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>
In order to support PRE_COPY, mlx5 driver is transferring 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.
The device is saving three kinds of states:
1) Initial state - when the device moves to PRE_COPY state.
2) Middle state - during PRE_COPY phase via VFIO_MIG_GET_PRECOPY_INFO.
There can be multiple states of this type.
3) Final state - when the device moves to STOP_COPY state.
After moving to PRE_COPY state, user is holding the saving migf FD and
can use it. For example: user can start transferring data via read()
callback. Also, user can switch from PRE_COPY to STOP_COPY whenever he
sees it fits. This will invoke saving of final state.
This means that mlx5 VFIO device can be switched to STOP_COPY without
transferring any data in PRE_COPY state. Therefore, when the device
moves to STOP_COPY, mlx5 will store the final state on a dedicated queue
entry on the list.
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/20221206083438.37807-9-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Refactor to use queue based data chunks on the migration file.
The SAVE command adds a chunk to the tail of the queue while the read()
API finds the required chunk and returns its data.
In case the queue is empty but the state of the migration file is
MLX5_MIGF_STATE_COMPLETE, read() may not be blocked but will return 0 to
indicate end of file.
This is a step towards maintaining multiple images and their meta data
(i.e. headers) on the migration file as part of next patches from the
series.
Note:
At that point, we still use a single chunk on the migration file but
becomes ready to support multiple.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-8-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Refactor migration file state to be an emum which is mutual exclusive.
As of that dropped the 'disabled' state as 'error' is the same from
functional point of view.
Next patches from the series will extend this enum for other relevant
states.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-7-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This patch refactors MKEY usage such as its life cycle will be as of the
migration file instead of allocating/destroying it upon each
SAVE/LOAD command.
This is a preparation step towards the PRE_COPY series where multiple
images will be SAVED/LOADED.
We achieve it by having a new struct named mlx5_vhca_data_buffer which
holds the mkey and its related stuff as of sg_append_table,
allocated_length, etc.
The above fields were taken out from the migration file main struct,
into mlx5_vhca_data_buffer dedicated struct with the proper helpers in
place.
For now we have a single mlx5_vhca_data_buffer per migration file.
However, in coming patches we'll have multiple of them to support
multiple images.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-6-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This patch refactors PD usage such as its life cycle will be as of the
migration file instead of allocating/destroying it upon each SAVE/LOAD
command.
This is a preparation step towards the PRE_COPY series where multiple
images will be SAVED/LOADED and a single PD can be simply reused.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-5-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Enforce a single SAVE command at a time.
As the SAVE command is an asynchronous one, we must enforce running only
a single command at a time.
This will preserve ordering between multiple calls and protect from
races on the migration file data structure.
This is a must for the next patches from the series where as part of
PRE_COPY we may have multiple images to be saved and multiple SAVE
commands may be issued from different flows.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Fix a typo in mlx5vf_cmd_load_vhca_state() to use the 'load' memory
layout.
As in/out sizes are equal for save and load commands there wasn't any
functional issue.
Fixes: f1d98f346e ("vfio/mlx5: Expose migration commands over mlx5 device")
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20221106174630.25909-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Now that everything is ready set the driver DMA logging callbacks if
supported by the device.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-11-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Handle async error events and health/recovery flow to safely stop the
tracker upon error scenarios.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-10-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Report dirty pages from tracker.
It includes:
Querying for dirty pages in a given IOVA range, this is done by
modifying the tracker into the reporting state and supplying the
required range.
Using the CQ event completion mechanism to be notified once data is
ready on the CQ/QP to be processed.
Once data is available turn on the corresponding bits in the bit map.
This functionality will be used as part of the 'log_read_and_clear'
driver callback in the next patches.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-9-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add support for creating and destroying page tracker object.
This object is used to control/report the device dirty pages.
As part of creating the tracker need to consider the device capabilities
for max ranges and adapt/combine ranges accordingly.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-8-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Init QP based resources for dirty tracking to be used upon start
logging.
It includes:
Creating the host and firmware RC QPs, move each of them to its expected
state based on the device specification, etc.
Creating the relevant resources which are needed by both QPs as of UAR,
PD, etc.
Creating the host receive side resources as of MKEY, CQ, receive WQEs,
etc.
The above resources are cleaned-up upon stop logging.
The tracker object that will be introduced by next patches will use
those resources.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-7-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio core checks whether the driver sets some migration op (e.g.
set_state/get_state) and accordingly calls its op.
However, currently mlx5 driver sets the above ops without regards to its
migration caps.
This might lead to unexpected usage/Oops if user space may call to the
above ops even if the driver doesn't support migration. As for example,
the migration state_mutex is not initialized in that case.
The cleanest way to manage that seems to split the migration ops from
the main device ops, this will let the driver setting them separately
from the main ops when it's applicable.
As part of that, validate ops construction on registration and include a
check for VFIO_MIGRATION_STOP_COPY since the uAPI claims it must be set
in migration_flags.
HISI driver was changed as well to match this scheme.
This scheme may enable down the road to come with some extra group of
ops (e.g. DMA log) that can be set without regards to the other options
based on driver caps.
Fixes: 6fadb02126 ("vfio/mlx5: Implement vfio_pci driver for mlx5 devices")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220628155910.171454-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Protect mlx5vf_disable_fds() upon close device to be called under the
state mutex as done in all other places.
This will prevent a race with any other flow which calls
mlx5vf_disable_fds() as of health/recovery upon
MLX5_PF_NOTIFY_DISABLE_VF event.
Encapsulate this functionality in a separate function named
mlx5vf_cmd_close_migratable() to consider migration caps and for further
usage upon close device.
Fixes: 6fadb02126 ("vfio/mlx5: Implement vfio_pci driver for mlx5 devices")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220628155910.171454-2-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Use the PF asynchronous command mode for the SAVE state command.
This enables returning earlier to user space upon issuing successfully
the command and improve latency by let things run in parallel.
Link: https://lore.kernel.org/r/20220510090206.90374-5-yishaih@nvidia.com
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Refactor to enable different VFs to run their commands over the PF
command interface in parallel and to not block one each other.
This is done by not using the global PF lock that was used before but
relying on the VF attach/detach mechanism to sync.
Link: https://lore.kernel.org/r/20220510090206.90374-4-yishaih@nvidia.com
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Manage the VF attach/detach callback from the PF.
This lets the driver to enable parallel VFs migration as will be
introduced in the next patch.
As part of this, reorganize the VF is migratable code to be in a
separate function and rename it to be set_migratable() to match its
functionality.
Link: https://lore.kernel.org/r/20220510090206.90374-3-yishaih@nvidia.com
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Expose migration commands over the device, it includes: suspend, resume,
get vhca id, query/save/load state.
As part of this adds the APIs and data structure that are needed to manage
the migration data.
Link: https://lore.kernel.org/all/20220224142024.147653-13-yishaih@nvidia.com
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
