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path: root/drivers/vfio/vfio_main.c
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2022-09-21vfio/ccw: Use the new device life cycle helpersKevin Tian
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 Tian
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 Hadas
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 Gunthorpe
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 Sahu
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 Gunthorpe
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 Gunthorpe
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>
2022-09-01vfio: Fold VFIO_GROUP_SET_CONTAINER into vfio_group_set_container()Jason Gunthorpe
No reason to split it up like this, just have one function to process the ioctl. Move the lock into the function as well to avoid having a lockdep annotation. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/6-v2-0f9e632d54fb+d6-vfio_ioctl_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-01vfio: Fold VFIO_GROUP_GET_DEVICE_FD into vfio_group_get_device_fd()Jason Gunthorpe
No reason to split it up like this, just have one function to process the ioctl. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/5-v2-0f9e632d54fb+d6-vfio_ioctl_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-08-08vfio: Move vfio.c to vfio_main.cJason Gunthorpe
If a source file has the same name as a module then kbuild only supports a single source file in the module. Rename vfio.c to vfio_main.c so that we can have more that one .c file in vfio.ko. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Link: https://lore.kernel.org/r/20220731125503.142683-5-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>