct virtqueue *_vq, dma_addr_t addr)
{
const struct vring_virtqueue *vq = to_vvq(_vq);
+ struct virtio_device *vdev = _vq->vdev;
if (!vq->use_map_api)
return false;
- return dma_need_sync(vring_dma_dev(vq), addr);
+ if (vdev->map)
+ return vdev->map->need_sync(vq->map, addr);
+ else
+ return dma_need_sync(vring_dma_dev(vq), addr);
}
EXPORT_SYMBOL_GPL(virtqueue_map_need_sync);
@@ -3240,12 +3356,17 @@ void virtqueue_map_sync_single_range_for_cpu(const struct virtqueue *_vq,
enum dma_data_direction dir)
{
const struct vring_virtqueue *vq = to_vvq(_vq);
- struct device *dev = vring_dma_dev(vq);
+ struct virtio_device *vdev = _vq->vdev;
if (!vq->use_map_api)
return;
- dma_sync_single_range_for_cpu(dev, addr, offset, size, dir);
+ if (vdev->map)
+ vdev->map->sync_single_for_cpu(vq->map,
+ addr + offset, size, dir);
+ else
+ dma_sync_single_range_for_cpu(vring_dma_dev(vq),
+ addr, offset, size, dir);
}
EXPORT_SYMBOL_GPL(virtqueue_map_sync_single_range_for_cpu);
@@ -3266,12 +3387,18 @@ void virtqueue_map_sync_single_range_for_device(const struct virtqueue *_vq,
enum dma_data_direction dir)
{
const struct vring_virtqueue *vq = to_vvq(_vq);
- struct device *dev = vring_dma_dev(vq);
+ struct virtio_device *vdev = _vq->vdev;
if (!vq->use_map_api)
return;
- dma_sync_single_range_for_device(dev, addr, offset, size, dir);
+ if (vdev->map)
+ vdev->map->sync_single_for_device(vq->map,
+ addr + offset,
+ size, dir);
+ else
+ dma_sync_single_range_for_device(vring_dma_dev(vq), addr,
+ offset, size, dir);
}
EXPORT_SYMBOL_GPL(virtqueue_map_sync_single_range_for_device);
diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
index dc557aa7c825..d4be689e3626 100644
--- a/drivers/virtio/virtio_vdpa.c
+++ b/drivers/virtio/virtio_vdpa.c
@@ -195,6 +195,9 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
goto error_new_virtqueue;
}
+ if (index == 0)
+ vdev->vmap = map;
+
vq->num_max = max_num;
/* Setup virtqueue callback */
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index b4ba1a99e5ab..3386a4a8d06b 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -166,9 +166,11 @@ struct virtio_device {
struct virtio_device_id id;
const struct virtio_config_ops *config;
const struct vringh_config_ops *vringh_config;
+ const struct virtio_map_ops *map;
struct list_head vqs;
VIRTIO_DECLARE_FEATURES(features);
void *priv;
+ union virtio_map vmap;
#ifdef CONFIG_VIRTIO_DEBUG
struct dentry *debugfs_dir;
u64 debugfs_filter_features[VIRTIO_FEATURES_DWORDS];
@@ -267,6 +269,29 @@ void unregister_virtio_driver(struct virtio_driver *drv);
module_driver(__virtio_driver, register_virtio_driver, \
unregister_virtio_driver)
+
+void *virtqueue_map_alloc_coherent(struct virtio_device *vdev,
+ union virtio_map mapping_token,
+ size_t size, dma_addr_t *dma_handle,
+ gfp_t gfp);
+
+void virtqueue_map_free_coherent(struct virtio_device *vdev,
+ union virtio_map mapping_token,
+ size_t size, void *vaddr,
+ dma_addr_t dma_handle);
+
+dma_addr_t virtqueue_map_page_attrs(const struct virtqueue *_vq,
+ struct page *page,
+ unsigned long offset,
+ size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs);
+
+void virtqueue_unmap_page_attrs(const struct virtqueue *_vq,
+ dma_addr_t dma_handle,
+ 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);
void virtqueue_unmap_single_attrs(const struct virtqueue *_vq, dma_addr_t addr,
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 8bf156dde554..52319dc5d5e0 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -139,6 +139,78 @@ struct virtio_config_ops {
int (*enable_vq_after_reset)(struct virtqueue *vq);
};
+/**
+ * struct virtio_map_ops - operations for mapping buffer for a virtio device
+ * Note: For transport that has its own mapping logic it must
+ * implements all of the operations
+ * @map_page: map a buffer to the device
+ * map: metadata for performing mapping
+ * page: the page that will be mapped by the device
+ * offset: the offset in the page for a buffer
+ * size: the buffer size
+ * dir: mapping direction
+ * attrs: mapping attributes
+ * Returns: the mapped address
+ * @unmap_page: unmap a buffer from the device
+ * map: device specific mapping map
+ * map_handle: the mapped address
+ * size: the buffer size
+ * dir: mapping direction
+ * attrs: unmapping attributes
+ * @sync_single_for_cpu: sync a single buffer from device to cpu
+ * map: metadata for performing mapping
+ * map_handle: the mapping address to sync
+ * size: the size of the buffer
+ * dir: synchronization direction
+ * @sync_single_for_device: sync a single buffer from cpu to device
+ * map: metadata for performing mapping
+ * map_handle: the mapping address to sync
+ * size: the size of the buffer
+ * dir: synchronization direction
+ * @alloc: alloc a coherent buffer mapping
+ * map: metadata for performing mapping
+ * size: the size of the buffer
+ * map_handle: the mapping address to sync
+ * gfp: allocation flag (GFP_XXX)
+ * Returns: virtual address of the allocated buffer
+ * @free: free a coherent buffer mapping
+ * map: metadata for performing mapping
+ * size: the size of the buffer
+ * vaddr: virtual address of the buffer
+ * map_handle: the mapping address to sync
+ * attrs: unmapping attributes
+ * @need_sync: if the buffer needs synchronization
+ * map: metadata for performing mapping
+ * map_handle: the mapped address
+ * Returns: whether the buffer needs synchronization
+ * @mapping_error: if the mapping address is error
+ * map: metadata for performing mapping
+ * map_handle: the mapped address
+ * @max_mapping_size: get the maximum buffer size that can be mapped
+ * map: metadata for performing mapping
+ * Returns: the maximum buffer size that can be mapped
+ */
+struct virtio_map_ops {
+ dma_addr_t (*map_page)(union virtio_map map, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir, unsigned long attrs);
+ void (*unmap_page)(union virtio_map map, dma_addr_t map_handle,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs);
+ void (*sync_single_for_cpu)(union virtio_map map, dma_addr_t map_handle,
+ size_t size, enum dma_data_direction dir);
+ void (*sync_single_for_device)(union virtio_map map,
+ dma_addr_t map_handle, size_t size,
+ enum dma_data_direction dir);
+ void *(*alloc)(union virtio_map map, size_t size,
+ dma_addr_t *map_handle, gfp_t gfp);
+ void (*free)(union virtio_map map, size_t size, void *vaddr,
+ dma_addr_t map_handle, unsigned long attrs);
+ bool (*need_sync)(union virtio_map map, dma_addr_t map_handle);
+ int (*mapping_error)(union virtio_map map, dma_addr_t map_handle);
+ size_t (*max_mapping_size)(union virtio_map map);
+};
+
/* If driver didn't advertise the feature, it will never appear. */
void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
unsigned int fbit);
--
2.31.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH V6 7/9] vdpa: support virtio_map
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
` (5 preceding siblings ...)
2025-08-21 6:46 ` [PATCH V6 6/9] virtio: introduce map ops in virtio core Jason Wang
@ 2025-08-21 6:46 ` Jason Wang
2025-08-21 6:46 ` [PATCH V6 8/9] vdpa: introduce map ops Jason Wang
` (3 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma; +Cc: virtualization, linux-kernel, hch
Virtio core switches from DMA device to virtio_map, let's do that
as well for vDPA.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vdpa/alibaba/eni_vdpa.c | 2 +-
drivers/vdpa/ifcvf/ifcvf_main.c | 2 +-
drivers/vdpa/mlx5/core/mr.c | 4 ++--
drivers/vdpa/mlx5/net/mlx5_vnet.c | 13 ++++++++-----
drivers/vdpa/octeon_ep/octep_vdpa_main.c | 2 +-
drivers/vdpa/pds/vdpa_dev.c | 2 +-
drivers/vdpa/solidrun/snet_main.c | 4 ++--
drivers/vdpa/vdpa.c | 2 +-
drivers/vdpa/vdpa_sim/vdpa_sim.c | 2 +-
drivers/vdpa/vdpa_user/vduse_dev.c | 2 +-
drivers/vdpa/virtio_pci/vp_vdpa.c | 2 +-
drivers/vhost/vdpa.c | 6 ++++--
drivers/virtio/virtio_vdpa.c | 11 +++++------
include/linux/vdpa.h | 15 ++++++++-------
14 files changed, 37 insertions(+), 32 deletions(-)
diff --git a/drivers/vdpa/alibaba/eni_vdpa.c b/drivers/vdpa/alibaba/eni_vdpa.c
index ad7f3447fe90..54aea086d08c 100644
--- a/drivers/vdpa/alibaba/eni_vdpa.c
+++ b/drivers/vdpa/alibaba/eni_vdpa.c
@@ -496,7 +496,7 @@ static int eni_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
pci_set_master(pdev);
pci_set_drvdata(pdev, eni_vdpa);
- eni_vdpa->vdpa.dma_dev = &pdev->dev;
+ eni_vdpa->vdpa.vmap.dma_dev = &pdev->dev;
eni_vdpa->queues = eni_vdpa_get_num_queues(eni_vdpa);
eni_vdpa->vring = devm_kcalloc(&pdev->dev, eni_vdpa->queues,
diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index ccf64d7bbfaa..979d188d74ee 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -713,7 +713,7 @@ static int ifcvf_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
ifcvf_mgmt_dev->adapter = adapter;
adapter->pdev = pdev;
- adapter->vdpa.dma_dev = &pdev->dev;
+ adapter->vdpa.vmap.dma_dev = &pdev->dev;
adapter->vdpa.mdev = mdev;
adapter->vf = vf;
vdpa_dev = &adapter->vdpa;
diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
index c7a20278bc3c..8870a7169267 100644
--- a/drivers/vdpa/mlx5/core/mr.c
+++ b/drivers/vdpa/mlx5/core/mr.c
@@ -378,7 +378,7 @@ static int map_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr
u64 pa, offset;
u64 paend;
struct scatterlist *sg;
- struct device *dma = mvdev->vdev.dma_dev;
+ struct device *dma = mvdev->vdev.vmap.dma_dev;
for (map = vhost_iotlb_itree_first(iotlb, mr->start, mr->end - 1);
map; map = vhost_iotlb_itree_next(map, mr->start, mr->end - 1)) {
@@ -432,7 +432,7 @@ static int map_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr
static void unmap_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr)
{
- struct device *dma = mvdev->vdev.dma_dev;
+ struct device *dma = mvdev->vdev.vmap.dma_dev;
destroy_direct_mr(mvdev, mr);
dma_unmap_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 0ed2fc28e1ce..a7e76f175914 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -3395,14 +3395,17 @@ static int mlx5_vdpa_reset_map(struct vdpa_device *vdev, unsigned int asid)
return err;
}
-static struct device *mlx5_get_vq_dma_dev(struct vdpa_device *vdev, u16 idx)
+static union virtio_map mlx5_get_vq_map(struct vdpa_device *vdev, u16 idx)
{
struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
+ union virtio_map map;
if (is_ctrl_vq_idx(mvdev, idx))
- return &vdev->dev;
+ map.dma_dev = &vdev->dev;
+ else
+ map.dma_dev = mvdev->vdev.vmap.dma_dev;
- return mvdev->vdev.dma_dev;
+ return map;
}
static void free_irqs(struct mlx5_vdpa_net *ndev)
@@ -3686,7 +3689,7 @@ static const struct vdpa_config_ops mlx5_vdpa_ops = {
.set_map = mlx5_vdpa_set_map,
.reset_map = mlx5_vdpa_reset_map,
.set_group_asid = mlx5_set_group_asid,
- .get_vq_dma_dev = mlx5_get_vq_dma_dev,
+ .get_vq_map = mlx5_get_vq_map,
.free = mlx5_vdpa_free,
.suspend = mlx5_vdpa_suspend,
.resume = mlx5_vdpa_resume, /* Op disabled if not supported. */
@@ -3965,7 +3968,7 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
}
ndev->mvdev.mlx_features = device_features;
- mvdev->vdev.dma_dev = &mdev->pdev->dev;
+ mvdev->vdev.vmap.dma_dev = &mdev->pdev->dev;
err = mlx5_vdpa_alloc_resources(&ndev->mvdev);
if (err)
goto err_alloc;
diff --git a/drivers/vdpa/octeon_ep/octep_vdpa_main.c b/drivers/vdpa/octeon_ep/octep_vdpa_main.c
index 9b49efd24391..5818dae133a3 100644
--- a/drivers/vdpa/octeon_ep/octep_vdpa_main.c
+++ b/drivers/vdpa/octeon_ep/octep_vdpa_main.c
@@ -516,7 +516,7 @@ static int octep_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
}
oct_vdpa->pdev = pdev;
- oct_vdpa->vdpa.dma_dev = &pdev->dev;
+ oct_vdpa->vdpa.vmap.dma_dev = &pdev->dev;
oct_vdpa->vdpa.mdev = mdev;
oct_vdpa->oct_hw = oct_hw;
vdpa_dev = &oct_vdpa->vdpa;
diff --git a/drivers/vdpa/pds/vdpa_dev.c b/drivers/vdpa/pds/vdpa_dev.c
index 301d95e08596..63d82263fb52 100644
--- a/drivers/vdpa/pds/vdpa_dev.c
+++ b/drivers/vdpa/pds/vdpa_dev.c
@@ -643,7 +643,7 @@ static int pds_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
pdev = vdpa_aux->padev->vf_pdev;
dma_dev = &pdev->dev;
- pdsv->vdpa_dev.dma_dev = dma_dev;
+ pdsv->vdpa_dev.vmap.dma_dev = dma_dev;
status = pds_vdpa_get_status(&pdsv->vdpa_dev);
if (status == 0xff) {
diff --git a/drivers/vdpa/solidrun/snet_main.c b/drivers/vdpa/solidrun/snet_main.c
index 55ec51c17ab3..39050aab147f 100644
--- a/drivers/vdpa/solidrun/snet_main.c
+++ b/drivers/vdpa/solidrun/snet_main.c
@@ -1052,8 +1052,8 @@ static int snet_vdpa_probe_vf(struct pci_dev *pdev)
*/
snet_reserve_irq_idx(pf_irqs ? pdev_pf : pdev, snet);
- /*set DMA device*/
- snet->vdpa.dma_dev = &pdev->dev;
+ /* set map metadata */
+ snet->vdpa.vmap.dma_dev = &pdev->dev;
/* Register VDPA device */
ret = vdpa_register_device(&snet->vdpa, snet->cfg->vq_num);
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 8a372b51c21a..c71debeb8471 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -151,7 +151,7 @@ static void vdpa_release_dev(struct device *d)
* Driver should use vdpa_alloc_device() wrapper macro instead of
* using this directly.
*
- * Return: Returns an error when parent/config/dma_dev is not set or fail to get
+ * Return: Returns an error when parent/config/map is not set or fail to get
* ida.
*/
struct vdpa_device *__vdpa_alloc_device(struct device *parent,
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index c204fc8e471a..22ee53538444 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -272,7 +272,7 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr,
vringh_set_iotlb(&vdpasim->vqs[i].vring, &vdpasim->iommu[0],
&vdpasim->iommu_lock);
- vdpasim->vdpa.dma_dev = dev;
+ vdpasim->vdpa.vmap.dma_dev = dev;
return vdpasim;
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 04620bb77203..f68ed569394c 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -2022,7 +2022,7 @@ static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name)
return ret;
}
set_dma_ops(&vdev->vdpa.dev, &vduse_dev_dma_ops);
- vdev->vdpa.dma_dev = &vdev->vdpa.dev;
+ vdev->vdpa.vmap.dma_dev = &vdev->vdpa.dev;
vdev->vdpa.mdev = &vduse_mgmt->mgmt_dev;
return 0;
diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
index 8787407f75b0..242641c0f2bd 100644
--- a/drivers/vdpa/virtio_pci/vp_vdpa.c
+++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
@@ -520,7 +520,7 @@ static int vp_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
vp_vdpa_mgtdev->vp_vdpa = vp_vdpa;
- vp_vdpa->vdpa.dma_dev = &pdev->dev;
+ vp_vdpa->vdpa.vmap.dma_dev = &pdev->dev;
vp_vdpa->queues = vp_modern_get_num_queues(mdev);
vp_vdpa->mdev = mdev;
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index af1e1fdfd9ed..05a481e4c385 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -1318,7 +1318,8 @@ static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
- struct device *dma_dev = vdpa_get_dma_dev(vdpa);
+ union virtio_map map = vdpa_get_map(vdpa);
+ struct device *dma_dev = map.dma_dev;
int ret;
/* Device want to do DMA by itself */
@@ -1353,7 +1354,8 @@ static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
{
struct vdpa_device *vdpa = v->vdpa;
- struct device *dma_dev = vdpa_get_dma_dev(vdpa);
+ union virtio_map map = vdpa_get_map(vdpa);
+ struct device *dma_dev = map.dma_dev;
if (v->domain) {
iommu_detach_device(v->domain, dma_dev);
diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
index d4be689e3626..8b27c6e8eebb 100644
--- a/drivers/virtio/virtio_vdpa.c
+++ b/drivers/virtio/virtio_vdpa.c
@@ -133,7 +133,6 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
const char *name, bool ctx)
{
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
- struct device *dma_dev;
const struct vdpa_config_ops *ops = vdpa->config;
bool (*notify)(struct virtqueue *vq) = virtio_vdpa_notify;
struct vdpa_callback cb;
@@ -182,11 +181,11 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
/* Create the vring */
align = ops->get_vq_align(vdpa);
- if (ops->get_vq_dma_dev)
- dma_dev = ops->get_vq_dma_dev(vdpa, index);
+ if (ops->get_vq_map)
+ map = ops->get_vq_map(vdpa, index);
else
- dma_dev = vdpa_get_dma_dev(vdpa);
- map.dma_dev = dma_dev;
+ map = vdpa_get_map(vdpa);
+
vq = vring_create_virtqueue_map(index, max_num, align, vdev,
true, may_reduce_num, ctx,
notify, callback, name, map);
@@ -467,7 +466,7 @@ static int virtio_vdpa_probe(struct vdpa_device *vdpa)
if (!vd_dev)
return -ENOMEM;
- vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa);
+ vd_dev->vdev.dev.parent = vdpa_get_map(vdpa).dma_dev;
vd_dev->vdev.dev.release = virtio_vdpa_release_dev;
vd_dev->vdev.config = &virtio_vdpa_config_ops;
vd_dev->vdpa = vdpa;
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 2e7a30fe6b92..ae0451945851 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -5,6 +5,7 @@
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/interrupt.h>
+#include <linux/virtio.h>
#include <linux/vhost_iotlb.h>
#include <linux/virtio_net.h>
#include <linux/virtio_blk.h>
@@ -70,7 +71,7 @@ struct vdpa_mgmt_dev;
/**
* struct vdpa_device - representation of a vDPA device
* @dev: underlying device
- * @dma_dev: the actual device that is performing DMA
+ * @vmap: the metadata passed to upper layer to be used for mapping
* @driver_override: driver name to force a match; do not set directly,
* because core frees it; use driver_set_override() to
* set or clear it.
@@ -87,7 +88,7 @@ struct vdpa_mgmt_dev;
*/
struct vdpa_device {
struct device dev;
- struct device *dma_dev;
+ union virtio_map vmap;
const char *driver_override;
const struct vdpa_config_ops *config;
struct rw_semaphore cf_lock; /* Protects get/set config */
@@ -352,11 +353,11 @@ struct vdpa_map_file {
* @vdev: vdpa device
* @asid: address space identifier
* Returns integer: success (0) or error (< 0)
- * @get_vq_dma_dev: Get the dma device for a specific
+ * @get_vq_map: Get the map metadata for a specific
* virtqueue (optional)
* @vdev: vdpa device
* @idx: virtqueue index
- * Returns pointer to structure device or error (NULL)
+ * Returns map token union error (NULL)
* @bind_mm: Bind the device to a specific address space
* so the vDPA framework can use VA when this
* callback is implemented. (optional)
@@ -436,7 +437,7 @@ struct vdpa_config_ops {
int (*reset_map)(struct vdpa_device *vdev, unsigned int asid);
int (*set_group_asid)(struct vdpa_device *vdev, unsigned int group,
unsigned int asid);
- struct device *(*get_vq_dma_dev)(struct vdpa_device *vdev, u16 idx);
+ union virtio_map (*get_vq_map)(struct vdpa_device *vdev, u16 idx);
int (*bind_mm)(struct vdpa_device *vdev, struct mm_struct *mm);
void (*unbind_mm)(struct vdpa_device *vdev);
@@ -520,9 +521,9 @@ static inline void vdpa_set_drvdata(struct vdpa_device *vdev, void *data)
dev_set_drvdata(&vdev->dev, data);
}
-static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev)
+static inline union virtio_map vdpa_get_map(struct vdpa_device *vdev)
{
- return vdev->dma_dev;
+ return vdev->vmap;
}
static inline int vdpa_reset(struct vdpa_device *vdev, u32 flags)
--
2.31.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH V6 8/9] vdpa: introduce map ops
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
` (6 preceding siblings ...)
2025-08-21 6:46 ` [PATCH V6 7/9] vdpa: support virtio_map Jason Wang
@ 2025-08-21 6:46 ` Jason Wang
2025-08-21 6:46 ` [PATCH V6 9/9] vduse: switch to use virtio map API instead of DMA API Jason Wang
` (2 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma
Cc: virtualization, linux-kernel, hch, Christoph Hellwig
Virtio core allows the transport to provide device or transport
specific mapping functions. This patch adds this support to vDPA. We
can simply do this by allowing the vDPA parent to register a
virtio_map_ops.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vdpa/alibaba/eni_vdpa.c | 3 ++-
drivers/vdpa/ifcvf/ifcvf_main.c | 3 ++-
drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +-
drivers/vdpa/octeon_ep/octep_vdpa_main.c | 4 ++--
drivers/vdpa/pds/vdpa_dev.c | 3 ++-
drivers/vdpa/solidrun/snet_main.c | 4 ++--
drivers/vdpa/vdpa.c | 3 +++
drivers/vdpa/vdpa_sim/vdpa_sim.c | 2 +-
drivers/vdpa/vdpa_user/vduse_dev.c | 3 ++-
drivers/vdpa/virtio_pci/vp_vdpa.c | 3 ++-
drivers/virtio/virtio_vdpa.c | 4 +++-
include/linux/vdpa.h | 10 +++++++---
12 files changed, 29 insertions(+), 15 deletions(-)
diff --git a/drivers/vdpa/alibaba/eni_vdpa.c b/drivers/vdpa/alibaba/eni_vdpa.c
index 54aea086d08c..e476504db0c8 100644
--- a/drivers/vdpa/alibaba/eni_vdpa.c
+++ b/drivers/vdpa/alibaba/eni_vdpa.c
@@ -478,7 +478,8 @@ static int eni_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return ret;
eni_vdpa = vdpa_alloc_device(struct eni_vdpa, vdpa,
- dev, &eni_vdpa_ops, 1, 1, NULL, false);
+ dev, &eni_vdpa_ops, NULL,
+ 1, 1, NULL, false);
if (IS_ERR(eni_vdpa)) {
ENI_ERR(pdev, "failed to allocate vDPA structure\n");
return PTR_ERR(eni_vdpa);
diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 979d188d74ee..6658dc74d915 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -705,7 +705,8 @@ static int ifcvf_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
vf = &ifcvf_mgmt_dev->vf;
pdev = vf->pdev;
adapter = vdpa_alloc_device(struct ifcvf_adapter, vdpa,
- &pdev->dev, &ifc_vdpa_ops, 1, 1, NULL, false);
+ &pdev->dev, &ifc_vdpa_ops,
+ NULL, 1, 1, NULL, false);
if (IS_ERR(adapter)) {
IFCVF_ERR(pdev, "Failed to allocate vDPA structure");
return PTR_ERR(adapter);
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index a7e76f175914..82034efb74fc 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -3882,7 +3882,7 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
}
ndev = vdpa_alloc_device(struct mlx5_vdpa_net, mvdev.vdev, mdev->device, &mgtdev->vdpa_ops,
- MLX5_VDPA_NUMVQ_GROUPS, MLX5_VDPA_NUM_AS, name, false);
+ NULL, MLX5_VDPA_NUMVQ_GROUPS, MLX5_VDPA_NUM_AS, name, false);
if (IS_ERR(ndev))
return PTR_ERR(ndev);
diff --git a/drivers/vdpa/octeon_ep/octep_vdpa_main.c b/drivers/vdpa/octeon_ep/octep_vdpa_main.c
index 5818dae133a3..9e8d07078606 100644
--- a/drivers/vdpa/octeon_ep/octep_vdpa_main.c
+++ b/drivers/vdpa/octeon_ep/octep_vdpa_main.c
@@ -508,8 +508,8 @@ static int octep_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
u64 device_features;
int ret;
- oct_vdpa = vdpa_alloc_device(struct octep_vdpa, vdpa, &pdev->dev, &octep_vdpa_ops, 1, 1,
- NULL, false);
+ oct_vdpa = vdpa_alloc_device(struct octep_vdpa, vdpa, &pdev->dev, &octep_vdpa_ops,
+ NULL, 1, 1, NULL, false);
if (IS_ERR(oct_vdpa)) {
dev_err(&pdev->dev, "Failed to allocate vDPA structure for octep vdpa device");
return PTR_ERR(oct_vdpa);
diff --git a/drivers/vdpa/pds/vdpa_dev.c b/drivers/vdpa/pds/vdpa_dev.c
index 63d82263fb52..36f61cc96e21 100644
--- a/drivers/vdpa/pds/vdpa_dev.c
+++ b/drivers/vdpa/pds/vdpa_dev.c
@@ -632,7 +632,8 @@ static int pds_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
}
pdsv = vdpa_alloc_device(struct pds_vdpa_device, vdpa_dev,
- dev, &pds_vdpa_ops, 1, 1, name, false);
+ dev, &pds_vdpa_ops, NULL,
+ 1, 1, name, false);
if (IS_ERR(pdsv)) {
dev_err(dev, "Failed to allocate vDPA structure: %pe\n", pdsv);
return PTR_ERR(pdsv);
diff --git a/drivers/vdpa/solidrun/snet_main.c b/drivers/vdpa/solidrun/snet_main.c
index 39050aab147f..4588211d57eb 100644
--- a/drivers/vdpa/solidrun/snet_main.c
+++ b/drivers/vdpa/solidrun/snet_main.c
@@ -1008,8 +1008,8 @@ static int snet_vdpa_probe_vf(struct pci_dev *pdev)
}
/* Allocate vdpa device */
- snet = vdpa_alloc_device(struct snet, vdpa, &pdev->dev, &snet_config_ops, 1, 1, NULL,
- false);
+ snet = vdpa_alloc_device(struct snet, vdpa, &pdev->dev, &snet_config_ops,
+ NULL, 1, 1, NULL, false);
if (!snet) {
SNET_ERR(pdev, "Failed to allocate a vdpa device\n");
ret = -ENOMEM;
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index c71debeb8471..ec4cb0162849 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -142,6 +142,7 @@ static void vdpa_release_dev(struct device *d)
* initialized but before registered.
* @parent: the parent device
* @config: the bus operations that is supported by this device
+ * @map: the map opeartions that is supported by this device
* @ngroups: number of groups supported by this device
* @nas: number of address spaces supported by this device
* @size: size of the parent structure that contains private data
@@ -156,6 +157,7 @@ static void vdpa_release_dev(struct device *d)
*/
struct vdpa_device *__vdpa_alloc_device(struct device *parent,
const struct vdpa_config_ops *config,
+ const struct virtio_map_ops *map,
unsigned int ngroups, unsigned int nas,
size_t size, const char *name,
bool use_va)
@@ -187,6 +189,7 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
vdev->dev.release = vdpa_release_dev;
vdev->index = err;
vdev->config = config;
+ vdev->map = map;
vdev->features_valid = false;
vdev->use_va = use_va;
vdev->ngroups = ngroups;
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 22ee53538444..c1c6431950e1 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -215,7 +215,7 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr,
else
ops = &vdpasim_config_ops;
- vdpa = __vdpa_alloc_device(NULL, ops,
+ vdpa = __vdpa_alloc_device(NULL, ops, NULL,
dev_attr->ngroups, dev_attr->nas,
dev_attr->alloc_size,
dev_attr->name, use_va);
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index f68ed569394c..ad782d20a8ed 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -2009,7 +2009,8 @@ static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name)
return -EEXIST;
vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev,
- &vduse_vdpa_config_ops, 1, 1, name, true);
+ &vduse_vdpa_config_ops, NULL,
+ 1, 1, name, true);
if (IS_ERR(vdev))
return PTR_ERR(vdev);
diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
index 242641c0f2bd..17a19a728c9c 100644
--- a/drivers/vdpa/virtio_pci/vp_vdpa.c
+++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
@@ -511,7 +511,8 @@ static int vp_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
int ret, i;
vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
- dev, &vp_vdpa_ops, 1, 1, name, false);
+ dev, &vp_vdpa_ops, NULL,
+ 1, 1, name, false);
if (IS_ERR(vp_vdpa)) {
dev_err(dev, "vp_vdpa: Failed to allocate vDPA structure\n");
diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
index 8b27c6e8eebb..2464fa655f09 100644
--- a/drivers/virtio/virtio_vdpa.c
+++ b/drivers/virtio/virtio_vdpa.c
@@ -466,9 +466,11 @@ static int virtio_vdpa_probe(struct vdpa_device *vdpa)
if (!vd_dev)
return -ENOMEM;
- vd_dev->vdev.dev.parent = vdpa_get_map(vdpa).dma_dev;
+ vd_dev->vdev.dev.parent = vdpa->map ? &vdpa->dev :
+ vdpa_get_map(vdpa).dma_dev;
vd_dev->vdev.dev.release = virtio_vdpa_release_dev;
vd_dev->vdev.config = &virtio_vdpa_config_ops;
+ vd_dev->vdev.map = vdpa->map;
vd_dev->vdpa = vdpa;
vd_dev->vdev.id.device = ops->get_device_id(vdpa);
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index ae0451945851..4cf21d6e9cfd 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -76,6 +76,7 @@ struct vdpa_mgmt_dev;
* because core frees it; use driver_set_override() to
* set or clear it.
* @config: the configuration ops for this device.
+ * @map: the map ops for this device
* @cf_lock: Protects get and set access to configuration layout.
* @index: device index
* @features_valid: were features initialized? for legacy guests
@@ -91,6 +92,7 @@ struct vdpa_device {
union virtio_map vmap;
const char *driver_override;
const struct vdpa_config_ops *config;
+ const struct virtio_map_ops *map;
struct rw_semaphore cf_lock; /* Protects get/set config */
unsigned int index;
bool features_valid;
@@ -447,6 +449,7 @@ struct vdpa_config_ops {
struct vdpa_device *__vdpa_alloc_device(struct device *parent,
const struct vdpa_config_ops *config,
+ const struct virtio_map_ops *map,
unsigned int ngroups, unsigned int nas,
size_t size, const char *name,
bool use_va);
@@ -458,6 +461,7 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
* @member: the name of struct vdpa_device within the @dev_struct
* @parent: the parent device
* @config: the bus operations that is supported by this device
+ * @map: the map operations that is supported by this device
* @ngroups: the number of virtqueue groups supported by this device
* @nas: the number of address spaces
* @name: name of the vdpa device
@@ -465,10 +469,10 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
*
* Return allocated data structure or ERR_PTR upon error
*/
-#define vdpa_alloc_device(dev_struct, member, parent, config, ngroups, nas, \
- name, use_va) \
+#define vdpa_alloc_device(dev_struct, member, parent, config, map, \
+ ngroups, nas, name, use_va) \
container_of((__vdpa_alloc_device( \
- parent, config, ngroups, nas, \
+ parent, config, map, ngroups, nas, \
(sizeof(dev_struct) + \
BUILD_BUG_ON_ZERO(offsetof( \
dev_struct, member))), name, use_va)), \
--
2.31.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH V6 9/9] vduse: switch to use virtio map API instead of DMA API
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
` (7 preceding siblings ...)
2025-08-21 6:46 ` [PATCH V6 8/9] vdpa: introduce map ops Jason Wang
@ 2025-08-21 6:46 ` Jason Wang
2025-08-25 3:18 ` [PATCH V6 0/9] Refine virtio mapping API Lei Yang
2025-08-26 11:30 ` Eugenio Perez Martin
10 siblings, 0 replies; 12+ messages in thread
From: Jason Wang @ 2025-08-21 6:46 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo, eperezma; +Cc: virtualization, linux-kernel, hch
Lacking the support of device specific mapping supported in virtio,
VDUSE must trick the DMA API in order to make virtio-vdpa transport
work. This is done by advertising vDPA device as dma device with a
VDUSE specific dma_ops even if it doesn't do DMA at all.
This will be fixed by this patch. Thanks to the new mapping operations
support by virtio and vDPA. VDUSE can simply switch to advertise its
specific mappings operations to virtio via virtio-vdpa then DMA API is
not needed for VDUSE any more and iova domain could be used as the
mapping token instead.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vdpa/Kconfig | 8 +--
drivers/vdpa/vdpa_user/iova_domain.c | 2 +-
drivers/vdpa/vdpa_user/iova_domain.h | 2 +-
drivers/vdpa/vdpa_user/vduse_dev.c | 78 ++++++++++++++--------------
include/linux/virtio.h | 4 ++
5 files changed, 46 insertions(+), 48 deletions(-)
diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig
index 559fb9d3271f..857cf288c876 100644
--- a/drivers/vdpa/Kconfig
+++ b/drivers/vdpa/Kconfig
@@ -34,13 +34,7 @@ config VDPA_SIM_BLOCK
config VDPA_USER
tristate "VDUSE (vDPA Device in Userspace) support"
- depends on EVENTFD && MMU && HAS_DMA
- #
- # This driver incorrectly tries to override the dma_ops. It should
- # never have done that, but for now keep it working on architectures
- # that use dma ops
- #
- depends on ARCH_HAS_DMA_OPS
+ depends on EVENTFD && MMU
select VHOST_IOTLB
select IOMMU_IOVA
help
diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c
index 58116f89d8da..ccaed24b7ef8 100644
--- a/drivers/vdpa/vdpa_user/iova_domain.c
+++ b/drivers/vdpa/vdpa_user/iova_domain.c
@@ -447,7 +447,7 @@ void vduse_domain_unmap_page(struct vduse_iova_domain *domain,
void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain,
size_t size, dma_addr_t *dma_addr,
- gfp_t flag, unsigned long attrs)
+ gfp_t flag)
{
struct iova_domain *iovad = &domain->consistent_iovad;
unsigned long limit = domain->iova_limit;
diff --git a/drivers/vdpa/vdpa_user/iova_domain.h b/drivers/vdpa/vdpa_user/iova_domain.h
index 7f3f0928ec78..1f3c30be272a 100644
--- a/drivers/vdpa/vdpa_user/iova_domain.h
+++ b/drivers/vdpa/vdpa_user/iova_domain.h
@@ -64,7 +64,7 @@ void vduse_domain_unmap_page(struct vduse_iova_domain *domain,
void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain,
size_t size, dma_addr_t *dma_addr,
- gfp_t flag, unsigned long attrs);
+ gfp_t flag);
void vduse_domain_free_coherent(struct vduse_iova_domain *domain, size_t size,
void *vaddr, dma_addr_t dma_addr,
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index ad782d20a8ed..e7bced0b5542 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -814,59 +814,53 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops = {
.free = vduse_vdpa_free,
};
-static void vduse_dev_sync_single_for_device(struct device *dev,
+static void vduse_dev_sync_single_for_device(union virtio_map token,
dma_addr_t dma_addr, size_t size,
enum dma_data_direction dir)
{
- struct vduse_dev *vdev = dev_to_vduse(dev);
- struct vduse_iova_domain *domain = vdev->domain;
+ struct vduse_iova_domain *domain = token.iova_domain;
vduse_domain_sync_single_for_device(domain, dma_addr, size, dir);
}
-static void vduse_dev_sync_single_for_cpu(struct device *dev,
+static void vduse_dev_sync_single_for_cpu(union virtio_map token,
dma_addr_t dma_addr, size_t size,
enum dma_data_direction dir)
{
- struct vduse_dev *vdev = dev_to_vduse(dev);
- struct vduse_iova_domain *domain = vdev->domain;
+ struct vduse_iova_domain *domain = token.iova_domain;
vduse_domain_sync_single_for_cpu(domain, dma_addr, size, dir);
}
-static dma_addr_t vduse_dev_map_page(struct device *dev, struct page *page,
+static dma_addr_t vduse_dev_map_page(union virtio_map token, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir,
unsigned long attrs)
{
- struct vduse_dev *vdev = dev_to_vduse(dev);
- struct vduse_iova_domain *domain = vdev->domain;
+ struct vduse_iova_domain *domain = token.iova_domain;
return vduse_domain_map_page(domain, page, offset, size, dir, attrs);
}
-static void vduse_dev_unmap_page(struct device *dev, dma_addr_t dma_addr,
- size_t size, enum dma_data_direction dir,
- unsigned long attrs)
+static void vduse_dev_unmap_page(union virtio_map token, dma_addr_t dma_addr,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
{
- struct vduse_dev *vdev = dev_to_vduse(dev);
- struct vduse_iova_domain *domain = vdev->domain;
+ struct vduse_iova_domain *domain = token.iova_domain;
return vduse_domain_unmap_page(domain, dma_addr, size, dir, attrs);
}
-static void *vduse_dev_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_addr, gfp_t flag,
- unsigned long attrs)
+static void *vduse_dev_alloc_coherent(union virtio_map token, size_t size,
+ dma_addr_t *dma_addr, gfp_t flag)
{
- struct vduse_dev *vdev = dev_to_vduse(dev);
- struct vduse_iova_domain *domain = vdev->domain;
+ struct vduse_iova_domain *domain = token.iova_domain;
unsigned long iova;
void *addr;
*dma_addr = DMA_MAPPING_ERROR;
addr = vduse_domain_alloc_coherent(domain, size,
- (dma_addr_t *)&iova, flag, attrs);
+ (dma_addr_t *)&iova, flag);
if (!addr)
return NULL;
@@ -875,31 +869,45 @@ static void *vduse_dev_alloc_coherent(struct device *dev, size_t size,
return addr;
}
-static void vduse_dev_free_coherent(struct device *dev, size_t size,
- void *vaddr, dma_addr_t dma_addr,
- unsigned long attrs)
+static void vduse_dev_free_coherent(union virtio_map token, size_t size,
+ void *vaddr, dma_addr_t dma_addr,
+ unsigned long attrs)
{
- struct vduse_dev *vdev = dev_to_vduse(dev);
- struct vduse_iova_domain *domain = vdev->domain;
+ struct vduse_iova_domain *domain = token.iova_domain;
vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs);
}
-static size_t vduse_dev_max_mapping_size(struct device *dev)
+static bool vduse_dev_need_sync(union virtio_map token, dma_addr_t dma_addr)
{
- struct vduse_dev *vdev = dev_to_vduse(dev);
- struct vduse_iova_domain *domain = vdev->domain;
+ struct vduse_iova_domain *domain = token.iova_domain;
+
+ return dma_addr < domain->bounce_size;
+}
+
+static int vduse_dev_mapping_error(union virtio_map token, dma_addr_t dma_addr)
+{
+ if (unlikely(dma_addr == DMA_MAPPING_ERROR))
+ return -ENOMEM;
+ return 0;
+}
+
+static size_t vduse_dev_max_mapping_size(union virtio_map token)
+{
+ struct vduse_iova_domain *domain = token.iova_domain;
return domain->bounce_size;
}
-static const struct dma_map_ops vduse_dev_dma_ops = {
+static const struct virtio_map_ops vduse_map_ops = {
.sync_single_for_device = vduse_dev_sync_single_for_device,
.sync_single_for_cpu = vduse_dev_sync_single_for_cpu,
.map_page = vduse_dev_map_page,
.unmap_page = vduse_dev_unmap_page,
.alloc = vduse_dev_alloc_coherent,
.free = vduse_dev_free_coherent,
+ .need_sync = vduse_dev_need_sync,
+ .mapping_error = vduse_dev_mapping_error,
.max_mapping_size = vduse_dev_max_mapping_size,
};
@@ -2003,27 +2011,18 @@ static struct vduse_mgmt_dev *vduse_mgmt;
static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name)
{
struct vduse_vdpa *vdev;
- int ret;
if (dev->vdev)
return -EEXIST;
vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev,
- &vduse_vdpa_config_ops, NULL,
+ &vduse_vdpa_config_ops, &vduse_map_ops,
1, 1, name, true);
if (IS_ERR(vdev))
return PTR_ERR(vdev);
dev->vdev = vdev;
vdev->dev = dev;
- vdev->vdpa.dev.dma_mask = &vdev->vdpa.dev.coherent_dma_mask;
- ret = dma_set_mask_and_coherent(&vdev->vdpa.dev, DMA_BIT_MASK(64));
- if (ret) {
- put_device(&vdev->vdpa.dev);
- return ret;
- }
- set_dma_ops(&vdev->vdpa.dev, &vduse_dev_dma_ops);
- vdev->vdpa.vmap.dma_dev = &vdev->vdpa.dev;
vdev->vdpa.mdev = &vduse_mgmt->mgmt_dev;
return 0;
@@ -2056,6 +2055,7 @@ static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
return -ENOMEM;
}
+ dev->vdev->vdpa.vmap.iova_domain = dev->domain;
ret = _vdpa_register_device(&dev->vdev->vdpa, dev->vq_num);
if (ret) {
put_device(&dev->vdev->vdpa.dev);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 3386a4a8d06b..96c66126c074 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -41,9 +41,13 @@ struct virtqueue {
void *priv;
};
+struct vduse_iova_domain;
+
union virtio_map {
/* Device that performs DMA */
struct device *dma_dev;
+ /* VDUSE specific mapping data */
+ struct vduse_iova_domain *iova_domain;
};
int virtqueue_add_outbuf(struct virtqueue *vq,
--
2.31.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH V6 0/9] Refine virtio mapping API
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
` (8 preceding siblings ...)
2025-08-21 6:46 ` [PATCH V6 9/9] vduse: switch to use virtio map API instead of DMA API Jason Wang
@ 2025-08-25 3:18 ` Lei Yang
2025-08-26 11:30 ` Eugenio Perez Martin
10 siblings, 0 replies; 12+ messages in thread
From: Lei Yang @ 2025-08-25 3:18 UTC (permalink / raw)
To: Jason Wang; +Cc: mst, xuanzhuo, eperezma, virtualization, linux-kernel, hch
Tested pass with virtio-net regression tests,everything works fine.
Tested-by: Lei Yang <leiyang@redhat.com>
On Thu, Aug 21, 2025 at 2:50 PM Jason Wang <jasowang@redhat.com> wrote:
>
> Hi all:
>
> Virtio used to be coupled with DMA API. This works fine for the device
> that do real DMA but not the others. For example, VDUSE nees to craft
> with DMA API in order to let the virtio-vdpa driver to work.
>
> This series tries to solve this issue by introducing the mapping API
> in the virtio core. So transport like vDPA can implement their own
> mapping logic without the need to hack with DMA API. The mapping API
> are abstracted with a new map operations in order to be re-used by
> transprot or device. So device like VDUSE can implement its own
> mapping loigc.
>
> For device that uses DMA (for example PCI device), the virtio core
> will still call DMA API directly without the need of implementing map
> ops per device/transport.
>
> Please review.
>
> Changes since V5:
>
> - Rename mapping_token to virtio_map
> - Do not use opaque void * pointer, just use a forward decalration of
> vduse_iova_domain
> - Remove unused variable and typo fixes
>
> Changes since V4:
>
> - Rename map_token to mapping_token
> - Introduce a union container for opaque token as well as the DMA
> device so we won't lose the type safety
> - Do not try to set DMA mask for VDUSE device
> - Introduce a new mapper_error op for API completeness
>
> Changes since V3:
>
> - Fix build error of PDS vDPA driver
>
> Changes since V2:
>
> - Drop VDUSE dependenct for HAS_DMA and ARCH_HAS_DMA_OPS
>
> Changes since V1:
>
> - Fix build error of mlx5_vdpa driver
>
>
> Jason Wang (9):
> virtio_ring: constify virtqueue pointer for DMA helpers
> virtio_ring: switch to use dma_{map|unmap}_page()
> virtio: rename dma helpers
> virtio: introduce virtio_map container union
> virtio_ring: rename dma_handle to map_handle
> virtio: introduce map ops in virtio core
> vdpa: support virtio_map
> vdpa: introduce map ops
> vduse: switch to use virtio map API instead of DMA API
>
> drivers/net/virtio_net.c | 28 +-
> drivers/vdpa/Kconfig | 8 +-
> drivers/vdpa/alibaba/eni_vdpa.c | 5 +-
> drivers/vdpa/ifcvf/ifcvf_main.c | 5 +-
> drivers/vdpa/mlx5/core/mr.c | 4 +-
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 15 +-
> drivers/vdpa/octeon_ep/octep_vdpa_main.c | 6 +-
> drivers/vdpa/pds/vdpa_dev.c | 5 +-
> drivers/vdpa/solidrun/snet_main.c | 8 +-
> drivers/vdpa/vdpa.c | 5 +-
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 +-
> drivers/vdpa/vdpa_user/iova_domain.c | 2 +-
> drivers/vdpa/vdpa_user/iova_domain.h | 2 +-
> drivers/vdpa/vdpa_user/vduse_dev.c | 79 ++--
> drivers/vdpa/virtio_pci/vp_vdpa.c | 5 +-
> drivers/vhost/vdpa.c | 6 +-
> drivers/virtio/virtio_ring.c | 459 ++++++++++++++---------
> drivers/virtio/virtio_vdpa.c | 20 +-
> include/linux/vdpa.h | 25 +-
> include/linux/virtio.h | 46 ++-
> include/linux/virtio_config.h | 72 ++++
> include/linux/virtio_ring.h | 7 +-
> 22 files changed, 531 insertions(+), 285 deletions(-)
>
> --
> 2.31.1
>
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH V6 0/9] Refine virtio mapping API
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
` (9 preceding siblings ...)
2025-08-25 3:18 ` [PATCH V6 0/9] Refine virtio mapping API Lei Yang
@ 2025-08-26 11:30 ` Eugenio Perez Martin
10 siblings, 0 replies; 12+ messages in thread
From: Eugenio Perez Martin @ 2025-08-26 11:30 UTC (permalink / raw)
To: Jason Wang; +Cc: mst, xuanzhuo, virtualization, linux-kernel, hch
On Thu, Aug 21, 2025 at 8:46 AM Jason Wang <jasowang@redhat.com> wrote:
>
> Hi all:
>
> Virtio used to be coupled with DMA API. This works fine for the device
> that do real DMA but not the others. For example, VDUSE nees to craft
> with DMA API in order to let the virtio-vdpa driver to work.
>
> This series tries to solve this issue by introducing the mapping API
> in the virtio core. So transport like vDPA can implement their own
> mapping logic without the need to hack with DMA API. The mapping API
> are abstracted with a new map operations in order to be re-used by
> transprot or device. So device like VDUSE can implement its own
> mapping loigc.
>
> For device that uses DMA (for example PCI device), the virtio core
> will still call DMA API directly without the need of implementing map
> ops per device/transport.
>
> Please review.
>
> Changes since V5:
>
> - Rename mapping_token to virtio_map
> - Do not use opaque void * pointer, just use a forward decalration of
> vduse_iova_domain
> - Remove unused variable and typo fixes
>
> Changes since V4:
>
> - Rename map_token to mapping_token
> - Introduce a union container for opaque token as well as the DMA
> device so we won't lose the type safety
> - Do not try to set DMA mask for VDUSE device
> - Introduce a new mapper_error op for API completeness
>
> Changes since V3:
>
> - Fix build error of PDS vDPA driver
>
> Changes since V2:
>
> - Drop VDUSE dependenct for HAS_DMA and ARCH_HAS_DMA_OPS
>
> Changes since V1:
>
> - Fix build error of mlx5_vdpa driver
>
>
> Jason Wang (9):
> virtio_ring: constify virtqueue pointer for DMA helpers
> virtio_ring: switch to use dma_{map|unmap}_page()
> virtio: rename dma helpers
> virtio: introduce virtio_map container union
> virtio_ring: rename dma_handle to map_handle
> virtio: introduce map ops in virtio core
> vdpa: support virtio_map
> vdpa: introduce map ops
> vduse: switch to use virtio map API instead of DMA API
>
> drivers/net/virtio_net.c | 28 +-
> drivers/vdpa/Kconfig | 8 +-
> drivers/vdpa/alibaba/eni_vdpa.c | 5 +-
> drivers/vdpa/ifcvf/ifcvf_main.c | 5 +-
> drivers/vdpa/mlx5/core/mr.c | 4 +-
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 15 +-
> drivers/vdpa/octeon_ep/octep_vdpa_main.c | 6 +-
> drivers/vdpa/pds/vdpa_dev.c | 5 +-
> drivers/vdpa/solidrun/snet_main.c | 8 +-
> drivers/vdpa/vdpa.c | 5 +-
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 +-
> drivers/vdpa/vdpa_user/iova_domain.c | 2 +-
> drivers/vdpa/vdpa_user/iova_domain.h | 2 +-
> drivers/vdpa/vdpa_user/vduse_dev.c | 79 ++--
> drivers/vdpa/virtio_pci/vp_vdpa.c | 5 +-
> drivers/vhost/vdpa.c | 6 +-
> drivers/virtio/virtio_ring.c | 459 ++++++++++++++---------
> drivers/virtio/virtio_vdpa.c | 20 +-
> include/linux/vdpa.h | 25 +-
> include/linux/virtio.h | 46 ++-
> include/linux/virtio_config.h | 72 ++++
> include/linux/virtio_ring.h | 7 +-
> 22 files changed, 531 insertions(+), 285 deletions(-)
>
> --
> 2.31.1
>
Reviewed-by: Eugenio Pérez <eperezma@redhat.com>
Thanks!
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2025-08-26 11:31 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-08-21 6:46 [PATCH V6 0/9] Refine virtio mapping API Jason Wang
2025-08-21 6:46 ` [PATCH V6 1/9] virtio_ring: constify virtqueue pointer for DMA helpers Jason Wang
2025-08-21 6:46 ` [PATCH V6 2/9] virtio_ring: switch to use dma_{map|unmap}_page() Jason Wang
2025-08-21 6:46 ` [PATCH V6 3/9] virtio: rename dma helpers Jason Wang
2025-08-21 6:46 ` [PATCH V6 4/9] virtio: introduce virtio_map container union Jason Wang
2025-08-21 6:46 ` [PATCH V6 5/9] virtio_ring: rename dma_handle to map_handle Jason Wang
2025-08-21 6:46 ` [PATCH V6 6/9] virtio: introduce map ops in virtio core Jason Wang
2025-08-21 6:46 ` [PATCH V6 7/9] vdpa: support virtio_map Jason Wang
2025-08-21 6:46 ` [PATCH V6 8/9] vdpa: introduce map ops Jason Wang
2025-08-21 6:46 ` [PATCH V6 9/9] vduse: switch to use virtio map API instead of DMA API Jason Wang
2025-08-25 3:18 ` [PATCH V6 0/9] Refine virtio mapping API Lei Yang
2025-08-26 11:30 ` Eugenio Perez Martin
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