[PATCH v6 00/18] IOMMUFD Dirty Tracking

[PATCH v6 00/18] IOMMUFD Dirty Tracking

[Joao Martins]

v6 is a replacement of what's in iommufd next:
https://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd.git/log/?h=for-next

base-commit: b5f9e63278d6f32789478acf1ed41d21d92b36cf

(from the iommufd tree)

=========>8=========

Presented herewith is a series that extends IOMMUFD to have IOMMU
hardware support for dirty bit in the IOPTEs.

Today, AMD Milan (or more recent) supports it while ARM SMMUv3.2
alongside VT-D rev3.x also do support.  One intended use-case (but not
restricted!) is to support Live Migration with SR-IOV, specially useful
for live migrateable PCI devices that can't supply its own dirty
tracking hardware blocks amongst others.

At a quick glance, IOMMUFD lets the userspace create the IOAS with a
set of a IOVA ranges mapped to some physical memory composing an IO
pagetable. This is then created via HWPT_ALLOC or attached to a
particular device/hwpt, consequently creating the IOMMU domain and share
a common IO page table representing the endporint DMA-addressable guest
address space. In IOMMUFD Dirty tracking (since v2 of the series) it
will require via the HWPT_ALLOC model only, as opposed to simpler
autodomains model.

The result is an hw_pagetable which represents the
iommu_domain which will be directly manipulated. The IOMMUFD UAPI,
and the iommu/iommufd kAPI are then extended to provide:

1) Enforcement that only devices with dirty tracking support are attached
to an IOMMU domain, to cover the case where this isn't all homogenous in
the platform. While initially this is more aimed at possible heterogenous nature
of ARM while x86 gets future proofed, should any such ocasion occur.

The device dirty tracking enforcement on attach_dev is made whether the
dirty_ops are set or not. Given that attach always checks for dirty
ops and IOMMU_CAP_DIRTY, while writing this it almost wanted this to
move to upper layer but semantically iommu driver should do the
checking.

2) Toggling of Dirty Tracking on the iommu_domain. We model as the most
common case of changing hardware translation control structures dynamically
(x86) while making it easier to have an always-enabled mode. In the
RFCv1, the ARM specific case is suggested to be always enabled instead of
having to enable the per-PTE DBM control bit (what I previously called
"range tracking"). Here, setting/clearing tracking means just clearing the
dirty bits at start. The 'real' tracking of whether dirty
tracking is enabled is stored in the IOMMU driver, hence no new
fields are added to iommufd pagetable structures, except for the
iommu_domain dirty ops part via adding a dirty_ops field to
iommu_domain. We use that too for IOMMUFD to know if dirty tracking
is supported and toggleable without having iommu drivers replicate said
checks.

3) Add a capability probing for dirty tracking, leveraging the
per-device iommu_capable() and adding a IOMMU_CAP_DIRTY. It extends
the GET_HW_INFO ioctl which takes a device ID to return some generic
capabilities *in addition*. Possible values enumarated by `enum
iommufd_hw_capabilities`.

4) Read the I/O PTEs and marshal its dirtyiness into a bitmap. The bitmap
indexes on a page_size basis the IOVAs that got written by the device.
While performing the marshalling also drivers need to clear the dirty bits
from IOPTE and allow the kAPI caller to batch the much needed IOTLB flush.
There's no copy of bitmaps to userspace backed memory, all is zerocopy
based to not add more cost to the iommu driver IOPT walker. This shares
functionality with VFIO device dirty tracking via the IOVA bitmap APIs. So
far this is a test-and-clear kind of interface given that the IOPT walk is
going to be expensive. In addition this also adds the ability to read dirty
bit info without clearing the PTE info. This is meant to cover the
unmap-and-read-dirty use-case, and avoid the second IOTLB flush.

The only dependency is:
* Have domain_alloc_user() API with flags [2] already queued (iommufd/for-next).

The series is organized as follows:

* Patches 1-4: Takes care of the iommu domain operations to be added.
The idea is to abstract iommu drivers from any idea of how bitmaps are
stored or propagated back to the caller, as well as allowing
control/batching over IOTLB flush. So there's a data structure and an
helper that only tells the upper layer that an IOVA range got dirty.
This logic is shared with VFIO and it's meant to walking the bitmap
user memory, and kmap-ing plus setting bits as needed. IOMMU driver
just has an idea of a 'dirty bitmap state' and recording an IOVA as
dirty.

* Patches 5-9, 13-18: Adds the UAPIs for IOMMUFD, and selftests. The
selftests cover some corner cases on boundaries handling of the bitmap
and various bitmap sizes that exercise. I haven't included huge IOVA
ranges to avoid risking the selftests failing to execute due to OOM
issues of mmaping big buffers.

* Patches 10-11: AMD IOMMU implementation, particularly on those having
HDSup support. Tested with a Qemu amd-iommu with HDSUp emulated[0]. And
tested with live migration with VFs (but with IOMMU dirty tracking).

* Patches 12: Intel IOMMU rev3.x+ implementation. Tested with a Qemu
based intel-iommu vIOMMU with SSADS emulation support[0].

On AMD/Intel I have tested this with emulation and then live migration in
AMD hardware;

The qemu iommu emulation bits are to increase coverage of this code and
hopefully make this more broadly available for fellow contributors/devs,
old version[1]; it uses Yi's 2 commits to have hw_info() supported (still
needs a bit of cleanup) on top of a recent Zhenzhong series of IOMMUFD
QEMU bringup work: see here[0]. It includes IOMMUFD dirty tracking for
Live migration and with live migration tested. I won't be exactly
following up a v2 of QEMU patches until IOMMUFD tracking lands.

Feedback or any comments are very much appreciated.

Thanks!
        Joao

[0] https://github.com/jpemartins/qemu/commits/iommufd-v3
[1] https://lore.kernel.org/qemu-devel/20220428211351.3897-1-joao.m.martins@oracle.com/
[2] https://lore.kernel.org/linux-iommu/20230919092523.39286-1-yi.l.liu@intel.com/
[3] https://github.com/jpemartins/linux/commits/iommufd-v3
[4] https://lore.kernel.org/linux-iommu/20230518204650.14541-1-joao.m.martins@oracle.com/
[5] https://lore.kernel.org/kvm/20220428210933.3583-1-joao.m.martins@oracle.com/
[6] https://github.com/jpemartins/linux/commits/smmu-iommufd-v3
[7] https://lore.kernel.org/linux-iommu/20230923012511.10379-1-joao.m.martins@oracle.com/
[8] https://lore.kernel.org/linux-iommu/20231018202715.69734-1-joao.m.martins@oracle.com/
[9] https://lore.kernel.org/linux-iommu/20231020222804.21850-1-joao.m.martins@oracle.com/

Changes since v5[9]:
* Fixes various linux-next/krobot build warnings and failures namely:
- Move IOMMUFD_DRIVER kconfig definition changes into drivers/iommu/Kconfig
  to address a arm32 issue (with !IOMMU_SUPPORT) module dependency warning
  https://lore.kernel.org/kvm/20231023115520.3530120-1-arnd@kernel.org/
- Implement the !IOMMU_API prototypes for patch 4, fixing a sparc64
  randconfig build warning when !IOMMU_API is done while having ARM32 IO_PGTABLE
  builtin
  https://lore.kernel.org/linux-mm/202310232131.TOhkKzZa-lkp@intel.com/
- Fix htmldocs warnings in the individual patches:
  https://lore.kernel.org/linux-next/20231023164721.1cb43dd6@canb.auug.org.au/
- Fix lack of div_u64 build error in 32-bit builds (i386, arm32, xtensa,
  microblaze) by reworking all checks in iommufd_check_iova_ranges() and moving
  it into iopt_read_and_clear_data(). The checks being redone no longer
  implement a u64 division, while improving the range checks all together.
  My 32-bit kernel compilation failures are at least fixed after this
  and I haven't spotted any warnings from this series.
  https://lore.kernel.org/linux-iommu/b7834d1e-d198-45ee-b15d-12bd235bc57f@app.fastmail.com/
  https://lore.kernel.org/oe-kbuild-all/202310231933.c8k54ybn-lkp@intel.com/
  https://lore.kernel.org/oe-kbuild-all/202310240246.FyXNZrbZ-lkp@intel.com/
  https://lore.kernel.org/lkml/9e56e94d-536e-435a-afb0-4738e6eddedc@infradead.org/
* Comments in v5 not triggered by krobot (yet):
- Fix GET_DIRTY_BITMAP selftest to copy bitmap data (when we set in the
  mock-domain pagetables) instead of directly changing user memory. This was
  leading to selftests run failures as reported by Nicolin Chen
- Fix a build issue of selftests which included bitmap.h header headers,
  by importing the implementation from
  include/asm-generic/bitops/generic-non-atomic.h and avoid the non-UAPI headers
  all together. While doing so use set_bit() instead of __set_bit().
  Also reported by Nicolin Chen
- Fix GET_DIRTY_BITMAP struct declaration to have a u64 data instead of
  a pointer. Change the io_pagetable reflecting bitmap::data type change to have
  u64_to_user_ptr() as it should be done. (Arnd Bergmann)
- Run through clang-format and fix any issues where applicable (3 small
  formatting things only, but left others that were seemingly according to
  the style of the file).
- Rename intel iommu patch subject to have SS instead of SL as the
  latter is old VTd spec naming. And use 'iommu/vt-d' for component name
  instead of 'iommu/intel'. Rename slads_supported() into
  ssads_supported() to adhere to the new naming. (Yi Liu)

Changes since v4[8]:
* Rename HWPT_SET_DIRTY to HWPT_SET_DIRTY_TRACKING 
* Rename IOMMU_CAP_DIRTY to IOMMU_CAP_DIRTY_TRACKING
* Rename HWPT_GET_DIRTY_IOVA to HWPT_GET_DIRTY_BITMAP
* Rename IOMMU_HWPT_ALLOC_ENFORCE_DIRTY to IOMMU_HWPT_ALLOC_DIRTY_TRACKING
  including commit messages, code comments. Additionally change the
  variable in drivers from enforce_dirty to dirty_tracking.
* Reflect all the mass renaming in commit messages/structs/docs.
* Fix the enums prefix to be IOMMU_HWPT like everyone else
* UAPI docs fixes/spelling and minor consistency issues/adjustments
* Change function exit style in __iommu_read_and_clear_dirty to return
  right away instead of storing ret and returning at the end.
* Check 0 page_size and replace find-first-bit + left-shift with a
  simple divide in iommufd_check_iova_range()
* Handle empty iommu domains when setting dirty tracking in intel-iommu;
  Verified and amd-iommu was already the case.
* Remove unnecessary extra check for PGTT type
* Fix comment on function clearing the SLADE bit
* Fix wrong check that validates domain_alloc_user()
  accepted flags in amd-iommu driver
* Skip IOTLB domain flush if no devices exist on the iommu domain,
while setting dirty tracking in amd-iommu driver.
* Collect Reviewed-by tags by Jason, Lu Baolu, Brett, Kevin, Alex

Changes since v3[7]:
* Consolidate previous patch 9 and 10 into a single patch,
while removing iommufd_dirty_bitmap structure to instead use
the UAPI defined structure iommu_hwpt_get_dirty_iova and
pass around internally in iommufd.
* Iterate over areas from within the IOVA bitmap iterator
* Drop check for specific flags in hw_pagetable
* Drop assignment that calculates iopt_alignment, to instead
use iopt_alignment directly
* Move IOVA bitmap into iommufd and introduce IOMMUFD_DRIVER
bool kconfig which designates the usage of dirty tracking related
bitmaps (i.e. VFIO and IOMMU drivers right now).
* Update IOVA bitmap header files to account for IOMMUFD_DRIVER
being disabled
* Sort new IOMMUFD ioctls accordingly
* Move IOVA bitmap symbols to IOMMUFD namespace and update its
users by importing new namespace (new patch 3)
* Remove AMD IOMMU kernel log feature printing from series
* Remove struct amd_iommu from do_iommu_domain_alloc() function
and derive it from within do_iommu_domain_alloc().
* Consolidate pte_test_dirty() and pte_test_and_clear_dirty()
by passing flags and deciding whether to test or test_and_clear.
* Add a comment on top of the -EINVAL attach_device() failure when
dirty tracking is enforcement but IOMMU does not support dirty tracking
* Add Reviewed-by given by Suravee
* Select IOMMUFD_DRIVER if IOMMUFD is enabled on supported IOMMU drivers
* Remove spurious rcu_read_{,un}lock() from Intel/AMD iommus
* Fix unwinding in dirty tracking set failure case in intel-iommu
* Avoid unnecesary locking when checking dmar_domain::dirty_tracking
* Rename intel_iommu_slads_supported() to a slads_supported() macro
following intel-iommu style
* Change the XOR check into a == in set_dirty_tracking iommu op
* Consolidate PTE test or test-and-clear into single helper
* Improve intel_pasid_setup_dirty_tracking() to: use rate limited printk;
avoid unnecessary update if state is already the desired one;
do a clflush on non-coherent devices; remove the qi_flush_piotlb(); and
fail on unsupported pgtts.
* Remove the first_level support and always fail domain_alloc_user on those
cases with it being no use case ATM. Doing so lets us remove some code
for such handling in set_dirty_tracking
* Error out the pasid device attach when dirty tracking is enforced
as we don't support that either.
* Reorganize the series to have selftests at the end, and core/driver
enablement first.

Changes since RFCv2[4]:
* Testing has always occured on the new code, but now it has seen
Live Migration coverage with extra QEMU work on AMD hardware.
* General commit message improvements
* Remove spurious headers in selftests
* Exported some symbols to actually allow things to build when IOMMUFD
is built as a module. (Alex Williamson)
* Switch the enforcing to be done on IOMMU domain allocation via
domain_alloc_user (Jason, Robin, Lu Baolu)
* Removed RCU series from Lu Baolu (Jason)
* Switch set_dirty/read_dirty/clear_dirty to down_read() (Jason)
* Make sure it check for area::pages (Jason)
* Move clearing dirties before set dirty a helper (Jason)
* Avoid breaking IOMMUFD selftests UAPI (Jason)
* General improvements to testing
* Add coverage to new out_capabilities support in HW_INFO.
* Address Shameer/Robin comments in smmu-v3 (code is on a branch[6])
  - Properly check for FEAT_HD together with COHERENCY
  - Remove the pgsize_bitmap check
  - Limit the quirk set to s1 pgtbl_cfg.
  - Fix commit message on dubious sentence on DBM usecase

Changes since RFCv1[5]:
Too many changes but the major items were:
* Majorirty of the changes from Jason/Kevin/Baolu/Suravee:
- Improve structure and rework most commit messages
- Drop all of the VFIO-compat series
- Drop the unmap-get-dirty API
- Tie this to HWPT only, no more autodomains handling;
- Rework the UAPI widely by:
  - Having a IOMMU_DEVICE_GET_CAPS which allows to fetching capabilities
    of devices, specifically test dirty tracking support for an individual
    device
  - Add a enforce-dirty flag to the IOMMU domain via HWPT_ALLOC
  - SET_DIRTY now clears dirty tracking before asking iommu driver to do so;
  - New GET_DIRTY_IOVA flag that does not clear dirty bits
  - Add coverage for all added APIs
  - Expand GET_DIRTY_IOVA tests to cover IOVA bitmap corner cases tests
  that I had in separate; I only excluded the Terabyte IOVA range
  usecases (which test bitmaps 2M+) because those will most likely fail
  to be run as selftests (not sure yet how I can include those). I am
  not exactly sure how I can cover those, unless I do 'fake IOVA maps'
  *somehow* which do not necessarily require real buffers.
- Handle most comments in intel-iommu. Only remaining one for v3 is the
  PTE walker which will be done better.
- Handle all comments in amd-iommu, most of which regarding locking.
  Only one remaining is v3 same as Intel;
- Reflect the UAPI changes into iommu driver implementations, including
persisting dirty tracking enabling in new attach_dev calls, as well as
enforcing attach_dev enforces the requested domain flags;
* Comments from Yi Sun in making sure that dirty tracking isn't
restricted into SS only, so relax the check for FL support because it's
always enabled. (Yi Sun)
* Most of code that was in v1 for dirty bitmaps got rewritten and
repurpose to also cover VFIO case; so reuse this infra here too for both.
(Jason)
* Take Robin's suggestion of always enabling dirty tracking and set_dirty
just clearing bits on 'activation', and make that a generic property to
ensure we always get accurate results between starting and stopping
tracking. (Robin Murphy)
* Address all comments from SMMUv3 into how we enable/test the DBM, or the
bits in the context descriptor with io-pgtable::quirks, etc
(Robin, Shameerali)

Joao Martins (18):
  vfio/iova_bitmap: Export more API symbols
  vfio: Move iova_bitmap into iommufd
  iommufd/iova_bitmap: Move symbols to IOMMUFD namespace
  iommu: Add iommu_domain ops for dirty tracking
  iommufd: Add a flag to enforce dirty tracking on attach
  iommufd: Add IOMMU_HWPT_SET_DIRTY_TRACKING
  iommufd: Add IOMMU_HWPT_GET_DIRTY_BITMAP
  iommufd: Add capabilities to IOMMU_GET_HW_INFO
  iommufd: Add a flag to skip clearing of IOPTE dirty
  iommu/amd: Add domain_alloc_user based domain allocation
  iommu/amd: Access/Dirty bit support in IOPTEs
  iommu/vt-d: Access/Dirty bit support for SS domains
  iommufd/selftest: Expand mock_domain with dev_flags
  iommufd/selftest: Test IOMMU_HWPT_ALLOC_DIRTY_TRACKING
  iommufd/selftest: Test IOMMU_HWPT_SET_DIRTY_TRACKING
  iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP
  iommufd/selftest: Test out_capabilities in IOMMU_GET_HW_INFO
  iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR flag

 drivers/iommu/Kconfig                         |   4 +
 drivers/iommu/amd/Kconfig                     |   1 +
 drivers/iommu/amd/amd_iommu_types.h           |  12 +
 drivers/iommu/amd/io_pgtable.c                |  68 ++++++
 drivers/iommu/amd/iommu.c                     | 144 +++++++++++-
 drivers/iommu/intel/Kconfig                   |   1 +
 drivers/iommu/intel/iommu.c                   | 103 ++++++++-
 drivers/iommu/intel/iommu.h                   |  16 ++
 drivers/iommu/intel/pasid.c                   | 109 +++++++++
 drivers/iommu/intel/pasid.h                   |   4 +
 drivers/iommu/iommufd/Makefile                |   1 +
 drivers/iommu/iommufd/device.c                |   4 +
 drivers/iommu/iommufd/hw_pagetable.c          |  51 ++++-
 drivers/iommu/iommufd/io_pagetable.c          | 172 ++++++++++++++
 drivers/iommu/iommufd/iommufd_private.h       |  22 ++
 drivers/iommu/iommufd/iommufd_test.h          |  21 ++
 drivers/{vfio => iommu/iommufd}/iova_bitmap.c |   5 +-
 drivers/iommu/iommufd/main.c                  |   7 +
 drivers/iommu/iommufd/selftest.c              | 187 +++++++++++++++-
 drivers/vfio/Makefile                         |   3 +-
 drivers/vfio/pci/mlx5/Kconfig                 |   1 +
 drivers/vfio/pci/mlx5/main.c                  |   1 +
 drivers/vfio/pci/pds/Kconfig                  |   1 +
 drivers/vfio/pci/pds/pci_drv.c                |   1 +
 drivers/vfio/vfio_main.c                      |   1 +
 include/linux/io-pgtable.h                    |   4 +
 include/linux/iommu.h                         |  70 ++++++
 include/linux/iova_bitmap.h                   |  26 +++
 include/uapi/linux/iommufd.h                  |  96 ++++++++
 tools/testing/selftests/iommu/iommufd.c       | 211 ++++++++++++++++++
 .../selftests/iommu/iommufd_fail_nth.c        |   2 +-
 tools/testing/selftests/iommu/iommufd_utils.h | 206 ++++++++++++++++-
 32 files changed, 1528 insertions(+), 27 deletions(-)
 rename drivers/{vfio => iommu/iommufd}/iova_bitmap.c (98%)

-- 
2.17.2

[PATCH v6 01/18] vfio/iova_bitmap: Export more API symbols

[Joao Martins]

In preparation to move iova_bitmap into iommufd, export the rest of API
symbols that will be used in what could be used by modules, namely:

	iova_bitmap_alloc
	iova_bitmap_free
	iova_bitmap_for_each

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/vfio/iova_bitmap.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/vfio/iova_bitmap.c b/drivers/vfio/iova_bitmap.c
index 0848f920efb7..f54b56388e00 100644
--- a/drivers/vfio/iova_bitmap.c
+++ b/drivers/vfio/iova_bitmap.c
@@ -268,6 +268,7 @@ struct iova_bitmap *iova_bitmap_alloc(unsigned long iova, size_t length,
 	iova_bitmap_free(bitmap);
 	return ERR_PTR(rc);
 }
+EXPORT_SYMBOL_GPL(iova_bitmap_alloc);
 
 /**
  * iova_bitmap_free() - Frees an IOVA bitmap object
@@ -289,6 +290,7 @@ void iova_bitmap_free(struct iova_bitmap *bitmap)
 
 	kfree(bitmap);
 }
+EXPORT_SYMBOL_GPL(iova_bitmap_free);
 
 /*
  * Returns the remaining bitmap indexes from mapped_total_index to process for
@@ -387,6 +389,7 @@ int iova_bitmap_for_each(struct iova_bitmap *bitmap, void *opaque,
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(iova_bitmap_for_each);
 
 /**
  * iova_bitmap_set() - Records an IOVA range in bitmap
-- 
2.17.2

[PATCH v6 02/18] vfio: Move iova_bitmap into iommufd

[Joao Martins]

Both VFIO and IOMMUFD will need iova bitmap for storing dirties and walking
the user bitmaps, so move to the common dependency into IOMMUFD.  In doing
so, create the symbol IOMMUFD_DRIVER which designates the builtin code that
will be used by drivers when selected. Today this means MLX5_VFIO_PCI and
PDS_VFIO_PCI. IOMMU drivers will do the same (in future patches) when
supporting dirty tracking and select IOMMUFD_DRIVER accordingly.

Given that the symbol maybe be disabled, add header definitions in
iova_bitmap.h for when IOMMUFD_DRIVER=n

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/iommu/Kconfig                         |  4 +++
 drivers/iommu/iommufd/Makefile                |  1 +
 drivers/{vfio => iommu/iommufd}/iova_bitmap.c |  0
 drivers/vfio/Makefile                         |  3 +--
 drivers/vfio/pci/mlx5/Kconfig                 |  1 +
 drivers/vfio/pci/pds/Kconfig                  |  1 +
 include/linux/iova_bitmap.h                   | 26 +++++++++++++++++++
 7 files changed, 34 insertions(+), 2 deletions(-)
 rename drivers/{vfio => iommu/iommufd}/iova_bitmap.c (100%)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 2b12b583ef4b..5cc869db1b79 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -7,6 +7,10 @@ config IOMMU_IOVA
 config IOMMU_API
 	bool
 
+config IOMMUFD_DRIVER
+	bool
+	default n
+
 menuconfig IOMMU_SUPPORT
 	bool "IOMMU Hardware Support"
 	depends on MMU
diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile
index 8aeba81800c5..34b446146961 100644
--- a/drivers/iommu/iommufd/Makefile
+++ b/drivers/iommu/iommufd/Makefile
@@ -11,3 +11,4 @@ iommufd-y := \
 iommufd-$(CONFIG_IOMMUFD_TEST) += selftest.o
 
 obj-$(CONFIG_IOMMUFD) += iommufd.o
+obj-$(CONFIG_IOMMUFD_DRIVER) += iova_bitmap.o
diff --git a/drivers/vfio/iova_bitmap.c b/drivers/iommu/iommufd/iova_bitmap.c
similarity index 100%
rename from drivers/vfio/iova_bitmap.c
rename to drivers/iommu/iommufd/iova_bitmap.c
diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile
index c82ea032d352..68c05705200f 100644
--- a/drivers/vfio/Makefile
+++ b/drivers/vfio/Makefile
@@ -1,8 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_VFIO) += vfio.o
 
-vfio-y += vfio_main.o \
-	  iova_bitmap.o
+vfio-y += vfio_main.o
 vfio-$(CONFIG_VFIO_DEVICE_CDEV) += device_cdev.o
 vfio-$(CONFIG_VFIO_GROUP) += group.o
 vfio-$(CONFIG_IOMMUFD) += iommufd.o
diff --git a/drivers/vfio/pci/mlx5/Kconfig b/drivers/vfio/pci/mlx5/Kconfig
index 7088edc4fb28..c3ced56b7787 100644
--- a/drivers/vfio/pci/mlx5/Kconfig
+++ b/drivers/vfio/pci/mlx5/Kconfig
@@ -3,6 +3,7 @@ config MLX5_VFIO_PCI
 	tristate "VFIO support for MLX5 PCI devices"
 	depends on MLX5_CORE
 	select VFIO_PCI_CORE
+	select IOMMUFD_DRIVER
 	help
 	  This provides migration support for MLX5 devices using the VFIO
 	  framework.
diff --git a/drivers/vfio/pci/pds/Kconfig b/drivers/vfio/pci/pds/Kconfig
index 407b3fd32733..fff368a8183b 100644
--- a/drivers/vfio/pci/pds/Kconfig
+++ b/drivers/vfio/pci/pds/Kconfig
@@ -5,6 +5,7 @@ config PDS_VFIO_PCI
 	tristate "VFIO support for PDS PCI devices"
 	depends on PDS_CORE
 	select VFIO_PCI_CORE
+	select IOMMUFD_DRIVER
 	help
 	  This provides generic PCI support for PDS devices using the VFIO
 	  framework.
diff --git a/include/linux/iova_bitmap.h b/include/linux/iova_bitmap.h
index c006cf0a25f3..1c338f5e5b7a 100644
--- a/include/linux/iova_bitmap.h
+++ b/include/linux/iova_bitmap.h
@@ -7,6 +7,7 @@
 #define _IOVA_BITMAP_H_
 
 #include <linux/types.h>
+#include <linux/errno.h>
 
 struct iova_bitmap;
 
@@ -14,6 +15,7 @@ typedef int (*iova_bitmap_fn_t)(struct iova_bitmap *bitmap,
 				unsigned long iova, size_t length,
 				void *opaque);
 
+#if IS_ENABLED(CONFIG_IOMMUFD_DRIVER)
 struct iova_bitmap *iova_bitmap_alloc(unsigned long iova, size_t length,
 				      unsigned long page_size,
 				      u64 __user *data);
@@ -22,5 +24,29 @@ int iova_bitmap_for_each(struct iova_bitmap *bitmap, void *opaque,
 			 iova_bitmap_fn_t fn);
 void iova_bitmap_set(struct iova_bitmap *bitmap,
 		     unsigned long iova, size_t length);
+#else
+static inline struct iova_bitmap *iova_bitmap_alloc(unsigned long iova,
+						    size_t length,
+						    unsigned long page_size,
+						    u64 __user *data)
+{
+	return NULL;
+}
+
+static inline void iova_bitmap_free(struct iova_bitmap *bitmap)
+{
+}
+
+static inline int iova_bitmap_for_each(struct iova_bitmap *bitmap, void *opaque,
+				       iova_bitmap_fn_t fn)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void iova_bitmap_set(struct iova_bitmap *bitmap,
+				   unsigned long iova, size_t length)
+{
+}
+#endif
 
 #endif
-- 
2.17.2

[PATCH v6 03/18] iommufd/iova_bitmap: Move symbols to IOMMUFD namespace

[Joao Martins]

Have the IOVA bitmap exported symbols adhere to the IOMMUFD symbol
export convention i.e. using the IOMMUFD namespace. In doing so,
import the namespace in the current users. This means VFIO and the
vfio-pci drivers that use iova_bitmap_set().

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/iommu/iommufd/iova_bitmap.c | 8 ++++----
 drivers/vfio/pci/mlx5/main.c        | 1 +
 drivers/vfio/pci/pds/pci_drv.c      | 1 +
 drivers/vfio/vfio_main.c            | 1 +
 4 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommufd/iova_bitmap.c b/drivers/iommu/iommufd/iova_bitmap.c
index f54b56388e00..0a92c9eeaf7f 100644
--- a/drivers/iommu/iommufd/iova_bitmap.c
+++ b/drivers/iommu/iommufd/iova_bitmap.c
@@ -268,7 +268,7 @@ struct iova_bitmap *iova_bitmap_alloc(unsigned long iova, size_t length,
 	iova_bitmap_free(bitmap);
 	return ERR_PTR(rc);
 }
-EXPORT_SYMBOL_GPL(iova_bitmap_alloc);
+EXPORT_SYMBOL_NS_GPL(iova_bitmap_alloc, IOMMUFD);
 
 /**
  * iova_bitmap_free() - Frees an IOVA bitmap object
@@ -290,7 +290,7 @@ void iova_bitmap_free(struct iova_bitmap *bitmap)
 
 	kfree(bitmap);
 }
-EXPORT_SYMBOL_GPL(iova_bitmap_free);
+EXPORT_SYMBOL_NS_GPL(iova_bitmap_free, IOMMUFD);
 
 /*
  * Returns the remaining bitmap indexes from mapped_total_index to process for
@@ -389,7 +389,7 @@ int iova_bitmap_for_each(struct iova_bitmap *bitmap, void *opaque,
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(iova_bitmap_for_each);
+EXPORT_SYMBOL_NS_GPL(iova_bitmap_for_each, IOMMUFD);
 
 /**
  * iova_bitmap_set() - Records an IOVA range in bitmap
@@ -423,4 +423,4 @@ void iova_bitmap_set(struct iova_bitmap *bitmap,
 		cur_bit += nbits;
 	} while (cur_bit <= last_bit);
 }
-EXPORT_SYMBOL_GPL(iova_bitmap_set);
+EXPORT_SYMBOL_NS_GPL(iova_bitmap_set, IOMMUFD);
diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c
index 42ec574a8622..5cf2b491d15a 100644
--- a/drivers/vfio/pci/mlx5/main.c
+++ b/drivers/vfio/pci/mlx5/main.c
@@ -1376,6 +1376,7 @@ static struct pci_driver mlx5vf_pci_driver = {
 
 module_pci_driver(mlx5vf_pci_driver);
 
+MODULE_IMPORT_NS(IOMMUFD);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Max Gurtovoy <mgurtovoy@nvidia.com>");
 MODULE_AUTHOR("Yishai Hadas <yishaih@nvidia.com>");
diff --git a/drivers/vfio/pci/pds/pci_drv.c b/drivers/vfio/pci/pds/pci_drv.c
index ab4b5958e413..dd8c00c895a2 100644
--- a/drivers/vfio/pci/pds/pci_drv.c
+++ b/drivers/vfio/pci/pds/pci_drv.c
@@ -204,6 +204,7 @@ static struct pci_driver pds_vfio_pci_driver = {
 
 module_pci_driver(pds_vfio_pci_driver);
 
+MODULE_IMPORT_NS(IOMMUFD);
 MODULE_DESCRIPTION(PDS_VFIO_DRV_DESCRIPTION);
 MODULE_AUTHOR("Brett Creeley <brett.creeley@amd.com>");
 MODULE_LICENSE("GPL");
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 40732e8ed4c6..a96d97da367d 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -1693,6 +1693,7 @@ static void __exit vfio_cleanup(void)
 module_init(vfio_init);
 module_exit(vfio_cleanup);
 
+MODULE_IMPORT_NS(IOMMUFD);
 MODULE_VERSION(DRIVER_VERSION);
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR(DRIVER_AUTHOR);
-- 
2.17.2

[PATCH v6 04/18] iommu: Add iommu_domain ops for dirty tracking

[Joao Martins]

Add to iommu domain operations a set of callbacks to perform dirty
tracking, particulary to start and stop tracking and to read and clear the
dirty data.

Drivers are generally expected to dynamically change its translation
structures to toggle the tracking and flush some form of control state
structure that stands in the IOVA translation path. Though it's not
mandatory, as drivers can also enable dirty tracking at boot, and just
clear the dirty bits before setting dirty tracking. For each of the newly
added IOMMU core APIs:

iommu_cap::IOMMU_CAP_DIRTY_TRACKING: new device iommu_capable value when
probing for capabilities of the device.

.set_dirty_tracking(): an iommu driver is expected to change its
translation structures and enable dirty tracking for the devices in the
iommu_domain. For drivers making dirty tracking always-enabled, it should
just return 0.

.read_and_clear_dirty(): an iommu driver is expected to walk the pagetables
for the iova range passed in and use iommu_dirty_bitmap_record() to record
dirty info per IOVA. When detecting that a given IOVA is dirty it should
also clear its dirty state from the PTE, *unless* the flag
IOMMU_DIRTY_NO_CLEAR is passed in -- flushing is steered from the caller of
the domain_op via iotlb_gather. The iommu core APIs use the same data
structure in use for dirty tracking for VFIO device dirty (struct
iova_bitmap) abstracted by iommu_dirty_bitmap_record() helper function.

domain::dirty_ops: IOMMU domains will store the dirty ops depending on
whether the iommu device supports dirty tracking or not. iommu drivers can
then use this field to figure if the dirty tracking is supported+enforced
on attach. The enforcement is enable via domain_alloc_user() which is done
via IOMMUFD hwpt flag introduced later.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 include/linux/io-pgtable.h |  4 +++
 include/linux/iommu.h      | 70 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index 1b7a44b35616..25142a0e2fc2 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -166,6 +166,10 @@ struct io_pgtable_ops {
 			      struct iommu_iotlb_gather *gather);
 	phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
 				    unsigned long iova);
+	int (*read_and_clear_dirty)(struct io_pgtable_ops *ops,
+				    unsigned long iova, size_t size,
+				    unsigned long flags,
+				    struct iommu_dirty_bitmap *dirty);
 };
 
 /**
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 3861d66b65c1..1d42bdb37cbc 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -13,6 +13,7 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/of.h>
+#include <linux/iova_bitmap.h>
 #include <uapi/linux/iommu.h>
 
 #define IOMMU_READ	(1 << 0)
@@ -37,6 +38,7 @@ struct bus_type;
 struct device;
 struct iommu_domain;
 struct iommu_domain_ops;
+struct iommu_dirty_ops;
 struct notifier_block;
 struct iommu_sva;
 struct iommu_fault_event;
@@ -95,6 +97,8 @@ struct iommu_domain_geometry {
 struct iommu_domain {
 	unsigned type;
 	const struct iommu_domain_ops *ops;
+	const struct iommu_dirty_ops *dirty_ops;
+
 	unsigned long pgsize_bitmap;	/* Bitmap of page sizes in use */
 	struct iommu_domain_geometry geometry;
 	struct iommu_dma_cookie *iova_cookie;
@@ -133,6 +137,7 @@ enum iommu_cap {
 	 * usefully support the non-strict DMA flush queue.
 	 */
 	IOMMU_CAP_DEFERRED_FLUSH,
+	IOMMU_CAP_DIRTY_TRACKING,	/* IOMMU supports dirty tracking */
 };
 
 /* These are the possible reserved region types */
@@ -227,6 +232,35 @@ struct iommu_iotlb_gather {
 	bool			queued;
 };
 
+/**
+ * struct iommu_dirty_bitmap - Dirty IOVA bitmap state
+ * @bitmap: IOVA bitmap
+ * @gather: Range information for a pending IOTLB flush
+ */
+struct iommu_dirty_bitmap {
+	struct iova_bitmap *bitmap;
+	struct iommu_iotlb_gather *gather;
+};
+
+/* Read but do not clear any dirty bits */
+#define IOMMU_DIRTY_NO_CLEAR (1 << 0)
+
+/**
+ * struct iommu_dirty_ops - domain specific dirty tracking operations
+ * @set_dirty_tracking: Enable or Disable dirty tracking on the iommu domain
+ * @read_and_clear_dirty: Walk IOMMU page tables for dirtied PTEs marshalled
+ *                        into a bitmap, with a bit represented as a page.
+ *                        Reads the dirty PTE bits and clears it from IO
+ *                        pagetables.
+ */
+struct iommu_dirty_ops {
+	int (*set_dirty_tracking)(struct iommu_domain *domain, bool enabled);
+	int (*read_and_clear_dirty)(struct iommu_domain *domain,
+				    unsigned long iova, size_t size,
+				    unsigned long flags,
+				    struct iommu_dirty_bitmap *dirty);
+};
+
 /**
  * struct iommu_ops - iommu ops and capabilities
  * @capable: check capability
@@ -641,6 +675,28 @@ static inline bool iommu_iotlb_gather_queued(struct iommu_iotlb_gather *gather)
 	return gather && gather->queued;
 }
 
+static inline void iommu_dirty_bitmap_init(struct iommu_dirty_bitmap *dirty,
+					   struct iova_bitmap *bitmap,
+					   struct iommu_iotlb_gather *gather)
+{
+	if (gather)
+		iommu_iotlb_gather_init(gather);
+
+	dirty->bitmap = bitmap;
+	dirty->gather = gather;
+}
+
+static inline void iommu_dirty_bitmap_record(struct iommu_dirty_bitmap *dirty,
+					     unsigned long iova,
+					     unsigned long length)
+{
+	if (dirty->bitmap)
+		iova_bitmap_set(dirty->bitmap, iova, length);
+
+	if (dirty->gather)
+		iommu_iotlb_gather_add_range(dirty->gather, iova, length);
+}
+
 /* PCI device grouping function */
 extern struct iommu_group *pci_device_group(struct device *dev);
 /* Generic device grouping function */
@@ -746,6 +802,8 @@ struct iommu_fwspec {};
 struct iommu_device {};
 struct iommu_fault_param {};
 struct iommu_iotlb_gather {};
+struct iommu_dirty_bitmap {};
+struct iommu_dirty_ops {};
 
 static inline bool iommu_present(const struct bus_type *bus)
 {
@@ -978,6 +1036,18 @@ static inline bool iommu_iotlb_gather_queued(struct iommu_iotlb_gather *gather)
 	return false;
 }
 
+static inline void iommu_dirty_bitmap_init(struct iommu_dirty_bitmap *dirty,
+					   struct iova_bitmap *bitmap,
+					   struct iommu_iotlb_gather *gather)
+{
+}
+
+static inline void iommu_dirty_bitmap_record(struct iommu_dirty_bitmap *dirty,
+					     unsigned long iova,
+					     unsigned long length)
+{
+}
+
 static inline void iommu_device_unregister(struct iommu_device *iommu)
 {
 }
-- 
2.17.2

[PATCH v6 05/18] iommufd: Add a flag to enforce dirty tracking on attach

[Joao Martins]

Throughout IOMMU domain lifetime that wants to use dirty tracking, some
guarantees are needed such that any device attached to the iommu_domain
supports dirty tracking.

The idea is to handle a case where IOMMU in the system are assymetric
feature-wise and thus the capability may not be supported for all devices.
The enforcement is done by adding a flag into HWPT_ALLOC namely:

	IOMMU_HWPT_ALLOC_DIRTY_TRACKING

.. Passed in HWPT_ALLOC ioctl() flags. The enforcement is done by creating
a iommu_domain via domain_alloc_user() and validating the requested flags
with what the device IOMMU supports (and failing accordingly) advertised).
Advertising the new IOMMU domain feature flag requires that the individual
iommu driver capability is supported when a future device attachment
happens.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/iommu/iommufd/hw_pagetable.c | 4 +++-
 include/uapi/linux/iommufd.h         | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 8b3d2875d642..dd50ca9e2c09 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -157,7 +157,9 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
 	struct iommufd_ioas *ioas;
 	int rc;
 
-	if ((cmd->flags & (~IOMMU_HWPT_ALLOC_NEST_PARENT)) || cmd->__reserved)
+	if ((cmd->flags & ~(IOMMU_HWPT_ALLOC_NEST_PARENT |
+			    IOMMU_HWPT_ALLOC_DIRTY_TRACKING)) ||
+	    cmd->__reserved)
 		return -EOPNOTSUPP;
 
 	idev = iommufd_get_device(ucmd, cmd->dev_id);
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index be7a95042677..c76248410120 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -351,9 +351,12 @@ struct iommu_vfio_ioas {
  * enum iommufd_hwpt_alloc_flags - Flags for HWPT allocation
  * @IOMMU_HWPT_ALLOC_NEST_PARENT: If set, allocate a HWPT that can serve as
  *                                the parent HWPT in a nesting configuration.
+ * @IOMMU_HWPT_ALLOC_DIRTY_TRACKING: Dirty tracking support for device IOMMU is
+ *                                   enforced on device attachment
  */
 enum iommufd_hwpt_alloc_flags {
 	IOMMU_HWPT_ALLOC_NEST_PARENT = 1 << 0,
+	IOMMU_HWPT_ALLOC_DIRTY_TRACKING = 1 << 1,
 };
 
 /**
-- 
2.17.2

[PATCH v6 06/18] iommufd: Add IOMMU_HWPT_SET_DIRTY_TRACKING

[Joao Martins]

Every IOMMU driver should be able to implement the needed iommu domain ops
to control dirty tracking.

Connect a hw_pagetable to the IOMMU core dirty tracking ops, specifically
the ability to enable/disable dirty tracking on an IOMMU domain
(hw_pagetable id). To that end add an io_pagetable kernel API to toggle
dirty tracking:

* iopt_set_dirty_tracking(iopt, [domain], state)

The intended caller of this is via the hw_pagetable object that is created.

Internally it will ensure the leftover dirty state is cleared /right
before/ dirty tracking starts. This is also useful for iommu drivers which
may decide that dirty tracking is always-enabled at boot without wanting to
toggle dynamically via corresponding iommu domain op.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/iommu/iommufd/hw_pagetable.c    | 24 +++++++++++
 drivers/iommu/iommufd/io_pagetable.c    | 54 +++++++++++++++++++++++++
 drivers/iommu/iommufd/iommufd_private.h | 12 ++++++
 drivers/iommu/iommufd/main.c            |  3 ++
 include/uapi/linux/iommufd.h            | 28 +++++++++++++
 5 files changed, 121 insertions(+)

diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index dd50ca9e2c09..c3b7bd9bfcbb 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -196,3 +196,27 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
 	iommufd_put_object(&idev->obj);
 	return rc;
 }
+
+int iommufd_hwpt_set_dirty_tracking(struct iommufd_ucmd *ucmd)
+{
+	struct iommu_hwpt_set_dirty_tracking *cmd = ucmd->cmd;
+	struct iommufd_hw_pagetable *hwpt;
+	struct iommufd_ioas *ioas;
+	int rc = -EOPNOTSUPP;
+	bool enable;
+
+	if (cmd->flags & ~IOMMU_HWPT_DIRTY_TRACKING_ENABLE)
+		return rc;
+
+	hwpt = iommufd_get_hwpt(ucmd, cmd->hwpt_id);
+	if (IS_ERR(hwpt))
+		return PTR_ERR(hwpt);
+
+	ioas = hwpt->ioas;
+	enable = cmd->flags & IOMMU_HWPT_DIRTY_TRACKING_ENABLE;
+
+	rc = iopt_set_dirty_tracking(&ioas->iopt, hwpt->domain, enable);
+
+	iommufd_put_object(&hwpt->obj);
+	return rc;
+}
diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
index 3a598182b761..41c2efb6ff15 100644
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -412,6 +412,60 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt,
 	return 0;
 }
 
+static int iopt_clear_dirty_data(struct io_pagetable *iopt,
+				 struct iommu_domain *domain)
+{
+	const struct iommu_dirty_ops *ops = domain->dirty_ops;
+	struct iommu_iotlb_gather gather;
+	struct iommu_dirty_bitmap dirty;
+	struct iopt_area *area;
+	int ret = 0;
+
+	lockdep_assert_held_read(&iopt->iova_rwsem);
+
+	iommu_dirty_bitmap_init(&dirty, NULL, &gather);
+
+	for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area;
+	     area = iopt_area_iter_next(area, 0, ULONG_MAX)) {
+		if (!area->pages)
+			continue;
+
+		ret = ops->read_and_clear_dirty(domain, iopt_area_iova(area),
+						iopt_area_length(area), 0,
+						&dirty);
+		if (ret)
+			break;
+	}
+
+	iommu_iotlb_sync(domain, &gather);
+	return ret;
+}
+
+int iopt_set_dirty_tracking(struct io_pagetable *iopt,
+			    struct iommu_domain *domain, bool enable)
+{
+	const struct iommu_dirty_ops *ops = domain->dirty_ops;
+	int ret = 0;
+
+	if (!ops)
+		return -EOPNOTSUPP;
+
+	down_read(&iopt->iova_rwsem);
+
+	/* Clear dirty bits from PTEs to ensure a clean snapshot */
+	if (enable) {
+		ret = iopt_clear_dirty_data(iopt, domain);
+		if (ret)
+			goto out_unlock;
+	}
+
+	ret = ops->set_dirty_tracking(domain, enable);
+
+out_unlock:
+	up_read(&iopt->iova_rwsem);
+	return ret;
+}
+
 int iopt_get_pages(struct io_pagetable *iopt, unsigned long iova,
 		   unsigned long length, struct list_head *pages_list)
 {
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 3064997a0181..b09750848da6 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -8,6 +8,7 @@
 #include <linux/xarray.h>
 #include <linux/refcount.h>
 #include <linux/uaccess.h>
+#include <uapi/linux/iommufd.h>
 
 struct iommu_domain;
 struct iommu_group;
@@ -70,6 +71,9 @@ int iopt_unmap_iova(struct io_pagetable *iopt, unsigned long iova,
 		    unsigned long length, unsigned long *unmapped);
 int iopt_unmap_all(struct io_pagetable *iopt, unsigned long *unmapped);
 
+int iopt_set_dirty_tracking(struct io_pagetable *iopt,
+			    struct iommu_domain *domain, bool enable);
+
 void iommufd_access_notify_unmap(struct io_pagetable *iopt, unsigned long iova,
 				 unsigned long length);
 int iopt_table_add_domain(struct io_pagetable *iopt,
@@ -240,6 +244,14 @@ struct iommufd_hw_pagetable {
 	struct list_head hwpt_item;
 };
 
+static inline struct iommufd_hw_pagetable *
+iommufd_get_hwpt(struct iommufd_ucmd *ucmd, u32 id)
+{
+	return container_of(iommufd_get_object(ucmd->ictx, id,
+					       IOMMUFD_OBJ_HW_PAGETABLE),
+			    struct iommufd_hw_pagetable, obj);
+}
+int iommufd_hwpt_set_dirty_tracking(struct iommufd_ucmd *ucmd);
 struct iommufd_hw_pagetable *
 iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 			   struct iommufd_device *idev, u32 flags,
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index e71523cbd0de..46fedd779714 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -307,6 +307,7 @@ union ucmd_buffer {
 	struct iommu_destroy destroy;
 	struct iommu_hw_info info;
 	struct iommu_hwpt_alloc hwpt;
+	struct iommu_hwpt_set_dirty_tracking set_dirty_tracking;
 	struct iommu_ioas_alloc alloc;
 	struct iommu_ioas_allow_iovas allow_iovas;
 	struct iommu_ioas_copy ioas_copy;
@@ -342,6 +343,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
 		 __reserved),
 	IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc,
 		 __reserved),
+	IOCTL_OP(IOMMU_HWPT_SET_DIRTY_TRACKING, iommufd_hwpt_set_dirty_tracking,
+		 struct iommu_hwpt_set_dirty_tracking, __reserved),
 	IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl,
 		 struct iommu_ioas_alloc, out_ioas_id),
 	IOCTL_OP(IOMMU_IOAS_ALLOW_IOVAS, iommufd_ioas_allow_iovas,
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index c76248410120..5c82b68c88f3 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -47,6 +47,7 @@ enum {
 	IOMMUFD_CMD_VFIO_IOAS,
 	IOMMUFD_CMD_HWPT_ALLOC,
 	IOMMUFD_CMD_GET_HW_INFO,
+	IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING,
 };
 
 /**
@@ -453,4 +454,31 @@ struct iommu_hw_info {
 	__u32 __reserved;
 };
 #define IOMMU_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_GET_HW_INFO)
+
+/*
+ * enum iommufd_hwpt_set_dirty_tracking_flags - Flags for steering dirty
+ *                                              tracking
+ * @IOMMU_HWPT_DIRTY_TRACKING_ENABLE: Enable dirty tracking
+ */
+enum iommufd_hwpt_set_dirty_tracking_flags {
+	IOMMU_HWPT_DIRTY_TRACKING_ENABLE = 1,
+};
+
+/**
+ * struct iommu_hwpt_set_dirty_tracking - ioctl(IOMMU_HWPT_SET_DIRTY_TRACKING)
+ * @size: sizeof(struct iommu_hwpt_set_dirty_tracking)
+ * @flags: Combination of enum iommufd_hwpt_set_dirty_tracking_flags
+ * @hwpt_id: HW pagetable ID that represents the IOMMU domain
+ * @__reserved: Must be 0
+ *
+ * Toggle dirty tracking on an HW pagetable.
+ */
+struct iommu_hwpt_set_dirty_tracking {
+	__u32 size;
+	__u32 flags;
+	__u32 hwpt_id;
+	__u32 __reserved;
+};
+#define IOMMU_HWPT_SET_DIRTY_TRACKING _IO(IOMMUFD_TYPE, \
+					  IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING)
 #endif
-- 
2.17.2

[PATCH v6 07/18] iommufd: Add IOMMU_HWPT_GET_DIRTY_BITMAP

[Joao Martins]

Connect a hw_pagetable to the IOMMU core dirty tracking
read_and_clear_dirty iommu domain op. It exposes all of the functionality
for the UAPI that read the dirtied IOVAs while clearing the Dirty bits from
the PTEs.

In doing so, add an IO pagetable API iopt_read_and_clear_dirty_data() that
performs the reading of dirty IOPTEs for a given IOVA range and then
copying back to userspace bitmap.

Underneath it uses the IOMMU domain kernel API which will read the dirty
bits, as well as atomically clearing the IOPTE dirty bit and flushing the
IOTLB at the end. The IOVA bitmaps usage takes care of the iteration of the
bitmaps user pages efficiently and without copies. Within the iterator
function we iterate over io-pagetable contigous areas that have been
mapped.

Contrary to past incantation of a similar interface in VFIO the IOVA range
to be scanned is tied in to the bitmap size, thus the application needs to
pass a appropriately sized bitmap address taking into account the iova
range being passed *and* page size ... as opposed to allowing bitmap-iova
!= iova.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/iommu/iommufd/hw_pagetable.c    |  22 +++++
 drivers/iommu/iommufd/io_pagetable.c    | 113 ++++++++++++++++++++++++
 drivers/iommu/iommufd/iommufd_private.h |  10 +++
 drivers/iommu/iommufd/main.c            |   4 +
 include/uapi/linux/iommufd.h            |  35 ++++++++
 5 files changed, 184 insertions(+)

diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index c3b7bd9bfcbb..7316f69110ef 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -220,3 +220,25 @@ int iommufd_hwpt_set_dirty_tracking(struct iommufd_ucmd *ucmd)
 	iommufd_put_object(&hwpt->obj);
 	return rc;
 }
+
+int iommufd_hwpt_get_dirty_bitmap(struct iommufd_ucmd *ucmd)
+{
+	struct iommu_hwpt_get_dirty_bitmap *cmd = ucmd->cmd;
+	struct iommufd_hw_pagetable *hwpt;
+	struct iommufd_ioas *ioas;
+	int rc = -EOPNOTSUPP;
+
+	if ((cmd->flags || cmd->__reserved))
+		return -EOPNOTSUPP;
+
+	hwpt = iommufd_get_hwpt(ucmd, cmd->hwpt_id);
+	if (IS_ERR(hwpt))
+		return PTR_ERR(hwpt);
+
+	ioas = hwpt->ioas;
+	rc = iopt_read_and_clear_dirty_data(&ioas->iopt, hwpt->domain,
+					    cmd->flags, cmd);
+
+	iommufd_put_object(&hwpt->obj);
+	return rc;
+}
diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
index 41c2efb6ff15..255264e796fb 100644
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -15,6 +15,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/errno.h>
+#include <uapi/linux/iommufd.h>
 
 #include "io_pagetable.h"
 #include "double_span.h"
@@ -412,6 +413,118 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt,
 	return 0;
 }
 
+struct iova_bitmap_fn_arg {
+	struct io_pagetable *iopt;
+	struct iommu_domain *domain;
+	struct iommu_dirty_bitmap *dirty;
+};
+
+static int __iommu_read_and_clear_dirty(struct iova_bitmap *bitmap,
+					unsigned long iova, size_t length,
+					void *opaque)
+{
+	struct iopt_area *area;
+	struct iopt_area_contig_iter iter;
+	struct iova_bitmap_fn_arg *arg = opaque;
+	struct iommu_domain *domain = arg->domain;
+	struct iommu_dirty_bitmap *dirty = arg->dirty;
+	const struct iommu_dirty_ops *ops = domain->dirty_ops;
+	unsigned long last_iova = iova + length - 1;
+	int ret;
+
+	iopt_for_each_contig_area(&iter, area, arg->iopt, iova, last_iova) {
+		unsigned long last = min(last_iova, iopt_area_last_iova(area));
+
+		ret = ops->read_and_clear_dirty(domain, iter.cur_iova,
+						last - iter.cur_iova + 1, 0,
+						dirty);
+		if (ret)
+			return ret;
+	}
+
+	if (!iopt_area_contig_done(&iter))
+		return -EINVAL;
+	return 0;
+}
+
+static int
+iommu_read_and_clear_dirty(struct iommu_domain *domain,
+			   struct io_pagetable *iopt, unsigned long flags,
+			   struct iommu_hwpt_get_dirty_bitmap *bitmap)
+{
+	const struct iommu_dirty_ops *ops = domain->dirty_ops;
+	struct iommu_iotlb_gather gather;
+	struct iommu_dirty_bitmap dirty;
+	struct iova_bitmap_fn_arg arg;
+	struct iova_bitmap *iter;
+	int ret = 0;
+
+	if (!ops || !ops->read_and_clear_dirty)
+		return -EOPNOTSUPP;
+
+	iter = iova_bitmap_alloc(bitmap->iova, bitmap->length,
+				 bitmap->page_size,
+				 u64_to_user_ptr(bitmap->data));
+	if (IS_ERR(iter))
+		return -ENOMEM;
+
+	iommu_dirty_bitmap_init(&dirty, iter, &gather);
+
+	arg.iopt = iopt;
+	arg.domain = domain;
+	arg.dirty = &dirty;
+	iova_bitmap_for_each(iter, &arg, __iommu_read_and_clear_dirty);
+
+	iommu_iotlb_sync(domain, &gather);
+	iova_bitmap_free(iter);
+
+	return ret;
+}
+
+int iommufd_check_iova_range(struct io_pagetable *iopt,
+			     struct iommu_hwpt_get_dirty_bitmap *bitmap)
+{
+	size_t iommu_pgsize = iopt->iova_alignment;
+	u64 last_iova;
+
+	if (check_add_overflow(bitmap->iova, bitmap->length - 1, &last_iova))
+		return -EOVERFLOW;
+
+	if (bitmap->iova > ULONG_MAX || last_iova > ULONG_MAX)
+		return -EOVERFLOW;
+
+	if ((bitmap->iova & (iommu_pgsize - 1)) ||
+	    ((last_iova + 1) & (iommu_pgsize - 1)))
+		return -EINVAL;
+
+	if (!bitmap->page_size)
+		return -EINVAL;
+
+	if ((bitmap->iova & (bitmap->page_size - 1)) ||
+	    ((last_iova + 1) & (bitmap->page_size - 1)))
+		return -EINVAL;
+
+	return 0;
+}
+
+int iopt_read_and_clear_dirty_data(struct io_pagetable *iopt,
+				   struct iommu_domain *domain,
+				   unsigned long flags,
+				   struct iommu_hwpt_get_dirty_bitmap *bitmap)
+{
+	int ret;
+
+	ret = iommufd_check_iova_range(iopt, bitmap);
+	if (ret)
+		return ret;
+
+	down_read(&iopt->iova_rwsem);
+	ret = iommu_read_and_clear_dirty(domain, iopt, flags, bitmap);
+	up_read(&iopt->iova_rwsem);
+
+	return ret;
+}
+
 static int iopt_clear_dirty_data(struct io_pagetable *iopt,
 				 struct iommu_domain *domain)
 {
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index b09750848da6..034129130db3 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -8,6 +8,8 @@
 #include <linux/xarray.h>
 #include <linux/refcount.h>
 #include <linux/uaccess.h>
+#include <linux/iommu.h>
+#include <linux/iova_bitmap.h>
 #include <uapi/linux/iommufd.h>
 
 struct iommu_domain;
@@ -71,6 +73,10 @@ int iopt_unmap_iova(struct io_pagetable *iopt, unsigned long iova,
 		    unsigned long length, unsigned long *unmapped);
 int iopt_unmap_all(struct io_pagetable *iopt, unsigned long *unmapped);
 
+int iopt_read_and_clear_dirty_data(struct io_pagetable *iopt,
+				   struct iommu_domain *domain,
+				   unsigned long flags,
+				   struct iommu_hwpt_get_dirty_bitmap *bitmap);
 int iopt_set_dirty_tracking(struct io_pagetable *iopt,
 			    struct iommu_domain *domain, bool enable);
 
@@ -226,6 +232,8 @@ int iommufd_option_rlimit_mode(struct iommu_option *cmd,
 			       struct iommufd_ctx *ictx);
 
 int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd);
+int iommufd_check_iova_range(struct io_pagetable *iopt,
+			     struct iommu_hwpt_get_dirty_bitmap *bitmap);
 
 /*
  * A HW pagetable is called an iommu_domain inside the kernel. This user object
@@ -252,6 +260,8 @@ iommufd_get_hwpt(struct iommufd_ucmd *ucmd, u32 id)
 			    struct iommufd_hw_pagetable, obj);
 }
 int iommufd_hwpt_set_dirty_tracking(struct iommufd_ucmd *ucmd);
+int iommufd_hwpt_get_dirty_bitmap(struct iommufd_ucmd *ucmd);
+
 struct iommufd_hw_pagetable *
 iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 			   struct iommufd_device *idev, u32 flags,
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 46fedd779714..d50f42a730aa 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -307,6 +307,7 @@ union ucmd_buffer {
 	struct iommu_destroy destroy;
 	struct iommu_hw_info info;
 	struct iommu_hwpt_alloc hwpt;
+	struct iommu_hwpt_get_dirty_bitmap get_dirty_bitmap;
 	struct iommu_hwpt_set_dirty_tracking set_dirty_tracking;
 	struct iommu_ioas_alloc alloc;
 	struct iommu_ioas_allow_iovas allow_iovas;
@@ -343,6 +344,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
 		 __reserved),
 	IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc,
 		 __reserved),
+	IOCTL_OP(IOMMU_HWPT_GET_DIRTY_BITMAP, iommufd_hwpt_get_dirty_bitmap,
+		 struct iommu_hwpt_get_dirty_bitmap, data),
 	IOCTL_OP(IOMMU_HWPT_SET_DIRTY_TRACKING, iommufd_hwpt_set_dirty_tracking,
 		 struct iommu_hwpt_set_dirty_tracking, __reserved),
 	IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl,
@@ -555,5 +558,6 @@ MODULE_ALIAS_MISCDEV(VFIO_MINOR);
 MODULE_ALIAS("devname:vfio/vfio");
 #endif
 MODULE_IMPORT_NS(IOMMUFD_INTERNAL);
+MODULE_IMPORT_NS(IOMMUFD);
 MODULE_DESCRIPTION("I/O Address Space Management for passthrough devices");
 MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 5c82b68c88f3..dce38e32ca84 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -48,6 +48,7 @@ enum {
 	IOMMUFD_CMD_HWPT_ALLOC,
 	IOMMUFD_CMD_GET_HW_INFO,
 	IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING,
+	IOMMUFD_CMD_HWPT_GET_DIRTY_BITMAP,
 };
 
 /**
@@ -481,4 +482,38 @@ struct iommu_hwpt_set_dirty_tracking {
 };
 #define IOMMU_HWPT_SET_DIRTY_TRACKING _IO(IOMMUFD_TYPE, \
 					  IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING)
+
+/**
+ * struct iommu_hwpt_get_dirty_bitmap - ioctl(IOMMU_HWPT_GET_DIRTY_BITMAP)
+ * @size: sizeof(struct iommu_hwpt_get_dirty_bitmap)
+ * @hwpt_id: HW pagetable ID that represents the IOMMU domain
+ * @flags: Must be zero
+ * @__reserved: Must be 0
+ * @iova: base IOVA of the bitmap first bit
+ * @length: IOVA range size
+ * @page_size: page size granularity of each bit in the bitmap
+ * @data: bitmap where to set the dirty bits. The bitmap bits each
+ *        represent a page_size which you deviate from an arbitrary iova.
+ *
+ * Checking a given IOVA is dirty:
+ *
+ *  data[(iova / page_size) / 64] & (1ULL << ((iova / page_size) % 64))
+ *
+ * Walk the IOMMU pagetables for a given IOVA range to return a bitmap
+ * with the dirty IOVAs. In doing so it will also by default clear any
+ * dirty bit metadata set in the IOPTE.
+ */
+struct iommu_hwpt_get_dirty_bitmap {
+	__u32 size;
+	__u32 hwpt_id;
+	__u32 flags;
+	__u32 __reserved;
+	__aligned_u64 iova;
+	__aligned_u64 length;
+	__aligned_u64 page_size;
+	__aligned_u64 data;
+};
+#define IOMMU_HWPT_GET_DIRTY_BITMAP _IO(IOMMUFD_TYPE, \
+					IOMMUFD_CMD_HWPT_GET_DIRTY_BITMAP)
+
 #endif
-- 
2.17.2

[PATCH v6 08/18] iommufd: Add capabilities to IOMMU_GET_HW_INFO

[Joao Martins]

Extend IOMMUFD_CMD_GET_HW_INFO op to query generic iommu capabilities for a
given device.

Capabilities are IOMMU agnostic and use device_iommu_capable() API passing
one of the IOMMU_CAP_*. Enumerate IOMMU_CAP_DIRTY_TRACKING for now in the
out_capabilities field returned back to userspace.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/iommu/iommufd/device.c |  4 ++++
 include/uapi/linux/iommufd.h   | 17 +++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index e88fa73a45e6..2a41fd2b6ef8 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -1185,6 +1185,10 @@ int iommufd_get_hw_info(struct iommufd_ucmd *ucmd)
 	 */
 	cmd->data_len = data_len;
 
+	cmd->out_capabilities = 0;
+	if (device_iommu_capable(idev->dev, IOMMU_CAP_DIRTY_TRACKING))
+		cmd->out_capabilities |= IOMMU_HW_CAP_DIRTY_TRACKING;
+
 	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
 out_free:
 	kfree(data);
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index dce38e32ca84..036ebc6c19cf 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -418,6 +418,20 @@ enum iommu_hw_info_type {
 	IOMMU_HW_INFO_TYPE_INTEL_VTD,
 };
 
+/**
+ * enum iommufd_hw_capabilities
+ * @IOMMU_HW_CAP_DIRTY_TRACKING: IOMMU hardware support for dirty tracking
+ *                               If available, it means the following APIs
+ *                               are supported:
+ *
+ *                                   IOMMU_HWPT_GET_DIRTY_BITMAP
+ *                                   IOMMU_HWPT_SET_DIRTY_TRACKING
+ *
+ */
+enum iommufd_hw_capabilities {
+	IOMMU_HW_CAP_DIRTY_TRACKING = 1 << 0,
+};
+
 /**
  * struct iommu_hw_info - ioctl(IOMMU_GET_HW_INFO)
  * @size: sizeof(struct iommu_hw_info)
@@ -429,6 +443,8 @@ enum iommu_hw_info_type {
  *             the iommu type specific hardware information data
  * @out_data_type: Output the iommu hardware info type as defined in the enum
  *                 iommu_hw_info_type.
+ * @out_capabilities: Output the generic iommu capability info type as defined
+ *                    in the enum iommu_hw_capabilities.
  * @__reserved: Must be 0
  *
  * Query an iommu type specific hardware information data from an iommu behind
@@ -453,6 +469,7 @@ struct iommu_hw_info {
 	__aligned_u64 data_uptr;
 	__u32 out_data_type;
 	__u32 __reserved;
+	__aligned_u64 out_capabilities;
 };
 #define IOMMU_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_GET_HW_INFO)
 
-- 
2.17.2

[PATCH v6 09/18] iommufd: Add a flag to skip clearing of IOPTE dirty

[Joao Martins]

VFIO has an operation where it unmaps an IOVA while returning a bitmap with
the dirty data. In reality the operation doesn't quite query the IO
pagetables that the PTE was dirty or not. Instead it marks as dirty on
anything that was mapped, and doing so in one syscall.

In IOMMUFD the equivalent is done in two operations by querying with
GET_DIRTY_IOVA followed by UNMAP_IOVA. However, this would incur two TLB
flushes given that after clearing dirty bits IOMMU implementations require
invalidating their IOTLB, plus another invalidation needed for the UNMAP.
To allow dirty bits to be queried faster, add a flag
(IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR) that requests to not clear the dirty
bits from the PTE (but just reading them), under the expectation that the
next operation is the unmap. An alternative is to unmap and just
perpectually mark as dirty as that's the same behaviour as today. So here
equivalent functionally can be provided with unmap alone, and if real dirty
info is required it will amortize the cost while querying.

There's still a race against DMA where in theory the unmap of the IOVA
(when the guest invalidates the IOTLB via emulated iommu) would race
against the VF performing DMA on the same IOVA. As discussed in [0], we are
accepting to resolve this race as throwing away the DMA and it doesn't
matter if it hit physical DRAM or not, the VM can't tell if we threw it
away because the DMA was blocked or because we failed to copy the DRAM.

[0] https://lore.kernel.org/linux-iommu/20220502185239.GR8364@nvidia.com/

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/iommu/iommufd/hw_pagetable.c |  3 ++-
 drivers/iommu/iommufd/io_pagetable.c |  9 +++++++--
 include/uapi/linux/iommufd.h         | 15 ++++++++++++++-
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 7316f69110ef..72a5269984b0 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -228,7 +228,8 @@ int iommufd_hwpt_get_dirty_bitmap(struct iommufd_ucmd *ucmd)
 	struct iommufd_ioas *ioas;
 	int rc = -EOPNOTSUPP;
 
-	if ((cmd->flags || cmd->__reserved))
+	if ((cmd->flags & ~(IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR)) ||
+	    cmd->__reserved)
 		return -EOPNOTSUPP;
 
 	hwpt = iommufd_get_hwpt(ucmd, cmd->hwpt_id);
diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
index 255264e796fb..9f060abe53b6 100644
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -414,6 +414,7 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt,
 }
 
 struct iova_bitmap_fn_arg {
+	unsigned long flags;
 	struct io_pagetable *iopt;
 	struct iommu_domain *domain;
 	struct iommu_dirty_bitmap *dirty;
@@ -430,13 +431,14 @@ static int __iommu_read_and_clear_dirty(struct iova_bitmap *bitmap,
 	struct iommu_dirty_bitmap *dirty = arg->dirty;
 	const struct iommu_dirty_ops *ops = domain->dirty_ops;
 	unsigned long last_iova = iova + length - 1;
+	unsigned long flags = arg->flags;
 	int ret;
 
 	iopt_for_each_contig_area(&iter, area, arg->iopt, iova, last_iova) {
 		unsigned long last = min(last_iova, iopt_area_last_iova(area));
 
 		ret = ops->read_and_clear_dirty(domain, iter.cur_iova,
-						last - iter.cur_iova + 1, 0,
+						last - iter.cur_iova + 1, flags,
 						dirty);
 		if (ret)
 			return ret;
@@ -470,12 +472,15 @@ iommu_read_and_clear_dirty(struct iommu_domain *domain,
 
 	iommu_dirty_bitmap_init(&dirty, iter, &gather);
 
+	arg.flags = flags;
 	arg.iopt = iopt;
 	arg.domain = domain;
 	arg.dirty = &dirty;
 	iova_bitmap_for_each(iter, &arg, __iommu_read_and_clear_dirty);
 
-	iommu_iotlb_sync(domain, &gather);
+	if (!(flags & IOMMU_DIRTY_NO_CLEAR))
+		iommu_iotlb_sync(domain, &gather);
+
 	iova_bitmap_free(iter);
 
 	return ret;
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 036ebc6c19cf..c44eecf5d318 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -500,11 +500,24 @@ struct iommu_hwpt_set_dirty_tracking {
 #define IOMMU_HWPT_SET_DIRTY_TRACKING _IO(IOMMUFD_TYPE, \
 					  IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING)
 
+/**
+ * enum iommufd_hwpt_get_dirty_bitmap_flags - Flags for getting dirty bits
+ * @IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR: Just read the PTEs without clearing
+ *                                        any dirty bits metadata. This flag
+ *                                        can be passed in the expectation
+ *                                        where the next operation is an unmap
+ *                                        of the same IOVA range.
+ *
+ */
+enum iommufd_hwpt_get_dirty_bitmap_flags {
+	IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR = 1,
+};
+
 /**
  * struct iommu_hwpt_get_dirty_bitmap - ioctl(IOMMU_HWPT_GET_DIRTY_BITMAP)
  * @size: sizeof(struct iommu_hwpt_get_dirty_bitmap)
  * @hwpt_id: HW pagetable ID that represents the IOMMU domain
- * @flags: Must be zero
+ * @flags: Combination of enum iommufd_hwpt_get_dirty_bitmap_flags
  * @__reserved: Must be 0
  * @iova: base IOVA of the bitmap first bit
  * @length: IOVA range size
-- 
2.17.2

[PATCH v6 10/18] iommu/amd: Add domain_alloc_user based domain allocation

[Joao Martins]

Add the domain_alloc_user op implementation. To that end, refactor
amd_iommu_domain_alloc() to receive a dev pointer and flags, while renaming
it too, such that it becomes a common function shared with
domain_alloc_user() implementation. The sole difference with
domain_alloc_user() is that we initialize also other fields that
iommu_domain_alloc() does. It lets it return the iommu domain correctly
initialized in one function.

This is in preparation to add dirty enforcement on AMD implementation of
domain_alloc_user.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/iommu.c | 44 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 41 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 95bd7c25ba6f..667e23b0ab0d 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -37,6 +37,7 @@
 #include <asm/iommu.h>
 #include <asm/gart.h>
 #include <asm/dma.h>
+#include <uapi/linux/iommufd.h>
 
 #include "amd_iommu.h"
 #include "../dma-iommu.h"
@@ -2155,28 +2156,64 @@ static inline u64 dma_max_address(void)
 	return ((1ULL << PM_LEVEL_SHIFT(amd_iommu_gpt_level)) - 1);
 }
 
-static struct iommu_domain *amd_iommu_domain_alloc(unsigned type)
+static struct iommu_domain *do_iommu_domain_alloc(unsigned int type,
+						  struct device *dev, u32 flags)
 {
 	struct protection_domain *domain;
+	struct amd_iommu *iommu = NULL;
+
+	if (dev) {
+		iommu = rlookup_amd_iommu(dev);
+		if (!iommu)
+			return ERR_PTR(-ENODEV);
+	}
 
 	/*
 	 * Since DTE[Mode]=0 is prohibited on SNP-enabled system,
 	 * default to use IOMMU_DOMAIN_DMA[_FQ].
 	 */
 	if (amd_iommu_snp_en && (type == IOMMU_DOMAIN_IDENTITY))
-		return NULL;
+		return ERR_PTR(-EINVAL);
 
 	domain = protection_domain_alloc(type);
 	if (!domain)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	domain->domain.geometry.aperture_start = 0;
 	domain->domain.geometry.aperture_end   = dma_max_address();
 	domain->domain.geometry.force_aperture = true;
 
+	if (iommu) {
+		domain->domain.type = type;
+		domain->domain.pgsize_bitmap = iommu->iommu.ops->pgsize_bitmap;
+		domain->domain.ops = iommu->iommu.ops->default_domain_ops;
+	}
+
 	return &domain->domain;
 }
 
+static struct iommu_domain *amd_iommu_domain_alloc(unsigned int type)
+{
+	struct iommu_domain *domain;
+
+	domain = do_iommu_domain_alloc(type, NULL, 0);
+	if (IS_ERR(domain))
+		return NULL;
+
+	return domain;
+}
+
+static struct iommu_domain *amd_iommu_domain_alloc_user(struct device *dev,
+							u32 flags)
+{
+	unsigned int type = IOMMU_DOMAIN_UNMANAGED;
+
+	if (flags)
+		return ERR_PTR(-EOPNOTSUPP);
+
+	return do_iommu_domain_alloc(type, dev, flags);
+}
+
 static void amd_iommu_domain_free(struct iommu_domain *dom)
 {
 	struct protection_domain *domain;
@@ -2464,6 +2501,7 @@ static bool amd_iommu_enforce_cache_coherency(struct iommu_domain *domain)
 const struct iommu_ops amd_iommu_ops = {
 	.capable = amd_iommu_capable,
 	.domain_alloc = amd_iommu_domain_alloc,
+	.domain_alloc_user = amd_iommu_domain_alloc_user,
 	.probe_device = amd_iommu_probe_device,
 	.release_device = amd_iommu_release_device,
 	.probe_finalize = amd_iommu_probe_finalize,
-- 
2.17.2

[PATCH v6 11/18] iommu/amd: Access/Dirty bit support in IOPTEs

[Joao Martins]

IOMMU advertises Access/Dirty bits if the extended feature register reports
it. Relevant AMD IOMMU SDM ref[0] "1.3.8 Enhanced Support for Access and
Dirty Bits"

To enable it set the DTE flag in bits 7 and 8 to enable access, or
access+dirty. With that, the IOMMU starts marking the D and A flags on
every Memory Request or ATS translation request. It is on the VMM side to
steer whether to enable dirty tracking or not, rather than wrongly doing in
IOMMU. Relevant AMD IOMMU SDM ref [0], "Table 7. Device Table Entry (DTE)
Field Definitions" particularly the entry "HAD".

To actually toggle on and off it's relatively simple as it's setting 2 bits
on DTE and flush the device DTE cache.

To get what's dirtied use existing AMD io-pgtable support, by walking the
pagetables over each IOVA, with fetch_pte().  The IOTLB flushing is left to
the caller (much like unmap), and iommu_dirty_bitmap_record() is the one
adding page-ranges to invalidate. This allows caller to batch the flush
over a big span of IOVA space, without the iommu wondering about when to
flush.

Worthwhile sections from AMD IOMMU SDM:

"2.2.3.1 Host Access Support"
"2.2.3.2 Host Dirty Support"

For details on how IOMMU hardware updates the dirty bit see, and expects
from its consequent clearing by CPU:

"2.2.7.4 Updating Accessed and Dirty Bits in the Guest Address Tables"
"2.2.7.5 Clearing Accessed and Dirty Bits"

Quoting the SDM:

"The setting of accessed and dirty status bits in the page tables is
visible to both the CPU and the peripheral when sharing guest page tables.
The IOMMU interlocked operations to update A and D bits must be 64-bit
operations and naturally aligned on a 64-bit boundary"

.. and for the IOMMU update sequence to Dirty bit, essentially is states:

1. Decodes the read and write intent from the memory access.
2. If P=0 in the page descriptor, fail the access.
3. Compare the A & D bits in the descriptor with the read and write
intent in the request.
4. If the A or D bits need to be updated in the descriptor:
* Start atomic operation.
* Read the descriptor as a 64-bit access.
* If the descriptor no longer appears to require an update, release the
atomic lock with
no further action and continue to step 5.
* Calculate the new A & D bits.
* Write the descriptor as a 64-bit access.
* End atomic operation.
5. Continue to the next stage of translation or to the memory access.

Access/Dirty bits readout also need to consider the non-default page-sizes
(aka replicated PTEs as mentined by manual), as AMD supports all powers of
two (except 512G) page sizes.

Select IOMMUFD_DRIVER only if IOMMUFD is enabled considering that IOMMU
dirty tracking requires IOMMUFD.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/Kconfig           |   1 +
 drivers/iommu/amd/amd_iommu_types.h |  12 ++++
 drivers/iommu/amd/io_pgtable.c      |  68 +++++++++++++++++++
 drivers/iommu/amd/iommu.c           | 102 +++++++++++++++++++++++++++-
 4 files changed, 182 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd/Kconfig b/drivers/iommu/amd/Kconfig
index 9b5fc3356bf2..8bd4c3b183ec 100644
--- a/drivers/iommu/amd/Kconfig
+++ b/drivers/iommu/amd/Kconfig
@@ -10,6 +10,7 @@ config AMD_IOMMU
 	select IOMMU_API
 	select IOMMU_IOVA
 	select IOMMU_IO_PGTABLE
+	select IOMMUFD_DRIVER if IOMMUFD
 	depends on X86_64 && PCI && ACPI && HAVE_CMPXCHG_DOUBLE
 	help
 	  With this option you can enable support for AMD IOMMU hardware in
diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index 7dc30c2b56b3..dec4e5c2b66b 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -97,7 +97,9 @@
 #define FEATURE_GATS_MASK	(3ULL)
 #define FEATURE_GAM_VAPIC	BIT_ULL(21)
 #define FEATURE_GIOSUP		BIT_ULL(48)
+#define FEATURE_HASUP		BIT_ULL(49)
 #define FEATURE_EPHSUP		BIT_ULL(50)
+#define FEATURE_HDSUP		BIT_ULL(52)
 #define FEATURE_SNP		BIT_ULL(63)
 
 #define FEATURE_PASID_SHIFT	32
@@ -212,6 +214,7 @@
 /* macros and definitions for device table entries */
 #define DEV_ENTRY_VALID         0x00
 #define DEV_ENTRY_TRANSLATION   0x01
+#define DEV_ENTRY_HAD           0x07
 #define DEV_ENTRY_PPR           0x34
 #define DEV_ENTRY_IR            0x3d
 #define DEV_ENTRY_IW            0x3e
@@ -370,10 +373,16 @@
 #define PTE_LEVEL_PAGE_SIZE(level)			\
 	(1ULL << (12 + (9 * (level))))
 
+/*
+ * The IOPTE dirty bit
+ */
+#define IOMMU_PTE_HD_BIT (6)
+
 /*
  * Bit value definition for I/O PTE fields
  */
 #define IOMMU_PTE_PR	BIT_ULL(0)
+#define IOMMU_PTE_HD	BIT_ULL(IOMMU_PTE_HD_BIT)
 #define IOMMU_PTE_U	BIT_ULL(59)
 #define IOMMU_PTE_FC	BIT_ULL(60)
 #define IOMMU_PTE_IR	BIT_ULL(61)
@@ -384,6 +393,7 @@
  */
 #define DTE_FLAG_V	BIT_ULL(0)
 #define DTE_FLAG_TV	BIT_ULL(1)
+#define DTE_FLAG_HAD	(3ULL << 7)
 #define DTE_FLAG_GIOV	BIT_ULL(54)
 #define DTE_FLAG_GV	BIT_ULL(55)
 #define DTE_GLX_SHIFT	(56)
@@ -413,6 +423,7 @@
 
 #define IOMMU_PAGE_MASK (((1ULL << 52) - 1) & ~0xfffULL)
 #define IOMMU_PTE_PRESENT(pte) ((pte) & IOMMU_PTE_PR)
+#define IOMMU_PTE_DIRTY(pte) ((pte) & IOMMU_PTE_HD)
 #define IOMMU_PTE_PAGE(pte) (iommu_phys_to_virt((pte) & IOMMU_PAGE_MASK))
 #define IOMMU_PTE_MODE(pte) (((pte) >> 9) & 0x07)
 
@@ -563,6 +574,7 @@ struct protection_domain {
 	int nid;		/* Node ID */
 	u64 *gcr3_tbl;		/* Guest CR3 table */
 	unsigned long flags;	/* flags to find out type of domain */
+	bool dirty_tracking;	/* dirty tracking is enabled in the domain */
 	unsigned dev_cnt;	/* devices assigned to this domain */
 	unsigned dev_iommu[MAX_IOMMUS]; /* per-IOMMU reference count */
 };
diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
index 2892aa1b4dc1..6c0621f6f572 100644
--- a/drivers/iommu/amd/io_pgtable.c
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -486,6 +486,73 @@ static phys_addr_t iommu_v1_iova_to_phys(struct io_pgtable_ops *ops, unsigned lo
 	return (__pte & ~offset_mask) | (iova & offset_mask);
 }
 
+static bool pte_test_and_clear_dirty(u64 *ptep, unsigned long size,
+				     unsigned long flags)
+{
+	bool test_only = flags & IOMMU_DIRTY_NO_CLEAR;
+	bool dirty = false;
+	int i, count;
+
+	/*
+	 * 2.2.3.2 Host Dirty Support
+	 * When a non-default page size is used , software must OR the
+	 * Dirty bits in all of the replicated host PTEs used to map
+	 * the page. The IOMMU does not guarantee the Dirty bits are
+	 * set in all of the replicated PTEs. Any portion of the page
+	 * may have been written even if the Dirty bit is set in only
+	 * one of the replicated PTEs.
+	 */
+	count = PAGE_SIZE_PTE_COUNT(size);
+	for (i = 0; i < count && test_only; i++) {
+		if (test_bit(IOMMU_PTE_HD_BIT, (unsigned long *)&ptep[i])) {
+			dirty = true;
+			break;
+		}
+	}
+
+	for (i = 0; i < count && !test_only; i++) {
+		if (test_and_clear_bit(IOMMU_PTE_HD_BIT,
+				       (unsigned long *)&ptep[i])) {
+			dirty = true;
+		}
+	}
+
+	return dirty;
+}
+
+static int iommu_v1_read_and_clear_dirty(struct io_pgtable_ops *ops,
+					 unsigned long iova, size_t size,
+					 unsigned long flags,
+					 struct iommu_dirty_bitmap *dirty)
+{
+	struct amd_io_pgtable *pgtable = io_pgtable_ops_to_data(ops);
+	unsigned long end = iova + size - 1;
+
+	do {
+		unsigned long pgsize = 0;
+		u64 *ptep, pte;
+
+		ptep = fetch_pte(pgtable, iova, &pgsize);
+		if (ptep)
+			pte = READ_ONCE(*ptep);
+		if (!ptep || !IOMMU_PTE_PRESENT(pte)) {
+			pgsize = pgsize ?: PTE_LEVEL_PAGE_SIZE(0);
+			iova += pgsize;
+			continue;
+		}
+
+		/*
+		 * Mark the whole IOVA range as dirty even if only one of
+		 * the replicated PTEs were marked dirty.
+		 */
+		if (pte_test_and_clear_dirty(ptep, pgsize, flags))
+			iommu_dirty_bitmap_record(dirty, iova, pgsize);
+		iova += pgsize;
+	} while (iova < end);
+
+	return 0;
+}
+
 /*
  * ----------------------------------------------------
  */
@@ -527,6 +594,7 @@ static struct io_pgtable *v1_alloc_pgtable(struct io_pgtable_cfg *cfg, void *coo
 	pgtable->iop.ops.map_pages    = iommu_v1_map_pages;
 	pgtable->iop.ops.unmap_pages  = iommu_v1_unmap_pages;
 	pgtable->iop.ops.iova_to_phys = iommu_v1_iova_to_phys;
+	pgtable->iop.ops.read_and_clear_dirty = iommu_v1_read_and_clear_dirty;
 
 	return &pgtable->iop;
 }
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 667e23b0ab0d..caad10f9cee3 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -66,6 +66,7 @@ LIST_HEAD(hpet_map);
 LIST_HEAD(acpihid_map);
 
 const struct iommu_ops amd_iommu_ops;
+const struct iommu_dirty_ops amd_dirty_ops;
 
 static ATOMIC_NOTIFIER_HEAD(ppr_notifier);
 int amd_iommu_max_glx_val = -1;
@@ -1611,6 +1612,9 @@ static void set_dte_entry(struct amd_iommu *iommu, u16 devid,
 			pte_root |= 1ULL << DEV_ENTRY_PPR;
 	}
 
+	if (domain->dirty_tracking)
+		pte_root |= DTE_FLAG_HAD;
+
 	if (domain->flags & PD_IOMMUV2_MASK) {
 		u64 gcr3 = iommu_virt_to_phys(domain->gcr3_tbl);
 		u64 glx  = domain->glx;
@@ -2156,9 +2160,15 @@ static inline u64 dma_max_address(void)
 	return ((1ULL << PM_LEVEL_SHIFT(amd_iommu_gpt_level)) - 1);
 }
 
+static bool amd_iommu_hd_support(struct amd_iommu *iommu)
+{
+	return iommu && (iommu->features & FEATURE_HDSUP);
+}
+
 static struct iommu_domain *do_iommu_domain_alloc(unsigned int type,
 						  struct device *dev, u32 flags)
 {
+	bool dirty_tracking = flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
 	struct protection_domain *domain;
 	struct amd_iommu *iommu = NULL;
 
@@ -2175,6 +2185,9 @@ static struct iommu_domain *do_iommu_domain_alloc(unsigned int type,
 	if (amd_iommu_snp_en && (type == IOMMU_DOMAIN_IDENTITY))
 		return ERR_PTR(-EINVAL);
 
+	if (dirty_tracking && !amd_iommu_hd_support(iommu))
+		return ERR_PTR(-EOPNOTSUPP);
+
 	domain = protection_domain_alloc(type);
 	if (!domain)
 		return ERR_PTR(-ENOMEM);
@@ -2187,6 +2200,9 @@ static struct iommu_domain *do_iommu_domain_alloc(unsigned int type,
 		domain->domain.type = type;
 		domain->domain.pgsize_bitmap = iommu->iommu.ops->pgsize_bitmap;
 		domain->domain.ops = iommu->iommu.ops->default_domain_ops;
+
+		if (dirty_tracking)
+			domain->domain.dirty_ops = &amd_dirty_ops;
 	}
 
 	return &domain->domain;
@@ -2208,7 +2224,7 @@ static struct iommu_domain *amd_iommu_domain_alloc_user(struct device *dev,
 {
 	unsigned int type = IOMMU_DOMAIN_UNMANAGED;
 
-	if (flags)
+	if (flags & ~IOMMU_HWPT_ALLOC_DIRTY_TRACKING)
 		return ERR_PTR(-EOPNOTSUPP);
 
 	return do_iommu_domain_alloc(type, dev, flags);
@@ -2251,6 +2267,13 @@ static int amd_iommu_attach_device(struct iommu_domain *dom,
 
 	dev_data->defer_attach = false;
 
+	/*
+	 * Restrict to devices with compatible IOMMU hardware support
+	 * when enforcement of dirty tracking is enabled.
+	 */
+	if (dom->dirty_ops && !amd_iommu_hd_support(iommu))
+		return -EINVAL;
+
 	if (dev_data->domain)
 		detach_device(dev);
 
@@ -2369,6 +2392,11 @@ static bool amd_iommu_capable(struct device *dev, enum iommu_cap cap)
 		return true;
 	case IOMMU_CAP_DEFERRED_FLUSH:
 		return true;
+	case IOMMU_CAP_DIRTY_TRACKING: {
+		struct amd_iommu *iommu = rlookup_amd_iommu(dev);
+
+		return amd_iommu_hd_support(iommu);
+	}
 	default:
 		break;
 	}
@@ -2376,6 +2404,73 @@ static bool amd_iommu_capable(struct device *dev, enum iommu_cap cap)
 	return false;
 }
 
+static int amd_iommu_set_dirty_tracking(struct iommu_domain *domain,
+					bool enable)
+{
+	struct protection_domain *pdomain = to_pdomain(domain);
+	struct dev_table_entry *dev_table;
+	struct iommu_dev_data *dev_data;
+	bool domain_flush = false;
+	struct amd_iommu *iommu;
+	unsigned long flags;
+	u64 pte_root;
+
+	spin_lock_irqsave(&pdomain->lock, flags);
+	if (!(pdomain->dirty_tracking ^ enable)) {
+		spin_unlock_irqrestore(&pdomain->lock, flags);
+		return 0;
+	}
+
+	list_for_each_entry(dev_data, &pdomain->dev_list, list) {
+		iommu = rlookup_amd_iommu(dev_data->dev);
+		if (!iommu)
+			continue;
+
+		dev_table = get_dev_table(iommu);
+		pte_root = dev_table[dev_data->devid].data[0];
+
+		pte_root = (enable ? pte_root | DTE_FLAG_HAD :
+				     pte_root & ~DTE_FLAG_HAD);
+
+		/* Flush device DTE */
+		dev_table[dev_data->devid].data[0] = pte_root;
+		device_flush_dte(dev_data);
+		domain_flush = true;
+	}
+
+	/* Flush IOTLB to mark IOPTE dirty on the next translation(s) */
+	if (domain_flush) {
+		amd_iommu_domain_flush_tlb_pde(pdomain);
+		amd_iommu_domain_flush_complete(pdomain);
+	}
+	pdomain->dirty_tracking = enable;
+	spin_unlock_irqrestore(&pdomain->lock, flags);
+
+	return 0;
+}
+
+static int amd_iommu_read_and_clear_dirty(struct iommu_domain *domain,
+					  unsigned long iova, size_t size,
+					  unsigned long flags,
+					  struct iommu_dirty_bitmap *dirty)
+{
+	struct protection_domain *pdomain = to_pdomain(domain);
+	struct io_pgtable_ops *ops = &pdomain->iop.iop.ops;
+	unsigned long lflags;
+
+	if (!ops || !ops->read_and_clear_dirty)
+		return -EOPNOTSUPP;
+
+	spin_lock_irqsave(&pdomain->lock, lflags);
+	if (!pdomain->dirty_tracking && dirty->bitmap) {
+		spin_unlock_irqrestore(&pdomain->lock, lflags);
+		return -EINVAL;
+	}
+	spin_unlock_irqrestore(&pdomain->lock, lflags);
+
+	return ops->read_and_clear_dirty(ops, iova, size, flags, dirty);
+}
+
 static void amd_iommu_get_resv_regions(struct device *dev,
 				       struct list_head *head)
 {
@@ -2498,6 +2593,11 @@ static bool amd_iommu_enforce_cache_coherency(struct iommu_domain *domain)
 	return true;
 }
 
+const struct iommu_dirty_ops amd_dirty_ops = {
+	.set_dirty_tracking = amd_iommu_set_dirty_tracking,
+	.read_and_clear_dirty = amd_iommu_read_and_clear_dirty,
+};
+
 const struct iommu_ops amd_iommu_ops = {
 	.capable = amd_iommu_capable,
 	.domain_alloc = amd_iommu_domain_alloc,
-- 
2.17.2

[PATCH v6 12/18] iommu/vt-d: Access/Dirty bit support for SS domains

[Joao Martins]

IOMMU advertises Access/Dirty bits for second-stage page table if the
extended capability DMAR register reports it (ECAP, mnemonic ECAP.SSADS).
The first stage table is compatible with CPU page table thus A/D bits are
implicitly supported. Relevant Intel IOMMU SDM ref for first stage table
"3.6.2 Accessed, Extended Accessed, and Dirty Flags" and second stage table
"3.7.2 Accessed and Dirty Flags".

First stage page table is enabled by default so it's allowed to set dirty
tracking and no control bits needed, it just returns 0. To use SSADS, set
bit 9 (SSADE) in the scalable-mode PASID table entry and flush the IOTLB
via pasid_flush_caches() following the manual. Relevant SDM refs:

"3.7.2 Accessed and Dirty Flags"
"6.5.3.3 Guidance to Software for Invalidations,
 Table 23. Guidance to Software for Invalidations"

PTE dirty bit is located in bit 9 and it's cached in the IOTLB so flush
IOTLB to make sure IOMMU attempts to set the dirty bit again. Note that
iommu_dirty_bitmap_record() will add the IOVA to iotlb_gather and thus the
caller of the iommu op will flush the IOTLB. Relevant manuals over the
hardware translation is chapter 6 with some special mention to:

"6.2.3.1 Scalable-Mode PASID-Table Entry Programming Considerations"
"6.2.4 IOTLB"

Select IOMMUFD_DRIVER only if IOMMUFD is enabled, given that IOMMU dirty
tracking requires IOMMUFD.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/iommu/intel/Kconfig |   1 +
 drivers/iommu/intel/iommu.c | 103 +++++++++++++++++++++++++++++++++-
 drivers/iommu/intel/iommu.h |  16 ++++++
 drivers/iommu/intel/pasid.c | 109 ++++++++++++++++++++++++++++++++++++
 drivers/iommu/intel/pasid.h |   4 ++
 5 files changed, 232 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig
index 2e56bd79f589..f5348b80652b 100644
--- a/drivers/iommu/intel/Kconfig
+++ b/drivers/iommu/intel/Kconfig
@@ -15,6 +15,7 @@ config INTEL_IOMMU
 	select DMA_OPS
 	select IOMMU_API
 	select IOMMU_IOVA
+	select IOMMUFD_DRIVER if IOMMUFD
 	select NEED_DMA_MAP_STATE
 	select DMAR_TABLE
 	select SWIOTLB
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 017aed5813d8..eb92a201cc0b 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -300,6 +300,7 @@ static int iommu_skip_te_disable;
 #define IDENTMAP_AZALIA		4
 
 const struct iommu_ops intel_iommu_ops;
+const struct iommu_dirty_ops intel_dirty_ops;
 
 static bool translation_pre_enabled(struct intel_iommu *iommu)
 {
@@ -4079,8 +4080,10 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags)
 {
 	struct iommu_domain *domain;
 	struct intel_iommu *iommu;
+	bool dirty_tracking;
 
-	if (flags & (~IOMMU_HWPT_ALLOC_NEST_PARENT))
+	if (flags &
+	    (~(IOMMU_HWPT_ALLOC_NEST_PARENT | IOMMU_HWPT_ALLOC_DIRTY_TRACKING)))
 		return ERR_PTR(-EOPNOTSUPP);
 
 	iommu = device_to_iommu(dev, NULL, NULL);
@@ -4090,6 +4093,10 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags)
 	if ((flags & IOMMU_HWPT_ALLOC_NEST_PARENT) && !ecap_nest(iommu->ecap))
 		return ERR_PTR(-EOPNOTSUPP);
 
+	dirty_tracking = (flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING);
+	if (dirty_tracking && !ssads_supported(iommu))
+		return ERR_PTR(-EOPNOTSUPP);
+
 	/*
 	 * domain_alloc_user op needs to fully initialize a domain
 	 * before return, so uses iommu_domain_alloc() here for
@@ -4098,6 +4105,15 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags)
 	domain = iommu_domain_alloc(dev->bus);
 	if (!domain)
 		domain = ERR_PTR(-ENOMEM);
+
+	if (!IS_ERR(domain) && dirty_tracking) {
+		if (to_dmar_domain(domain)->use_first_level) {
+			iommu_domain_free(domain);
+			return ERR_PTR(-EOPNOTSUPP);
+		}
+		domain->dirty_ops = &intel_dirty_ops;
+	}
+
 	return domain;
 }
 
@@ -4121,6 +4137,9 @@ static int prepare_domain_attach_device(struct iommu_domain *domain,
 	if (dmar_domain->force_snooping && !ecap_sc_support(iommu->ecap))
 		return -EINVAL;
 
+	if (domain->dirty_ops && !ssads_supported(iommu))
+		return -EINVAL;
+
 	/* check if this iommu agaw is sufficient for max mapped address */
 	addr_width = agaw_to_width(iommu->agaw);
 	if (addr_width > cap_mgaw(iommu->cap))
@@ -4375,6 +4394,8 @@ static bool intel_iommu_capable(struct device *dev, enum iommu_cap cap)
 		return dmar_platform_optin();
 	case IOMMU_CAP_ENFORCE_CACHE_COHERENCY:
 		return ecap_sc_support(info->iommu->ecap);
+	case IOMMU_CAP_DIRTY_TRACKING:
+		return ssads_supported(info->iommu);
 	default:
 		return false;
 	}
@@ -4772,6 +4793,9 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
 	if (!pasid_supported(iommu) || dev_is_real_dma_subdevice(dev))
 		return -EOPNOTSUPP;
 
+	if (domain->dirty_ops)
+		return -EINVAL;
+
 	if (context_copied(iommu, info->bus, info->devfn))
 		return -EBUSY;
 
@@ -4830,6 +4854,83 @@ static void *intel_iommu_hw_info(struct device *dev, u32 *length, u32 *type)
 	return vtd;
 }
 
+static int intel_iommu_set_dirty_tracking(struct iommu_domain *domain,
+					  bool enable)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct device_domain_info *info;
+	int ret;
+
+	spin_lock(&dmar_domain->lock);
+	if (dmar_domain->dirty_tracking == enable)
+		goto out_unlock;
+
+	list_for_each_entry(info, &dmar_domain->devices, link) {
+		ret = intel_pasid_setup_dirty_tracking(info->iommu,
+						       info->domain, info->dev,
+						       IOMMU_NO_PASID, enable);
+		if (ret)
+			goto err_unwind;
+	}
+
+	dmar_domain->dirty_tracking = enable;
+out_unlock:
+	spin_unlock(&dmar_domain->lock);
+
+	return 0;
+
+err_unwind:
+	list_for_each_entry(info, &dmar_domain->devices, link)
+		intel_pasid_setup_dirty_tracking(info->iommu, dmar_domain,
+						 info->dev, IOMMU_NO_PASID,
+						 dmar_domain->dirty_tracking);
+	spin_unlock(&dmar_domain->lock);
+	return ret;
+}
+
+static int intel_iommu_read_and_clear_dirty(struct iommu_domain *domain,
+					    unsigned long iova, size_t size,
+					    unsigned long flags,
+					    struct iommu_dirty_bitmap *dirty)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	unsigned long end = iova + size - 1;
+	unsigned long pgsize;
+
+	/*
+	 * IOMMUFD core calls into a dirty tracking disabled domain without an
+	 * IOVA bitmap set in order to clean dirty bits in all PTEs that might
+	 * have occurred when we stopped dirty tracking. This ensures that we
+	 * never inherit dirtied bits from a previous cycle.
+	 */
+	if (!dmar_domain->dirty_tracking && dirty->bitmap)
+		return -EINVAL;
+
+	do {
+		struct dma_pte *pte;
+		int lvl = 0;
+
+		pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &lvl,
+				     GFP_ATOMIC);
+		pgsize = level_size(lvl) << VTD_PAGE_SHIFT;
+		if (!pte || !dma_pte_present(pte)) {
+			iova += pgsize;
+			continue;
+		}
+
+		if (dma_sl_pte_test_and_clear_dirty(pte, flags))
+			iommu_dirty_bitmap_record(dirty, iova, pgsize);
+		iova += pgsize;
+	} while (iova < end);
+
+	return 0;
+}
+
+const struct iommu_dirty_ops intel_dirty_ops = {
+	.set_dirty_tracking = intel_iommu_set_dirty_tracking,
+	.read_and_clear_dirty = intel_iommu_read_and_clear_dirty,
+};
+
 const struct iommu_ops intel_iommu_ops = {
 	.capable		= intel_iommu_capable,
 	.hw_info		= intel_iommu_hw_info,
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index c18fb699c87a..3bb569146229 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -48,6 +48,9 @@
 #define DMA_FL_PTE_DIRTY	BIT_ULL(6)
 #define DMA_FL_PTE_XD		BIT_ULL(63)
 
+#define DMA_SL_PTE_DIRTY_BIT	9
+#define DMA_SL_PTE_DIRTY	BIT_ULL(DMA_SL_PTE_DIRTY_BIT)
+
 #define ADDR_WIDTH_5LEVEL	(57)
 #define ADDR_WIDTH_4LEVEL	(48)
 
@@ -539,6 +542,8 @@ enum {
 #define sm_supported(iommu)	(intel_iommu_sm && ecap_smts((iommu)->ecap))
 #define pasid_supported(iommu)	(sm_supported(iommu) &&			\
 				 ecap_pasid((iommu)->ecap))
+#define ssads_supported(iommu) (sm_supported(iommu) &&                 \
+				ecap_slads((iommu)->ecap))
 
 struct pasid_entry;
 struct pasid_state_entry;
@@ -592,6 +597,7 @@ struct dmar_domain {
 					 * otherwise, goes through the second
 					 * level.
 					 */
+	u8 dirty_tracking:1;		/* Dirty tracking is enabled */
 
 	spinlock_t lock;		/* Protect device tracking lists */
 	struct list_head devices;	/* all devices' list */
@@ -781,6 +787,16 @@ static inline bool dma_pte_present(struct dma_pte *pte)
 	return (pte->val & 3) != 0;
 }
 
+static inline bool dma_sl_pte_test_and_clear_dirty(struct dma_pte *pte,
+						   unsigned long flags)
+{
+	if (flags & IOMMU_DIRTY_NO_CLEAR)
+		return (pte->val & DMA_SL_PTE_DIRTY) != 0;
+
+	return test_and_clear_bit(DMA_SL_PTE_DIRTY_BIT,
+				  (unsigned long *)&pte->val);
+}
+
 static inline bool dma_pte_superpage(struct dma_pte *pte)
 {
 	return (pte->val & DMA_PTE_LARGE_PAGE);
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 8f92b92f3d2a..b9264b9174e8 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -277,6 +277,11 @@ static inline void pasid_set_bits(u64 *ptr, u64 mask, u64 bits)
 	WRITE_ONCE(*ptr, (old & ~mask) | bits);
 }
 
+static inline u64 pasid_get_bits(u64 *ptr)
+{
+	return READ_ONCE(*ptr);
+}
+
 /*
  * Setup the DID(Domain Identifier) field (Bit 64~79) of scalable mode
  * PASID entry.
@@ -335,6 +340,36 @@ static inline void pasid_set_fault_enable(struct pasid_entry *pe)
 	pasid_set_bits(&pe->val[0], 1 << 1, 0);
 }
 
+/*
+ * Enable second level A/D bits by setting the SLADE (Second Level
+ * Access Dirty Enable) field (Bit 9) of a scalable mode PASID
+ * entry.
+ */
+static inline void pasid_set_ssade(struct pasid_entry *pe)
+{
+	pasid_set_bits(&pe->val[0], 1 << 9, 1 << 9);
+}
+
+/*
+ * Disable second level A/D bits by clearing the SLADE (Second Level
+ * Access Dirty Enable) field (Bit 9) of a scalable mode PASID
+ * entry.
+ */
+static inline void pasid_clear_ssade(struct pasid_entry *pe)
+{
+	pasid_set_bits(&pe->val[0], 1 << 9, 0);
+}
+
+/*
+ * Checks if second level A/D bits specifically the SLADE (Second Level
+ * Access Dirty Enable) field (Bit 9) of a scalable mode PASID
+ * entry is set.
+ */
+static inline bool pasid_get_ssade(struct pasid_entry *pe)
+{
+	return pasid_get_bits(&pe->val[0]) & (1 << 9);
+}
+
 /*
  * Setup the WPE(Write Protect Enable) field (Bit 132) of a
  * scalable mode PASID entry.
@@ -627,6 +662,8 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
 	pasid_set_translation_type(pte, PASID_ENTRY_PGTT_SL_ONLY);
 	pasid_set_fault_enable(pte);
 	pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
+	if (domain->dirty_tracking)
+		pasid_set_ssade(pte);
 
 	pasid_set_present(pte);
 	spin_unlock(&iommu->lock);
@@ -636,6 +673,78 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
 	return 0;
 }
 
+/*
+ * Set up dirty tracking on a second only or nested translation type.
+ */
+int intel_pasid_setup_dirty_tracking(struct intel_iommu *iommu,
+				     struct dmar_domain *domain,
+				     struct device *dev, u32 pasid,
+				     bool enabled)
+{
+	struct pasid_entry *pte;
+	u16 did, pgtt;
+
+	spin_lock(&iommu->lock);
+
+	pte = intel_pasid_get_entry(dev, pasid);
+	if (!pte) {
+		spin_unlock(&iommu->lock);
+		dev_err_ratelimited(
+			dev, "Failed to get pasid entry of PASID %d\n", pasid);
+		return -ENODEV;
+	}
+
+	did = domain_id_iommu(domain, iommu);
+	pgtt = pasid_pte_get_pgtt(pte);
+	if (pgtt != PASID_ENTRY_PGTT_SL_ONLY &&
+	    pgtt != PASID_ENTRY_PGTT_NESTED) {
+		spin_unlock(&iommu->lock);
+		dev_err_ratelimited(
+			dev,
+			"Dirty tracking not supported on translation type %d\n",
+			pgtt);
+		return -EOPNOTSUPP;
+	}
+
+	if (pasid_get_ssade(pte) == enabled) {
+		spin_unlock(&iommu->lock);
+		return 0;
+	}
+
+	if (enabled)
+		pasid_set_ssade(pte);
+	else
+		pasid_clear_ssade(pte);
+	spin_unlock(&iommu->lock);
+
+	if (!ecap_coherent(iommu->ecap))
+		clflush_cache_range(pte, sizeof(*pte));
+
+	/*
+	 * From VT-d spec table 25 "Guidance to Software for Invalidations":
+	 *
+	 * - PASID-selective-within-Domain PASID-cache invalidation
+	 *   If (PGTT=SS or Nested)
+	 *    - Domain-selective IOTLB invalidation
+	 *   Else
+	 *    - PASID-selective PASID-based IOTLB invalidation
+	 * - If (pasid is RID_PASID)
+	 *    - Global Device-TLB invalidation to affected functions
+	 *   Else
+	 *    - PASID-based Device-TLB invalidation (with S=1 and
+	 *      Addr[63:12]=0x7FFFFFFF_FFFFF) to affected functions
+	 */
+	pasid_cache_invalidation_with_pasid(iommu, did, pasid);
+
+	iommu->flush.flush_iotlb(iommu, did, 0, 0, DMA_TLB_DSI_FLUSH);
+
+	/* Device IOTLB doesn't need to be flushed in caching mode. */
+	if (!cap_caching_mode(iommu->cap))
+		devtlb_invalidation_with_pasid(iommu, dev, pasid);
+
+	return 0;
+}
+
 /*
  * Set up the scalable mode pasid entry for passthrough translation type.
  */
diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h
index 4e9e68c3c388..958050b093aa 100644
--- a/drivers/iommu/intel/pasid.h
+++ b/drivers/iommu/intel/pasid.h
@@ -106,6 +106,10 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
 int intel_pasid_setup_second_level(struct intel_iommu *iommu,
 				   struct dmar_domain *domain,
 				   struct device *dev, u32 pasid);
+int intel_pasid_setup_dirty_tracking(struct intel_iommu *iommu,
+				     struct dmar_domain *domain,
+				     struct device *dev, u32 pasid,
+				     bool enabled);
 int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
 				   struct dmar_domain *domain,
 				   struct device *dev, u32 pasid);
-- 
2.17.2

[PATCH v6 13/18] iommufd/selftest: Expand mock_domain with dev_flags

[Joao Martins]

Expand mock_domain test to be able to manipulate the device capabilities.
This allows testing with mockdev without dirty tracking support advertised
and thus make sure enforce_dirty test does the expected.

To avoid breaking IOMMUFD_TEST UABI replicate the mock_domain struct and
thus add an input dev_flags at the end.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/iommu/iommufd/iommufd_test.h          | 12 ++++++++
 drivers/iommu/iommufd/selftest.c              | 11 +++++--
 tools/testing/selftests/iommu/iommufd_utils.h | 29 +++++++++++++++++++
 3 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/iommufd/iommufd_test.h b/drivers/iommu/iommufd/iommufd_test.h
index 3f3644375bf1..9817edcd8968 100644
--- a/drivers/iommu/iommufd/iommufd_test.h
+++ b/drivers/iommu/iommufd/iommufd_test.h
@@ -19,6 +19,7 @@ enum {
 	IOMMU_TEST_OP_SET_TEMP_MEMORY_LIMIT,
 	IOMMU_TEST_OP_MOCK_DOMAIN_REPLACE,
 	IOMMU_TEST_OP_ACCESS_REPLACE_IOAS,
+	IOMMU_TEST_OP_MOCK_DOMAIN_FLAGS,
 };
 
 enum {
@@ -40,6 +41,10 @@ enum {
 	MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES = 1 << 0,
 };
 
+enum {
+	MOCK_FLAGS_DEVICE_NO_DIRTY = 1 << 0,
+};
+
 struct iommu_test_cmd {
 	__u32 size;
 	__u32 op;
@@ -56,6 +61,13 @@ struct iommu_test_cmd {
 			/* out_idev_id is the standard iommufd_bind object */
 			__u32 out_idev_id;
 		} mock_domain;
+		struct {
+			__u32 out_stdev_id;
+			__u32 out_hwpt_id;
+			__u32 out_idev_id;
+			/* Expand mock_domain to set mock device flags */
+			__u32 dev_flags;
+		} mock_domain_flags;
 		struct {
 			__u32 pt_id;
 		} mock_domain_replace;
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index fe7e3c7d933a..bd3704b28bfb 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -96,6 +96,7 @@ enum selftest_obj_type {
 
 struct mock_dev {
 	struct device dev;
+	unsigned long flags;
 };
 
 struct selftest_obj {
@@ -381,7 +382,7 @@ static void mock_dev_release(struct device *dev)
 	kfree(mdev);
 }
 
-static struct mock_dev *mock_dev_create(void)
+static struct mock_dev *mock_dev_create(unsigned long dev_flags)
 {
 	struct mock_dev *mdev;
 	int rc;
@@ -391,6 +392,7 @@ static struct mock_dev *mock_dev_create(void)
 		return ERR_PTR(-ENOMEM);
 
 	device_initialize(&mdev->dev);
+	mdev->flags = dev_flags;
 	mdev->dev.release = mock_dev_release;
 	mdev->dev.bus = &iommufd_mock_bus_type.bus;
 
@@ -426,6 +428,7 @@ static int iommufd_test_mock_domain(struct iommufd_ucmd *ucmd,
 	struct iommufd_device *idev;
 	struct selftest_obj *sobj;
 	u32 pt_id = cmd->id;
+	u32 dev_flags = 0;
 	u32 idev_id;
 	int rc;
 
@@ -436,7 +439,10 @@ static int iommufd_test_mock_domain(struct iommufd_ucmd *ucmd,
 	sobj->idev.ictx = ucmd->ictx;
 	sobj->type = TYPE_IDEV;
 
-	sobj->idev.mock_dev = mock_dev_create();
+	if (cmd->op == IOMMU_TEST_OP_MOCK_DOMAIN_FLAGS)
+		dev_flags = cmd->mock_domain_flags.dev_flags;
+
+	sobj->idev.mock_dev = mock_dev_create(dev_flags);
 	if (IS_ERR(sobj->idev.mock_dev)) {
 		rc = PTR_ERR(sobj->idev.mock_dev);
 		goto out_sobj;
@@ -1019,6 +1025,7 @@ int iommufd_test(struct iommufd_ucmd *ucmd)
 						 cmd->add_reserved.start,
 						 cmd->add_reserved.length);
 	case IOMMU_TEST_OP_MOCK_DOMAIN:
+	case IOMMU_TEST_OP_MOCK_DOMAIN_FLAGS:
 		return iommufd_test_mock_domain(ucmd, cmd);
 	case IOMMU_TEST_OP_MOCK_DOMAIN_REPLACE:
 		return iommufd_test_mock_domain_replace(
diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
index be4970a84977..1e0736adc991 100644
--- a/tools/testing/selftests/iommu/iommufd_utils.h
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -74,6 +74,35 @@ static int _test_cmd_mock_domain(int fd, unsigned int ioas_id, __u32 *stdev_id,
 	EXPECT_ERRNO(_errno, _test_cmd_mock_domain(self->fd, ioas_id, \
 						   stdev_id, hwpt_id, NULL))
 
+static int _test_cmd_mock_domain_flags(int fd, unsigned int ioas_id,
+				       __u32 stdev_flags, __u32 *stdev_id,
+				       __u32 *hwpt_id, __u32 *idev_id)
+{
+	struct iommu_test_cmd cmd = {
+		.size = sizeof(cmd),
+		.op = IOMMU_TEST_OP_MOCK_DOMAIN_FLAGS,
+		.id = ioas_id,
+		.mock_domain_flags = { .dev_flags = stdev_flags },
+	};
+	int ret;
+
+	ret = ioctl(fd, IOMMU_TEST_CMD, &cmd);
+	if (ret)
+		return ret;
+	if (stdev_id)
+		*stdev_id = cmd.mock_domain_flags.out_stdev_id;
+	assert(cmd.id != 0);
+	if (hwpt_id)
+		*hwpt_id = cmd.mock_domain_flags.out_hwpt_id;
+	if (idev_id)
+		*idev_id = cmd.mock_domain_flags.out_idev_id;
+	return 0;
+}
+#define test_err_mock_domain_flags(_errno, ioas_id, flags, stdev_id, hwpt_id) \
+	EXPECT_ERRNO(_errno,                                                  \
+		     _test_cmd_mock_domain_flags(self->fd, ioas_id, flags,    \
+						 stdev_id, hwpt_id, NULL))
+
 static int _test_cmd_mock_domain_replace(int fd, __u32 stdev_id, __u32 pt_id,
 					 __u32 *hwpt_id)
 {
-- 
2.17.2

[PATCH v6 14/18] iommufd/selftest: Test IOMMU_HWPT_ALLOC_DIRTY_TRACKING

[Joao Martins]

In order to selftest the iommu domain dirty enforcing implement the
mock_domain necessary support and add a new dev_flags to test that the
hwpt_alloc/attach_device fails as expected.

Expand the existing mock_domain fixture with a enforce_dirty test that
exercises the hwpt_alloc and device attachment.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/iommu/iommufd/selftest.c              | 37 +++++++++++++-
 tools/testing/selftests/iommu/iommufd.c       | 49 +++++++++++++++++++
 tools/testing/selftests/iommu/iommufd_utils.h |  3 ++
 3 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index bd3704b28bfb..78362f2334f5 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -119,6 +119,11 @@ static void mock_domain_blocking_free(struct iommu_domain *domain)
 static int mock_domain_nop_attach(struct iommu_domain *domain,
 				  struct device *dev)
 {
+	struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
+
+	if (domain->dirty_ops && (mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY))
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -147,6 +152,25 @@ static void *mock_domain_hw_info(struct device *dev, u32 *length, u32 *type)
 	return info;
 }
 
+static int mock_domain_set_dirty_tracking(struct iommu_domain *domain,
+					  bool enable)
+{
+	return 0;
+}
+
+static int mock_domain_read_and_clear_dirty(struct iommu_domain *domain,
+					    unsigned long iova, size_t size,
+					    unsigned long flags,
+					    struct iommu_dirty_bitmap *dirty)
+{
+	return 0;
+}
+
+const struct iommu_dirty_ops dirty_ops = {
+	.set_dirty_tracking = mock_domain_set_dirty_tracking,
+	.read_and_clear_dirty = mock_domain_read_and_clear_dirty,
+};
+
 static const struct iommu_ops mock_ops;
 
 static struct iommu_domain *mock_domain_alloc(unsigned int iommu_domain_type)
@@ -174,12 +198,20 @@ static struct iommu_domain *mock_domain_alloc(unsigned int iommu_domain_type)
 static struct iommu_domain *
 mock_domain_alloc_user(struct device *dev, u32 flags)
 {
+	struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
 	struct iommu_domain *domain;
 
-	if (flags & (~IOMMU_HWPT_ALLOC_NEST_PARENT))
+	if (flags &
+	    (~(IOMMU_HWPT_ALLOC_NEST_PARENT | IOMMU_HWPT_ALLOC_DIRTY_TRACKING)))
+		return ERR_PTR(-EOPNOTSUPP);
+
+	if ((flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING) &&
+	    (mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY))
 		return ERR_PTR(-EOPNOTSUPP);
 
 	domain = mock_domain_alloc(IOMMU_DOMAIN_UNMANAGED);
+	if (domain && !(mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY))
+		domain->dirty_ops = &dirty_ops;
 	if (!domain)
 		domain = ERR_PTR(-ENOMEM);
 	return domain;
@@ -387,6 +419,9 @@ static struct mock_dev *mock_dev_create(unsigned long dev_flags)
 	struct mock_dev *mdev;
 	int rc;
 
+	if (dev_flags & ~(MOCK_FLAGS_DEVICE_NO_DIRTY))
+		return ERR_PTR(-EINVAL);
+
 	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
 	if (!mdev)
 		return ERR_PTR(-ENOMEM);
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index 6323153d277b..6bebba183426 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -1433,6 +1433,55 @@ TEST_F(iommufd_mock_domain, alloc_hwpt)
 	}
 }
 
+FIXTURE(iommufd_dirty_tracking)
+{
+	int fd;
+	uint32_t ioas_id;
+	uint32_t hwpt_id;
+	uint32_t stdev_id;
+	uint32_t idev_id;
+};
+
+FIXTURE_SETUP(iommufd_dirty_tracking)
+{
+	self->fd = open("/dev/iommu", O_RDWR);
+	ASSERT_NE(-1, self->fd);
+
+	test_ioctl_ioas_alloc(&self->ioas_id);
+	test_cmd_mock_domain(self->ioas_id, &self->stdev_id, &self->hwpt_id,
+			     &self->idev_id);
+}
+
+FIXTURE_TEARDOWN(iommufd_dirty_tracking)
+{
+	teardown_iommufd(self->fd, _metadata);
+}
+
+TEST_F(iommufd_dirty_tracking, enforce_dirty)
+{
+	uint32_t ioas_id, stddev_id, idev_id;
+	uint32_t hwpt_id, _hwpt_id;
+	uint32_t dev_flags;
+
+	/* Regular case */
+	dev_flags = MOCK_FLAGS_DEVICE_NO_DIRTY;
+	test_cmd_hwpt_alloc(self->idev_id, self->ioas_id,
+			    IOMMU_HWPT_ALLOC_DIRTY_TRACKING, &hwpt_id);
+	test_cmd_mock_domain(hwpt_id, &stddev_id, NULL, NULL);
+	test_err_mock_domain_flags(EINVAL, hwpt_id, dev_flags, &stddev_id,
+				   NULL);
+	test_ioctl_destroy(stddev_id);
+	test_ioctl_destroy(hwpt_id);
+
+	/* IOMMU device does not support dirty tracking */
+	test_ioctl_ioas_alloc(&ioas_id);
+	test_cmd_mock_domain_flags(ioas_id, dev_flags, &stddev_id, &_hwpt_id,
+				   &idev_id);
+	test_err_hwpt_alloc(EOPNOTSUPP, idev_id, ioas_id,
+			    IOMMU_HWPT_ALLOC_DIRTY_TRACKING, &hwpt_id);
+	test_ioctl_destroy(stddev_id);
+}
+
 /* VFIO compatibility IOCTLs */
 
 TEST_F(iommufd, simple_ioctls)
diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
index 1e0736adc991..4ddafa29e638 100644
--- a/tools/testing/selftests/iommu/iommufd_utils.h
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -98,6 +98,9 @@ static int _test_cmd_mock_domain_flags(int fd, unsigned int ioas_id,
 		*idev_id = cmd.mock_domain_flags.out_idev_id;
 	return 0;
 }
+#define test_cmd_mock_domain_flags(ioas_id, flags, stdev_id, hwpt_id, idev_id) \
+	ASSERT_EQ(0, _test_cmd_mock_domain_flags(self->fd, ioas_id, flags,     \
+						 stdev_id, hwpt_id, idev_id))
 #define test_err_mock_domain_flags(_errno, ioas_id, flags, stdev_id, hwpt_id) \
 	EXPECT_ERRNO(_errno,                                                  \
 		     _test_cmd_mock_domain_flags(self->fd, ioas_id, flags,    \
-- 
2.17.2

[PATCH v6 15/18] iommufd/selftest: Test IOMMU_HWPT_SET_DIRTY_TRACKING

[Joao Martins]

Change mock_domain to supporting dirty tracking and add tests to exercise
the new SET_DIRTY_TRACKING API in the iommufd_dirty_tracking selftest
fixture.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/iommu/iommufd/selftest.c              | 16 ++++++++++++++++
 tools/testing/selftests/iommu/iommufd.c       | 15 +++++++++++++++
 tools/testing/selftests/iommu/iommufd_utils.h | 17 +++++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 78362f2334f5..2773275566af 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -24,6 +24,7 @@ static struct platform_device *selftest_iommu_dev;
 size_t iommufd_test_memory_limit = 65536;
 
 enum {
+	MOCK_DIRTY_TRACK = 1,
 	MOCK_IO_PAGE_SIZE = PAGE_SIZE / 2,
 
 	/*
@@ -86,6 +87,7 @@ void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd,
 }
 
 struct mock_iommu_domain {
+	unsigned long flags;
 	struct iommu_domain domain;
 	struct xarray pfns;
 };
@@ -155,6 +157,20 @@ static void *mock_domain_hw_info(struct device *dev, u32 *length, u32 *type)
 static int mock_domain_set_dirty_tracking(struct iommu_domain *domain,
 					  bool enable)
 {
+	struct mock_iommu_domain *mock =
+		container_of(domain, struct mock_iommu_domain, domain);
+	unsigned long flags = mock->flags;
+
+	if (enable && !domain->dirty_ops)
+		return -EINVAL;
+
+	/* No change? */
+	if (!(enable ^ !!(flags & MOCK_DIRTY_TRACK)))
+		return 0;
+
+	flags = (enable ? flags | MOCK_DIRTY_TRACK : flags & ~MOCK_DIRTY_TRACK);
+
+	mock->flags = flags;
 	return 0;
 }
 
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index 6bebba183426..8c46012006e1 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -1482,6 +1482,21 @@ TEST_F(iommufd_dirty_tracking, enforce_dirty)
 	test_ioctl_destroy(stddev_id);
 }
 
+TEST_F(iommufd_dirty_tracking, set_dirty_tracking)
+{
+	uint32_t stddev_id;
+	uint32_t hwpt_id;
+
+	test_cmd_hwpt_alloc(self->idev_id, self->ioas_id,
+			    IOMMU_HWPT_ALLOC_DIRTY_TRACKING, &hwpt_id);
+	test_cmd_mock_domain(hwpt_id, &stddev_id, NULL, NULL);
+	test_cmd_set_dirty_tracking(hwpt_id, true);
+	test_cmd_set_dirty_tracking(hwpt_id, false);
+
+	test_ioctl_destroy(stddev_id);
+	test_ioctl_destroy(hwpt_id);
+}
+
 /* VFIO compatibility IOCTLs */
 
 TEST_F(iommufd, simple_ioctls)
diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
index 4ddafa29e638..e37af6291b22 100644
--- a/tools/testing/selftests/iommu/iommufd_utils.h
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -179,6 +179,23 @@ static int _test_cmd_access_replace_ioas(int fd, __u32 access_id,
 #define test_cmd_access_replace_ioas(access_id, ioas_id) \
 	ASSERT_EQ(0, _test_cmd_access_replace_ioas(self->fd, access_id, ioas_id))
 
+static int _test_cmd_set_dirty_tracking(int fd, __u32 hwpt_id, bool enabled)
+{
+	struct iommu_hwpt_set_dirty_tracking cmd = {
+		.size = sizeof(cmd),
+		.flags = enabled ? IOMMU_HWPT_DIRTY_TRACKING_ENABLE : 0,
+		.hwpt_id = hwpt_id,
+	};
+	int ret;
+
+	ret = ioctl(fd, IOMMU_HWPT_SET_DIRTY_TRACKING, &cmd);
+	if (ret)
+		return -errno;
+	return 0;
+}
+#define test_cmd_set_dirty_tracking(hwpt_id, enabled) \
+	ASSERT_EQ(0, _test_cmd_set_dirty_tracking(self->fd, hwpt_id, enabled))
+
 static int _test_cmd_create_access(int fd, unsigned int ioas_id,
 				   __u32 *access_id, unsigned int flags)
 {
-- 
2.17.2

[PATCH v6 16/18] iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP

[Joao Martins]

Add a new test ioctl for simulating the dirty IOVAs in the mock domain, and
implement the mock iommu domain ops that get the dirty tracking supported.

The selftest exercises the usual main workflow of:

1) Setting dirty tracking from the iommu domain
2) Read and clear dirty IOPTEs

Different fixtures will test different IOVA range sizes, that exercise
corner cases of the bitmaps.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 drivers/iommu/iommufd/iommufd_test.h          |   9 ++
 drivers/iommu/iommufd/selftest.c              | 107 ++++++++++++++-
 tools/testing/selftests/iommu/iommufd.c       |  96 +++++++++++++
 tools/testing/selftests/iommu/iommufd_utils.h | 127 ++++++++++++++++++
 4 files changed, 334 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/iommufd/iommufd_test.h b/drivers/iommu/iommufd/iommufd_test.h
index 9817edcd8968..1f2e93d3d4e8 100644
--- a/drivers/iommu/iommufd/iommufd_test.h
+++ b/drivers/iommu/iommufd/iommufd_test.h
@@ -20,6 +20,7 @@ enum {
 	IOMMU_TEST_OP_MOCK_DOMAIN_REPLACE,
 	IOMMU_TEST_OP_ACCESS_REPLACE_IOAS,
 	IOMMU_TEST_OP_MOCK_DOMAIN_FLAGS,
+	IOMMU_TEST_OP_DIRTY,
 };
 
 enum {
@@ -107,6 +108,14 @@ struct iommu_test_cmd {
 		struct {
 			__u32 ioas_id;
 		} access_replace_ioas;
+		struct {
+			__u32 flags;
+			__aligned_u64 iova;
+			__aligned_u64 length;
+			__aligned_u64 page_size;
+			__aligned_u64 uptr;
+			__aligned_u64 out_nr_dirty;
+		} dirty;
 	};
 	__u32 last;
 };
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 2773275566af..4eb86025dde9 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -37,6 +37,7 @@ enum {
 	_MOCK_PFN_START = MOCK_PFN_MASK + 1,
 	MOCK_PFN_START_IOVA = _MOCK_PFN_START,
 	MOCK_PFN_LAST_IOVA = _MOCK_PFN_START,
+	MOCK_PFN_DIRTY_IOVA = _MOCK_PFN_START << 1,
 };
 
 /*
@@ -179,6 +180,31 @@ static int mock_domain_read_and_clear_dirty(struct iommu_domain *domain,
 					    unsigned long flags,
 					    struct iommu_dirty_bitmap *dirty)
 {
+	struct mock_iommu_domain *mock =
+		container_of(domain, struct mock_iommu_domain, domain);
+	unsigned long i, max = size / MOCK_IO_PAGE_SIZE;
+	void *ent, *old;
+
+	if (!(mock->flags & MOCK_DIRTY_TRACK) && dirty->bitmap)
+		return -EINVAL;
+
+	for (i = 0; i < max; i++) {
+		unsigned long cur = iova + i * MOCK_IO_PAGE_SIZE;
+
+		ent = xa_load(&mock->pfns, cur / MOCK_IO_PAGE_SIZE);
+		if (ent && (xa_to_value(ent) & MOCK_PFN_DIRTY_IOVA)) {
+			unsigned long val;
+
+			/* Clear dirty */
+			val = xa_to_value(ent) & ~MOCK_PFN_DIRTY_IOVA;
+			old = xa_store(&mock->pfns, cur / MOCK_IO_PAGE_SIZE,
+				       xa_mk_value(val), GFP_KERNEL);
+			WARN_ON_ONCE(ent != old);
+			iommu_dirty_bitmap_record(dirty, cur,
+						  MOCK_IO_PAGE_SIZE);
+		}
+	}
+
 	return 0;
 }
 
@@ -310,7 +336,7 @@ static size_t mock_domain_unmap_pages(struct iommu_domain *domain,
 
 		for (cur = 0; cur != pgsize; cur += MOCK_IO_PAGE_SIZE) {
 			ent = xa_erase(&mock->pfns, iova / MOCK_IO_PAGE_SIZE);
-			WARN_ON(!ent);
+
 			/*
 			 * iommufd generates unmaps that must be a strict
 			 * superset of the map's performend So every starting
@@ -320,13 +346,13 @@ static size_t mock_domain_unmap_pages(struct iommu_domain *domain,
 			 * passed to map_pages
 			 */
 			if (first) {
-				WARN_ON(!(xa_to_value(ent) &
-					  MOCK_PFN_START_IOVA));
+				WARN_ON(ent && !(xa_to_value(ent) &
+						 MOCK_PFN_START_IOVA));
 				first = false;
 			}
 			if (pgcount == 1 && cur + MOCK_IO_PAGE_SIZE == pgsize)
-				WARN_ON(!(xa_to_value(ent) &
-					  MOCK_PFN_LAST_IOVA));
+				WARN_ON(ent && !(xa_to_value(ent) &
+						 MOCK_PFN_LAST_IOVA));
 
 			iova += MOCK_IO_PAGE_SIZE;
 			ret += MOCK_IO_PAGE_SIZE;
@@ -1053,6 +1079,71 @@ static_assert((unsigned int)MOCK_ACCESS_RW_WRITE == IOMMUFD_ACCESS_RW_WRITE);
 static_assert((unsigned int)MOCK_ACCESS_RW_SLOW_PATH ==
 	      __IOMMUFD_ACCESS_RW_SLOW_PATH);
 
+static int iommufd_test_dirty(struct iommufd_ucmd *ucmd, unsigned int mockpt_id,
+			      unsigned long iova, size_t length,
+			      unsigned long page_size, void __user *uptr,
+			      u32 flags)
+{
+	unsigned long bitmap_size, i, max = length / page_size;
+	struct iommu_test_cmd *cmd = ucmd->cmd;
+	struct iommufd_hw_pagetable *hwpt;
+	struct mock_iommu_domain *mock;
+	int rc, count = 0;
+	void *tmp;
+
+	if (iova % page_size || length % page_size || !uptr)
+		return -EINVAL;
+
+	hwpt = get_md_pagetable(ucmd, mockpt_id, &mock);
+	if (IS_ERR(hwpt))
+		return PTR_ERR(hwpt);
+
+	if (!(mock->flags & MOCK_DIRTY_TRACK)) {
+		rc = -EINVAL;
+		goto out_put;
+	}
+
+	bitmap_size = max / BITS_PER_BYTE;
+
+	tmp = kvzalloc(bitmap_size, GFP_KERNEL_ACCOUNT);
+	if (!tmp) {
+		rc = -ENOMEM;
+		goto out_put;
+	}
+
+	if (copy_from_user(tmp, uptr, bitmap_size)) {
+		rc = -EFAULT;
+		goto out_free;
+	}
+
+	for (i = 0; i < max; i++) {
+		unsigned long cur = iova + i * page_size;
+		void *ent, *old;
+
+		if (!test_bit(i, (unsigned long *)tmp))
+			continue;
+
+		ent = xa_load(&mock->pfns, cur / page_size);
+		if (ent) {
+			unsigned long val;
+
+			val = xa_to_value(ent) | MOCK_PFN_DIRTY_IOVA;
+			old = xa_store(&mock->pfns, cur / page_size,
+				       xa_mk_value(val), GFP_KERNEL);
+			WARN_ON_ONCE(ent != old);
+			count++;
+		}
+	}
+
+	cmd->dirty.out_nr_dirty = count;
+	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
+out_free:
+	kvfree(tmp);
+out_put:
+	iommufd_put_object(&hwpt->obj);
+	return rc;
+}
+
 void iommufd_selftest_destroy(struct iommufd_object *obj)
 {
 	struct selftest_obj *sobj = container_of(obj, struct selftest_obj, obj);
@@ -1118,6 +1209,12 @@ int iommufd_test(struct iommufd_ucmd *ucmd)
 			return -EINVAL;
 		iommufd_test_memory_limit = cmd->memory_limit.limit;
 		return 0;
+	case IOMMU_TEST_OP_DIRTY:
+		return iommufd_test_dirty(ucmd, cmd->id, cmd->dirty.iova,
+					  cmd->dirty.length,
+					  cmd->dirty.page_size,
+					  u64_to_user_ptr(cmd->dirty.uptr),
+					  cmd->dirty.flags);
 	default:
 		return -EOPNOTSUPP;
 	}
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index 8c46012006e1..891250acf47e 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -1440,13 +1440,47 @@ FIXTURE(iommufd_dirty_tracking)
 	uint32_t hwpt_id;
 	uint32_t stdev_id;
 	uint32_t idev_id;
+	unsigned long page_size;
+	unsigned long bitmap_size;
+	void *bitmap;
+	void *buffer;
+};
+
+FIXTURE_VARIANT(iommufd_dirty_tracking)
+{
+	unsigned long buffer_size;
 };
 
 FIXTURE_SETUP(iommufd_dirty_tracking)
 {
+	void *vrc;
+	int rc;
+
 	self->fd = open("/dev/iommu", O_RDWR);
 	ASSERT_NE(-1, self->fd);
 
+	rc = posix_memalign(&self->buffer, HUGEPAGE_SIZE, variant->buffer_size);
+	if (rc || !self->buffer) {
+		SKIP(return, "Skipping buffer_size=%lu due to errno=%d",
+			   variant->buffer_size, rc);
+	}
+
+	assert((uintptr_t)self->buffer % HUGEPAGE_SIZE == 0);
+	vrc = mmap(self->buffer, variant->buffer_size, PROT_READ | PROT_WRITE,
+		   MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+	assert(vrc == self->buffer);
+
+	self->page_size = MOCK_PAGE_SIZE;
+	self->bitmap_size =
+		variant->buffer_size / self->page_size / BITS_PER_BYTE;
+
+	/* Provision with an extra (MOCK_PAGE_SIZE) for the unaligned case */
+	rc = posix_memalign(&self->bitmap, PAGE_SIZE,
+			    self->bitmap_size + MOCK_PAGE_SIZE);
+	assert(!rc);
+	assert(self->bitmap);
+	assert((uintptr_t)self->bitmap % PAGE_SIZE == 0);
+
 	test_ioctl_ioas_alloc(&self->ioas_id);
 	test_cmd_mock_domain(self->ioas_id, &self->stdev_id, &self->hwpt_id,
 			     &self->idev_id);
@@ -1454,9 +1488,41 @@ FIXTURE_SETUP(iommufd_dirty_tracking)
 
 FIXTURE_TEARDOWN(iommufd_dirty_tracking)
 {
+	munmap(self->buffer, variant->buffer_size);
+	munmap(self->bitmap, self->bitmap_size);
 	teardown_iommufd(self->fd, _metadata);
 }
 
+FIXTURE_VARIANT_ADD(iommufd_dirty_tracking, domain_dirty128k)
+{
+	/* one u32 index bitmap */
+	.buffer_size = 128UL * 1024UL,
+};
+
+FIXTURE_VARIANT_ADD(iommufd_dirty_tracking, domain_dirty256k)
+{
+	/* one u64 index bitmap */
+	.buffer_size = 256UL * 1024UL,
+};
+
+FIXTURE_VARIANT_ADD(iommufd_dirty_tracking, domain_dirty640k)
+{
+	/* two u64 index and trailing end bitmap */
+	.buffer_size = 640UL * 1024UL,
+};
+
+FIXTURE_VARIANT_ADD(iommufd_dirty_tracking, domain_dirty128M)
+{
+	/* 4K bitmap (128M IOVA range) */
+	.buffer_size = 128UL * 1024UL * 1024UL,
+};
+
+FIXTURE_VARIANT_ADD(iommufd_dirty_tracking, domain_dirty256M)
+{
+	/* 8K bitmap (256M IOVA range) */
+	.buffer_size = 256UL * 1024UL * 1024UL,
+};
+
 TEST_F(iommufd_dirty_tracking, enforce_dirty)
 {
 	uint32_t ioas_id, stddev_id, idev_id;
@@ -1497,6 +1563,36 @@ TEST_F(iommufd_dirty_tracking, set_dirty_tracking)
 	test_ioctl_destroy(hwpt_id);
 }
 
+TEST_F(iommufd_dirty_tracking, get_dirty_bitmap)
+{
+	uint32_t stddev_id;
+	uint32_t hwpt_id;
+	uint32_t ioas_id;
+
+	test_ioctl_ioas_alloc(&ioas_id);
+	test_ioctl_ioas_map_fixed_id(ioas_id, self->buffer,
+				     variant->buffer_size, MOCK_APERTURE_START);
+
+	test_cmd_hwpt_alloc(self->idev_id, ioas_id,
+			    IOMMU_HWPT_ALLOC_DIRTY_TRACKING, &hwpt_id);
+	test_cmd_mock_domain(hwpt_id, &stddev_id, NULL, NULL);
+
+	test_cmd_set_dirty_tracking(hwpt_id, true);
+
+	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
+				MOCK_APERTURE_START, self->page_size,
+				self->bitmap, self->bitmap_size, _metadata);
+
+	/* PAGE_SIZE unaligned bitmap */
+	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
+				MOCK_APERTURE_START, self->page_size,
+				self->bitmap + MOCK_PAGE_SIZE,
+				self->bitmap_size, _metadata);
+
+	test_ioctl_destroy(stddev_id);
+	test_ioctl_destroy(hwpt_id);
+}
+
 /* VFIO compatibility IOCTLs */
 
 TEST_F(iommufd, simple_ioctls)
diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
index e37af6291b22..b129cf23b824 100644
--- a/tools/testing/selftests/iommu/iommufd_utils.h
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -16,6 +16,25 @@
 /* Hack to make assertions more readable */
 #define _IOMMU_TEST_CMD(x) IOMMU_TEST_CMD
 
+/* Imported from include/asm-generic/bitops/generic-non-atomic.h */
+#define BITS_PER_BYTE 8
+#define BITS_PER_LONG __BITS_PER_LONG
+#define BIT_MASK(nr) (1UL << ((nr) % __BITS_PER_LONG))
+#define BIT_WORD(nr) ((nr) / __BITS_PER_LONG)
+
+static inline void set_bit(unsigned int nr, unsigned long *addr)
+{
+	unsigned long mask = BIT_MASK(nr);
+	unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+
+	*p |= mask;
+}
+
+static inline bool test_bit(unsigned int nr, unsigned long *addr)
+{
+	return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG - 1)));
+}
+
 static void *buffer;
 static unsigned long BUFFER_SIZE;
 
@@ -196,6 +215,103 @@ static int _test_cmd_set_dirty_tracking(int fd, __u32 hwpt_id, bool enabled)
 #define test_cmd_set_dirty_tracking(hwpt_id, enabled) \
 	ASSERT_EQ(0, _test_cmd_set_dirty_tracking(self->fd, hwpt_id, enabled))
 
+static int _test_cmd_get_dirty_bitmap(int fd, __u32 hwpt_id, size_t length,
+				      __u64 iova, size_t page_size,
+				      __u64 *bitmap)
+{
+	struct iommu_hwpt_get_dirty_bitmap cmd = {
+		.size = sizeof(cmd),
+		.hwpt_id = hwpt_id,
+		.iova = iova,
+		.length = length,
+		.page_size = page_size,
+		.data = (uintptr_t)bitmap,
+	};
+	int ret;
+
+	ret = ioctl(fd, IOMMU_HWPT_GET_DIRTY_BITMAP, &cmd);
+	if (ret)
+		return ret;
+	return 0;
+}
+
+#define test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size,    \
+				  bitmap)                                  \
+	ASSERT_EQ(0, _test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, \
+						page_size, bitmap))
+
+static int _test_cmd_mock_domain_set_dirty(int fd, __u32 hwpt_id, size_t length,
+					   __u64 iova, size_t page_size,
+					   __u64 *bitmap, __u64 *dirty)
+{
+	struct iommu_test_cmd cmd = {
+		.size = sizeof(cmd),
+		.op = IOMMU_TEST_OP_DIRTY,
+		.id = hwpt_id,
+		.dirty = {
+			.iova = iova,
+			.length = length,
+			.page_size = page_size,
+			.uptr = (uintptr_t)bitmap,
+		}
+	};
+	int ret;
+
+	ret = ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_DIRTY), &cmd);
+	if (ret)
+		return -ret;
+	if (dirty)
+		*dirty = cmd.dirty.out_nr_dirty;
+	return 0;
+}
+
+#define test_cmd_mock_domain_set_dirty(fd, hwpt_id, length, iova, page_size, \
+				       bitmap, nr)                           \
+	ASSERT_EQ(0,                                                         \
+		  _test_cmd_mock_domain_set_dirty(fd, hwpt_id, length, iova, \
+						  page_size, bitmap, nr))
+
+static int _test_mock_dirty_bitmaps(int fd, __u32 hwpt_id, size_t length,
+				    __u64 iova, size_t page_size, __u64 *bitmap,
+				    __u64 bitmap_size,
+				    struct __test_metadata *_metadata)
+{
+	unsigned long i, count, nbits = bitmap_size * BITS_PER_BYTE;
+	unsigned long nr = nbits / 2;
+	__u64 out_dirty = 0;
+
+	/* Mark all even bits as dirty in the mock domain */
+	for (count = 0, i = 0; i < nbits; count += !(i % 2), i++)
+		if (!(i % 2))
+			set_bit(i, (unsigned long *)bitmap);
+	ASSERT_EQ(nr, count);
+
+	test_cmd_mock_domain_set_dirty(fd, hwpt_id, length, iova, page_size,
+				       bitmap, &out_dirty);
+	ASSERT_EQ(nr, out_dirty);
+
+	/* Expect all even bits as dirty in the user bitmap */
+	memset(bitmap, 0, bitmap_size);
+	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap);
+	for (count = 0, i = 0; i < nbits; count += !(i % 2), i++)
+		ASSERT_EQ(!(i % 2), test_bit(i, (unsigned long *)bitmap));
+	ASSERT_EQ(count, out_dirty);
+
+	memset(bitmap, 0, bitmap_size);
+	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap);
+
+	/* It as read already -- expect all zeroes */
+	for (i = 0; i < nbits; i++)
+		ASSERT_EQ(0, test_bit(i, (unsigned long *)bitmap));
+
+	return 0;
+}
+#define test_mock_dirty_bitmaps(hwpt_id, length, iova, page_size, bitmap,      \
+				bitmap_size, _metadata)                        \
+	ASSERT_EQ(0, _test_mock_dirty_bitmaps(self->fd, hwpt_id, length, iova, \
+					      page_size, bitmap, bitmap_size,  \
+					      _metadata))
+
 static int _test_cmd_create_access(int fd, unsigned int ioas_id,
 				   __u32 *access_id, unsigned int flags)
 {
@@ -320,6 +436,17 @@ static int _test_ioctl_ioas_map(int fd, unsigned int ioas_id, void *buffer,
 					     IOMMU_IOAS_MAP_READABLE));       \
 	})
 
+#define test_ioctl_ioas_map_fixed_id(ioas_id, buffer, length, iova)           \
+	({                                                                    \
+		__u64 __iova = iova;                                          \
+		ASSERT_EQ(0,                                                  \
+			  _test_ioctl_ioas_map(                               \
+				  self->fd, ioas_id, buffer, length, &__iova, \
+				  IOMMU_IOAS_MAP_FIXED_IOVA |                 \
+					  IOMMU_IOAS_MAP_WRITEABLE |          \
+					  IOMMU_IOAS_MAP_READABLE));          \
+	})
+
 #define test_err_ioctl_ioas_map_fixed(_errno, buffer, length, iova)           \
 	({                                                                    \
 		__u64 __iova = iova;                                          \
-- 
2.17.2

[PATCH v6 17/18] iommufd/selftest: Test out_capabilities in IOMMU_GET_HW_INFO

[Joao Martins]

Enumerate the capabilities from the mock device and test whether it
advertises as expected. Include it as part of the iommufd_dirty_tracking
fixture.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 drivers/iommu/iommufd/selftest.c              | 13 +++++++++-
 tools/testing/selftests/iommu/iommufd.c       | 17 +++++++++++++
 .../selftests/iommu/iommufd_fail_nth.c        |  2 +-
 tools/testing/selftests/iommu/iommufd_utils.h | 24 ++++++++++++-------
 4 files changed, 45 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 4eb86025dde9..0eb01d1f9df8 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -376,7 +376,18 @@ static phys_addr_t mock_domain_iova_to_phys(struct iommu_domain *domain,
 
 static bool mock_domain_capable(struct device *dev, enum iommu_cap cap)
 {
-	return cap == IOMMU_CAP_CACHE_COHERENCY;
+	struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
+
+	switch (cap) {
+	case IOMMU_CAP_CACHE_COHERENCY:
+		return true;
+	case IOMMU_CAP_DIRTY_TRACKING:
+		return !(mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY);
+	default:
+		break;
+	}
+
+	return false;
 }
 
 static void mock_domain_set_plaform_dma_ops(struct device *dev)
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index 891250acf47e..f4f8bd17ae67 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -1563,6 +1563,23 @@ TEST_F(iommufd_dirty_tracking, set_dirty_tracking)
 	test_ioctl_destroy(hwpt_id);
 }
 
+TEST_F(iommufd_dirty_tracking, device_dirty_capability)
+{
+	uint32_t caps = 0;
+	uint32_t stddev_id;
+	uint32_t hwpt_id;
+
+	test_cmd_hwpt_alloc(self->idev_id, self->ioas_id, 0, &hwpt_id);
+	test_cmd_mock_domain(hwpt_id, &stddev_id, NULL, NULL);
+	test_cmd_get_hw_capabilities(self->idev_id, caps,
+				     IOMMU_HW_CAP_DIRTY_TRACKING);
+	ASSERT_EQ(IOMMU_HW_CAP_DIRTY_TRACKING,
+		  caps & IOMMU_HW_CAP_DIRTY_TRACKING);
+
+	test_ioctl_destroy(stddev_id);
+	test_ioctl_destroy(hwpt_id);
+}
+
 TEST_F(iommufd_dirty_tracking, get_dirty_bitmap)
 {
 	uint32_t stddev_id;
diff --git a/tools/testing/selftests/iommu/iommufd_fail_nth.c b/tools/testing/selftests/iommu/iommufd_fail_nth.c
index 31386be42439..ff735bdd833e 100644
--- a/tools/testing/selftests/iommu/iommufd_fail_nth.c
+++ b/tools/testing/selftests/iommu/iommufd_fail_nth.c
@@ -612,7 +612,7 @@ TEST_FAIL_NTH(basic_fail_nth, device)
 				  &idev_id))
 		return -1;
 
-	if (_test_cmd_get_hw_info(self->fd, idev_id, &info, sizeof(info)))
+	if (_test_cmd_get_hw_info(self->fd, idev_id, &info, sizeof(info), NULL))
 		return -1;
 
 	if (_test_cmd_hwpt_alloc(self->fd, idev_id, ioas_id, 0, &hwpt_id))
diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
index b129cf23b824..2410d06f5a34 100644
--- a/tools/testing/selftests/iommu/iommufd_utils.h
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -535,8 +535,8 @@ static void teardown_iommufd(int fd, struct __test_metadata *_metadata)
 #endif
 
 /* @data can be NULL */
-static int _test_cmd_get_hw_info(int fd, __u32 device_id,
-				 void *data, size_t data_len)
+static int _test_cmd_get_hw_info(int fd, __u32 device_id, void *data,
+				 size_t data_len, uint32_t *capabilities)
 {
 	struct iommu_test_hw_info *info = (struct iommu_test_hw_info *)data;
 	struct iommu_hw_info cmd = {
@@ -544,6 +544,7 @@ static int _test_cmd_get_hw_info(int fd, __u32 device_id,
 		.dev_id = device_id,
 		.data_len = data_len,
 		.data_uptr = (uint64_t)data,
+		.out_capabilities = 0,
 	};
 	int ret;
 
@@ -580,14 +581,19 @@ static int _test_cmd_get_hw_info(int fd, __u32 device_id,
 			assert(!info->flags);
 	}
 
+	if (capabilities)
+		*capabilities = cmd.out_capabilities;
+
 	return 0;
 }
 
-#define test_cmd_get_hw_info(device_id, data, data_len)         \
-	ASSERT_EQ(0, _test_cmd_get_hw_info(self->fd, device_id, \
-					   data, data_len))
+#define test_cmd_get_hw_info(device_id, data, data_len)               \
+	ASSERT_EQ(0, _test_cmd_get_hw_info(self->fd, device_id, data, \
+					   data_len, NULL))
+
+#define test_err_get_hw_info(_errno, device_id, data, data_len)               \
+	EXPECT_ERRNO(_errno, _test_cmd_get_hw_info(self->fd, device_id, data, \
+						   data_len, NULL))
 
-#define test_err_get_hw_info(_errno, device_id, data, data_len) \
-	EXPECT_ERRNO(_errno,                                    \
-		     _test_cmd_get_hw_info(self->fd, device_id, \
-					   data, data_len))
+#define test_cmd_get_hw_capabilities(device_id, caps, mask) \
+	ASSERT_EQ(0, _test_cmd_get_hw_info(self->fd, device_id, NULL, 0, &caps))
-- 
2.17.2

[PATCH v6 18/18] iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR flag

[Joao Martins]

Change test_mock_dirty_bitmaps() to pass a flag where it specifies the flag
under test. The test does the same thing as the GET_DIRTY_BITMAP regular
test. Except that it tests whether the dirtied bits are fetched all the
same a second time, as opposed to observing them cleared.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 drivers/iommu/iommufd/selftest.c              | 15 +++++---
 tools/testing/selftests/iommu/iommufd.c       | 38 ++++++++++++++++++-
 tools/testing/selftests/iommu/iommufd_utils.h | 26 ++++++++-----
 3 files changed, 61 insertions(+), 18 deletions(-)

diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 0eb01d1f9df8..d8551c9d5b6c 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -193,13 +193,16 @@ static int mock_domain_read_and_clear_dirty(struct iommu_domain *domain,
 
 		ent = xa_load(&mock->pfns, cur / MOCK_IO_PAGE_SIZE);
 		if (ent && (xa_to_value(ent) & MOCK_PFN_DIRTY_IOVA)) {
-			unsigned long val;
-
 			/* Clear dirty */
-			val = xa_to_value(ent) & ~MOCK_PFN_DIRTY_IOVA;
-			old = xa_store(&mock->pfns, cur / MOCK_IO_PAGE_SIZE,
-				       xa_mk_value(val), GFP_KERNEL);
-			WARN_ON_ONCE(ent != old);
+			if (!(flags & IOMMU_DIRTY_NO_CLEAR)) {
+				unsigned long val;
+
+				val = xa_to_value(ent) & ~MOCK_PFN_DIRTY_IOVA;
+				old = xa_store(&mock->pfns,
+					       cur / MOCK_IO_PAGE_SIZE,
+					       xa_mk_value(val), GFP_KERNEL);
+				WARN_ON_ONCE(ent != old);
+			}
 			iommu_dirty_bitmap_record(dirty, cur,
 						  MOCK_IO_PAGE_SIZE);
 		}
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index f4f8bd17ae67..76a4351e3434 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -1598,13 +1598,47 @@ TEST_F(iommufd_dirty_tracking, get_dirty_bitmap)
 
 	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
 				MOCK_APERTURE_START, self->page_size,
-				self->bitmap, self->bitmap_size, _metadata);
+				self->bitmap, self->bitmap_size, 0, _metadata);
 
 	/* PAGE_SIZE unaligned bitmap */
 	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
 				MOCK_APERTURE_START, self->page_size,
 				self->bitmap + MOCK_PAGE_SIZE,
-				self->bitmap_size, _metadata);
+				self->bitmap_size, 0, _metadata);
+
+	test_ioctl_destroy(stddev_id);
+	test_ioctl_destroy(hwpt_id);
+}
+
+TEST_F(iommufd_dirty_tracking, get_dirty_bitmap_no_clear)
+{
+	uint32_t stddev_id;
+	uint32_t hwpt_id;
+	uint32_t ioas_id;
+
+	test_ioctl_ioas_alloc(&ioas_id);
+	test_ioctl_ioas_map_fixed_id(ioas_id, self->buffer,
+				     variant->buffer_size, MOCK_APERTURE_START);
+
+	test_cmd_hwpt_alloc(self->idev_id, ioas_id,
+			    IOMMU_HWPT_ALLOC_DIRTY_TRACKING, &hwpt_id);
+	test_cmd_mock_domain(hwpt_id, &stddev_id, NULL, NULL);
+
+	test_cmd_set_dirty_tracking(hwpt_id, true);
+
+	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
+				MOCK_APERTURE_START, self->page_size,
+				self->bitmap, self->bitmap_size,
+				IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR,
+				_metadata);
+
+	/* Unaligned bitmap */
+	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
+				MOCK_APERTURE_START, self->page_size,
+				self->bitmap + MOCK_PAGE_SIZE,
+				self->bitmap_size,
+				IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR,
+				_metadata);
 
 	test_ioctl_destroy(stddev_id);
 	test_ioctl_destroy(hwpt_id);
diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
index 2410d06f5a34..e263bf80a977 100644
--- a/tools/testing/selftests/iommu/iommufd_utils.h
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -217,11 +217,12 @@ static int _test_cmd_set_dirty_tracking(int fd, __u32 hwpt_id, bool enabled)
 
 static int _test_cmd_get_dirty_bitmap(int fd, __u32 hwpt_id, size_t length,
 				      __u64 iova, size_t page_size,
-				      __u64 *bitmap)
+				      __u64 *bitmap, __u32 flags)
 {
 	struct iommu_hwpt_get_dirty_bitmap cmd = {
 		.size = sizeof(cmd),
 		.hwpt_id = hwpt_id,
+		.flags = flags,
 		.iova = iova,
 		.length = length,
 		.page_size = page_size,
@@ -236,9 +237,9 @@ static int _test_cmd_get_dirty_bitmap(int fd, __u32 hwpt_id, size_t length,
 }
 
 #define test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size,    \
-				  bitmap)                                  \
+				  bitmap, flags)                           \
 	ASSERT_EQ(0, _test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, \
-						page_size, bitmap))
+						page_size, bitmap, flags))
 
 static int _test_cmd_mock_domain_set_dirty(int fd, __u32 hwpt_id, size_t length,
 					   __u64 iova, size_t page_size,
@@ -273,7 +274,7 @@ static int _test_cmd_mock_domain_set_dirty(int fd, __u32 hwpt_id, size_t length,
 
 static int _test_mock_dirty_bitmaps(int fd, __u32 hwpt_id, size_t length,
 				    __u64 iova, size_t page_size, __u64 *bitmap,
-				    __u64 bitmap_size,
+				    __u64 bitmap_size, __u32 flags,
 				    struct __test_metadata *_metadata)
 {
 	unsigned long i, count, nbits = bitmap_size * BITS_PER_BYTE;
@@ -292,25 +293,30 @@ static int _test_mock_dirty_bitmaps(int fd, __u32 hwpt_id, size_t length,
 
 	/* Expect all even bits as dirty in the user bitmap */
 	memset(bitmap, 0, bitmap_size);
-	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap);
+	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap,
+				  flags);
 	for (count = 0, i = 0; i < nbits; count += !(i % 2), i++)
 		ASSERT_EQ(!(i % 2), test_bit(i, (unsigned long *)bitmap));
 	ASSERT_EQ(count, out_dirty);
 
 	memset(bitmap, 0, bitmap_size);
-	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap);
+	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap,
+				  flags);
 
 	/* It as read already -- expect all zeroes */
-	for (i = 0; i < nbits; i++)
-		ASSERT_EQ(0, test_bit(i, (unsigned long *)bitmap));
+	for (i = 0; i < nbits; i++) {
+		ASSERT_EQ(!(i % 2) && (flags &
+				       IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR),
+			  test_bit(i, (unsigned long *)bitmap));
+	}
 
 	return 0;
 }
 #define test_mock_dirty_bitmaps(hwpt_id, length, iova, page_size, bitmap,      \
-				bitmap_size, _metadata)                        \
+				bitmap_size, flags, _metadata)                 \
 	ASSERT_EQ(0, _test_mock_dirty_bitmaps(self->fd, hwpt_id, length, iova, \
 					      page_size, bitmap, bitmap_size,  \
-					      _metadata))
+					      flags, _metadata))
 
 static int _test_cmd_create_access(int fd, unsigned int ioas_id,
 				   __u32 *access_id, unsigned int flags)
-- 
2.17.2

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Jason Gunthorpe]

On Tue, Oct 24, 2023 at 02:50:51PM +0100, Joao Martins wrote:
> v6 is a replacement of what's in iommufd next:
> https://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd.git/log/?h=for-next
> 
> Joao Martins (18):
>   vfio/iova_bitmap: Export more API symbols
>   vfio: Move iova_bitmap into iommufd
>   iommufd/iova_bitmap: Move symbols to IOMMUFD namespace
>   iommu: Add iommu_domain ops for dirty tracking
>   iommufd: Add a flag to enforce dirty tracking on attach
>   iommufd: Add IOMMU_HWPT_SET_DIRTY_TRACKING
>   iommufd: Add IOMMU_HWPT_GET_DIRTY_BITMAP
>   iommufd: Add capabilities to IOMMU_GET_HW_INFO
>   iommufd: Add a flag to skip clearing of IOPTE dirty
>   iommu/amd: Add domain_alloc_user based domain allocation
>   iommu/amd: Access/Dirty bit support in IOPTEs
>   iommu/vt-d: Access/Dirty bit support for SS domains
>   iommufd/selftest: Expand mock_domain with dev_flags
>   iommufd/selftest: Test IOMMU_HWPT_ALLOC_DIRTY_TRACKING
>   iommufd/selftest: Test IOMMU_HWPT_SET_DIRTY_TRACKING
>   iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP
>   iommufd/selftest: Test out_capabilities in IOMMU_GET_HW_INFO
>   iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR flag

Ok, I refreshed the series, thanks!

Jason

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Nicolin Chen]

On Tue, Oct 24, 2023 at 12:55:12PM -0300, Jason Gunthorpe wrote:
> On Tue, Oct 24, 2023 at 02:50:51PM +0100, Joao Martins wrote:
> > v6 is a replacement of what's in iommufd next:
> > https://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd.git/log/?h=for-next
> > 
> > Joao Martins (18):
> >   vfio/iova_bitmap: Export more API symbols
> >   vfio: Move iova_bitmap into iommufd
> >   iommufd/iova_bitmap: Move symbols to IOMMUFD namespace
> >   iommu: Add iommu_domain ops for dirty tracking
> >   iommufd: Add a flag to enforce dirty tracking on attach
> >   iommufd: Add IOMMU_HWPT_SET_DIRTY_TRACKING
> >   iommufd: Add IOMMU_HWPT_GET_DIRTY_BITMAP
> >   iommufd: Add capabilities to IOMMU_GET_HW_INFO
> >   iommufd: Add a flag to skip clearing of IOPTE dirty
> >   iommu/amd: Add domain_alloc_user based domain allocation
> >   iommu/amd: Access/Dirty bit support in IOPTEs
> >   iommu/vt-d: Access/Dirty bit support for SS domains
> >   iommufd/selftest: Expand mock_domain with dev_flags
> >   iommufd/selftest: Test IOMMU_HWPT_ALLOC_DIRTY_TRACKING
> >   iommufd/selftest: Test IOMMU_HWPT_SET_DIRTY_TRACKING
> >   iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP
> >   iommufd/selftest: Test out_capabilities in IOMMU_GET_HW_INFO
> >   iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR flag
> 
> Ok, I refreshed the series, thanks!

Selftest is passing with this version.

Cheers
Nicolin

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Zhangfei Gao]

Hi, Joao

On Tue, 24 Oct 2023 at 21:51, Joao Martins <joao.m.martins@oracle.com> wrote:
>
> v6 is a replacement of what's in iommufd next:
> https://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd.git/log/?h=for-next
>
> base-commit: b5f9e63278d6f32789478acf1ed41d21d92b36cf
>
> (from the iommufd tree)
>
> =========>8=========
>
> Presented herewith is a series that extends IOMMUFD to have IOMMU
> hardware support for dirty bit in the IOPTEs.
>
> Today, AMD Milan (or more recent) supports it while ARM SMMUv3.2
> alongside VT-D rev3.x also do support.  One intended use-case (but not
> restricted!) is to support Live Migration with SR-IOV, specially useful
> for live migrateable PCI devices that can't supply its own dirty
> tracking hardware blocks amongst others.
>
> At a quick glance, IOMMUFD lets the userspace create the IOAS with a
> set of a IOVA ranges mapped to some physical memory composing an IO
> pagetable. This is then created via HWPT_ALLOC or attached to a
> particular device/hwpt, consequently creating the IOMMU domain and share
> a common IO page table representing the endporint DMA-addressable guest
> address space. In IOMMUFD Dirty tracking (since v2 of the series) it
> will require via the HWPT_ALLOC model only, as opposed to simpler
> autodomains model.
>
> The result is an hw_pagetable which represents the
> iommu_domain which will be directly manipulated. The IOMMUFD UAPI,
> and the iommu/iommufd kAPI are then extended to provide:
>
> 1) Enforcement that only devices with dirty tracking support are attached
> to an IOMMU domain, to cover the case where this isn't all homogenous in
> the platform. While initially this is more aimed at possible heterogenous nature
> of ARM while x86 gets future proofed, should any such ocasion occur.
>
> The device dirty tracking enforcement on attach_dev is made whether the
> dirty_ops are set or not. Given that attach always checks for dirty
> ops and IOMMU_CAP_DIRTY, while writing this it almost wanted this to
> move to upper layer but semantically iommu driver should do the
> checking.
>
> 2) Toggling of Dirty Tracking on the iommu_domain. We model as the most
> common case of changing hardware translation control structures dynamically
> (x86) while making it easier to have an always-enabled mode. In the
> RFCv1, the ARM specific case is suggested to be always enabled instead of
> having to enable the per-PTE DBM control bit (what I previously called
> "range tracking"). Here, setting/clearing tracking means just clearing the
> dirty bits at start. The 'real' tracking of whether dirty
> tracking is enabled is stored in the IOMMU driver, hence no new
> fields are added to iommufd pagetable structures, except for the
> iommu_domain dirty ops part via adding a dirty_ops field to
> iommu_domain. We use that too for IOMMUFD to know if dirty tracking
> is supported and toggleable without having iommu drivers replicate said
> checks.
>
> 3) Add a capability probing for dirty tracking, leveraging the
> per-device iommu_capable() and adding a IOMMU_CAP_DIRTY. It extends
> the GET_HW_INFO ioctl which takes a device ID to return some generic
> capabilities *in addition*. Possible values enumarated by `enum
> iommufd_hw_capabilities`.
>
> 4) Read the I/O PTEs and marshal its dirtyiness into a bitmap. The bitmap
> indexes on a page_size basis the IOVAs that got written by the device.
> While performing the marshalling also drivers need to clear the dirty bits
> from IOPTE and allow the kAPI caller to batch the much needed IOTLB flush.
> There's no copy of bitmaps to userspace backed memory, all is zerocopy
> based to not add more cost to the iommu driver IOPT walker. This shares
> functionality with VFIO device dirty tracking via the IOVA bitmap APIs. So
> far this is a test-and-clear kind of interface given that the IOPT walk is
> going to be expensive. In addition this also adds the ability to read dirty
> bit info without clearing the PTE info. This is meant to cover the
> unmap-and-read-dirty use-case, and avoid the second IOTLB flush.
>
> The only dependency is:
> * Have domain_alloc_user() API with flags [2] already queued (iommufd/for-next).
>
> The series is organized as follows:
>
> * Patches 1-4: Takes care of the iommu domain operations to be added.
> The idea is to abstract iommu drivers from any idea of how bitmaps are
> stored or propagated back to the caller, as well as allowing
> control/batching over IOTLB flush. So there's a data structure and an
> helper that only tells the upper layer that an IOVA range got dirty.
> This logic is shared with VFIO and it's meant to walking the bitmap
> user memory, and kmap-ing plus setting bits as needed. IOMMU driver
> just has an idea of a 'dirty bitmap state' and recording an IOVA as
> dirty.
>
> * Patches 5-9, 13-18: Adds the UAPIs for IOMMUFD, and selftests. The
> selftests cover some corner cases on boundaries handling of the bitmap
> and various bitmap sizes that exercise. I haven't included huge IOVA
> ranges to avoid risking the selftests failing to execute due to OOM
> issues of mmaping big buffers.
>
> * Patches 10-11: AMD IOMMU implementation, particularly on those having
> HDSup support. Tested with a Qemu amd-iommu with HDSUp emulated[0]. And
> tested with live migration with VFs (but with IOMMU dirty tracking).
>
> * Patches 12: Intel IOMMU rev3.x+ implementation. Tested with a Qemu
> based intel-iommu vIOMMU with SSADS emulation support[0].
>
> On AMD/Intel I have tested this with emulation and then live migration in
> AMD hardware;
>
> The qemu iommu emulation bits are to increase coverage of this code and
> hopefully make this more broadly available for fellow contributors/devs,
> old version[1]; it uses Yi's 2 commits to have hw_info() supported (still
> needs a bit of cleanup) on top of a recent Zhenzhong series of IOMMUFD
> QEMU bringup work: see here[0]. It includes IOMMUFD dirty tracking for
> Live migration and with live migration tested. I won't be exactly
> following up a v2 of QEMU patches until IOMMUFD tracking lands.
>
> Feedback or any comments are very much appreciated.
>
> Thanks!
>         Joao

Is this patchset enough for iommufd live migration?

Just tried live migration in local machine,
reports "VFIO migration is not supported in kernel"

Thanks

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Yi Liu]

On 2024/10/29 10:35, Zhangfei Gao wrote:
> VFIO migration is not supported in kernel

do you have a vfio-pci-xxx driver that suits your device? Looks
like your case failed when checking the VFIO_DEVICE_FEATURE_GET | 
VFIO_DEVICE_FEATURE_MIGRATION via VFIO_DEVICE_FEATURE.

-- 
Regards,
Yi Liu

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Zhangfei Gao]

On Tue, 29 Oct 2024 at 10:48, Yi Liu <yi.l.liu@intel.com> wrote:
>
> On 2024/10/29 10:35, Zhangfei Gao wrote:
> > VFIO migration is not supported in kernel
>
> do you have a vfio-pci-xxx driver that suits your device? Looks
> like your case failed when checking the VFIO_DEVICE_FEATURE_GET |
> VFIO_DEVICE_FEATURE_MIGRATION via VFIO_DEVICE_FEATURE.

Thanks Yi for the guidance.

Yes,
ioctl VFIO_DEVICE_FEATURE  with VFIO_DEVICE_FEATURE_MIGRATION fails.
Since
if (!device->mig_ops)
    return -ENOTTY;

Now drivers/vfio/pci/vfio_pci.c is used, without mig_ops.
Looks like I have to use other devices like
drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c, still in check.

Thanks Yi.

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Yi Liu]

On 2024/10/29 16:05, Zhangfei Gao wrote:
> On Tue, 29 Oct 2024 at 10:48, Yi Liu <yi.l.liu@intel.com> wrote:
>>
>> On 2024/10/29 10:35, Zhangfei Gao wrote:
>>> VFIO migration is not supported in kernel
>>
>> do you have a vfio-pci-xxx driver that suits your device? Looks
>> like your case failed when checking the VFIO_DEVICE_FEATURE_GET |
>> VFIO_DEVICE_FEATURE_MIGRATION via VFIO_DEVICE_FEATURE.
> 
> Thanks Yi for the guidance.
> 
> Yes,
> ioctl VFIO_DEVICE_FEATURE  with VFIO_DEVICE_FEATURE_MIGRATION fails.
> Since
> if (!device->mig_ops)
>      return -ENOTTY;
> 
> Now drivers/vfio/pci/vfio_pci.c is used, without mig_ops.
> Looks like I have to use other devices like
> drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c, still in check.

indeed. You need to bind your device to a variant driver named vfio-pci-xxx
which will provide the mig_ops and even dirty logging feature. Good luck.

-- 
Regards,
Yi Liu

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Zhangfei Gao]

On Tue, 24 Oct 2023 at 21:51, Joao Martins <joao.m.martins@oracle.com> wrote:
>
> v6 is a replacement of what's in iommufd next:
> https://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd.git/log/?h=for-next
>
> base-commit: b5f9e63278d6f32789478acf1ed41d21d92b36cf
>
> (from the iommufd tree)
>
> =========>8=========
>
> Presented herewith is a series that extends IOMMUFD to have IOMMU
> hardware support for dirty bit in the IOPTEs.
>
> Today, AMD Milan (or more recent) supports it while ARM SMMUv3.2
> alongside VT-D rev3.x also do support.  One intended use-case (but not
> restricted!) is to support Live Migration with SR-IOV, specially useful
> for live migrateable PCI devices that can't supply its own dirty
> tracking hardware blocks amongst others.
>
> At a quick glance, IOMMUFD lets the userspace create the IOAS with a
> set of a IOVA ranges mapped to some physical memory composing an IO
> pagetable. This is then created via HWPT_ALLOC or attached to a
> particular device/hwpt, consequently creating the IOMMU domain and share
> a common IO page table representing the endporint DMA-addressable guest
> address space. In IOMMUFD Dirty tracking (since v2 of the series) it
> will require via the HWPT_ALLOC model only, as opposed to simpler
> autodomains model.
>
> The result is an hw_pagetable which represents the
> iommu_domain which will be directly manipulated. The IOMMUFD UAPI,
> and the iommu/iommufd kAPI are then extended to provide:
>
> 1) Enforcement that only devices with dirty tracking support are attached
> to an IOMMU domain, to cover the case where this isn't all homogenous in
> the platform. While initially this is more aimed at possible heterogenous nature
> of ARM while x86 gets future proofed, should any such ocasion occur.
>
> The device dirty tracking enforcement on attach_dev is made whether the
> dirty_ops are set or not. Given that attach always checks for dirty
> ops and IOMMU_CAP_DIRTY, while writing this it almost wanted this to
> move to upper layer but semantically iommu driver should do the
> checking.
>
> 2) Toggling of Dirty Tracking on the iommu_domain. We model as the most
> common case of changing hardware translation control structures dynamically
> (x86) while making it easier to have an always-enabled mode. In the
> RFCv1, the ARM specific case is suggested to be always enabled instead of
> having to enable the per-PTE DBM control bit (what I previously called
> "range tracking"). Here, setting/clearing tracking means just clearing the
> dirty bits at start. The 'real' tracking of whether dirty
> tracking is enabled is stored in the IOMMU driver, hence no new
> fields are added to iommufd pagetable structures, except for the
> iommu_domain dirty ops part via adding a dirty_ops field to
> iommu_domain. We use that too for IOMMUFD to know if dirty tracking
> is supported and toggleable without having iommu drivers replicate said
> checks.
>
> 3) Add a capability probing for dirty tracking, leveraging the
> per-device iommu_capable() and adding a IOMMU_CAP_DIRTY. It extends
> the GET_HW_INFO ioctl which takes a device ID to return some generic
> capabilities *in addition*. Possible values enumarated by `enum
> iommufd_hw_capabilities`.
>
> 4) Read the I/O PTEs and marshal its dirtyiness into a bitmap. The bitmap
> indexes on a page_size basis the IOVAs that got written by the device.
> While performing the marshalling also drivers need to clear the dirty bits
> from IOPTE and allow the kAPI caller to batch the much needed IOTLB flush.
> There's no copy of bitmaps to userspace backed memory, all is zerocopy
> based to not add more cost to the iommu driver IOPT walker. This shares
> functionality with VFIO device dirty tracking via the IOVA bitmap APIs. So
> far this is a test-and-clear kind of interface given that the IOPT walk is
> going to be expensive. In addition this also adds the ability to read dirty
> bit info without clearing the PTE info. This is meant to cover the
> unmap-and-read-dirty use-case, and avoid the second IOTLB flush.
>
> The only dependency is:
> * Have domain_alloc_user() API with flags [2] already queued (iommufd/for-next).
>
> The series is organized as follows:
>
> * Patches 1-4: Takes care of the iommu domain operations to be added.
> The idea is to abstract iommu drivers from any idea of how bitmaps are
> stored or propagated back to the caller, as well as allowing
> control/batching over IOTLB flush. So there's a data structure and an
> helper that only tells the upper layer that an IOVA range got dirty.
> This logic is shared with VFIO and it's meant to walking the bitmap
> user memory, and kmap-ing plus setting bits as needed. IOMMU driver
> just has an idea of a 'dirty bitmap state' and recording an IOVA as
> dirty.
>
> * Patches 5-9, 13-18: Adds the UAPIs for IOMMUFD, and selftests. The
> selftests cover some corner cases on boundaries handling of the bitmap
> and various bitmap sizes that exercise. I haven't included huge IOVA
> ranges to avoid risking the selftests failing to execute due to OOM
> issues of mmaping big buffers.
>
> * Patches 10-11: AMD IOMMU implementation, particularly on those having
> HDSup support. Tested with a Qemu amd-iommu with HDSUp emulated[0]. And
> tested with live migration with VFs (but with IOMMU dirty tracking).
>
> * Patches 12: Intel IOMMU rev3.x+ implementation. Tested with a Qemu
> based intel-iommu vIOMMU with SSADS emulation support[0].
>
> On AMD/Intel I have tested this with emulation and then live migration in
> AMD hardware;
>
> The qemu iommu emulation bits are to increase coverage of this code and
> hopefully make this more broadly available for fellow contributors/devs,
> old version[1]; it uses Yi's 2 commits to have hw_info() supported (still
> needs a bit of cleanup) on top of a recent Zhenzhong series of IOMMUFD
> QEMU bringup work: see here[0]. It includes IOMMUFD dirty tracking for
> Live migration and with live migration tested. I won't be exactly
> following up a v2 of QEMU patches until IOMMUFD tracking lands.
>
> Feedback or any comments are very much appreciated.
>
> Thanks!
>         Joao

Hi, Joao and Yi

I just tried this on aarch64, live migration with "iommu=nested-smmuv3"
It does not work.

vbasedev->dirty_pages_supported=0

qemu-system-aarch64: -device
vfio-pci-nohotplug,host=0000:75:00.1,iommufd=iommufd0,enable-migration=on,x-pre-copy-dirty-page-tracking=off:
warning: 0000:75:00.1: VFIO device doesn't support device and IOMMU
dirty tracking

qemu-system-aarch64: -device
vfio-pci-nohotplug,host=0000:75:00.1,iommufd=iommufd0,enable-migration=on,x-pre-copy-dirty-page-tracking=off:
vfio 0000:75:00.1: 0000:75:00.1: Migration is currently not supported
with vIOMMU enabled

hw/vfio/migration.c
    if (vfio_viommu_preset(vbasedev)) {
        error_setg(&err, "%s: Migration is currently not supported "
                   "with vIOMMU enabled", vbasedev->name);
        goto add_blocker;
    }

Is this mean live migration with vIOMMU is still not ready,
It is not an error. It is how they are blocking migration till all
other related feature support is added for vIOMMU.
And still need more work to enable  migration with vIOMMU?

By the way, live migration works if removing "iommu=nested-smmuv3".

Any suggestions?

Thanks

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Jason Gunthorpe]

On Wed, Oct 30, 2024 at 11:15:02PM +0800, Zhangfei Gao wrote:
> hw/vfio/migration.c
>     if (vfio_viommu_preset(vbasedev)) {
>         error_setg(&err, "%s: Migration is currently not supported "
>                    "with vIOMMU enabled", vbasedev->name);
>         goto add_blocker;
>     }

The viommu driver itself does not support live migration, it would
need to preserve all the guest configuration and bring it all back. It
doesn't know how to do that yet.

Jason

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Joao Martins]

On 30/10/2024 15:36, Jason Gunthorpe wrote:
> On Wed, Oct 30, 2024 at 11:15:02PM +0800, Zhangfei Gao wrote:
>> hw/vfio/migration.c
>>     if (vfio_viommu_preset(vbasedev)) {
>>         error_setg(&err, "%s: Migration is currently not supported "
>>                    "with vIOMMU enabled", vbasedev->name);
>>         goto add_blocker;
>>     }
> 
> The viommu driver itself does not support live migration, it would
> need to preserve all the guest configuration and bring it all back. It
> doesn't know how to do that yet.

It's more of vfio code, not quite related to actually hw vIOMMU.

There's some vfio migration + vIOMMU support patches I have to follow up (v5)
but unexpected set backs unrelated to work delay some of my plans for qemu 9.2.
I expect to resume in few weeks. I can point you to a branch while I don't
submit (provided soft-freeze is coming)

	Joao

RE: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Shameerali Kolothum Thodi]

Hi Joao,

> -----Original Message-----
> From: Joao Martins <joao.m.martins@oracle.com>
> Sent: Wednesday, October 30, 2024 3:47 PM
> To: Jason Gunthorpe <jgg@nvidia.com>; Zhangfei Gao
> <zhangfei.gao@linaro.org>
> Cc: iommu@lists.linux.dev; Kevin Tian <kevin.tian@intel.com>; Shameerali
> Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>; Lu Baolu
> <baolu.lu@linux.intel.com>; Yi Liu <yi.l.liu@intel.com>; Yi Y Sun
> <yi.y.sun@intel.com>; Nicolin Chen <nicolinc@nvidia.com>; Joerg Roedel
> <joro@8bytes.org>; Suravee Suthikulpanit
> <suravee.suthikulpanit@amd.com>; Will Deacon <will@kernel.org>; Robin
> Murphy <robin.murphy@arm.com>; Zhenzhong Duan
> <zhenzhong.duan@intel.com>; Alex Williamson
> <alex.williamson@redhat.com>; kvm@vger.kernel.org; Shameer Kolothum
> <shamiali2008@gmail.com>; Wangzhou (B) <wangzhou1@hisilicon.com>
> Subject: Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking
> 
> On 30/10/2024 15:36, Jason Gunthorpe wrote:
> > On Wed, Oct 30, 2024 at 11:15:02PM +0800, Zhangfei Gao wrote:
> >> hw/vfio/migration.c
> >>     if (vfio_viommu_preset(vbasedev)) {
> >>         error_setg(&err, "%s: Migration is currently not supported "
> >>                    "with vIOMMU enabled", vbasedev->name);
> >>         goto add_blocker;
> >>     }
> >
> > The viommu driver itself does not support live migration, it would
> > need to preserve all the guest configuration and bring it all back. It
> > doesn't know how to do that yet.
> 
> It's more of vfio code, not quite related to actually hw vIOMMU.
> 
> There's some vfio migration + vIOMMU support patches I have to follow up
> (v5)

Are you referring this series here?
https://lore.kernel.org/qemu-devel/d5d30f58-31f0-1103-6956-377de34a790c@redhat.com/T/

Is that enabling migration only if Guest doesn’t do any DMA translations? 

> but unexpected set backs unrelated to work delay some of my plans for
> qemu 9.2.
> I expect to resume in few weeks. I can point you to a branch while I don't
> submit (provided soft-freeze is coming)

Also, I think we need a mechanism for page fault handling in case Guest handles 
the stage 1 plus dirty tracking for stage 1 as well.

Thanks,
Shameer

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Joao Martins]

On 30/10/2024 15:57, Shameerali Kolothum Thodi wrote:
>> On 30/10/2024 15:36, Jason Gunthorpe wrote:
>>> On Wed, Oct 30, 2024 at 11:15:02PM +0800, Zhangfei Gao wrote:
>>>> hw/vfio/migration.c
>>>>     if (vfio_viommu_preset(vbasedev)) {
>>>>         error_setg(&err, "%s: Migration is currently not supported "
>>>>                    "with vIOMMU enabled", vbasedev->name);
>>>>         goto add_blocker;
>>>>     }
>>>
>>> The viommu driver itself does not support live migration, it would
>>> need to preserve all the guest configuration and bring it all back. It
>>> doesn't know how to do that yet.
>>
>> It's more of vfio code, not quite related to actually hw vIOMMU.
>>
>> There's some vfio migration + vIOMMU support patches I have to follow up
>> (v5)
> 
> Are you referring this series here?
> https://lore.kernel.org/qemu-devel/d5d30f58-31f0-1103-6956-377de34a790c@redhat.com/T/
> 
> Is that enabling migration only if Guest doesn’t do any DMA translations? 
> 
No, it does it when guest is using the sw vIOMMU too. to be clear: this has
nothing to do with nested IOMMU or if the guest is doing (emulated) dirty tracking.

When the guest doesn't do DMA translation is this patch:

https://lore.kernel.org/qemu-devel/20230908120521.50903-1-joao.m.martins@oracle.com/

>> but unexpected set backs unrelated to work delay some of my plans for
>> qemu 9.2.
>> I expect to resume in few weeks. I can point you to a branch while I don't
>> submit (provided soft-freeze is coming)
> 
> Also, I think we need a mechanism for page fault handling in case Guest handles 
> the stage 1 plus dirty tracking for stage 1 as well.
> 

I have emulation for x86 iommus to dirty tracking, but that is unrelated to L0
live migration -- It's more for testing in the lack of recent hardware. Even
emulated page fault handling doesn't affect this unless you have to re-map/map
new IOVA, which would also be covered in this series I think.

Unless you are talking about physical IOPF that qemu may terminate, though we
don't have such support in Qemu atm.

RE: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: Joao Martins <joao.m.martins@oracle.com>
> Sent: Wednesday, October 30, 2024 4:57 PM
> To: Shameerali Kolothum Thodi
> <shameerali.kolothum.thodi@huawei.com>; Jason Gunthorpe
> <jgg@nvidia.com>; Zhangfei Gao <zhangfei.gao@linaro.org>
> Cc: iommu@lists.linux.dev; Kevin Tian <kevin.tian@intel.com>; Lu Baolu
> <baolu.lu@linux.intel.com>; Yi Liu <yi.l.liu@intel.com>; Yi Y Sun
> <yi.y.sun@intel.com>; Nicolin Chen <nicolinc@nvidia.com>; Joerg Roedel
> <joro@8bytes.org>; Suravee Suthikulpanit
> <suravee.suthikulpanit@amd.com>; Will Deacon <will@kernel.org>; Robin
> Murphy <robin.murphy@arm.com>; Zhenzhong Duan
> <zhenzhong.duan@intel.com>; Alex Williamson
> <alex.williamson@redhat.com>; kvm@vger.kernel.org; Shameer Kolothum
> <shamiali2008@gmail.com>; Wangzhou (B) <wangzhou1@hisilicon.com>
> Subject: Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking
> 
> On 30/10/2024 15:57, Shameerali Kolothum Thodi wrote:
> >> On 30/10/2024 15:36, Jason Gunthorpe wrote:
> >>> On Wed, Oct 30, 2024 at 11:15:02PM +0800, Zhangfei Gao wrote:
> >>>> hw/vfio/migration.c
> >>>>     if (vfio_viommu_preset(vbasedev)) {
> >>>>         error_setg(&err, "%s: Migration is currently not supported "
> >>>>                    "with vIOMMU enabled", vbasedev->name);
> >>>>         goto add_blocker;
> >>>>     }
> >>>
> >>> The viommu driver itself does not support live migration, it would
> >>> need to preserve all the guest configuration and bring it all back. It
> >>> doesn't know how to do that yet.
> >>
> >> It's more of vfio code, not quite related to actually hw vIOMMU.
> >>
> >> There's some vfio migration + vIOMMU support patches I have to follow
> up
> >> (v5)
> >
> > Are you referring this series here?
> > https://lore.kernel.org/qemu-devel/d5d30f58-31f0-1103-6956-
> 377de34a790c@redhat.com/T/
> >
> > Is that enabling migration only if Guest doesn’t do any DMA translations?
> >
> No, it does it when guest is using the sw vIOMMU too. to be clear: this has
> nothing to do with nested IOMMU or if the guest is doing (emulated) dirty
> tracking.

Ok. Thanks for explaining. So just to clarify, this works for Intel vt-d with
" caching-mode=on". ie, no real 2 stage setup is required  like in ARM
 SMMUv3.

> When the guest doesn't do DMA translation is this patch:
> 
> https://lore.kernel.org/qemu-devel/20230908120521.50903-1-
> joao.m.martins@oracle.com/

Ok.

> 
> >> but unexpected set backs unrelated to work delay some of my plans for
> >> qemu 9.2.
> >> I expect to resume in few weeks. I can point you to a branch while I don't
> >> submit (provided soft-freeze is coming)
> >
> > Also, I think we need a mechanism for page fault handling in case Guest
> handles
> > the stage 1 plus dirty tracking for stage 1 as well.
> >
> 
> I have emulation for x86 iommus to dirty tracking, but that is unrelated to
> L0
> live migration -- It's more for testing in the lack of recent hardware. Even
> emulated page fault handling doesn't affect this unless you have to re-
> map/map
> new IOVA, which would also be covered in this series I think.
> 
> Unless you are talking about physical IOPF that qemu may terminate,
> though we
> don't have such support in Qemu atm.

Yeah I was referring to ARM SMMUv3 cases, where we need nested-smmuv3
support for vfio-pci assignment. Another usecase we have is support SVA in
Guest,  with hardware capable  of physical IOPF.

I will take a look at your series above and will see what else is required
to support ARM. Please CC if you plan to respin or have a latest branch.
Thanks for your efforts.

Shameer
 

Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking

[Joao Martins]

On 30/10/2024 18:41, Shameerali Kolothum Thodi wrote:
>> -----Original Message-----
>> From: Joao Martins <joao.m.martins@oracle.com>
>> Sent: Wednesday, October 30, 2024 4:57 PM
>> To: Shameerali Kolothum Thodi
>> <shameerali.kolothum.thodi@huawei.com>; Jason Gunthorpe
>> <jgg@nvidia.com>; Zhangfei Gao <zhangfei.gao@linaro.org>
>> Cc: iommu@lists.linux.dev; Kevin Tian <kevin.tian@intel.com>; Lu Baolu
>> <baolu.lu@linux.intel.com>; Yi Liu <yi.l.liu@intel.com>; Yi Y Sun
>> <yi.y.sun@intel.com>; Nicolin Chen <nicolinc@nvidia.com>; Joerg Roedel
>> <joro@8bytes.org>; Suravee Suthikulpanit
>> <suravee.suthikulpanit@amd.com>; Will Deacon <will@kernel.org>; Robin
>> Murphy <robin.murphy@arm.com>; Zhenzhong Duan
>> <zhenzhong.duan@intel.com>; Alex Williamson
>> <alex.williamson@redhat.com>; kvm@vger.kernel.org; Shameer Kolothum
>> <shamiali2008@gmail.com>; Wangzhou (B) <wangzhou1@hisilicon.com>
>> Subject: Re: [PATCH v6 00/18] IOMMUFD Dirty Tracking
>> On 30/10/2024 15:57, Shameerali Kolothum Thodi wrote:
>>>> On 30/10/2024 15:36, Jason Gunthorpe wrote:
>>>>> On Wed, Oct 30, 2024 at 11:15:02PM +0800, Zhangfei Gao wrote:
>>>> but unexpected set backs unrelated to work delay some of my plans for
>>>> qemu 9.2.
>>>> I expect to resume in few weeks. I can point you to a branch while I don't
>>>> submit (provided soft-freeze is coming)
>>>
>>> Also, I think we need a mechanism for page fault handling in case Guest
>> handles
>>> the stage 1 plus dirty tracking for stage 1 as well.
>>>
>>
>> I have emulation for x86 iommus to dirty tracking, but that is unrelated to
>> L0
>> live migration -- It's more for testing in the lack of recent hardware. Even
>> emulated page fault handling doesn't affect this unless you have to re-
>> map/map
>> new IOVA, which would also be covered in this series I think.
>>
>> Unless you are talking about physical IOPF that qemu may terminate,
>> though we
>> don't have such support in Qemu atm.
> 
> Yeah I was referring to ARM SMMUv3 cases, where we need nested-smmuv3
> support for vfio-pci assignment. Another usecase we have is support SVA in
> Guest,  with hardware capable  of physical IOPF.
> 
> I will take a look at your series above and will see what else is required> to
support ARM. Please CC if you plan to respin or have a latest branch.
> Thanks for your efforts.

Right, the series about works for emulated intel-iommu and I had some patches
for virtio-iommu (which got simpler thanks to Eric's work on aw-bits). amd-iommu
is easily added too (but it needs to work with guest non-passthrough mode first
before we get there). The only thing you need to do in iommu emulation side is
to expose IOMMU_ATTR_MAX_IOVA[0], and it should be all. For guests hw-nesting /
iopf I don't think I see it affected considering the GPA space remains the same
and we still have a parent pagetable to get the stage 2 A/D bits (like non
nested case).

[0]
https://lore.kernel.org/qemu-devel/20230622214845.3980-11-joao.m.martins@oracle.com/

	Joao