7 Commits

Author SHA1 Message Date
Nicolin Chen
34a255e676 vfio: Replace phys_pfn with pages for vfio_pin_pages()
Most of the callers of vfio_pin_pages() want "struct page *" and the
low-level mm code to pin pages returns a list of "struct page *" too.
So there's no gain in converting "struct page *" to PFN in between.

Replace the output parameter "phys_pfn" list with a "pages" list, to
simplify callers. This also allows us to replace the vfio_iommu_type1
implementation with a more efficient one.

And drop the pfn_valid check in the gvt code, as there is no need to
do such a check at a page-backed struct page pointer.

For now, also update vfio_iommu_type1 to fit this new parameter too.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-11-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-25 13:41:22 -06:00
Nicolin Chen
44abdd1646 vfio: Pass in starting IOVA to vfio_pin/unpin_pages API
The vfio_pin/unpin_pages() so far accepted arrays of PFNs of user IOVA.
Among all three callers, there was only one caller possibly passing in
a non-contiguous PFN list, which is now ensured to have contiguous PFN
inputs too.

Pass in the starting address with "iova" alone to simplify things, so
callers no longer need to maintain a PFN list or to pin/unpin one page
at a time. This also allows VFIO to use more efficient implementations
of pin/unpin_pages.

For now, also update vfio_iommu_type1 to fit this new parameter too,
while keeping its input intact (being user_iova) since we don't want
to spend too much effort swapping its parameters and local variables
at that level.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-6-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-25 13:41:22 -06:00
Nicolin Chen
e8f90717ed vfio: Make vfio_unpin_pages() return void
There's only one caller that checks its return value with a WARN_ON_ONCE,
while all other callers don't check the return value at all. Above that,
an undo function should not fail. So, simplify the API to return void by
embedding similar WARN_ONs.

Also for users to pinpoint which condition fails, separate WARN_ON lines,
yet remove the "driver->ops->unpin_pages" check, since it's unreasonable
for callers to unpin on something totally random that wasn't even pinned.
And remove NULL pointer checks for they would trigger oops vs. warnings.
Note that npage is already validated in the vfio core, thus drop the same
check in the type1 code.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-2-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-23 07:29:10 -06:00
Jason Gunthorpe
8cfc5b6075 vfio: Replace the iommu notifier with a device list
Instead of bouncing the function call to the driver op through a blocking
notifier just have the iommu layer call it directly.

Register each device that is being attached to the iommu with the lower
driver which then threads them on a linked list and calls the appropriate
driver op at the right time.

Currently the only use is if dma_unmap() is defined.

Also, fully lock all the debugging tests on the pinning path that a
dma_unmap is registered.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-20 11:57:59 -06:00
Jason Gunthorpe
ce4b4657ff vfio: Replace the DMA unmapping notifier with a callback
Instead of having drivers register the notifier with explicit code just
have them provide a dma_unmap callback op in their driver ops and rely on
the core code to wire it up.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-20 11:57:59 -06:00
Christoph Hellwig
c3c0fa9d94 vfio: clean up the check for mediated device in vfio_iommu_type1
Pass the group flags to ->attach_group and remove the messy check for
the bus type.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-12-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-09-30 12:46:44 -06:00
Christoph Hellwig
8cc02d22d7 vfio: move the vfio_iommu_driver_ops interface out of <linux/vfio.h>
Create a new private drivers/vfio/vfio.h header for the interface between
the VFIO core and the iommu drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-10-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-09-30 12:46:44 -06:00