This was missed during the initial implementation. The VFIO PCI encodes
the vf_token inside the device name when opening the device from the group
FD, something like:
"0000:04:10.0 vf_token=bd8d9d2b-5a5f-4f5a-a211-f591514ba1f3"
This is used to control access to a VF unless there is co-ordination with
the owner of the PF.
Since we no longer have a device name in the cdev path, pass the token
directly through VFIO_DEVICE_BIND_IOMMUFD using an optional field
indicated by VFIO_DEVICE_BIND_FLAG_TOKEN.
Fixes: 5fcc26969a ("vfio: Add VFIO_DEVICE_BIND_IOMMUFD")
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/0-v3-bdd8716e85fe+3978a-vfio_token_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
MLX cap pg_track_log_max_msg_size consists of 5 bits, value of which is
used as power of 2 for max_msg_size. This can lead to multiplication
overflow between max_msg_size (u32) and integer constant, and afterwards
incorrect value is being written to rq_size.
Fix this issue by extending integer constant to u64 type.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Artem Sadovnikov <a.sadovnikov@ispras.ru>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20250701144017.2410-2-a.sadovnikov@ispras.ru
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Change the creation of mkey to be performed in multiple steps:
data allocation, DMA setup and actual call to HW to create that mkey.
In this new flow, the whole input to MKEY command is saved to eliminate
the need to keep array of pointers for DMA addresses for receive list
and in the future patches for send list too.
In addition to memory size reduce and elimination of unnecessary data
movements to set MKEY input, the code is prepared for future reuse.
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/d4ad0384fbd1e23a607cbbe9e5756748f3a761d9.1747747694.git.leon@kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
allocated_length is a multiple of page size and number of pages,
so let's change the functions to accept number of pages. This improves
code readability, simplifies buffer handling, and enables combining DMA
send/receive operations, as will be introduced in the next patches.
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/76f39993d2ca0311b3bcfe56038a669d03926815.1747747694.git.leon@kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The previous commit removed the page_list argument from
alloc_pages_bulk_noprof() along with the alloc_pages_bulk_list() function.
Now that only the *_array() flavour of the API remains, we can do the
following renaming (along with the _noprof() ones):
alloc_pages_bulk_array -> alloc_pages_bulk
alloc_pages_bulk_array_mempolicy -> alloc_pages_bulk_mempolicy
alloc_pages_bulk_array_node -> alloc_pages_bulk_node
Link: https://lkml.kernel.org/r/275a3bbc0be20fbe9002297d60045e67ab3d4ada.1734991165.git.luizcap@redhat.com
Signed-off-by: Luiz Capitulino <luizcap@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- Fix migration dirty page tracking support in the mlx5-vfio-pci
variant driver in configurations where the system page size exceeds
the device maximum message size, and anticipate device updates where
the opposite may also be required. (Yishai Hadas)
-----BEGIN PGP SIGNATURE-----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=oI9e
-----END PGP SIGNATURE-----
Merge tag 'vfio-v6.13-rc3' of https://github.com/awilliam/linux-vfio
Pull vfio fix from Alex Williamson:
- Fix migration dirty page tracking support in the mlx5-vfio-pci
variant driver in configurations where the system page size exceeds
the device maximum message size, and anticipate device updates where
the opposite may also be required (Yishai Hadas)
* tag 'vfio-v6.13-rc3' of https://github.com/awilliam/linux-vfio:
vfio/mlx5: Align the page tracking max message size with the device capability
Align the page tracking maximum message size with the device's
capability instead of relying on PAGE_SIZE.
This adjustment resolves a mismatch on systems where PAGE_SIZE is 64K,
but the firmware only supports a maximum message size of 4K.
Now that we rely on the device's capability for max_message_size, we
must account for potential future increases in its value.
Key considerations include:
- Supporting message sizes that exceed a single system page (e.g., an 8K
message on a 4K system).
- Ensuring the RQ size is adjusted to accommodate at least 4
WQEs/messages, in line with the device specification.
The above has been addressed as part of the patch.
Fixes: 79c3cf2799 ("vfio/mlx5: Init QP based resources for dirty tracking")
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Tested-by: Yingshun Cui <yicui@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20241205122654.235619-1-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Fix unwind flows in mlx5vf_pci_save_device_data() and
mlx5vf_pci_resume_device_data() to avoid freeing the migf pointer at the
'end' label, as this will be handled by fput(migf->filp) through
mlx5vf_release_file().
To ensure mlx5vf_release_file() functions correctly, move the
initialization of migf fields (such as migf->lock) to occur before any
potential unwind flow, as these fields may be accessed within
mlx5vf_release_file().
Fixes: 9945a67ea4 ("vfio/mlx5: Refactor PD usage")
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20241114095318.16556-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Fix an unwind issue in mlx5vf_add_migration_pages().
If a set of pages is allocated but fails to be added to the SG table,
they need to be freed to prevent a memory leak.
Any pages successfully added to the SG table will be freed as part of
mlx5vf_free_data_buffer().
Fixes: 6fadb02126 ("vfio/mlx5: Implement vfio_pci driver for mlx5 devices")
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20241114095318.16556-2-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable live migration only once the firmware supports PRE_COPY.
PRE_COPY has been supported by the firmware for a long time already [1]
and is required to achieve a low downtime upon live migration.
This lets us clean up some old code that is not applicable those days
while PRE_COPY is fully supported by the firmware.
[1] The minimum firmware version that supports PRE_COPY is 28.36.1010,
it was released in January 2023.
No firmware without PRE_COPY support ever available to users.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20240306105624.114830-1-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Let firmware knows upon leaving PRE_COPY back to RUNNING as of some
error in the target/migration cancellation.
This will let firmware cleaning its internal resources that were turned
on upon PRE_COPY.
The flow is based on the device specification in this area.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/r/20240205124828.232701-6-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Block incremental query which is state-dependent once the migration file
was previously marked with state error.
This may prevent redundant calls to firmware upon PRE_COPY which will
end-up with a failure and a syndrome printed in dmesg.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/r/20240205124828.232701-5-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The SAVE command uses the async command interface over the PF.
Upon a failure in the firmware -EREMOTEIO is returned.
In that case call mlx5_cmd_out_err() to let it print the command failure
details including the firmware syndrome.
Note:
The other commands in the driver use the sync command interface in a way
that a firmware syndrome is printed upon an error inside mlx5_core.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/r/20240205124828.232701-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add support for tracker object change event by referring to its
MLX5_EVENT_TYPE_OBJECT_CHANGE event when occurs.
This lets the driver recognize whether the firmware moved the tracker
object to an error state.
In that case, the driver will skip/block any usage of that object
including an early exit in case the object was previously marked with an
error.
This functionality also covers the case when no CQE is delivered as of
the error state.
The driver was adapted to the device specification to handle the above.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/r/20240205124828.232701-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQRRRCHOFoQz/8F5bUaFwuHvBreFYQUCZUDu2wAKCRCFwuHvBreF
YcdeAQDaBmjyGLrRIlzPyohF6FrombyWo2512n51Hs8IHR4IvQEA3oRNgQ2tsJRr
1UPuOqnOD5T/oVX6AkUPRBwanCUQwwM=
=nyJ3
-----END PGP SIGNATURE-----
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
...
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>
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
Link: https://lore.kernel.org/r/20231024135109.73787-3-joao.m.martins@oracle.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>
Now that all pieces are in place, activate the chunk mode functionality
based on device capabilities.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230911093856.81910-10-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add support for READING in chunk mode.
In case the last SAVE command recognized that there was still some image
to be read, however, there was no available chunk to use for, this task
was delayed for the reader till one chunk will be consumed and becomes
available.
In the above case, a work will be executed to read in the background the
next image from the device.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230911093856.81910-9-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add support for SAVING in chunk mode, it includes running a work
that will fill the next chunk from the device.
In case the number of available chunks will reach the MAX_NUM_CHUNKS,
the next chunk SAVING will be delayed till the reader will consume one
chunk.
The next patch from the series will add the reader part of the chunk
mode.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230911093856.81910-8-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This patch is another preparation step towards working in chunk mode.
It pre-allocates chunks for the STOP_COPY phase to let the driver use
them immediately and prevent an extra allocation upon that phase.
Before that patch we had a single large buffer that was dedicated for
the STOP_COPY phase as there was a single SAVE in the source for the
last image.
Once we'll move to chunk mode the idea is to have some small buffers
that will be used upon the STOP_COPY phase.
The driver will read-ahead from the firmware the full state in
small/optimized chunks while letting QEMU/user space read in parallel
the available data.
Each buffer holds its chunk number to let it be recognized down the road
in the coming patches.
The chunk buffer size is picked-up based on the minimum size that
firmware requires, the total full size and some max value in the driver
code which was set to 8MB to achieve some optimized downtime in the
general case.
As the chunk mode is applicable even if we move directly to STOP_COPY
the buffers preparation and some other related stuff is done
unconditionally with regards to STOP/PRE-COPY.
Note:
In that phase in the series we still didn't activate the chunk mode and
the first buffer will be used in all the places.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230911093856.81910-7-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Upon chunk mode there may be multiple images that will be read from the
device upon STOP_COPY.
This patch is some preparation for that mode by replacing the relevant
stuff to a better matching name.
As part of that, be stricter to recognize PRE_COPY error only when it
didn't occur on a STOP_COPY chunk.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230911093856.81910-6-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Once the device supports 'chunk mode' the driver can support state size
which is larger than 4GB.
In that case the device has the capability to split a single image to
multiple chunks as long as the software provides a buffer in the minimum
size reported by the device.
The driver should query for the minimum buffer size required using
QUERY_VHCA_MIGRATION_STATE command with the 'chunk' bit set in its
input, in that case, the output will include both the minimum buffer
size (i.e. required_umem_size) and also the remaining total size to be
reported/used where that it will be applicable.
At that point in the series the 'chunk' bit is off, the last patch will
activate the feature once all pieces will be ready.
Note:
Before this change we were limited to 4GB state size as of 4 bytes max
value based on the device specification for the query/save/load
commands.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230911093856.81910-5-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Upon a successful SAVE callback there is no need to activate a work, all
the required stuff can be done directly.
As so, refactor the above flow to activate a work only upon an error.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230911093856.81910-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Post of disabling the SAVING migration file, which includes setting the
file state to be MLX5_MIGF_STATE_ERROR, call to wake_up_interruptible()
on its poll_wait member.
This lets any potential reader which is waiting already for data as part
of mlx5vf_save_read() to wake up, recognize the error state and return
with an error.
Post of that we don't need to rely on any other condition to wake up
the reader as of the returning of the SAVE command that was previously
executed, etc.
In addition, this change will simplify error flows (e.g health recovery)
once we'll move to chunk mode and multiple SAVE commands may run in the
STOP_COPY phase as we won't need to rely any more on a SAVE command to
wake-up a potential waiting reader.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230911093856.81910-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
- VFIO direct character device (cdev) interface support. This extracts
the vfio device fd from the container and group model, and is intended
to be the native uAPI for use with IOMMUFD. (Yi Liu)
- Enhancements to the PCI hot reset interface in support of cdev usage.
(Yi Liu)
- Fix a potential race between registering and unregistering vfio files
in the kvm-vfio interface and extend use of a lock to avoid extra
drop and acquires. (Dmitry Torokhov)
- A new vfio-pci variant driver for the AMD/Pensando Distributed Services
Card (PDS) Ethernet device, supporting live migration. (Brett Creeley)
- Cleanups to remove redundant owner setup in cdx and fsl bus drivers,
and simplify driver init/exit in fsl code. (Li Zetao)
- Fix uninitialized hole in data structure and pad capability structures
for alignment. (Stefan Hajnoczi)
-----BEGIN PGP SIGNATURE-----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=eKSR
-----END PGP SIGNATURE-----
Merge tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- VFIO direct character device (cdev) interface support. This extracts
the vfio device fd from the container and group model, and is
intended to be the native uAPI for use with IOMMUFD (Yi Liu)
- Enhancements to the PCI hot reset interface in support of cdev usage
(Yi Liu)
- Fix a potential race between registering and unregistering vfio files
in the kvm-vfio interface and extend use of a lock to avoid extra
drop and acquires (Dmitry Torokhov)
- A new vfio-pci variant driver for the AMD/Pensando Distributed
Services Card (PDS) Ethernet device, supporting live migration (Brett
Creeley)
- Cleanups to remove redundant owner setup in cdx and fsl bus drivers,
and simplify driver init/exit in fsl code (Li Zetao)
- Fix uninitialized hole in data structure and pad capability
structures for alignment (Stefan Hajnoczi)
* tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfio: (53 commits)
vfio/pds: Send type for SUSPEND_STATUS command
vfio/pds: fix return value in pds_vfio_get_lm_file()
pds_core: Fix function header descriptions
vfio: align capability structures
vfio/type1: fix cap_migration information leak
vfio/fsl-mc: Use module_fsl_mc_driver macro to simplify the code
vfio/cdx: Remove redundant initialization owner in vfio_cdx_driver
vfio/pds: Add Kconfig and documentation
vfio/pds: Add support for firmware recovery
vfio/pds: Add support for dirty page tracking
vfio/pds: Add VFIO live migration support
vfio/pds: register with the pds_core PF
pds_core: Require callers of register/unregister to pass PF drvdata
vfio/pds: Initial support for pds VFIO driver
vfio: Commonize combine_ranges for use in other VFIO drivers
kvm/vfio: avoid bouncing the mutex when adding and deleting groups
kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add()
docs: vfio: Add vfio device cdev description
vfio: Compile vfio_group infrastructure optionally
vfio: Move the IOMMU_CAP_CACHE_COHERENCY check in __vfio_register_dev()
...
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>
This commit enables the dynamic allocation of EQs at runtime, allowing
for more flexibility in managing completion EQs and reducing the memory
overhead of driver load. Whenever a CQ is created for a given vector
index, the driver will lookup to see if there is an already mapped
completion EQ for that vector, if so, utilize it. Otherwise, allocate a
new EQ on demand and then utilize it for the CQ completion events.
Add a protection lock to the EQ table to protect from concurrent EQ
creation attempts.
While at it, replace mlx5_vector2irqn()/mlx5_vector2eqn() with
mlx5_comp_eqn_get() and mlx5_comp_irqn_get() which will allocate an
EQ on demand if no EQ is found for the given vector.
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
To accurately represent its purpose, rename the function that retrieves
the value of maximum vectors from mlx5_comp_vectors_count() to
mlx5_comp_vectors_max().
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
It should be possible to select vfio-pci variant drivers without building
vfio-pci itself, which implies each variant driver should select
vfio-pci-core.
Fix the top level vfio Makefile to traverse pci based on vfio-pci-core
rather than vfio-pci.
Mark MMAP and INTX options depending on vfio-pci-core to cleanup resulting
config if core is not enabled.
Push all PCI related vfio options to a sub-menu and make descriptions
consistent.
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20230614193948.477036-2-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Fix the report of dirty_bytes upon pre-copy to include both the existing
data on the migration file and the device extra bytes.
This gives a better close estimation to what can be passed any more as
part of pre-copy.
Fixes: 0dce165b1a ("vfio/mlx5: Introduce vfio precopy ioctl implementation")
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20230308155723.108218-1-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Fix range size calculation to include the last byte of each range.
In addition, log round up the length of the total ranges to be stricter.
Fixes: c1d050b0d1 ("vfio/mlx5: Create and destroy page tracker object")
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20230208152234.32370-1-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Improve the target side flow to reduce downtime as of below.
- Support reading an optional record which includes the expected
stop_copy size.
- Once the source sends this record data, which expects to be sent as
part of the pre_copy flow, prepare the data buffers that may be large
enough to hold the final stop_copy data.
The above reduces the migration downtime as the relevant stuff that is
needed to load the image data is prepared ahead as part of pre_copy.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20230124144955.139901-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Improve the source side flow upon pre_copy as of below.
- Prepare the stop_copy buffers as part of moving to pre_copy.
- Send to the target a record that includes the expected
stop_copy size to let it optimize its stop_copy flow as well.
As for sending the target this new record type (i.e.
MLX5_MIGF_HEADER_TAG_STOP_COPY_SIZE) we split the current 64 header
flags bits into 32 flags bits and another 32 tag bits, each record may
have a tag and a flag whether it's optional or mandatory. Optional
records will be ignored in the target.
The above reduces the downtime upon stop_copy as the relevant data stuff
is prepared ahead as part of pre_copy.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20230124144955.139901-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add a check whether VF is migratable. Only if VF is migratable, mark the
VFIO device as migration capable.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20230124144955.139901-2-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Allow loading of larger images than 512 MB by dropping the arbitrary
hard-coded value that we have today and move to use the max device
loading value which is for now 4GB.
As part of that we move to use the GFP_KERNEL_ACCOUNT option upon
allocating the persistent data of mlx5 and rely on the cgroup to provide
the memory limit for the given user.
The GFP_KERNEL_ACCOUNT option lets the memory allocator know that this
is untrusted allocation triggered from userspace and should be a subject
of kmem accounting, and as such it is controlled by the cgroup
mechanism.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230108154427.32609-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Prevent calling roundup_pow_of_two() with value of 0 as it causes the
below UBSAN note.
Move this code and its few extra related lines to be called only when
it's really applicable.
UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13
shift exponent 64 is too large for 64-bit type 'long unsigned int'
CPU: 15 PID: 1639 Comm: live_migration Not tainted 6.1.0-rc4 #1116
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x45/0x59
ubsan_epilogue+0x5/0x36
__ubsan_handle_shift_out_of_bounds.cold+0x61/0xef
? lock_is_held_type+0x98/0x110
? rcu_read_lock_sched_held+0x3f/0x70
mlx5vf_create_rc_qp.cold+0xe4/0xf2 [mlx5_vfio_pci]
mlx5vf_start_page_tracker+0x769/0xcd0 [mlx5_vfio_pci]
vfio_device_fops_unl_ioctl+0x63f/0x700 [vfio]
__x64_sys_ioctl+0x433/0x9a0
do_syscall_64+0x3d/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>
Fixes: 79c3cf2799 ("vfio/mlx5: Init QP based resources for dirty tracking")
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230108154427.32609-2-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
- 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)
-----BEGIN PGP SIGNATURE-----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=q9xs
-----END PGP SIGNATURE-----
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
...
This code frees the wrong "buf" variable and results in an error pointer
dereference.
Fixes: 34e2f27143 ("vfio/mlx5: Introduce multiple loads")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/Y5IKia5SaiVxYmG5@kili
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The copy_to_user() function returns the number of bytes remaining to
be copied but we want to return a negative error code here.
Fixes: 0dce165b1a ("vfio/mlx5: Introduce vfio precopy ioctl implementation")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/Y5IKVknlf5Z5NPtU@kili
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Now that everything has been set up for MIGRATION_PRE_COPY, enable it.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-15-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Before a SAVE command is issued, a QUERY command is issued in order to
know the device data size.
In case PRE_COPY is used, the above commands are issued while the device
is running. Thus, it is possible that between the QUERY and the SAVE
commands the state of the device will be changed significantly and thus
the SAVE will fail.
Currently, if a SAVE command is failing, the driver will fail the
migration. In the above case, don't fail the migration, but don't allow
for new SAVEs to be executed while the device is in a RUNNING state.
Once the device will be moved to STOP_COPY, SAVE can be executed again
and the full device state will be read.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-14-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
In order to support PRE_COPY, mlx5 driver transfers multiple states
(images) of the device. e.g.: the source VF can save and transfer
multiple states, and the target VF will load them by that order.
This patch implements the changes for the target VF to decompose the
header for each state and to write and load multiple states.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-13-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
During PRE_COPY the migration data FD may have a temporary "end of
stream" that is reached when the initial_bytes were read and no other
dirty data exists yet.
For instance, this may indicate that the device is idle and not
currently dirtying any internal state. When read() is done on this
temporary end of stream the kernel driver should return ENOMSG from
read(). Userspace can wait for more data or consider moving to
STOP_COPY.
To not block the user upon read() and let it get ENOMSG we add a new
state named MLX5_MIGF_STATE_PRE_COPY on the migration file.
In addition, we add the MLX5_MIGF_STATE_SAVE_LAST state to block the
read() once we call the last SAVE upon moving to STOP_COPY.
Any further error will be marked with MLX5_MIGF_STATE_ERROR and the user
won't be blocked.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-12-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio precopy ioctl returns an estimation of data available for
transferring from the device.
Whenever a user is using VFIO_MIG_GET_PRECOPY_INFO, track the current
state of the device, and if needed, append the dirty data to the
transfer FD data. This is done by saving a middle state.
As mlx5 runs the SAVE command asynchronously, make sure to query for
incremental data only once there is no active save command.
Running both in parallel, might end-up with a failure in the incremental
query command on un-tracked vhca.
Also, a middle state will be saved only after the previous state has
finished its SAVE command and has been fully transferred, this prevents
endless use resources.
Co-developed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-11-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
As mentioned in the previous patches, mlx5 is transferring multiple
states when the PRE_COPY protocol is used. This states mechanism
requires the target VM to know the states' size in order to execute
multiple loads. Therefore, add SW header, with the needed information,
for each saved state the source VM is transferring to the target VM.
This patch implements the source VM handling of the headers, following
patch will implement the target VM handling of the headers.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-10-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
