[PATCH v4 0/7] Re-enable IDXD kernel workqueue under DMA API

Jacob Pan
2023-04-07T18:02:00Z

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 reserve global PASIDs from SVA APIs. We can then
re-enable the kernel work queues and use them under DMA API.

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

Thanks,

Jacob

---
Changelog:
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 (7):
iommu/vt-d: Use non-privileged mode for all PASIDs
iommu/vt-d: Remove PASID supervisor request support
iommu: Support allocation of global PASIDs outside SVA
iommu/vt-d: Reserve RID_PASID from global PASID space
iommu/vt-d: Make device pasid attachment explicit
iommu/vt-d: Implement set_dev_pasid domain op
dmaengine/idxd: Re-enable kernel workqueue under DMA API

drivers/dma/idxd/device.c | 30 +-----
drivers/dma/idxd/init.c | 60 +++++++++++-
drivers/dma/idxd/sysfs.c | 7 --
drivers/iommu/intel/iommu.c | 180 +++++++++++++++++++++++++++++-------
drivers/iommu/intel/iommu.h | 8 ++
drivers/iommu/intel/pasid.c | 43 ---------
drivers/iommu/intel/pasid.h | 7 --
drivers/iommu/iommu-sva.c | 10 +-
drivers/iommu/iommu.c | 33 +++++++
include/linux/iommu.h | 11 +++
10 files changed, 262 insertions(+), 127 deletions(-)

--
2.25.1