[PATCH v5 0/7] Re-enable IDXD kernel workqueue under DMA API

Jacob Pan
2023-04-27T17:45:46Z

Hi all,

IDXD kernel work queues were disabled due to the flawed use of kernel VA
and SVA API.
Link: https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/

The solution is to enable it under DMA API where IDXD shared workqueue users
can use ENQCMDS to submit work on buffers mapped by DMA API.

This patchset adds support for attaching PASID to the device's default
domain and the ability to allocate global PASIDs from IOMMU APIs. We can then
re-enable the kernel work queues and use them under DMA API.

This depends on the IOASID removal series. (merged)
https://lore.kernel.org/all/ZCaUBJvUMsJyD7EW@8bytes.org/

Thanks,

Jacob

---
Changelog:
v5:
- exclude two patches related to supervisor mode, taken by VT-d
maintainer Baolu.
- move PASID range check into allocation API so that device drivers
only need to pass in struct device*. (Kevin)
- factor out helper functions in device-domain attach (Baolu)
- make explicit use of RID_PASID across architectures
v4:
- move dummy functions outside ifdef CONFIG_IOMMU_SVA (Baolu)
- dropped domain type check while disabling idxd system PASID (Baolu)

v3:
- moved global PASID allocation API from SVA to IOMMU (Kevin)
- remove #ifdef around global PASID reservation during boot (Baolu)
- remove restriction on PASID 0 allocation (Baolu)
- fix a bug in sysfs domain change when attaching devices
- clear idxd user interrupt enable bit after disabling device( Fenghua)
v2:
- refactored device PASID attach domain ops based on Baolu's early patch
- addressed TLB flush gap
- explicitly reserve RID_PASID from SVA PASID number space
- get dma domain directly, avoid checking domain types

Jacob Pan (6):
iommu: Generalize default PCIe requester ID PASID
iommu/sva: Explicitly exclude RID_PASID from SVA
iommu: Move global PASID allocation from SVA to core
iommu/vt-d: Prepare PASID attachment beyond RID_PASID
iommu/vt-d: Implement set_dev_pasid domain op
dmaengine/idxd: Re-enable kernel workqueue under DMA API

Lu Baolu (1):
iommu/vt-d: Factoring out PASID set up helper function

drivers/dma/idxd/device.c | 30 +----
drivers/dma/idxd/init.c | 60 ++++++++-
drivers/dma/idxd/sysfs.c | 7 --
drivers/iommu/intel/iommu.c | 240 +++++++++++++++++++++++++++++-------
drivers/iommu/intel/iommu.h | 8 ++
drivers/iommu/intel/pasid.c | 2 +-
drivers/iommu/intel/pasid.h | 1 -
drivers/iommu/iommu-sva.c | 25 +---
drivers/iommu/iommu.c | 24 ++++
include/linux/iommu.h | 10 ++
10 files changed, 305 insertions(+), 102 deletions(-)

--
2.25.1