[v3,00/10] Let iommufd charge IOPTE allocations to the memory cgroup

Message

Jason Gunthorpe Jan. 23, 2023, 8:35 p.m. UTC

iommufd follows the same design as KVM and uses memory cgroups to limit
the amount of kernel memory a iommufd file descriptor can pin down. The
various internal data structures already use GFP_KERNEL_ACCOUNT to charge
its own memory.

However, one of the biggest consumers of kernel memory is the IOPTEs
stored under the iommu_domain and these allocations are not tracked.

This series is the first step in fixing it.

The iommu driver contract already includes a 'gfp' argument to the
map_pages op, allowing iommufd to specify GFP_KERNEL_ACCOUNT and then
having the driver allocate the IOPTE tables with that flag will capture a
significant amount of the allocations.

Update the iommu_map() API to pass in the GFP argument, and fix all call
sites. Replace iommu_map_atomic().

Audit the "enterprise" iommu drivers to make sure they do the right thing.
Intel and S390 ignore the GFP argument and always use GFP_ATOMIC. This is
problematic for iommufd anyhow, so fix it. AMD and ARM SMMUv2/3 are
already correct.

A follow up series will be needed to capture the allocations made when the
iommu_domain itself is allocated, which will complete the job.

v3:
 - Leave a GFP_ATOMIC in "Add a gfp parameter to iommu_map_sg()"
   and move the conversion to gfp argument to "Use the gfp parameter in
   __iommu_dma_alloc_noncontiguous()"
 - Mask off the zone/policy flags from gfp before doing internal
   allocations and add a comment about Robin's note that this is to keep
   the buffer and internal seperate.
v2: https://lore.kernel.org/r/[e-mail]
 - Prohibit bad GFP flags in the iommu wrappers
 - Split out the new GFP_KERNEL usages into dedicated patches so it is
   easier to check. No code change after the full series
v1: https://lore.kernel.org/r/[e-mail]

Jason Gunthorpe (10):
  iommu: Add a gfp parameter to iommu_map()
  iommu: Remove iommu_map_atomic()
  iommu: Add a gfp parameter to iommu_map_sg()
  iommu/dma: Use the gfp parameter in __iommu_dma_alloc_noncontiguous()
  iommufd: Use GFP_KERNEL_ACCOUNT for iommu_map()
  iommu/intel: Add a gfp parameter to alloc_pgtable_page()
  iommu/intel: Support the gfp argument to the map_pages op
  iommu/intel: Use GFP_KERNEL in sleepable contexts
  iommu/s390: Push the gfp parameter to the kmem_cache_alloc()'s
  iommu/s390: Use GFP_KERNEL in sleepable contexts

 arch/arm/mm/dma-mapping.c                     | 11 ++--
 arch/s390/include/asm/pci_dma.h               |  5 +-
 arch/s390/pci/pci_dma.c                       | 31 ++++++-----
 .../drm/nouveau/nvkm/subdev/instmem/gk20a.c   |  3 +-
 drivers/gpu/drm/tegra/drm.c                   |  2 +-
 drivers/gpu/host1x/cdma.c                     |  2 +-
 drivers/infiniband/hw/usnic/usnic_uiom.c      |  4 +-
 drivers/iommu/dma-iommu.c                     | 18 +++++--
 drivers/iommu/intel/iommu.c                   | 36 +++++++------
 drivers/iommu/intel/iommu.h                   |  2 +-
 drivers/iommu/intel/pasid.c                   |  2 +-
 drivers/iommu/iommu.c                         | 53 +++++++------------
 drivers/iommu/iommufd/pages.c                 |  6 ++-
 drivers/iommu/s390-iommu.c                    | 15 +++---
 drivers/media/platform/qcom/venus/firmware.c  |  2 +-
 drivers/net/ipa/ipa_mem.c                     |  6 ++-
 drivers/net/wireless/ath/ath10k/snoc.c        |  2 +-
 drivers/net/wireless/ath/ath11k/ahb.c         |  4 +-
 drivers/remoteproc/remoteproc_core.c          |  5 +-
 drivers/vfio/vfio_iommu_type1.c               |  9 ++--
 drivers/vhost/vdpa.c                          |  2 +-
 include/linux/iommu.h                         | 31 +++--------
 22 files changed, 126 insertions(+), 125 deletions(-)


base-commit: 5dc4c995db9eb45f6373a956eb1f69460e69e6d4

Comments

Joerg Roedel Jan. 25, 2023, 10:59 a.m. UTC | #1

On Mon, Jan 23, 2023 at 04:35:53PM -0400, Jason Gunthorpe wrote:
> Jason Gunthorpe (10):
>   iommu: Add a gfp parameter to iommu_map()
>   iommu: Remove iommu_map_atomic()
>   iommu: Add a gfp parameter to iommu_map_sg()
>   iommu/dma: Use the gfp parameter in __iommu_dma_alloc_noncontiguous()
>   iommufd: Use GFP_KERNEL_ACCOUNT for iommu_map()
>   iommu/intel: Add a gfp parameter to alloc_pgtable_page()
>   iommu/intel: Support the gfp argument to the map_pages op
>   iommu/intel: Use GFP_KERNEL in sleepable contexts
>   iommu/s390: Push the gfp parameter to the kmem_cache_alloc()'s
>   iommu/s390: Use GFP_KERNEL in sleepable contexts

Merged into branch iommu-memory-accounting and merged that branch into
core.

The merge commit contains your cover-letter descriptions. Given all
tests pass I will push it out later today.

Regards,

	Joerg