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2022-12-15Merge tag 'vfio-v6.2-rc1' of https://github.com/awilliam/linux-vfioLinus Torvalds1-25/+120
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 ...
2022-12-06vfio: Extend the device migration protocol with PRE_COPYJason Gunthorpe1-2/+72
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>
2022-12-05vfio: Fold vfio_virqfd.ko into vfio.koJason Gunthorpe1-0/+7
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>
2022-12-05vfio: Move vfio group specific code into group.cYi Liu1-870/+7
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>
2022-12-05vfio: Refactor dma APIs for emulated devicesYi Liu1-11/+14
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>
2022-12-05vfio: Wrap vfio group module init/clean code into helpersYi Liu1-20/+36
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>
2022-12-05vfio: Refactor vfio_device open and closeYi Liu1-46/+87
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>
2022-12-05vfio: Make vfio_device_open() truly device specificYi Liu1-17/+29
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>
2022-12-05vfio: Swap order of vfio_device_container_register() and open_device()Yi Liu1-8/+9
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>
2022-12-05vfio: Set device->group in helper functionYi Liu1-15/+26
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>
2022-12-05vfio: Create wrappers for group register/unregisterYi Liu1-7/+16
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>
2022-12-05vfio: Move the sanity check of the group to vfio_create_group()Jason Gunthorpe1-37/+25
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>
2022-12-05vfio: Simplify vfio_create_group()Jason Gunthorpe1-23/+10
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>
2022-12-02Merge tag 'v6.1-rc7' into iommufd.git for-nextJason Gunthorpe1-0/+13
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>
2022-12-02vfio: Move container related MODULE_ALIAS statements into container.cJason Gunthorpe1-2/+0
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: cdc71fe4ecbf ("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>
2022-12-02vfio-iommufd: Support iommufd for emulated VFIO devicesJason Gunthorpe1-1/+121
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>
2022-12-02vfio-iommufd: Support iommufd for physical VFIO devicesJason Gunthorpe1-2/+13
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>
2022-12-02vfio-iommufd: Allow iommufd to be used in place of a container fdJason Gunthorpe1-14/+74
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>
2022-12-02vfio: Use IOMMU_CAP_ENFORCE_CACHE_COHERENCY for vfio_file_enforced_coherent()Jason Gunthorpe1-13/+16
iommufd doesn't establish the iommu_domains until after the device FD is opened, even if the container has been set. This design is part of moving away from the group centric iommu APIs. This is fine, except that the normal sequence of establishing the kvm wbinvd won't work: group = open("/dev/vfio/XX") ioctl(group, VFIO_GROUP_SET_CONTAINER) ioctl(kvm, KVM_DEV_VFIO_GROUP_ADD) ioctl(group, VFIO_GROUP_GET_DEVICE_FD) As the domains don't start existing until GET_DEVICE_FD. Further, GET_DEVICE_FD requires that KVM_DEV_VFIO_GROUP_ADD already be done as that is what sets the group->kvm and thus device->kvm for the driver to use during open. Now that we have device centric cap ops and the new IOMMU_CAP_ENFORCE_CACHE_COHERENCY we know what the iommu_domain will be capable of without having to create it. Use this to compute vfio_file_enforced_coherent() and resolve the ordering problems. VFIO always tries to upgrade domains to enforce cache coherency, it never attaches a device that supports enforce cache coherency to a less capable domain, so the cap test is a sufficient proxy for the ultimate outcome. iommufd also ensures that devices that set the cap will be connected to enforcing domains. Link: https://lore.kernel.org/r/4-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>
2022-12-02vfio: Rename vfio_device_assign/unassign_container()Jason Gunthorpe1-3/+3
These functions don't really assign anything anymore, they just increment some refcounts and do a sanity check. Call them vfio_group_[un]use_container() Link: https://lore.kernel.org/r/3-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: 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>
2022-12-02vfio: Move vfio_device_assign_container() into vfio_device_first_open()Jason Gunthorpe1-13/+11
The only thing this function does is assert the group has an assigned container and incrs refcounts. The overall model we have is that once a container_users refcount is incremented it cannot be de-assigned from the group - vfio_group_ioctl_unset_container() will fail and the group FD cannot be closed. Thus we do not need to check this on every device FD open, just the first. Reorganize the code so that only the first open and last close manages the container. Link: https://lore.kernel.org/r/2-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: 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>
2022-12-02vfio: Move vfio_device driver open/close code to a functionJason Gunthorpe1-42/+53
This error unwind is getting complicated. Move all the code into two pair'd function. The functions should be called when the open_count == 1 after incrementing/before decrementing. Link: https://lore.kernel.org/r/1-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: Nicolin Chen <nicolinc@nvidia.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>
2022-11-14vfio: Add an option to get migration data sizeYishai Hadas1-0/+32
Add an option to get migration data size by introducing a new migration feature named VFIO_DEVICE_FEATURE_MIG_DATA_SIZE. Upon VFIO_DEVICE_FEATURE_GET the estimated data length that will be required to complete STOP_COPY is returned. This option may better enable user space to consider before moving to STOP_COPY whether it can meet the downtime SLA based on the returned data. The patch also includes the implementation for mlx5 and hisi for this new option to make it feature complete for the existing drivers in this area. Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Longfang Liu <liulongfang@huawei.com> Link: https://lore.kernel.org/r/20221106174630.25909-2-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10vfio: Export the device set open countAnthony DeRossi1-0/+13
The open count of a device set is the sum of the open counts of all devices in the set. Drivers can use this value to determine whether shared resources are in use without tracking them manually or accessing the private open_count in vfio_device. Signed-off-by: Anthony DeRossi <ajderossi@gmail.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20221110014027.28780-3-ajderossi@gmail.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10vfio: Fix container device registration life cycleAnthony DeRossi1-5/+8
In vfio_device_open(), vfio_device_container_register() is always called when open_count == 1. On error, vfio_device_container_unregister() is only called when open_count == 1 and close_device is set. This leaks a registration for devices without a close_device implementation. In vfio_device_fops_release(), vfio_device_container_unregister() is called unconditionally. This can cause a device to be unregistered multiple times. Treating container device registration/unregistration uniformly (always when open_count == 1) fixes both issues. Fixes: ce4b4657ff18 ("vfio: Replace the DMA unmapping notifier with a callback") Signed-off-by: Anthony DeRossi <ajderossi@gmail.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20221110014027.28780-2-ajderossi@gmail.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10vfio: Remove vfio_free_deviceEric Farman1-18/+4
With the "mess" sorted out, we should be able to inline the vfio_free_device call introduced by commit cb9ff3f3b84c ("vfio: Add helpers for unifying vfio_device life cycle") and remove them from driver release callbacks. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> # vfio-ap part Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20221104142007.1314999-8-farman@linux.ibm.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10vfio/ccw: replace vfio_init_device with _alloc_Eric Farman1-5/+5
Now that we have a reasonable separation of structs that follow the subchannel and mdev lifecycles, there's no reason we can't call the official vfio_alloc_device routine for our private data, and behave like everyone else. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20221104142007.1314999-7-farman@linux.ibm.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-07vfio: More vfio_file_is_group() use casesAlex Williamson1-3/+3
Replace further open coded tests with helper. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/166516896843.1215571.5378890510536477434.stgit@omen Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-07vfio: Make the group FD disassociate from the iommu_groupJason Gunthorpe1-23/+44
Allow the vfio_group struct to exist with a NULL iommu_group pointer. When the pointer is NULL the vfio_group users promise not to touch the iommu_group. This allows a driver to be hot unplugged while userspace is keeping the group FD open. Remove all the code waiting for the group FD to close. This fixes a userspace regression where we learned that virtnodedevd leaves a group FD open even though the /dev/ node for it has been deleted and all the drivers for it unplugged. Fixes: ca5f21b25749 ("vfio: Follow a strict lifetime for struct iommu_group") Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Tested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/3-v2-15417f29324e+1c-vfio_group_disassociate_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-07vfio: Hold a reference to the iommu_group in kvm for SPAPRJason Gunthorpe1-2/+4
SPAPR exists completely outside the normal iommu driver framework, the groups it creates are fake and are only created to enable VFIO's uAPI. Thus, it does not need to follow the iommu core rule that the iommu_group will only be touched while a driver is attached. Carry a group reference into KVM and have KVM directly manage the lifetime of this object independently of VFIO. This means KVM no longer relies on the vfio group file being valid to maintain the group reference. Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/2-v2-15417f29324e+1c-vfio_group_disassociate_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-07vfio: Add vfio_file_is_group()Jason Gunthorpe1-1/+15
This replaces uses of vfio_file_iommu_group() which were only detecting if the file is a VFIO file with no interest in the actual group. The only remaning user of vfio_file_iommu_group() is in KVM for the SPAPR stuff. It passes the iommu_group into the arch code through kvm for some reason. Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Tested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/1-v2-15417f29324e+1c-vfio_group_disassociate_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04vfio: Change vfio_group->group_rwsem to a mutexJason Gunthorpe1-23/+24
These days not much is using the read side: - device first open - ioctl_get_status - device FD release - check enforced_coherent None of this is performance, so just make it into a normal mutex. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/2-v1-917e3647f123+b1a-vfio_group_users_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04vfio: Remove the vfio_group->users and users_compJason Gunthorpe1-26/+19
Kevin points out that the users is really just tracking if group->opened_file is set, so we can simplify this code to a wait_queue that looks for !opened_file under the group_rwsem. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/1-v1-917e3647f123+b1a-vfio_group_users_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-27vfio: Follow a strict lifetime for struct iommu_groupJason Gunthorpe1-23/+45
The iommu_group comes from the struct device that a driver has been bound to and then created a struct vfio_device against. To keep the iommu layer sane we want to have a simple rule that only an attached driver should be using the iommu API. Particularly only an attached driver should hold ownership. In VFIO's case since it uses the group APIs and it shares between different drivers it is a bit more complicated, but the principle still holds. Solve this by waiting for all users of the vfio_group to stop before allowing vfio_unregister_group_dev() to complete. This is done with a new completion to know when the users go away and an additional refcount to keep track of how many device drivers are sharing the vfio group. The last driver to be unregistered will clean up the group. This solves crashes in the S390 iommu driver that come because VFIO ends up racing releasing ownership (which attaches the default iommu_domain to the device) with the removal of that same device from the iommu driver. This is a side case that iommu drivers should not have to cope with. iommu driver failed to attach the default/blocking domain WARNING: CPU: 0 PID: 5082 at drivers/iommu/iommu.c:1961 iommu_detach_group+0x6c/0x80 Modules linked in: macvtap macvlan tap vfio_pci vfio_pci_core irqbypass vfio_virqfd kvm nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables nfnetlink mlx5_ib sunrpc ib_uverbs ism smc uvdevice ib_core s390_trng eadm_sch tape_3590 tape tape_class vfio_ccw mdev vfio_iommu_type1 vfio zcrypt_cex4 sch_fq_codel configfs ghash_s390 prng chacha_s390 libchacha aes_s390 mlx5_core des_s390 libdes sha3_512_s390 nvme sha3_256_s390 sha512_s390 sha256_s390 sha1_s390 sha_common nvme_core zfcp scsi_transport_fc pkey zcrypt rng_core autofs4 CPU: 0 PID: 5082 Comm: qemu-system-s39 Tainted: G W 6.0.0-rc3 #5 Hardware name: IBM 3931 A01 782 (LPAR) Krnl PSW : 0704c00180000000 000000095bb10d28 (iommu_detach_group+0x70/0x80) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000001 0000000900000027 0000000000000039 000000095c97ffe0 00000000fffeffff 00000009fc290000 00000000af1fda50 00000000af590b58 00000000af1fdaf0 0000000135c7a320 0000000135e52258 0000000135e52200 00000000a29e8000 00000000af590b40 000000095bb10d24 0000038004b13c98 Krnl Code: 000000095bb10d18: c020003d56fc larl %r2,000000095c2bbb10 000000095bb10d1e: c0e50019d901 brasl %r14,000000095be4bf20 #000000095bb10d24: af000000 mc 0,0 >000000095bb10d28: b904002a lgr %r2,%r10 000000095bb10d2c: ebaff0a00004 lmg %r10,%r15,160(%r15) 000000095bb10d32: c0f4001aa867 brcl 15,000000095be65e00 000000095bb10d38: c004002168e0 brcl 0,000000095bf3def8 000000095bb10d3e: eb6ff0480024 stmg %r6,%r15,72(%r15) Call Trace: [<000000095bb10d28>] iommu_detach_group+0x70/0x80 ([<000000095bb10d24>] iommu_detach_group+0x6c/0x80) [<000003ff80243b0e>] vfio_iommu_type1_detach_group+0x136/0x6c8 [vfio_iommu_type1] [<000003ff80137780>] __vfio_group_unset_container+0x58/0x158 [vfio] [<000003ff80138a16>] vfio_group_fops_unl_ioctl+0x1b6/0x210 [vfio] pci 0004:00:00.0: Removing from iommu group 4 [<000000095b5b62e8>] __s390x_sys_ioctl+0xc0/0x100 [<000000095be5d3b4>] __do_syscall+0x1d4/0x200 [<000000095be6c072>] system_call+0x82/0xb0 Last Breaking-Event-Address: [<000000095be4bf80>] __warn_printk+0x60/0x68 It indicates that domain->ops->attach_dev() failed because the driver has already passed the point of destructing the device. Fixes: 9ac8545199a1 ("iommu: Fix use-after-free in iommu_release_device") Reported-by: Matthew Rosato <mjrosato@linux.ibm.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/0-v2-a3c5f4429e2a+55-iommu_group_lifetime_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-22vfio: Move container code into drivers/vfio/container.cJason Gunthorpe1-691/+1
All the functions that dereference struct vfio_container are moved into container.c. Simple code motion, no functional change. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/8-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-22vfio: Split the register_device ops call into functionsJason Gunthorpe1-16/+23
This is a container item. A following patch will move the vfio_container functions to their own .c file. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/7-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-22vfio: Rename vfio_ioctl_check_extension()Jason Gunthorpe1-5/+6
To vfio_container_ioctl_check_extension(). A following patch will turn this into a non-static function, make it clear it is related to the container. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/6-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-22vfio: Split out container code from the init/cleanup functionsJason Gunthorpe1-18/+36
This miscdev, noiommu driver and a couple of globals are all container items. Move this init into its own functions. A following patch will move the vfio_container functions to their own .c file. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/5-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-22vfio: Remove #ifdefs around CONFIG_VFIO_NOIOMMUJason Gunthorpe1-24/+19
This can all be accomplished using typical IS_ENABLED techniques, drop it all. Also rename the variable to vfio_noiommu so this can be made global in following patches. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/4-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-22vfio: Split the container logic into vfio_container_attach_group()Jason Gunthorpe1-30/+48
This splits up the ioctl of vfio_group_ioctl_set_container() so it determines the type of file then invokes a type specific attachment function. Future patches will add iommufd to this function as an alternative type. A following patch will move the vfio_container functions to their own .c file. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/3-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-22vfio: Rename __vfio_group_unset_container()Jason Gunthorpe1-6/+5
To vfio_group_detach_container(). This function is really a container function. Fold the WARN_ON() into it as a precondition assertion. A following patch will move the vfio_container functions to their own .c file. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/2-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-21vfio: Add struct device to vfio_deviceYi Liu1-11/+53
and replace kref. With it a 'vfio-dev/vfioX' node is created under the sysfs path of the parent, indicating the device is bound to a vfio driver, e.g.: /sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0 It is also a preparatory step toward adding cdev for supporting future device-oriented uAPI. Add Documentation/ABI/testing/sysfs-devices-vfio-dev. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20220921104401.38898-16-kevin.tian@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-21vfio: Rename vfio_device_put() and vfio_device_try_get()Kevin Tian1-8/+9
With the addition of vfio_put_device() now the names become confusing. vfio_put_device() is clear from object life cycle p.o.v given kref. vfio_device_put()/vfio_device_try_get() are helpers for tracking users on a registered device. Now rename them: - vfio_device_put() -> vfio_device_put_registration() - vfio_device_try_get() -> vfio_device_try_get_registration() Signed-off-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/20220921104401.38898-15-kevin.tian@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-21vfio/ccw: Use the new device life cycle helpersKevin Tian1-18/+5
ccw is the only exception which cannot use vfio_alloc_device() because its private device structure is designed to serve both mdev and parent. Life cycle of the parent is managed by css_driver so vfio_ccw_private must be allocated/freed in css_driver probe/remove path instead of conforming to vfio core life cycle for mdev. Given that use a wait/completion scheme so the mdev remove path waits after vfio_put_device() until receiving a completion notification from @release. The completion indicates that all active references on vfio_device have been released. After that point although free of vfio_ccw_private is delayed to css_driver it's at least guaranteed to have no parallel reference on released vfio device part from other code paths. memset() in @probe is removed. vfio_device is either already cleared when probed for the first time or cleared in @release from last probe. The right fix is to introduce separate structures for mdev and parent, but this won't happen in short term per prior discussions. Remove vfio_init/uninit_group_dev() as no user now. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Link: https://lore.kernel.org/r/20220921104401.38898-14-kevin.tian@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-21vfio: Add helpers for unifying vfio_device life cycleKevin Tian1-0/+92
The idea is to let vfio core manage the vfio_device life cycle instead of duplicating the logic cross drivers. This is also a preparatory step for adding struct device into vfio_device. New pair of helpers together with a kref in vfio_device: - vfio_alloc_device() - vfio_put_device() Drivers can register @init/@release callbacks to manage any private state wrapping the vfio_device. However vfio-ccw doesn't fit this model due to a life cycle mess that its private structure mixes both parent and mdev info hence must be allocated/freed outside of the life cycle of vfio device. Per prior discussions this won't be fixed in short term by IBM folks. Instead of waiting for those modifications introduce another helper vfio_init_device() so ccw can call it to initialize a pre-allocated vfio_device. Further implication of the ccw trick is that vfio_device cannot be freed uniformly in vfio core. Instead, require *EVERY* driver to implement @release and free vfio_device inside. Then ccw can choose to delay the free at its own discretion. Another trick down the road is that kvzalloc() is used to accommodate the need of gvt which uses vzalloc() while all others use kzalloc(). So drivers should call a helper vfio_free_device() to free the vfio_device instead of assuming that kfree() or vfree() is appliable. Later once the ccw mess is fixed we can remove those tricks and fully handle structure alloc/free in vfio core. Existing vfio_{un}init_group_dev() will be deprecated after all existing usages are converted to the new model. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Co-developed-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/20220921104401.38898-2-kevin.tian@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-08vfio: Introduce the DMA logging feature supportYishai Hadas1-0/+175
Introduce the DMA logging feature support in the vfio core layer. It includes the processing of the device start/stop/report DMA logging UAPIs and calling the relevant driver 'op' to do the work. Specifically, Upon start, the core translates the given input ranges into an interval tree, checks for unexpected overlapping, non aligned ranges and then pass the translated input to the driver for start tracking the given ranges. Upon report, the core translates the given input user space bitmap and page size into an IOVA kernel bitmap iterator. Then it iterates it and call the driver to set the corresponding bits for the dirtied pages in a specific IOVA range. Upon stop, the driver is called to stop the previous started tracking. The next patches from the series will introduce the mlx5 driver implementation for the logging ops. Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Link: https://lore.kernel.org/r/20220908183448.195262-6-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-01vfio: Remove vfio_group dev_counterJason Gunthorpe1-6/+3
This counts the number of devices attached to a vfio_group, ie the number of items in the group->device_list. It is only read in vfio_pin_pages(), as some kind of protection against limitations in type1. However, with all the code cleanups in this area, now that vfio_pin_pages() accepts a vfio_device directly it is redundant. All drivers are already calling vfio_register_emulated_iommu_dev() which directly creates a group specifically for the device and thus it is guaranteed that there is a singleton group. Leave a note in the comment about this requirement and remove the logic. 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-v2-d4374a7bf0c9+c4-vfio_dev_counter_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-01vfio: Increment the runtime PM usage count during IOCTL callAbhishek Sahu1-3/+49
The vfio-pci based drivers will have runtime power management support where the user can put the device into the low power state and then PCI devices can go into the D3cold state. If the device is in the low power state and the user issues any IOCTL, then the device should be moved out of the low power state first. Once the IOCTL is serviced, then it can go into the low power state again. The runtime PM framework manages this with help of usage count. One option was to add the runtime PM related API's inside vfio-pci driver but some IOCTL (like VFIO_DEVICE_FEATURE) can follow a different path and more IOCTL can be added in the future. Also, the runtime PM will be added for vfio-pci based drivers variant currently, but the other VFIO based drivers can use the same in the future. So, this patch adds the runtime calls runtime-related API in the top-level IOCTL function itself. For the VFIO drivers which do not have runtime power management support currently, the runtime PM API's won't be invoked. Only for vfio-pci based drivers currently, the runtime PM API's will be invoked to increment and decrement the usage count. In the vfio-pci drivers also, the variant drivers can opt-out by incrementing the usage count during device-open. The pm_runtime_resume_and_get() checks the device current status and will return early if the device is already in the ACTIVE state. Taking this usage count incremented while servicing IOCTL will make sure that the user won't put the device into the low power state when any other IOCTL is being serviced in parallel. Let's consider the following scenario: 1. Some other IOCTL is called. 2. The user has opened another device instance and called the IOCTL for low power entry. 3. The low power entry IOCTL moves the device into the low power state. 4. The other IOCTL finishes. If we don't keep the usage count incremented then the device access will happen between step 3 and 4 while the device has already gone into the low power state. The pm_runtime_resume_and_get() will be the first call so its error should not be propagated to user space directly. For example, if pm_runtime_resume_and_get() can return -EINVAL for the cases where the user has passed the correct argument. So the pm_runtime_resume_and_get() errors have been masked behind -EIO. Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com> Link: https://lore.kernel.org/r/20220829114850.4341-3-abhsahu@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-01vfio: Split VFIO_GROUP_GET_STATUS into a functionJason Gunthorpe1-31/+30
This is the last sizable implementation in vfio_group_fops_unl_ioctl(), move it to a function so vfio_group_fops_unl_ioctl() is emptied out. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/8-v2-0f9e632d54fb+d6-vfio_ioctl_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-01vfio: Follow the naming pattern for vfio_group_ioctl_unset_container()Jason Gunthorpe1-11/+16
Make it clear that this is the body of the ioctl. Fold the locking into the function so it is self contained like the other ioctls. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/7-v2-0f9e632d54fb+d6-vfio_ioctl_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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