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* [PATCH v5 00/15] intel_iommu: Enable PASID support for passthrough device
@ 2026-05-09  4:07 Zhenzhong Duan
  2026-05-09  4:07 ` [PATCH v5 01/15] vfio/iommufd: Extend attach/detach_hwpt callback implementations with pasid Zhenzhong Duan
                   ` (14 more replies)
  0 siblings, 15 replies; 24+ messages in thread
From: Zhenzhong Duan @ 2026-05-09  4:07 UTC (permalink / raw)
  To: qemu-devel
  Cc: alex, clg, eric.auger, mst, jasowang, jgg, nicolinc, skolothumtho,
	joao.m.martins, clement.mathieu--drif, kevin.tian, yi.l.liu,
	xudong.hao, Zhenzhong Duan

Hi,

Now we already support first stage translation with passthrough device
backed by nested translation in host, but only for IOMMU_NO_PASID.

Structure VTDAddressSpace includes some elements suitable for emulated
device and passthrough device without PASID, e.g., address space,
different memory regions, etc, it is also protected by vtd iommu lock,
all these are useless and become a burden for passthrough device with
PASID.

When there are lots of PASIDs used in one device, the AS and MRs are
all registered to memory core and impact the whole system performance.

So instead of using VTDAddressSpace to cache pasid entry for each pasid
of a passthrough device, we define a light weight structure
VTDAccelPASIDCacheEntry with only necessary elements for each pasid. We
will use this struct as a parameter to conduct binding/unbinding to
nested hwpt, to record the current binded nested hwpt and even future
PRQ support. It's also designed to support IOMMU_NO_PASID.

The potential full definition of VTDAccelPASIDCacheEntry may like:

  typedef struct VTDAccelPASIDCacheEntry {
      VTDHostIOMMUDevice *vtd_hiod;
      VTDPASIDEntry pasid_entry;
      uint32_t pasid;
      uint32_t fs_hwpt_id;
      uint32_t fault_id;
      int fault_fd;
      QLIST_HEAD(, VTDPRQEntry) vtd_prq_list;
      IOMMUPRINotifier pri_notifier_entry;
      IOMMUPRINotifier *pri_notifier;
      QLIST_ENTRY(VTDAccelPASIDCacheEntry) next;
  } VTDAccelPASIDCacheEntry;

Based on newest master branch.
GIT branch: https://github.com/yiliu1765/qemu/tree/zhenzhong/iommufd_pasid.v5

PATCH01-08: Some preparing work
PATCH09-13: Handle PASID entry addition/removal and bind/unbind
PATCH14-15: Add PASID related check and enable PASID for passthrough device

Tests:
Tested with DSA device which driver uses 2 PASIDs by default.

Thanks
Zhenzhong

Changelog:
v5:
- use %u for pasid print (Shammer)
- s/attachment/detachment in API doc (Shammer)
- save iommu pasid in vtd_as to avoid the check of PCI pasid whenever possible (Clement)
- commit log minor tweak on patch3 and patch7 (Liuyi)
- use name 'pasid-bits' for pasid property (Liuyi)

v4:
- improve documents of VIOMMU_FLAGs (Cédric)
- add a cleanup patch to simplify the check between PCI pasid and VTD pasid (Clement)
- rebase to newest master branch

v3:
- fix @Pasid parameter's comment (Liuyi)
- introduce a wrapper vtd_accel_delete_pc() (Liuyi)
- drop patch12 in v2 to avoid a race condition (Clement)
- s/PASID_0/IOMMU_NO_PASID s/gloal/global s/as_it/hiod_it (Liuyi)
- make trace_vtd_device_at/detach_hwpt use IOMMU_NO_PASID (Liuyi)
- change _accel subfix style naming to vtd_accel_ prefix style (Liuyi)
- drop unnecessary parameter vtd_hiod* from vtd_destroy_old_fs_hwpt() (Liuyi)
- introduce a new flag VIOMMU_FLAG_WANT_PASID_ATTACH for pasid attach (Nicolin)

v2:
- move the check "s->pasid > PCI_EXT_CAP_PASID_MAX_WIDTH" to patch5 (Clement)
- move #include "hw/core/iommu.h" before #include "hw/core/qdev.h" (Liuyi)
- polish the comment about @Pasid parameter (Liuyi)
- s/pe/pasid_entry, s/as_it/hiod_it, s/vtd_find_add_pc/vtd_accel_fill_pc (Liuyi)
- s/VTDACCELPASIDCacheEntry/VTDAccelPASIDCacheEntry (Liuyi)
- add explanation in code about PASID removal before addition (Liuyi)
- polish the comment about scope of VTDAccelPASIDCacheEntry vs VTDPASIDCacheEntry (Liuyi)
- add an optimization to bypass PASID entry addition for PASID selective pv_inv_dsc (Liuyi)

v1:
- use naming pattern "XXX_SET_THENAME" same as smmu (Clement)
- fix s->pasid check (Clement)

RFCv2:
- extend attach/detach_hwpt() instead of introducing new callbacks (Shammer)
- Define IOMMU_NO_PASID for device attachment without pasid (Nicolin)
- update vtd_destroy_old_fs_hwpt()'s parameter for naming consistency (Clement)
- check pasid bits size to be no more than 20 bits (Clement)
- initialize local variable max_pasid_log2 to 0 (Cédric)


Zhenzhong Duan (15):
  vfio/iommufd: Extend attach/detach_hwpt callback implementations with
    pasid
  iommufd: Extend attach/detach_hwpt callbacks to support pasid
  vfio/iommufd: Create nesting parent hwpt with IOMMU_HWPT_ALLOC_PASID
    flag
  intel_iommu: Create the nested hwpt with IOMMU_HWPT_ALLOC_PASID flag
  intel_iommu: Rename pasid property to "pasid-bits" and define it as
    type uint8
  intel_iommu: Export some functions
  intel_iommu: Use IOMMU_NO_PASID and delete PASID_0
  intel_iommu: Refactor PASID processing to use IOMMU_NO_PASID
    internally
  intel_iommu_accel: Handle PASID entry addition for pc_inv_dsc request
  intel_iommu_accel: Handle PASID entry removal for pc_inv_dsc request
  intel_iommu_accel: Bypass PASID entry addition for just deleted entry
  intel_iommu_accel: Handle PASID entry removal for system reset
  intel_iommu_accel: Switch to VTDAccelPASIDCacheEntry for PASID
    bind/unbind and PIOTLB invalidation
  intel_iommu_accel: Add pasid bits size check
  intel_iommu: Expose flag VIOMMU_FLAG_PASID_SUPPORTED and
    VIOMMU_FLAG_WANT_PASID_ATTACH

 hw/i386/intel_iommu_accel.h    |  20 +-
 hw/i386/intel_iommu_internal.h |  44 +++-
 include/hw/core/iommu.h        |  13 ++
 include/hw/i386/intel_iommu.h  |   4 +-
 include/hw/vfio/vfio-device.h  |   1 +
 include/system/iommufd.h       |  18 +-
 include/system/memory.h        |   2 +-
 backends/iommufd.c             |   9 +-
 hw/arm/smmuv3-accel.c          |  12 +-
 hw/i386/intel_iommu.c          | 254 +++++++++-----------
 hw/i386/intel_iommu_accel.c    | 414 +++++++++++++++++++++++++++------
 hw/vfio/device.c               |  11 +
 hw/vfio/iommufd.c              |  56 +++--
 hw/vfio/trace-events           |   4 +-
 14 files changed, 607 insertions(+), 255 deletions(-)

-- 
2.47.3



^ permalink raw reply	[flat|nested] 24+ messages in thread

end of thread, other threads:[~2026-05-14 11:22 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-05-09  4:07 [PATCH v5 00/15] intel_iommu: Enable PASID support for passthrough device Zhenzhong Duan
2026-05-09  4:07 ` [PATCH v5 01/15] vfio/iommufd: Extend attach/detach_hwpt callback implementations with pasid Zhenzhong Duan
2026-05-09  4:07 ` [PATCH v5 02/15] iommufd: Extend attach/detach_hwpt callbacks to support pasid Zhenzhong Duan
2026-05-09  4:07 ` [PATCH v5 03/15] vfio/iommufd: Create nesting parent hwpt with IOMMU_HWPT_ALLOC_PASID flag Zhenzhong Duan
2026-05-09  4:07 ` [PATCH v5 04/15] intel_iommu: Create the nested " Zhenzhong Duan
2026-05-09  4:07 ` [PATCH v5 05/15] intel_iommu: Rename pasid property to "pasid-bits" and define it as type uint8 Zhenzhong Duan
2026-05-14 11:30   ` Yi Liu
2026-05-09  4:07 ` [PATCH v5 06/15] intel_iommu: Export some functions Zhenzhong Duan
2026-05-09  4:08 ` [PATCH v5 07/15] intel_iommu: Use IOMMU_NO_PASID and delete PASID_0 Zhenzhong Duan
2026-05-14 11:24   ` Yi Liu
2026-05-09  4:08 ` [PATCH v5 08/15] intel_iommu: Refactor PASID processing to use IOMMU_NO_PASID internally Zhenzhong Duan
2026-05-14 11:25   ` Yi Liu
2026-05-09  4:08 ` [PATCH v5 09/15] intel_iommu_accel: Handle PASID entry addition for pc_inv_dsc request Zhenzhong Duan
2026-05-14 11:25   ` Yi Liu
2026-05-09  4:08 ` [PATCH v5 10/15] intel_iommu_accel: Handle PASID entry removal " Zhenzhong Duan
2026-05-14 11:25   ` Yi Liu
2026-05-09  4:08 ` [PATCH v5 11/15] intel_iommu_accel: Bypass PASID entry addition for just deleted entry Zhenzhong Duan
2026-05-14 11:28   ` Yi Liu
2026-05-09  4:08 ` [PATCH v5 12/15] intel_iommu_accel: Handle PASID entry removal for system reset Zhenzhong Duan
2026-05-09  4:08 ` [PATCH v5 13/15] intel_iommu_accel: Switch to VTDAccelPASIDCacheEntry for PASID bind/unbind and PIOTLB invalidation Zhenzhong Duan
2026-05-09  4:08 ` [PATCH v5 14/15] intel_iommu_accel: Add pasid bits size check Zhenzhong Duan
2026-05-14 11:25   ` Yi Liu
2026-05-09  4:08 ` [PATCH v5 15/15] intel_iommu: Expose flag VIOMMU_FLAG_PASID_SUPPORTED and VIOMMU_FLAG_WANT_PASID_ATTACH Zhenzhong Duan
2026-05-14 11:25   ` Yi Liu

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