linux-stable.git/drivers/virtio/virtio_ring.c, branch linux-rolling-lts

virtio: fix kernel-doc for mapping/free_coherent functions

2025-12-18T13:03:23+00:00

[ Upstream commit f8113000855a8cc2c6d8e19b97a390f1c082285d ]

Documentation build reported:

  WARNING: ./drivers/virtio/virtio_ring.c:3174 function parameter 'vaddr' not described in 'virtqueue_map_free_coherent'
  WARNING: ./drivers/virtio/virtio_ring.c:3308 expecting prototype for virtqueue_mapping_error(). Prototype was for virtqueue_map_mapping_error() instead

The kernel-doc block for virtqueue_map_free_coherent() omitted the @vaddr parameter, and
the kernel-doc header for virtqueue_map_mapping_error() used the wrong function name
(virtqueue_mapping_error) instead of the actual function name.

This change updates:

  - the function name in the comment to virtqueue_map_mapping_error()
  - adds the missing @vaddr description in the comment for virtqueue_map_free_coherent()

Fixes: b41cb3bcf67f ("virtio: rename dma helpers")
Signed-off-by: Kriish Sharma 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Michael S. Tsirkin 
Message-Id: <20251110202920.2250244-1-kriish.sharma2006@gmail.com>
Signed-off-by: Sasha Levin

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2025-10-04T15:48:16+00:00

Pull virtio updates from Michael Tsirkin:
 "Just fixes and cleanups this time around. The mapping cleanups are
  preparing the ground for new features, though"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio-vdpa: Drop redundant conversion to bool
  vduse: Use fixed 4KB bounce pages for non-4KB page size
  vduse: switch to use virtio map API instead of DMA API
  vdpa: introduce map ops
  vdpa: support virtio_map
  virtio: introduce map ops in virtio core
  virtio_ring: rename dma_handle to map_handle
  virtio: introduce virtio_map container union
  virtio: rename dma helpers
  virtio_ring: switch to use dma_{map|unmap}_page()
  virtio_ring: constify virtqueue pointer for DMA helpers
  virtio_balloon: Remove redundant __GFP_NOWARN
  vhost: vringh: Fix copy_to_iter return value check
  vhost: vringh: Modify the return value check

virtio: introduce map ops in virtio core

2025-10-01T11:24:43+00:00

This patch introduces map operations for virtio device. Virtio used 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 
Message-Id: <20250821064641.5025-7-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Tested-by: Lei Yang 
Reviewed-by: Eugenio Pérez

virtio_ring: rename dma_handle to map_handle

2025-10-01T11:24:43+00:00

Following patch will introduce virtio map operations which means the
address is not necessarily used for DMA. Let's rename the dma_handle
to map_handle first.

Reviewed-by: Christoph Hellwig 
Reviewed-by: Xuan Zhuo 
Signed-off-by: Jason Wang 
Message-Id: <20250821064641.5025-6-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Tested-by: Lei Yang 
Reviewed-by: Eugenio Pérez

virtio: introduce virtio_map container union

2025-10-01T11:24:43+00:00

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 
Message-Id: <20250821064641.5025-5-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Tested-by: Lei Yang 
Reviewed-by: Eugenio Pérez

virtio: rename dma helpers

2025-10-01T11:24:43+00:00

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 
Reviewed-by: Xuan Zhuo 
Signed-off-by: Jason Wang 
Message-Id: <20250821064641.5025-4-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Tested-by: Lei Yang 
Reviewed-by: Eugenio Pérez

virtio_ring: switch to use dma_{map|unmap}_page()

2025-10-01T11:24:43+00:00

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 
Signed-off-by: Jason Wang 
Message-Id: <20250821064641.5025-3-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Tested-by: Lei Yang 
Reviewed-by: Eugenio Pérez

virtio_ring: constify virtqueue pointer for DMA helpers

2025-10-01T11:24:43+00:00

This patch constifies the virtqueue pointer for DMA helpers.

Reviewed-by: Christoph Hellwig 
Reviewed-by: Xuan Zhuo 
Reviewed-by: Eugenio Pérez 
Signed-off-by: Jason Wang 
Message-Id: <20250821064641.5025-2-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Tested-by: Lei Yang 
Reviewed-by: Eugenio Pérez

kmsan: convert kmsan_handle_dma to use physical addresses

2025-09-11T22:18:20+00:00

Convert the KMSAN DMA handling function from page-based to physical
address-based interface.

The refactoring renames kmsan_handle_dma() parameters from accepting
(struct page *page, size_t offset, size_t size) to (phys_addr_t phys,
size_t size). The existing semantics where callers are expected to
provide only kmap memory is continued here.

Reviewed-by: Jason Gunthorpe 
Signed-off-by: Leon Romanovsky 
Signed-off-by: Marek Szyprowski 
Link: https://lore.kernel.org/r/3557cbaf66e935bc794f37d2b891ef75cbf2c80c.1757423202.git.leonro@nvidia.com

virtio: document ENOSPC

2025-08-01T13:11:07+00:00

drivers handle ENOSPC specially since it's an error one can
get from a working VQ. Document the semantics.

Message-Id: <2e6ec46b8d5e6755be291cec8e2ec57ef286e97b.1748356035.git.mst@redhat.com>
Reported-by: Parav Pandit 
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Stefan Hajnoczi 
Reviewed-by: Parav Pandit