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path: root/include/linux/vfio.h
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2022-10-07vfio: Add vfio_file_is_group()Jason Gunthorpe
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>
2022-09-21vfio: Add struct device to vfio_deviceYi Liu
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/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>
2022-07-25vfio: Replace phys_pfn with pages for vfio_pin_pages()Nicolin Chen
Most of the callers of vfio_pin_pages() want "struct page *" and the low-level mm code to pin pages returns a list of "struct page *" too. So there's no gain in converting "struct page *" to PFN in between. Replace the output parameter "phys_pfn" list with a "pages" list, to simplify callers. This also allows us to replace the vfio_iommu_type1 implementation with a more efficient one. And drop the pfn_valid check in the gvt code, as there is no need to do such a check at a page-backed struct page pointer. For now, also update vfio_iommu_type1 to fit this new parameter too. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: Eric Farman <farman@linux.ibm.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Link: https://lore.kernel.org/r/20220723020256.30081-11-nicolinc@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-25vfio: Rename user_iova of vfio_dma_rw()Nicolin Chen
Following the updated vfio_pin/unpin_pages(), use the simpler "iova". Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Link: https://lore.kernel.org/r/20220723020256.30081-9-nicolinc@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-25vfio: Pass in starting IOVA to vfio_pin/unpin_pages APINicolin Chen
The vfio_pin/unpin_pages() so far accepted arrays of PFNs of user IOVA. Among all three callers, there was only one caller possibly passing in a non-contiguous PFN list, which is now ensured to have contiguous PFN inputs too. Pass in the starting address with "iova" alone to simplify things, so callers no longer need to maintain a PFN list or to pin/unpin one page at a time. This also allows VFIO to use more efficient implementations of pin/unpin_pages. For now, also update vfio_iommu_type1 to fit this new parameter too, while keeping its input intact (being user_iova) since we don't want to spend too much effort swapping its parameters and local variables at that level. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> Acked-by: Eric Farman <farman@linux.ibm.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Link: https://lore.kernel.org/r/20220723020256.30081-6-nicolinc@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-23vfio: Make vfio_unpin_pages() return voidNicolin Chen
There's only one caller that checks its return value with a WARN_ON_ONCE, while all other callers don't check the return value at all. Above that, an undo function should not fail. So, simplify the API to return void by embedding similar WARN_ONs. Also for users to pinpoint which condition fails, separate WARN_ON lines, yet remove the "driver->ops->unpin_pages" check, since it's unreasonable for callers to unpin on something totally random that wasn't even pinned. And remove NULL pointer checks for they would trigger oops vs. warnings. Note that npage is already validated in the vfio core, thus drop the same check in the type1 code. Suggested-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Link: https://lore.kernel.org/r/20220723020256.30081-2-nicolinc@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-20vfio: Replace the iommu notifier with a device listJason Gunthorpe
Instead of bouncing the function call to the driver op through a blocking notifier just have the iommu layer call it directly. Register each device that is being attached to the iommu with the lower driver which then threads them on a linked list and calls the appropriate driver op at the right time. Currently the only use is if dma_unmap() is defined. Also, fully lock all the debugging tests on the pinning path that a dma_unmap is registered. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/2-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-20vfio: Replace the DMA unmapping notifier with a callbackJason Gunthorpe
Instead of having drivers register the notifier with explicit code just have them provide a dma_unmap callback op in their driver ops and rely on the core code to wire it up. Suggested-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/1-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-06-30vfio: Split migration ops from main device opsYishai Hadas
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: 6fadb021266d ("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>
2022-06-27vfio: de-extern-ify function prototypesAlex Williamson
The use of 'extern' in function prototypes has been disrecommended in the kernel coding style for several years now, remove them from all vfio related files so contributors no longer need to decide between style and consistency. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/165471414407.203056.474032786990662279.stgit@omen Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-24vfio: remove VFIO_GROUP_NOTIFY_SET_KVMMatthew Rosato
Rather than relying on a notifier for associating the KVM with the group, let's assume that the association has already been made prior to device_open. The first time a device is opened associate the group KVM with the device. This fixes a user-triggerable oops in GVT. Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Zhi Wang <zhi.a.wang@intel.com> Link: https://lore.kernel.org/r/20220519183311.582380-2-mjrosato@linux.ibm.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-13vfio/pci: Use the struct file as the handle not the vfio_groupJason Gunthorpe
VFIO PCI does a security check as part of hot reset to prove that the user has permission to manipulate all the devices that will be impacted by the reset. Use a new API vfio_file_has_dev() to perform this security check against the struct file directly and remove the vfio_group from VFIO PCI. Since VFIO PCI was the last user of vfio_group_get_external_user() and vfio_group_put_external_user() remove it as well. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/8-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-13vfio: Change vfio_group_set_kvm() to vfio_file_set_kvm()Jason Gunthorpe
Just change the argument from struct vfio_group to struct file *. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/6-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-13vfio: Change vfio_external_check_extension() to vfio_file_enforced_coherent()Jason Gunthorpe
Instead of a general extension check change the function into a limited test if the iommu_domain has enforced coherency, which is the only thing kvm needs to query. Make the new op self contained by properly refcounting the container before touching it. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/5-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-13vfio: Remove vfio_external_group_match_file()Jason Gunthorpe
vfio_group_fops_open() ensures there is only ever one struct file open for any struct vfio_group at any time: /* Do we need multiple instances of the group open? Seems not. */ opened = atomic_cmpxchg(&group->opened, 0, 1); if (opened) { vfio_group_put(group); return -EBUSY; Therefor the struct file * can be used directly to search the list of VFIO groups that KVM keeps instead of using the vfio_external_group_match_file() callback to try to figure out if the passed in FD matches the list or not. Delete vfio_external_group_match_file(). Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/4-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-13vfio: Change vfio_external_user_iommu_id() to vfio_file_iommu_group()Jason Gunthorpe
The only caller wants to get a pointer to the struct iommu_group associated with the VFIO group file. Instead of returning the group ID then searching sysfs for that string to get the struct iommu_group just directly return the iommu_group pointer already held by the vfio_group struct. It already has a safe lifetime due to the struct file kref, the vfio_group and thus the iommu_group cannot be destroyed while the group file is open. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/3-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-11vfio/pci: Remove vfio_device_get_from_dev()Jason Gunthorpe
The last user of this function is in PCI callbacks that want to convert their struct pci_dev to a vfio_device. Instead of searching use the vfio_device available trivially through the drvdata. When a callback in the device_driver is called, the caller must hold the device_lock() on dev. The purpose of the device_lock is to prevent remove() from being called (see __device_release_driver), and allow the driver to safely interact with its drvdata without races. The PCI core correctly follows this and holds the device_lock() when calling error_detected (see report_error_detected) and sriov_configure (see sriov_numvfs_store). Further, since the drvdata holds a positive refcount on the vfio_device any access of the drvdata, under the device_lock(), from a driver callback needs no further protection or refcounting. Thus the remark in the vfio_device_get_from_dev() comment does not apply here, VFIO PCI drivers all call vfio_unregister_group_dev() from their remove callbacks under the device_lock() and cannot race with the remaining callers. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/2-v4-c841817a0349+8f-vfio_get_from_dev_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-11vfio: Remove dead codeJason Gunthorpe
Now that callers have been updated to use the vfio_device APIs the driver facing group interface is no longer used, delete it: - vfio_group_get_external_user_from_dev() - vfio_group_pin_pages() - vfio_group_unpin_pages() - vfio_group_iommu_domain() -- Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/6-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-11vfio/mdev: Pass in a struct vfio_device * to vfio_dma_rw()Jason Gunthorpe
Every caller has a readily available vfio_device pointer, use that instead of passing in a generic struct device. Change vfio_dma_rw() to take in the struct vfio_device and move the container users that would have been held by vfio_group_get_external_user_from_dev() to vfio_dma_rw() directly, like vfio_pin/unpin_pages(). Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/4-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-11vfio/mdev: Pass in a struct vfio_device * to vfio_pin/unpin_pages()Jason Gunthorpe
Every caller has a readily available vfio_device pointer, use that instead of passing in a generic struct device. The struct vfio_device already contains the group we need so this avoids complexity, extra refcountings, and a confusing lifecycle model. Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/3-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-11vfio: Make vfio_(un)register_notifier accept a vfio_deviceJason Gunthorpe
All callers have a struct vfio_device trivially available, pass it in directly and avoid calling the expensive vfio_group_get_from_dev(). Acked-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/1-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-03-03vfio: Extend the device migration protocol with RUNNING_P2PJason Gunthorpe
The RUNNING_P2P state is designed to support multiple devices in the same VM that are doing P2P transactions between themselves. When in RUNNING_P2P the device must be able to accept incoming P2P transactions but should not generate outgoing P2P transactions. As an optional extension to the mandatory states it is defined as in between STOP and RUNNING: STOP -> RUNNING_P2P -> RUNNING -> RUNNING_P2P -> STOP For drivers that are unable to support RUNNING_P2P the core code silently merges RUNNING_P2P and RUNNING together. Unless driver support is present, the new state cannot be used in SET_STATE. Drivers that support this will be required to implement 4 FSM arcs beyond the basic FSM. 2 of the basic FSM arcs become combination transitions. Compared to the v1 clarification, NDMA is redefined into FSM states and is described in terms of the desired P2P quiescent behavior, noting that halting all DMA is an acceptable implementation. Link: https://lore.kernel.org/all/20220224142024.147653-11-yishaih@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
2022-03-03vfio: Define device migration protocol v2Jason Gunthorpe
Replace the existing region based migration protocol with an ioctl based protocol. The two protocols have the same general semantic behaviors, but the way the data is transported is changed. This is the STOP_COPY portion of the new protocol, it defines the 5 states for basic stop and copy migration and the protocol to move the migration data in/out of the kernel. Compared to the clarification of the v1 protocol Alex proposed: https://lore.kernel.org/r/163909282574.728533.7460416142511440919.stgit@omen This has a few deliberate functional differences: - ERROR arcs allow the device function to remain unchanged. - The protocol is not required to return to the original state on transition failure. Instead userspace can execute an unwind back to the original state, reset, or do something else without needing kernel support. This simplifies the kernel design and should userspace choose a policy like always reset, avoids doing useless work in the kernel on error handling paths. - PRE_COPY is made optional, userspace must discover it before using it. This reflects the fact that the majority of drivers we are aware of right now will not implement PRE_COPY. - segmentation is not part of the data stream protocol, the receiver does not have to reproduce the framing boundaries. The hybrid FSM for the device_state is described as a Mealy machine by documenting each of the arcs the driver is required to implement. Defining the remaining set of old/new device_state transitions as 'combination transitions' which are naturally defined as taking multiple FSM arcs along the shortest path within the FSM's digraph allows a complete matrix of transitions. A new VFIO_DEVICE_FEATURE of VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE is defined to replace writing to the device_state field in the region. This allows returning a brand new FD whenever the requested transition opens a data transfer session. The VFIO core code implements the new feature and provides a helper function to the driver. Using the helper the driver only has to implement 6 of the FSM arcs and the other combination transitions are elaborated consistently from those arcs. A new VFIO_DEVICE_FEATURE of VFIO_DEVICE_FEATURE_MIGRATION is defined to report the capability for migration and indicate which set of states and arcs are supported by the device. The FSM provides a lot of flexibility to make backwards compatible extensions but the VFIO_DEVICE_FEATURE also allows for future breaking extensions for scenarios that cannot support even the basic STOP_COPY requirements. The VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE with the GET option (i.e. VFIO_DEVICE_FEATURE_GET) can be used to read the current migration state of the VFIO device. Data transfer sessions are now carried over a file descriptor, instead of the region. The FD functions for the lifetime of the data transfer session. read() and write() transfer the data with normal Linux stream FD semantics. This design allows future expansion to support poll(), io_uring, and other performance optimizations. The complicated mmap mode for data transfer is discarded as current qemu doesn't take meaningful advantage of it, and the new qemu implementation avoids substantially all the performance penalty of using a read() on the region. Link: https://lore.kernel.org/all/20220224142024.147653-10-yishaih@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
2022-03-03vfio: Have the core code decode the VFIO_DEVICE_FEATURE ioctlJason Gunthorpe
Invoke a new device op 'device_feature' to handle just the data array portion of the command. This lifts the ioctl validation to the core code and makes it simpler for either the core code, or layered drivers, to implement their own feature values. Provide vfio_check_feature() to consolidate checking the flags/etc against what the driver supports. Link: https://lore.kernel.org/all/20220224142024.147653-9-yishaih@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
2021-09-30vfio: move the vfio_iommu_driver_ops interface out of <linux/vfio.h>Christoph Hellwig
Create a new private drivers/vfio/vfio.h header for the interface between the VFIO core and the iommu drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-10-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-09-30vfio: remove unused method from vfio_iommu_driver_opsChristoph Hellwig
The read, write and mmap methods are never implemented, so remove them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-9-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-09-30vfio: simplify iommu group allocation for mediated devicesChristoph Hellwig
Reuse the logic in vfio_noiommu_group_alloc to allocate a fake single-device iommu group for mediated devices by factoring out a common function, and replacing the noiommu boolean field in struct vfio_group with an enum to distinguish the three different kinds of groups. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-8-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-09-30vfio: Move vfio_iommu_group_get() to vfio_register_group_dev()Jason Gunthorpe
We don't need to hold a reference to the group in the driver as well as obtain a reference to the same group as the first thing vfio_register_group_dev() does. Since the drivers never use the group move this all into the core code. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-2-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-08-11vfio: Remove struct vfio_device_ops open/releaseJason Gunthorpe
Nothing uses this anymore, delete it. Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/14-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-08-11vfio: Provide better generic support for open/release vfio_device_opsJason Gunthorpe
Currently the driver ops have an open/release pair that is called once each time a device FD is opened or closed. Add an additional set of open/close_device() ops which are called when the device FD is opened for the first time and closed for the last time. An analysis shows that all of the drivers require this semantic. Some are open coding it as part of their reflck implementation, and some are just buggy and miss it completely. To retain the current semantics PCI and FSL depend on, introduce the idea of a "device set" which is a grouping of vfio_device's that share the same lock around opening. The device set is established by providing a 'set_id' pointer. All vfio_device's that provide the same pointer will be joined to the same singleton memory and lock across the whole set. This effectively replaces the oddly named reflck. After conversion the set_id will be sourced from: - A struct device from a fsl_mc_device (fsl) - A struct pci_slot (pci) - A struct pci_bus (pci) - The struct vfio_device (everything) The design ensures that the above pointers are live as long as the vfio_device is registered, so they form reliable unique keys to group vfio_devices into sets. This implementation uses xarray instead of searching through the driver core structures, which simplifies the somewhat tricky locking in this area. Following patches convert all the drivers. Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/4-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-08-11vfio: Introduce a vfio_uninit_group_dev() API callMax Gurtovoy
This pairs with vfio_init_group_dev() and allows undoing any state that is stored in the vfio_device unrelated to registration. Add appropriately placed calls to all the drivers. The following patch will use this to add pre-registration state for the device set. Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/3-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio: Remove device_data from the vfio bus driver APIJason Gunthorpe
There are no longer any users, so it can go away. Everything is using container_of now. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <14-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio: Make vfio_device_ops pass a 'struct vfio_device *' instead of 'void *'Jason Gunthorpe
This is the standard kernel pattern, the ops associated with a struct get the struct pointer in for typesafety. The expected design is to use container_of to cleanly go from the subsystem level type to the driver level type without having any type erasure in a void *. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <12-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio/mdev: Use vfio_init/register/unregister_group_devJason Gunthorpe
mdev gets little benefit because it doesn't actually do anything, however it is the last user, so move the vfio_init/register/unregister_group_dev() code here for now. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Liu Yi L <yi.l.liu@intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <10-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio: Split creation of a vfio_device into init and register opsJason Gunthorpe
This makes the struct vfio_device part of the public interface so it can be used with container_of and so forth, as is typical for a Linux subystem. This is the first step to bring some type-safety to the vfio interface by allowing the replacement of 'void *' and 'struct device *' inputs with a simple and clear 'struct vfio_device *' For now the self-allocating vfio_add_group_dev() interface is kept so each user can be updated as a separate patch. The expected usage pattern is driver core probe() function: my_device = kzalloc(sizeof(*mydevice)); vfio_init_group_dev(&my_device->vdev, dev, ops, mydevice); /* other driver specific prep */ vfio_register_group_dev(&my_device->vdev); dev_set_drvdata(dev, my_device); driver core remove() function: my_device = dev_get_drvdata(dev); vfio_unregister_group_dev(&my_device->vdev); /* other driver specific tear down */ kfree(my_device); Allowing the driver to be able to use the drvdata and vfio_device to go to/from its own data. The pattern also makes it clear that vfio_register_group_dev() must be last in the sequence, as once it is called the core code can immediately start calling ops. The init/register gap is provided to allow for the driver to do setup before ops can be called and thus avoid races. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Liu Yi L <yi.l.liu@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <3-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-02-01vfio: iommu driver notify callbackSteve Sistare
Define a vfio_iommu_driver_ops notify callback, for sending events to the driver. Drivers are not required to provide the callback, and may ignore any events. The handling of events is driver specific. Define the CONTAINER_CLOSE event, called when the container's file descriptor is closed. This event signifies that no further state changes will occur via container ioctl's. Signed-off-by: Steve Sistare <steven.sistare@oracle.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-12-10vfio/type1: Add vfio_group_iommu_domain()Lu Baolu
Add the API for getting the domain from a vfio group. This could be used by the physical device drivers which rely on the vfio/mdev framework for mediated device user level access. The typical use case like below: unsigned int pasid; struct vfio_group *vfio_group; struct iommu_domain *iommu_domain; struct device *dev = mdev_dev(mdev); struct device *iommu_device = mdev_get_iommu_device(dev); if (!iommu_device || !iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX)) return -EINVAL; vfio_group = vfio_group_get_external_user_from_dev(dev); if (IS_ERR_OR_NULL(vfio_group)) return -EFAULT; iommu_domain = vfio_group_iommu_domain(vfio_group); if (IS_ERR_OR_NULL(iommu_domain)) { vfio_group_put_external_user(vfio_group); return -EFAULT; } pasid = iommu_aux_get_pasid(iommu_domain, iommu_device); if (pasid < 0) { vfio_group_put_external_user(vfio_group); return -EFAULT; } /* Program device context with pasid value. */ ... Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-05-28vfio: Selective dirty page tracking if IOMMU backed device pins pagesKirti Wankhede
Added a check such that only singleton IOMMU groups can pin pages. >From the point when vendor driver pins any pages, consider IOMMU group dirty page scope to be limited to pinned pages. To optimize to avoid walking list often, added flag pinned_page_dirty_scope to indicate if all of the vfio_groups for each vfio_domain in the domain_list dirty page scope is limited to pinned pages. This flag is updated on first pinned pages request for that IOMMU group and on attaching/detaching group. Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Neo Jia <cjia@nvidia.com> Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24Merge branches 'v5.7/vfio/alex-sriov-v3' and 'v5.7/vfio/yan-dma-rw-v4' into ↵Alex Williamson
v5.7/vfio/next
2020-03-24vfio: Include optional device match in vfio_device_ops callbacksAlex Williamson
Allow bus drivers to provide their own callback to match a device to the user provided string. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24vfio: avoid inefficient operations on VFIO group in vfio_pin/unpin_pagesYan Zhao
vfio_group_pin_pages() and vfio_group_unpin_pages() are introduced to avoid inefficient search/check/ref/deref opertions associated with VFIO group as those in each calling into vfio_pin_pages() and vfio_unpin_pages(). VFIO group is taken as arg directly. The callers combine search/check/ref/deref operations associated with VFIO group by calling vfio_group_get_external_user()/vfio_group_get_external_user_from_dev() beforehand, and vfio_group_put_external_user() afterwards. Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24vfio: introduce vfio_dma_rw to read/write a range of IOVAsYan Zhao
vfio_dma_rw will read/write a range of user space memory pointed to by IOVA into/from a kernel buffer without enforcing pinning the user space memory. TODO: mark the IOVAs to user space memory dirty if they are written in vfio_dma_rw(). Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24vfio: allow external user to get vfio group from deviceYan Zhao
external user calls vfio_group_get_external_user_from_dev() with a device pointer to get the VFIO group associated with this device. The VFIO group is checked to be vialbe and have IOMMU set. Then container user counter is increased and VFIO group reference is hold to prevent the VFIO group from disposal before external user exits. when the external user finishes using of the VFIO group, it calls vfio_group_put_external_user() to dereference the VFIO group and the container user counter. Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-20vfio: Simplify capability helperAlex Williamson
The vfio_info_add_capability() helper requires the caller to pass a capability ID, which it then uses to fill in header fields, assuming hard coded versions. This makes for an awkward and rigid interface. The only thing we want this helper to do is allocate sufficient space in the caps buffer and chain this capability into the list. Reduce it to that simple task. Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-07-26include/linux/vfio.h: Guard powerpc-specific functions with ↵Murilo Opsfelder Araujo
CONFIG_VFIO_SPAPR_EEH When CONFIG_EEH=y and CONFIG_VFIO_SPAPR_EEH=n, build fails with the following: drivers/vfio/pci/vfio_pci.o: In function `.vfio_pci_release': vfio_pci.c:(.text+0xa98): undefined reference to `.vfio_spapr_pci_eeh_release' drivers/vfio/pci/vfio_pci.o: In function `.vfio_pci_open': vfio_pci.c:(.text+0x1420): undefined reference to `.vfio_spapr_pci_eeh_open' In this case, vfio_pci.c should use the empty definitions of vfio_spapr_pci_eeh_open and vfio_spapr_pci_eeh_release functions. This patch fixes it by guarding these function definitions with CONFIG_VFIO_SPAPR_EEH, the symbol that controls whether vfio_spapr_eeh.c is built, which is where the non-empty versions of these functions are. We need to make use of IS_ENABLED() macro because CONFIG_VFIO_SPAPR_EEH is a tristate option. This issue was found during a randconfig build. Logs are here: http://kisskb.ellerman.id.au/kisskb/buildresult/12982362/ Signed-off-by: Murilo Opsfelder Araujo <mopsfelder@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-07-13Merge tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Include Intel XXV710 in INTx workaround (Alex Williamson) - Make use of ERR_CAST() for error return (Dan Carpenter) - Fix vfio_group release deadlock from iommu notifier (Alex Williamson) - Unset KVM-VFIO attributes only on group match (Alex Williamson) - Fix release path group/file matching with KVM-VFIO (Alex Williamson) - Remove unnecessary lock uses triggering lockdep splat (Alex Williamson) * tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio: vfio: Remove unnecessary uses of vfio_container.group_lock vfio: New external user group/file match kvm-vfio: Decouple only when we match a group vfio: Fix group release deadlock vfio: Use ERR_CAST() instead of open coding it vfio/pci: Add Intel XXV710 to hidden INTx devices