Commit Graph

85 Commits

Author SHA1 Message Date
Longfang Liu
2202844e44 vfio/migration: Add debugfs to live migration driver
There are multiple devices, software and operational steps involved
in the process of live migration. An error occurred on any node may
cause the live migration operation to fail.
This complex process makes it very difficult to locate and analyze
the cause when the function fails.

In order to quickly locate the cause of the problem when the
live migration fails, I added a set of debugfs to the vfio
live migration driver.

    +-------------------------------------------+
    |                                           |
    |                                           |
    |                  QEMU                     |
    |                                           |
    |                                           |
    +---+----------------------------+----------+
        |      ^                     |      ^
        |      |                     |      |
        |      |                     |      |
        v      |                     v      |
     +---------+--+               +---------+--+
     |src vfio_dev|               |dst vfio_dev|
     +--+---------+               +--+---------+
        |      ^                     |      ^
        |      |                     |      |
        v      |                     |      |
   +-----------+----+           +-----------+----+
   |src dev debugfs |           |dst dev debugfs |
   +----------------+           +----------------+

The entire debugfs directory will be based on the definition of
the CONFIG_DEBUG_FS macro. If this macro is not enabled, the
interfaces in vfio.h will be empty definitions, and the creation
and initialization of the debugfs directory will not be executed.

   vfio
    |
    +---<dev_name1>
    |    +---migration
    |        +--state
    |
    +---<dev_name2>
         +---migration
             +--state

debugfs will create a public root directory "vfio" file.
then create a dev_name() file for each live migration device.
First, create a unified state acquisition file of "migration"
in this device directory.
Then, create a public live migration state lookup file "state".

Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20231106072225.28577-2-liulongfang@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-12-04 14:29:08 -07:00
Linus Torvalds
463f46e114 iommufd for 6.7
This branch has three new iommufd capabilities:
 
  - Dirty tracking for DMA. AMD/ARM/Intel CPUs can now record if a DMA
    writes to a page in the IOPTEs within the IO page table. This can be used
    to generate a record of what memory is being dirtied by DMA activities
    during a VM migration process. A VMM like qemu will combine the IOMMU
    dirty bits with the CPU's dirty log to determine what memory to
    transfer.
 
    VFIO already has a DMA dirty tracking framework that requires PCI
    devices to implement tracking HW internally. The iommufd version
    provides an alternative that the VMM can select, if available. The two
    are designed to have very similar APIs.
 
  - Userspace controlled attributes for hardware page
    tables (HWPT/iommu_domain). There are currently a few generic attributes
    for HWPTs (support dirty tracking, and parent of a nest). This is an
    entry point for the userspace iommu driver to control the HW in detail.
 
  - Nested translation support for HWPTs. This is a 2D translation scheme
    similar to the CPU where a DMA goes through a first stage to determine
    an intermediate address which is then translated trough a second stage
    to a physical address.
 
    Like for CPU translation the first stage table would exist in VM
    controlled memory and the second stage is in the kernel and matches the
    VM's guest to physical map.
 
    As every IOMMU has a unique set of parameter to describe the S1 IO page
    table and its associated parameters the userspace IOMMU driver has to
    marshal the information into the correct format.
 
    This is 1/3 of the feature, it allows creating the nested translation
    and binding it to VFIO devices, however the API to support IOTLB and
    ATC invalidation of the stage 1 io page table, and forwarding of IO
    faults are still in progress.
 
 The series includes AMD and Intel support for dirty tracking. Intel
 support for nested translation.
 
 Along the way are a number of internal items:
 
  - New iommu core items: ops->domain_alloc_user(), ops->set_dirty_tracking,
    ops->read_and_clear_dirty(), IOMMU_DOMAIN_NESTED, and iommu_copy_struct_from_user
 
  - UAF fix in iopt_area_split()
 
  - Spelling fixes and some test suite improvement
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Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd updates from Jason Gunthorpe:
 "This brings three new iommufd capabilities:

   - Dirty tracking for DMA.

     AMD/ARM/Intel CPUs can now record if a DMA writes to a page in the
     IOPTEs within the IO page table. This can be used to generate a
     record of what memory is being dirtied by DMA activities during a
     VM migration process. A VMM like qemu will combine the IOMMU dirty
     bits with the CPU's dirty log to determine what memory to transfer.

     VFIO already has a DMA dirty tracking framework that requires PCI
     devices to implement tracking HW internally. The iommufd version
     provides an alternative that the VMM can select, if available. The
     two are designed to have very similar APIs.

   - Userspace controlled attributes for hardware page tables
     (HWPT/iommu_domain). There are currently a few generic attributes
     for HWPTs (support dirty tracking, and parent of a nest). This is
     an entry point for the userspace iommu driver to control the HW in
     detail.

   - Nested translation support for HWPTs. This is a 2D translation
     scheme similar to the CPU where a DMA goes through a first stage to
     determine an intermediate address which is then translated trough a
     second stage to a physical address.

     Like for CPU translation the first stage table would exist in VM
     controlled memory and the second stage is in the kernel and matches
     the VM's guest to physical map.

     As every IOMMU has a unique set of parameter to describe the S1 IO
     page table and its associated parameters the userspace IOMMU driver
     has to marshal the information into the correct format.

     This is 1/3 of the feature, it allows creating the nested
     translation and binding it to VFIO devices, however the API to
     support IOTLB and ATC invalidation of the stage 1 io page table,
     and forwarding of IO faults are still in progress.

  The series includes AMD and Intel support for dirty tracking. Intel
  support for nested translation.

  Along the way are a number of internal items:

   - New iommu core items: ops->domain_alloc_user(),
     ops->set_dirty_tracking, ops->read_and_clear_dirty(),
     IOMMU_DOMAIN_NESTED, and iommu_copy_struct_from_user

   - UAF fix in iopt_area_split()

   - Spelling fixes and some test suite improvement"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (52 commits)
  iommufd: Organize the mock domain alloc functions closer to Joerg's tree
  iommufd/selftest: Fix page-size check in iommufd_test_dirty()
  iommufd: Add iopt_area_alloc()
  iommufd: Fix missing update of domains_itree after splitting iopt_area
  iommu/vt-d: Disallow read-only mappings to nest parent domain
  iommu/vt-d: Add nested domain allocation
  iommu/vt-d: Set the nested domain to a device
  iommu/vt-d: Make domain attach helpers to be extern
  iommu/vt-d: Add helper to setup pasid nested translation
  iommu/vt-d: Add helper for nested domain allocation
  iommu/vt-d: Extend dmar_domain to support nested domain
  iommufd: Add data structure for Intel VT-d stage-1 domain allocation
  iommu/vt-d: Enhance capability check for nested parent domain allocation
  iommufd/selftest: Add coverage for IOMMU_HWPT_ALLOC with nested HWPTs
  iommufd/selftest: Add nested domain allocation for mock domain
  iommu: Add iommu_copy_struct_from_user helper
  iommufd: Add a nested HW pagetable object
  iommu: Pass in parent domain with user_data to domain_alloc_user op
  iommufd: Share iommufd_hwpt_alloc with IOMMUFD_OBJ_HWPT_NESTED
  iommufd: Derive iommufd_hwpt_paging from iommufd_hw_pagetable
  ...
2023-11-01 16:44:56 -10:00
Joao Martins
13578d4ebe iommufd/iova_bitmap: Move symbols to IOMMUFD namespace
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().

Link: https://lore.kernel.org/r/20231024135109.73787-4-joao.m.martins@oracle.com
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>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:42 -03:00
Alex Williamson
bd885fcf28 vfio: Fix smatch errors in vfio_combine_iova_ranges()
smatch reports:

vfio_combine_iova_ranges() error: uninitialized symbol 'last'.
vfio_combine_iova_ranges() error: potentially dereferencing uninitialized 'comb_end'.
vfio_combine_iova_ranges() error: potentially dereferencing uninitialized 'comb_start'.

These errors are only reachable via invalid input, in the case of
@last when we receive an empty rb-tree or for @comb_{start,end} if the
rb-tree is empty or otherwise fails to produce a second node that
reduces the gap.  Add tests with warnings for these cases.

Reported-by: Cong Liu <liucong2@kylinos.cn>
Link: https://lore.kernel.org/all/20230920095532.88135-1-liucong2@kylinos.cn
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Link: https://lore.kernel.org/r/20231002224325.3150842-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-10-09 15:56:09 -06:00
Linus Torvalds
4debf77169 iommufd for 6.6
This includes a shared branch with VFIO:
 
  - Enhance VFIO_DEVICE_GET_PCI_HOT_RESET_INFO so it can work with iommufd
    FDs, not just group FDs. This removes the last place in the uAPI that
    required the group fd.
 
  - Give VFIO a new device node /dev/vfio/devices/vfioX (the so called cdev
    node) which is very similar to the FD from VFIO_GROUP_GET_DEVICE_FD.
    The cdev is associated with the struct device that the VFIO driver is
    bound to and shows up in sysfs in the normal way.
 
  - Add a cdev IOCTL VFIO_DEVICE_BIND_IOMMUFD which allows a newly opened
    /dev/vfio/devices/vfioX to be associated with an IOMMUFD, this replaces
    the VFIO_GROUP_SET_CONTAINER flow.
 
  - Add cdev IOCTLs VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT to allow the IOMMU
    translation the vfio_device is associated with to be changed. This is a
    significant new feature for VFIO as previously each vfio_device was
    fixed to a single translation.
 
    The translation is under the control of iommufd, so it can be any of
    the different translation modes that iommufd is learning to create.
 
 At this point VFIO has compilation options to remove the legacy interfaces
 and in modern mode it behaves like a normal driver subsystem. The
 /dev/vfio/iommu and /dev/vfio/groupX nodes are not present and each
 vfio_device only has a /dev/vfio/devices/vfioX cdev node that represents
 the device.
 
 On top of this is built some of the new iommufd functionality:
 
  - IOMMU_HWPT_ALLOC allows userspace to directly create the low level
    IO Page table objects and affiliate them with IOAS objects that hold
    the translation mapping. This is the basic functionality for the
    normal IOMMU_DOMAIN_PAGING domains.
 
  - VFIO_DEVICE_ATTACH_IOMMUFD_PT can be used to replace the current
    translation. This is wired up to through all the layers down to the
    driver so the driver has the ability to implement a hitless
    replacement. This is necessary to fully support guest behaviors when
    emulating HW (eg guest atomic change of translation)
 
  - IOMMU_GET_HW_INFO returns information about the IOMMU driver HW that
    owns a VFIO device. This includes support for the Intel iommu, and
    patches have been posted for all the other server IOMMU.
 
 Along the way are a number of internal items:
 
  - New iommufd kapis iommufd_ctx_has_group(), iommufd_device_to_ictx(),
    iommufd_device_to_id(), iommufd_access_detach(), iommufd_ctx_from_fd(),
    iommufd_device_replace()
 
  - iommufd now internally tracks iommu_groups as it needs some per-group
    data
 
  - Reorganize how the internal hwpt allocation flows to have more robust
    locking
 
  - Improve the access interfaces to support detach and replace of an IOAS
    from an access
 
  - New selftests and a rework of how the selftests creates a mock iommu
    driver to be more like a real iommu driver
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Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd updates from Jason Gunthorpe:
 "On top of the vfio updates is built some new iommufd functionality:

   - IOMMU_HWPT_ALLOC allows userspace to directly create the low level
     IO Page table objects and affiliate them with IOAS objects that
     hold the translation mapping. This is the basic functionality for
     the normal IOMMU_DOMAIN_PAGING domains.

   - VFIO_DEVICE_ATTACH_IOMMUFD_PT can be used to replace the current
     translation. This is wired up to through all the layers down to the
     driver so the driver has the ability to implement a hitless
     replacement. This is necessary to fully support guest behaviors
     when emulating HW (eg guest atomic change of translation)

   - IOMMU_GET_HW_INFO returns information about the IOMMU driver HW
     that owns a VFIO device. This includes support for the Intel iommu,
     and patches have been posted for all the other server IOMMU.

  Along the way are a number of internal items:

   - New iommufd kernel APIs: iommufd_ctx_has_group(),
        iommufd_device_to_ictx(), iommufd_device_to_id(),
        iommufd_access_detach(), iommufd_ctx_from_fd(),
        iommufd_device_replace()

   - iommufd now internally tracks iommu_groups as it needs some
     per-group data

   - Reorganize how the internal hwpt allocation flows to have more
     robust locking

   - Improve the access interfaces to support detach and replace of an
     IOAS from an access

   - New selftests and a rework of how the selftests creates a mock
     iommu driver to be more like a real iommu driver"

Link: https://lore.kernel.org/lkml/ZO%2FTe6LU1ENf58ZW@nvidia.com/

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (34 commits)
  iommufd/selftest: Don't leak the platform device memory when unloading the module
  iommu/vt-d: Implement hw_info for iommu capability query
  iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO ioctl
  iommufd: Add IOMMU_GET_HW_INFO
  iommu: Add new iommu op to get iommu hardware information
  iommu: Move dev_iommu_ops() to private header
  iommufd: Remove iommufd_ref_to_users()
  iommufd/selftest: Make the mock iommu driver into a real driver
  vfio: Support IO page table replacement
  iommufd/selftest: Add IOMMU_TEST_OP_ACCESS_REPLACE_IOAS coverage
  iommufd: Add iommufd_access_replace() API
  iommufd: Use iommufd_access_change_ioas in iommufd_access_destroy_object
  iommufd: Add iommufd_access_change_ioas(_id) helpers
  iommufd: Allow passing in iopt_access_list_id to iopt_remove_access()
  vfio: Do not allow !ops->dma_unmap in vfio_pin/unpin_pages()
  iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC
  iommufd/selftest: Return the real idev id from selftest mock_domain
  iommufd: Add IOMMU_HWPT_ALLOC
  iommufd/selftest: Test iommufd_device_replace()
  iommufd: Make destroy_rwsem use a lock class per object type
  ...
2023-08-30 20:41:37 -07:00
Stefan Hajnoczi
a881b49694 vfio: align capability structures
The VFIO_DEVICE_GET_INFO, VFIO_DEVICE_GET_REGION_INFO, and
VFIO_IOMMU_GET_INFO ioctls fill in an info struct followed by capability
structs:

  +------+---------+---------+-----+
  | info | caps[0] | caps[1] | ... |
  +------+---------+---------+-----+

Both the info and capability struct sizes are not always multiples of
sizeof(u64), leaving u64 fields in later capability structs misaligned.

Userspace applications currently need to handle misalignment manually in
order to support CPU architectures and programming languages with strict
alignment requirements.

Make life easier for userspace by ensuring alignment in the kernel. This
is done by padding info struct definitions and by copying out zeroes
after capability structs that are not aligned.

The new layout is as follows:

  +------+---------+---+---------+-----+
  | info | caps[0] | 0 | caps[1] | ... |
  +------+---------+---+---------+-----+

In this example caps[0] has a size that is not multiples of sizeof(u64),
so zero padding is added to align the subsequent structure.

Adding zero padding between structs does not break the uapi. The memory
layout is specified by the info.cap_offset and caps[i].next fields
filled in by the kernel. Applications use these field values to locate
structs and are therefore unaffected by the addition of zero padding.

Note that code that copies out info structs with padding is updated to
always zero the struct and copy out as many bytes as userspace
requested. This makes the code shorter and avoids potential information
leaks by ensuring padding is initialized.

Originally-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230809203144.2880050-1-stefanha@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-08-17 12:17:44 -06:00
Brett Creeley
9a4087fab3 vfio: Commonize combine_ranges for use in other VFIO drivers
Currently only Mellanox uses the combine_ranges function. The
new pds_vfio driver also needs this function. So, move it to
a common location for other vendor drivers to use.

Also, fix RCT ordering while moving/renaming the function.

Cc: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20230807205755.29579-2-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-08-16 10:52:23 -06:00
Nicolin Chen
89e07fd468 vfio: Do not allow !ops->dma_unmap in vfio_pin/unpin_pages()
A driver that doesn't implement ops->dma_unmap shouldn't be allowed to do
vfio_pin/unpin_pages(), though it can use vfio_dma_rw() to access an iova
range. Deny !ops->dma_unmap cases in vfio_pin/unpin_pages().

Link: https://lore.kernel.org/r/85d622729d8f2334b35d42f1c568df1ededb9171.1690523699.git.nicolinc@nvidia.com
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-28 13:31:24 -03:00
Yi Liu
5398be2564 vfio: Move the IOMMU_CAP_CACHE_COHERENCY check in __vfio_register_dev()
The IOMMU_CAP_CACHE_COHERENCY check only applies to the physical devices
that are IOMMU-backed. But it is now in the group code. If want to compile
vfio_group infrastructure out, this check needs to be moved out of the group
code.

Another reason for this change is to fail the device registration for the
physical devices that do not have IOMMU if the group code is not compiled
as the cdev interface does not support such devices.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-25-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:20:41 -06:00
Yi Liu
b290a05fd8 vfio: Add VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT
This adds ioctl for userspace to attach device cdev fd to and detach
from IOAS/hw_pagetable managed by iommufd.

    VFIO_DEVICE_ATTACH_IOMMUFD_PT: attach vfio device to IOAS or hw_pagetable
				   managed by iommufd. Attach can be undo
				   by VFIO_DEVICE_DETACH_IOMMUFD_PT or device
				   fd close.
    VFIO_DEVICE_DETACH_IOMMUFD_PT: detach vfio device from the current attached
				   IOAS or hw_pagetable managed by iommufd.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-24-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:20:37 -06:00
Yi Liu
5fcc26969a vfio: Add VFIO_DEVICE_BIND_IOMMUFD
This adds ioctl for userspace to bind device cdev fd to iommufd.

    VFIO_DEVICE_BIND_IOMMUFD: bind device to an iommufd, hence gain DMA
			      control provided by the iommufd. open_device
			      op is called after bind_iommufd op.

Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230718135551.6592-23-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:20:32 -06:00
Yi Liu
ca9e45b414 vfio: Avoid repeated user pointer cast in vfio_device_fops_unl_ioctl()
This adds a local variable to store the user pointer cast result from arg.
It avoids the repeated casts in the code when more ioctls are added.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-22-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:20:15 -06:00
Yi Liu
5c6de3ea73 vfio: Test kvm pointer in _vfio_device_get_kvm_safe()
This saves some lines when adding the kvm get logic for the vfio_device
cdev path.

This also renames _vfio_device_get_kvm_safe() to be vfio_device_get_kvm_safe().

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-20-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:19:45 -06:00
Yi Liu
8b6f173a4c vfio: Add cdev for vfio_device
This adds cdev support for vfio_device. It allows the user to directly
open a vfio device w/o using the legacy container/group interface, as a
prerequisite for supporting new iommu features like nested translation
and etc.

The device fd opened in this manner doesn't have the capability to access
the device as the fops open() doesn't open the device until the successful
VFIO_DEVICE_BIND_IOMMUFD ioctl which will be added in a later patch.

With this patch, devices registered to vfio core would have both the legacy
group and the new device interfaces created.

- group interface : /dev/vfio/$groupID
- device interface: /dev/vfio/devices/vfioX - normal device
		    ("X" is a unique number across vfio devices)

For a given device, the user can identify the matching vfioX by searching
the vfio-dev folder under the sysfs path of the device. Take PCI device
(0000:6a:01.0) as an example, /sys/bus/pci/devices/0000\:6a\:01.0/vfio-dev/vfioX
implies the matching vfioX under /dev/vfio/devices/, and vfio-dev/vfioX/dev
contains the major:minor number of the matching /dev/vfio/devices/vfioX.
The user can get device fd by opening the /dev/vfio/devices/vfioX.

The vfio_device cdev logic in this patch:
*) __vfio_register_dev() path ends up doing cdev_device_add() for each
   vfio_device if VFIO_DEVICE_CDEV configured.
*) vfio_unregister_group_dev() path does cdev_device_del();

cdev interface does not support noiommu devices, so VFIO only creates the
legacy group interface for the physical devices that do not have IOMMU.
noiommu users should use the legacy group interface.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-19-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:19:40 -06:00
Yi Liu
38c24544e1 vfio: Move device_del() before waiting for the last vfio_device registration refcount
device_del() destroys the vfio-dev/vfioX under the sysfs for vfio_device.
There is no reason to keep it while the device is going to be unregistered.

This movement is also a preparation for adding vfio_device cdev. Kernel
should remove the cdev node of the vfio_device to avoid new registration
refcount increment while the device is going to be unregistered.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-18-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:19:26 -06:00
Yi Liu
291872a533 vfio: Move vfio_device_group_unregister() to be the first operation in unregister
This avoids endless vfio_device refcount increment by userspace, which
would keep blocking the vfio_unregister_group_dev().

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-17-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:19:22 -06:00
Yi Liu
9048c7341c vfio-iommufd: Add detach_ioas support for physical VFIO devices
This prepares for adding DETACH ioctl for physical VFIO devices.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-14-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:19:12 -06:00
Yi Liu
31014aef9e vfio: Record devid in vfio_device_file
.bind_iommufd() will generate an ID to represent this bond, which is
needed by userspace for further usage. Store devid in vfio_device_file
to avoid passing the pointer in multiple places.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-13-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:19:08 -06:00
Yi Liu
839e692fa4 vfio: Make vfio_df_open() single open for device cdev path
VFIO group has historically allowed multi-open of the device FD. This
was made secure because the "open" was executed via an ioctl to the
group FD which is itself only single open.

However, no known use of multiple device FDs today. It is kind of a
strange thing to do because new device FDs can naturally be created
via dup().

When we implement the new device uAPI (only used in cdev path) there is
no natural way to allow the device itself from being multi-opened in a
secure manner. Without the group FD we cannot prove the security context
of the opener.

Thus, when moving to the new uAPI we block the ability of opening
a device multiple times. Given old group path still allows it we store
a vfio_group pointer in struct vfio_device_file to differentiate.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-10-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:18:57 -06:00
Yi Liu
82d93f580f vfio: Block device access via device fd until device is opened
Allow the vfio_device file to be in a state where the device FD is
opened but the device cannot be used by userspace (i.e. its .open_device()
hasn't been called). This inbetween state is not used when the device
FD is spawned from the group FD, however when we create the device FD
directly by opening a cdev it will be opened in the blocked state.

The reason for the inbetween state is that userspace only gets a FD but
doesn't gain access permission until binding the FD to an iommufd. So in
the blocked state, only the bind operation is allowed. Completing bind
will allow user to further access the device.

This is implemented by adding a flag in struct vfio_device_file to mark
the blocked state and using a simple smp_load_acquire() to obtain the
flag value and serialize all the device setup with the thread accessing
this device.

Following this lockless scheme, it can safely handle the device FD
unbound->bound but it cannot handle bound->unbound. To allow this we'd
need to add a lock on all the vfio ioctls which seems costly. So once
device FD is bound, it remains bound until the FD is closed.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-8-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:18:50 -06:00
Yi Liu
05f37e1c03 vfio: Pass struct vfio_device_file * to vfio_device_open/close()
This avoids passing too much parameters in multiple functions. Per the
input parameter change, rename the function to be vfio_df_open/close().

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-7-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:18:47 -06:00
Yi Liu
34aeeecdb3 vfio: Accept vfio device file in the KVM facing kAPI
This makes the vfio file kAPIs to accept vfio device files, also a
preparation for vfio device cdev support.

For the kvm set with vfio device file, kvm pointer is stored in struct
vfio_device_file, and use kvm_ref_lock to protect kvm set and kvm
pointer usage within VFIO. This kvm pointer will be set to vfio_device
after device file is bound to iommufd in the cdev path.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-4-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:18:28 -06:00
Yi Liu
b1a59be8a2 vfio: Refine vfio file kAPIs for KVM
This prepares for making the below kAPIs to accept both group file
and device file instead of only vfio group file.

  bool vfio_file_enforced_coherent(struct file *file);
  void vfio_file_set_kvm(struct file *file, struct kvm *kvm);

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-3-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:18:22 -06:00
Yi Liu
b1a3b5c61d vfio: Allocate per device file structure
This is preparation for adding vfio device cdev support. vfio device
cdev requires:
1) A per device file memory to store the kvm pointer set by KVM. It will
   be propagated to vfio_device:kvm after the device cdev file is bound
   to an iommufd.
2) A mechanism to block device access through device cdev fd before it
   is bound to an iommufd.

To address the above requirements, this adds a per device file structure
named vfio_device_file. For now, it's only a wrapper of struct vfio_device
pointer. Other fields will be added to this per file structure in future
commits.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-2-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:18:17 -06:00
Yi Liu
a80e1de932 vfio: Add helper to search vfio_device in a dev_set
There are drivers that need to search vfio_device within a given dev_set.
e.g. vfio-pci. So add a helper.

vfio_pci_is_device_in_set() now returns -EBUSY in commit a882c16a2b
("vfio/pci: Change vfio_pci_try_bus_reset() to use the dev_set") where
it was trying to preserve the return of vfio_pci_try_zap_and_vma_lock_cb().
However, it makes more sense to return -ENODEV.

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718105542.4138-8-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:18:02 -06:00
Linus Torvalds
556eb8b791 Driver core changes for 6.4-rc1
Here is the large set of driver core changes for 6.4-rc1.
 
 Once again, a busy development cycle, with lots of changes happening in
 the driver core in the quest to be able to move "struct bus" and "struct
 class" into read-only memory, a task now complete with these changes.
 
 This will make the future rust interactions with the driver core more
 "provably correct" as well as providing more obvious lifetime rules for
 all busses and classes in the kernel.
 
 The changes required for this did touch many individual classes and
 busses as many callbacks were changed to take const * parameters
 instead.  All of these changes have been submitted to the various
 subsystem maintainers, giving them plenty of time to review, and most of
 them actually did so.
 
 Other than those changes, included in here are a small set of other
 things:
   - kobject logging improvements
   - cacheinfo improvements and updates
   - obligatory fw_devlink updates and fixes
   - documentation updates
   - device property cleanups and const * changes
   - firwmare loader dependency fixes.
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.4-rc1.

  Once again, a busy development cycle, with lots of changes happening
  in the driver core in the quest to be able to move "struct bus" and
  "struct class" into read-only memory, a task now complete with these
  changes.

  This will make the future rust interactions with the driver core more
  "provably correct" as well as providing more obvious lifetime rules
  for all busses and classes in the kernel.

  The changes required for this did touch many individual classes and
  busses as many callbacks were changed to take const * parameters
  instead. All of these changes have been submitted to the various
  subsystem maintainers, giving them plenty of time to review, and most
  of them actually did so.

  Other than those changes, included in here are a small set of other
  things:

   - kobject logging improvements

   - cacheinfo improvements and updates

   - obligatory fw_devlink updates and fixes

   - documentation updates

   - device property cleanups and const * changes

   - firwmare loader dependency fixes.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
  device property: make device_property functions take const device *
  driver core: update comments in device_rename()
  driver core: Don't require dynamic_debug for initcall_debug probe timing
  firmware_loader: rework crypto dependencies
  firmware_loader: Strip off \n from customized path
  zram: fix up permission for the hot_add sysfs file
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
  tty: make tty_class a static const structure
  driver core: class: remove struct class_interface * from callbacks
  driver core: class: mark the struct class in struct class_interface constant
  driver core: class: make class_register() take a const *
  driver core: class: mark class_release() as taking a const *
  driver core: remove incorrect comment for device_create*
  MIPS: vpe-cmp: remove module owner pointer from struct class usage.
  ...
2023-04-27 11:53:57 -07:00
Yi Liu
7d12578c5d vfio: Check the presence for iommufd callbacks in __vfio_register_dev()
After making the no-DMA drivers (samples/vfio-mdev) providing iommufd
callbacks, __vfio_register_dev() should check the presence of the iommufd
callbacks if CONFIG_IOMMUFD is enabled.

Link: https://lore.kernel.org/r/20230327093351.44505-7-yi.l.liu@intel.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-31 13:43:32 -03:00
Greg Kroah-Hartman
1aaba11da9 driver core: class: remove module * from class_create()
The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something.  So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:33 +01:00
Linus Torvalds
cac85e4616 VFIO updates for v6.3-rc1
- Remove redundant resource check in vfio-platform. (Angus Chen)
 
  - Use GFP_KERNEL_ACCOUNT for persistent userspace allocations, allowing
    removal of arbitrary kernel limits in favor of cgroup control.
    (Yishai Hadas)
 
  - mdev tidy-ups, including removing the module-only build restriction
    for sample drivers, Kconfig changes to select mdev support,
    documentation movement to keep sample driver usage instructions with
    sample drivers rather than with API docs, remove references to
    out-of-tree drivers in docs. (Christoph Hellwig)
 
  - Fix collateral breakages from mdev Kconfig changes. (Arnd Bergmann)
 
  - Make mlx5 migration support match device support, improve source
    and target flows to improve pre-copy support and reduce downtime.
    (Yishai Hadas)
 
  - Convert additional mdev sysfs case to use sysfs_emit(). (Bo Liu)
 
  - Resolve copy-paste error in mdev mbochs sample driver Kconfig.
    (Ye Xingchen)
 
  - Avoid propagating missing reset error in vfio-platform if reset
    requirement is relaxed by module option. (Tomasz Duszynski)
 
  - Range size fixes in mlx5 variant driver for missed last byte and
    stricter range calculation. (Yishai Hadas)
 
  - Fixes to suspended vaddr support and locked_vm accounting, excluding
    mdev configurations from the former due to potential to indefinitely
    block kernel threads, fix underflow and restore locked_vm on new mm.
    (Steve Sistare)
 
  - Update outdated vfio documentation due to new IOMMUFD interfaces in
    recent kernels. (Yi Liu)
 
  - Resolve deadlock between group_lock and kvm_lock, finally.
    (Matthew Rosato)
 
  - Fix NULL pointer in group initialization error path with IOMMUFD.
    (Yan Zhao)
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Merge tag 'vfio-v6.3-rc1' of https://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Remove redundant resource check in vfio-platform (Angus Chen)

 - Use GFP_KERNEL_ACCOUNT for persistent userspace allocations, allowing
   removal of arbitrary kernel limits in favor of cgroup control (Yishai
   Hadas)

 - mdev tidy-ups, including removing the module-only build restriction
   for sample drivers, Kconfig changes to select mdev support,
   documentation movement to keep sample driver usage instructions with
   sample drivers rather than with API docs, remove references to
   out-of-tree drivers in docs (Christoph Hellwig)

 - Fix collateral breakages from mdev Kconfig changes (Arnd Bergmann)

 - Make mlx5 migration support match device support, improve source and
   target flows to improve pre-copy support and reduce downtime (Yishai
   Hadas)

 - Convert additional mdev sysfs case to use sysfs_emit() (Bo Liu)

 - Resolve copy-paste error in mdev mbochs sample driver Kconfig (Ye
   Xingchen)

 - Avoid propagating missing reset error in vfio-platform if reset
   requirement is relaxed by module option (Tomasz Duszynski)

 - Range size fixes in mlx5 variant driver for missed last byte and
   stricter range calculation (Yishai Hadas)

 - Fixes to suspended vaddr support and locked_vm accounting, excluding
   mdev configurations from the former due to potential to indefinitely
   block kernel threads, fix underflow and restore locked_vm on new mm
   (Steve Sistare)

 - Update outdated vfio documentation due to new IOMMUFD interfaces in
   recent kernels (Yi Liu)

 - Resolve deadlock between group_lock and kvm_lock, finally (Matthew
   Rosato)

 - Fix NULL pointer in group initialization error path with IOMMUFD (Yan
   Zhao)

* tag 'vfio-v6.3-rc1' of https://github.com/awilliam/linux-vfio: (32 commits)
  vfio: Fix NULL pointer dereference caused by uninitialized group->iommufd
  docs: vfio: Update vfio.rst per latest interfaces
  vfio: Update the kdoc for vfio_device_ops
  vfio/mlx5: Fix range size calculation upon tracker creation
  vfio: no need to pass kvm pointer during device open
  vfio: fix deadlock between group lock and kvm lock
  vfio: revert "iommu driver notify callback"
  vfio/type1: revert "implement notify callback"
  vfio/type1: revert "block on invalid vaddr"
  vfio/type1: restore locked_vm
  vfio/type1: track locked_vm per dma
  vfio/type1: prevent underflow of locked_vm via exec()
  vfio/type1: exclude mdevs from VFIO_UPDATE_VADDR
  vfio: platform: ignore missing reset if disabled at module init
  vfio/mlx5: Improve the target side flow to reduce downtime
  vfio/mlx5: Improve the source side flow upon pre_copy
  vfio/mlx5: Check whether VF is migratable
  samples: fix the prompt about SAMPLE_VFIO_MDEV_MBOCHS
  vfio/mdev: Use sysfs_emit() to instead of sprintf()
  vfio-mdev: add back CONFIG_VFIO dependency
  ...
2023-02-25 11:52:57 -08:00
Matthew Rosato
b0d2d5697e vfio: no need to pass kvm pointer during device open
Nothing uses this value during vfio_device_open anymore so it's safe
to remove it.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230203215027.151988-3-mjrosato@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-02-09 11:41:25 -07:00
Matthew Rosato
2b48f52f2b vfio: fix deadlock between group lock and kvm lock
After 51cdc8bc12, we have another deadlock scenario between the
kvm->lock and the vfio group_lock with two different codepaths acquiring
the locks in different order.  Specifically in vfio_open_device, vfio
holds the vfio group_lock when issuing device->ops->open_device but some
drivers (like vfio-ap) need to acquire kvm->lock during their open_device
routine;  Meanwhile, kvm_vfio_release will acquire the kvm->lock first
before calling vfio_file_set_kvm which will acquire the vfio group_lock.

To resolve this, let's remove the need for the vfio group_lock from the
kvm_vfio_release codepath.  This is done by introducing a new spinlock to
protect modifications to the vfio group kvm pointer, and acquiring a kvm
ref from within vfio while holding this spinlock, with the reference held
until the last close for the device in question.

Fixes: 51cdc8bc12 ("kvm/vfio: Fix potential deadlock on vfio group_lock")
Reported-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230203215027.151988-2-mjrosato@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-02-09 11:41:25 -07:00
Jason Gunthorpe
c9a397cee9 vfio: Support VFIO_NOIOMMU with iommufd
Add a small amount of emulation to vfio_compat to accept the SET_IOMMU to
VFIO_NOIOMMU_IOMMU and have vfio just ignore iommufd if it is working on a
no-iommu enabled device.

Move the enable_unsafe_noiommu_mode module out of container.c into
vfio_main.c so that it is always available even if VFIO_CONTAINER=n.

This passes Alex's mini-test:

https://github.com/awilliam/tests/blob/master/vfio-noiommu-pci-device-open.c

Link: https://lore.kernel.org/r/0-v3-480cd64a16f7+1ad0-iommufd_noiommu_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-02-03 15:45:23 -04:00
Linus Torvalds
785d21ba2f VFIO updates for v6.2-rc1
- Replace deprecated git://github.com link in MAINTAINERS. (Palmer Dabbelt)
 
  - Simplify vfio/mlx5 with module_pci_driver() helper. (Shang XiaoJing)
 
  - Drop unnecessary buffer from ACPI call. (Rafael Mendonca)
 
  - Correct latent missing include issue in iova-bitmap and fix support
    for unaligned bitmaps.  Follow-up with better fix through refactor.
    (Joao Martins)
 
  - Rework ccw mdev driver to split private data from parent structure,
    better aligning with the mdev lifecycle and allowing us to remove
    a temporary workaround. (Eric Farman)
 
  - Add an interface to get an estimated migration data size for a device,
    allowing userspace to make informed decisions, ex. more accurately
    predicting VM downtime. (Yishai Hadas)
 
  - Fix minor typo in vfio/mlx5 array declaration. (Yishai Hadas)
 
  - Simplify module and Kconfig through consolidating SPAPR/EEH code and
    config options and folding virqfd module into main vfio module.
    (Jason Gunthorpe)
 
  - Fix error path from device_register() across all vfio mdev and sample
    drivers. (Alex Williamson)
 
  - Define migration pre-copy interface and implement for vfio/mlx5
    devices, allowing portions of the device state to be saved while the
    device continues operation, towards reducing the stop-copy state
    size. (Jason Gunthorpe, Yishai Hadas, Shay Drory)
 
  - Implement pre-copy for hisi_acc devices. (Shameer Kolothum)
 
  - Fixes to mdpy mdev driver remove path and error path on probe.
    (Shang XiaoJing)
 
  - vfio/mlx5 fixes for incorrect return after copy_to_user() fault and
    incorrect buffer freeing. (Dan Carpenter)
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Merge tag 'vfio-v6.2-rc1' of https://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Replace deprecated git://github.com link in MAINTAINERS (Palmer
   Dabbelt)

 - Simplify vfio/mlx5 with module_pci_driver() helper (Shang XiaoJing)

 - Drop unnecessary buffer from ACPI call (Rafael Mendonca)

 - Correct latent missing include issue in iova-bitmap and fix support
   for unaligned bitmaps. Follow-up with better fix through refactor
   (Joao Martins)

 - Rework ccw mdev driver to split private data from parent structure,
   better aligning with the mdev lifecycle and allowing us to remove a
   temporary workaround (Eric Farman)

 - Add an interface to get an estimated migration data size for a
   device, allowing userspace to make informed decisions, ex. more
   accurately predicting VM downtime (Yishai Hadas)

 - Fix minor typo in vfio/mlx5 array declaration (Yishai Hadas)

 - Simplify module and Kconfig through consolidating SPAPR/EEH code and
   config options and folding virqfd module into main vfio module (Jason
   Gunthorpe)

 - Fix error path from device_register() across all vfio mdev and sample
   drivers (Alex Williamson)

 - Define migration pre-copy interface and implement for vfio/mlx5
   devices, allowing portions of the device state to be saved while the
   device continues operation, towards reducing the stop-copy state size
   (Jason Gunthorpe, Yishai Hadas, Shay Drory)

 - Implement pre-copy for hisi_acc devices (Shameer Kolothum)

 - Fixes to mdpy mdev driver remove path and error path on probe (Shang
   XiaoJing)

 - vfio/mlx5 fixes for incorrect return after copy_to_user() fault and
   incorrect buffer freeing (Dan Carpenter)

* tag 'vfio-v6.2-rc1' of https://github.com/awilliam/linux-vfio: (42 commits)
  vfio/mlx5: error pointer dereference in error handling
  vfio/mlx5: fix error code in mlx5vf_precopy_ioctl()
  samples: vfio-mdev: Fix missing pci_disable_device() in mdpy_fb_probe()
  hisi_acc_vfio_pci: Enable PRE_COPY flag
  hisi_acc_vfio_pci: Move the dev compatibility tests for early check
  hisi_acc_vfio_pci: Introduce support for PRE_COPY state transitions
  hisi_acc_vfio_pci: Add support for precopy IOCTL
  vfio/mlx5: Enable MIGRATION_PRE_COPY flag
  vfio/mlx5: Fallback to STOP_COPY upon specific PRE_COPY error
  vfio/mlx5: Introduce multiple loads
  vfio/mlx5: Consider temporary end of stream as part of PRE_COPY
  vfio/mlx5: Introduce vfio precopy ioctl implementation
  vfio/mlx5: Introduce SW headers for migration states
  vfio/mlx5: Introduce device transitions of PRE_COPY
  vfio/mlx5: Refactor to use queue based data chunks
  vfio/mlx5: Refactor migration file state
  vfio/mlx5: Refactor MKEY usage
  vfio/mlx5: Refactor PD usage
  vfio/mlx5: Enforce a single SAVE command at a time
  vfio: Extend the device migration protocol with PRE_COPY
  ...
2022-12-15 13:12:15 -08:00
Jason Gunthorpe
4db52602a6 vfio: Extend the device migration protocol with PRE_COPY
The optional PRE_COPY states open the saving data transfer FD before
reaching STOP_COPY and allows the device to dirty track internal state
changes with the general idea to reduce the volume of data transferred
in the STOP_COPY stage.

While in PRE_COPY the device remains RUNNING, but the saving FD is open.

Only if the device also supports RUNNING_P2P can it support PRE_COPY_P2P,
which halts P2P transfers while continuing the saving FD.

PRE_COPY, with P2P support, requires the driver to implement 7 new arcs
and exists as an optional FSM branch between RUNNING and STOP_COPY:
    RUNNING -> PRE_COPY -> PRE_COPY_P2P -> STOP_COPY

A new ioctl VFIO_MIG_GET_PRECOPY_INFO is provided to allow userspace to
query the progress of the precopy operation in the driver with the idea it
will judge to move to STOP_COPY at least once the initial data set is
transferred, and possibly after the dirty size has shrunk appropriately.

This ioctl is valid only in PRE_COPY states and kernel driver should
return -EINVAL from any other migration state.

Compared to the v1 clarification, STOP_COPY -> PRE_COPY is blocked
and to be defined in future.
We also split the pending_bytes report into the initial and sustaining
values, e.g.: initial_bytes and dirty_bytes.
initial_bytes: Amount of initial precopy data.
dirty_bytes: Device state changes relative to data previously retrieved.
These fields are not required to have any bearing to STOP_COPY phase.

It is recommended to leave PRE_COPY for STOP_COPY only after the
initial_bytes field reaches zero. Leaving PRE_COPY earlier might make
things slower.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-12-06 12:36:43 -07:00
Jason Gunthorpe
e2d5570939 vfio: Fold vfio_virqfd.ko into vfio.ko
This is only 1.8k, putting it in its own module is not really
necessary. The kconfig infrastructure is still there to completely remove
it for systems that are trying for small footprint.

Put it in the main vfio.ko module now that kbuild can support multiple .c
files.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/5-v5-fc5346cacfd4+4c482-vfio_modules_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-12-05 12:04:32 -07:00
Yi Liu
9eefba8002 vfio: Move vfio group specific code into group.c
This prepares for compiling out vfio group after vfio device cdev is
added. No vfio_group decode code should be in vfio_main.c, and neither
device->group reference should be in vfio_main.c.

No functional change is intended.

Link: https://lore.kernel.org/r/20221201145535.589687-11-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Yu He <yu.he@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-05 08:56:01 -04:00
Yi Liu
8da7a0e79f vfio: Refactor dma APIs for emulated devices
To use group helpers instead of opening group related code in the
API. This prepares moving group specific code out of vfio_main.c.

Link: https://lore.kernel.org/r/20221201145535.589687-10-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-05 08:56:01 -04:00
Yi Liu
1334e47ee7 vfio: Wrap vfio group module init/clean code into helpers
This wraps the init/clean code of vfio group global variable to be
helpers, and prepares for further moving vfio group specific code into
separate file.

As container is used by group, so vfio_container_init/cleanup() is moved
into vfio_group_init/cleanup().

Link: https://lore.kernel.org/r/20221201145535.589687-9-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-05 08:56:01 -04:00
Yi Liu
5c8d3d93f6 vfio: Refactor vfio_device open and close
This refactor makes the vfio_device_open() to accept device, iommufd_ctx
pointer and kvm pointer. These parameters are generic items in today's
group path and future device cdev path. Caller of vfio_device_open()
should take care the necessary protections. e.g. the current group path
need to hold the group_lock to ensure the iommufd_ctx and kvm pointer are
valid.

This refactor also wraps the group spefcific codes in the device open and
close paths to be paired helpers like:

- vfio_device_group_open/close(): call vfio_device_open/close()
- vfio_device_group_use/unuse_iommu(): this pair is container specific.
				       iommufd vs. container is selected
				       in vfio_device_first_open().

Such helpers are supposed to be moved to group.c. While iommufd related
codes will be kept in the generic helpers since future device cdev path
also need to handle iommufd.

Link: https://lore.kernel.org/r/20221201145535.589687-8-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-05 08:56:01 -04:00
Yi Liu
5cfff07743 vfio: Make vfio_device_open() truly device specific
Then move group related logic into vfio_device_open_file(). Accordingly
introduce a vfio_device_close() to pair up.

Link: https://lore.kernel.org/r/20221201145535.589687-7-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-05 08:56:01 -04:00
Yi Liu
07b4658633 vfio: Swap order of vfio_device_container_register() and open_device()
This makes the DMA unmap callback registration to container be consistent
across the vfio iommufd compat mode and the legacy container mode.

In the vfio iommufd compat mode, this registration is done in the
vfio_iommufd_bind() when creating access which has an unmap callback. This
is prior to calling the open_device() op. The existing mdev drivers have
been converted to be OK with this order. So it is ok to swap the order of
vfio_device_container_register() and open_device() for legacy mode.

This also prepares for further moving group specific code into separate
source file.

Link: https://lore.kernel.org/r/20221201145535.589687-6-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-05 08:56:01 -04:00
Yi Liu
49ea02d390 vfio: Set device->group in helper function
This avoids referencing device->group in __vfio_register_dev().

Link: https://lore.kernel.org/r/20221201145535.589687-5-yi.l.liu@intel.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-05 08:56:01 -04:00
Yi Liu
32e0922821 vfio: Create wrappers for group register/unregister
This avoids decoding group fields in the common functions used by
vfio_device registration, and prepares for further moving the vfio group
specific code into separate file.

Link: https://lore.kernel.org/r/20221201145535.589687-4-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-05 08:56:01 -04:00
Jason Gunthorpe
dcb93d0364 vfio: Move the sanity check of the group to vfio_create_group()
This avoids opening group specific code in __vfio_register_dev() for the
sanity check if an (existing) group is not corrupted by having two copies
of the same struct device in it. It also simplifies the error unwind for
this sanity check since the failure can be detected in the group
allocation.

This also prepares for moving the group specific code into separate
group.c.

Grabbed from:
https://lore.kernel.org/kvm/20220922152338.2a2238fe.alex.williamson@redhat.com/

Link: https://lore.kernel.org/r/20221201145535.589687-3-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
2022-12-05 08:56:01 -04:00
Jason Gunthorpe
f794eec86c vfio: Simplify vfio_create_group()
The vfio.group_lock is now only used to serialize vfio_group creation and
destruction, we don't need a micro-optimization of searching, unlocking,
then allocating and searching again. Just hold the lock the whole time.

Grabbed from:
https://lore.kernel.org/kvm/20220922152338.2a2238fe.alex.williamson@redhat.com/

Link: https://lore.kernel.org/r/20221201145535.589687-2-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
2022-12-05 08:56:01 -04:00
Jason Gunthorpe
90337f526c Merge tag 'v6.1-rc7' into iommufd.git for-next
Resolve conflicts in drivers/vfio/vfio_main.c by using the iommfd version.
The rc fix was done a different way when iommufd patches reworked this
code.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-02 12:04:39 -04:00
Jason Gunthorpe
81ab9890da vfio: Move container related MODULE_ALIAS statements into container.c
The miscdev is in container.c, so should these related MODULE_ALIAS
statements. This is necessary for the next patch to be able to fully
disable /dev/vfio/vfio.

Fixes: cdc71fe4ec ("vfio: Move container code into drivers/vfio/container.c")
Link: https://lore.kernel.org/r/8-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Reported-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-02 11:52:04 -04:00
Jason Gunthorpe
4741f2e941 vfio-iommufd: Support iommufd for emulated VFIO devices
Emulated VFIO devices are calling vfio_register_emulated_iommu_dev() and
consist of all the mdev drivers.

Like the physical drivers, support for iommufd is provided by the driver
supplying the correct standard ops. Provide ops from the core that
duplicate what vfio_register_emulated_iommu_dev() does.

Emulated drivers are where it is more likely to see variation in the
iommfd support ops. For instance IDXD will probably need to setup both a
iommfd_device context linked to a PASID and an iommufd_access context to
support all their mdev operations.

Link: https://lore.kernel.org/r/7-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-02 11:52:03 -04:00
Jason Gunthorpe
a4d1f91db5 vfio-iommufd: Support iommufd for physical VFIO devices
This creates the iommufd_device for the physical VFIO drivers. These are
all the drivers that are calling vfio_register_group_dev() and expect the
type1 code to setup a real iommu_domain against their parent struct
device.

The design gives the driver a choice in how it gets connected to iommufd
by providing bind_iommufd/unbind_iommufd/attach_ioas callbacks to
implement as required. The core code provides three default callbacks for
physical mode using a real iommu_domain. This is suitable for drivers
using vfio_register_group_dev()

Link: https://lore.kernel.org/r/6-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-02 11:52:03 -04:00
Jason Gunthorpe
2a3dab19a0 vfio-iommufd: Allow iommufd to be used in place of a container fd
This makes VFIO_GROUP_SET_CONTAINER accept both a vfio container FD and an
iommufd.

In iommufd mode an IOAS will exist after the SET_CONTAINER, but it will
not be attached to any groups.

For VFIO this means that the VFIO_GROUP_GET_STATUS and
VFIO_GROUP_FLAGS_VIABLE works subtly differently. With the container FD
the iommu_group_claim_dma_owner() is done during SET_CONTAINER but for
IOMMUFD this is done during VFIO_GROUP_GET_DEVICE_FD. Meaning that
VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due to
viability.

As GET_DEVICE_FD can fail for many reasons already this is not expected to
be a meaningful difference.

Reorganize the tests for if the group has an assigned container or iommu
into a vfio_group_has_iommu() function and consolidate all the duplicated
WARN_ON's etc related to this.

Call container functions only if a container is actually present on the
group.

Link: https://lore.kernel.org/r/5-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-02 11:52:03 -04:00