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path: root/drivers/vfio/vfio.c
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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>
2022-08-06Merge tag 'vfio-v6.0-rc1' of https://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Cleanup use of extern in function prototypes (Alex Williamson) - Simplify bus_type usage and convert to device IOMMU interfaces (Robin Murphy) - Check missed return value and fix comment typos (Bo Liu) - Split migration ops from device ops and fix races in mlx5 migration support (Yishai Hadas) - Fix missed return value check in noiommu support (Liam Ni) - Hardening to clear buffer pointer to avoid use-after-free (Schspa Shi) - Remove requirement that only the same mm can unmap a previously mapped range (Li Zhe) - Adjust semaphore release vs device open counter (Yi Liu) - Remove unused arg from SPAPR support code (Deming Wang) - Rework vfio-ccw driver to better fit new mdev framework (Eric Farman, Michael Kawano) - Replace DMA unmap notifier with callbacks (Jason Gunthorpe) - Clarify SPAPR support comment relative to iommu_ops (Alexey Kardashevskiy) - Revise page pinning API towards compatibility with future iommufd support (Nicolin Chen) - Resolve issues in vfio-ccw, including use of DMA unmap callback (Eric Farman) * tag 'vfio-v6.0-rc1' of https://github.com/awilliam/linux-vfio: (40 commits) vfio/pci: fix the wrong word vfio/ccw: Check return code from subchannel quiesce vfio/ccw: Remove FSM Close from remove handlers vfio/ccw: Add length to DMA_UNMAP checks vfio: Replace phys_pfn with pages for vfio_pin_pages() vfio/ccw: Add kmap_local_page() for memcpy vfio: Rename user_iova of vfio_dma_rw() vfio/ccw: Change pa_pfn list to pa_iova list vfio/ap: Change saved_pfn to saved_iova vfio: Pass in starting IOVA to vfio_pin/unpin_pages API vfio/ccw: Only pass in contiguous pages vfio/ap: Pass in physical address of ind to ap_aqic() drm/i915/gvt: Replace roundup with DIV_ROUND_UP vfio: Make vfio_unpin_pages() return void vfio/spapr_tce: Fix the comment vfio: Replace the iommu notifier with a device list vfio: Replace the DMA unmapping notifier with a callback vfio/ccw: Move FSM open/close to MDEV open/close vfio/ccw: Refactor vfio_ccw_mdev_reset vfio/ccw: Create a CLOSE FSM event ...
2022-08-03Merge tag 'pull-work.lseek' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs lseek updates from Al Viro: "Jason's lseek series. Saner handling of 'lseek should fail with ESPIPE' - this gets rid of the magical no_llseek thing and makes checks consistent. In particular, the ad-hoc "can we do splice via internal pipe" checks got saner (and somewhat more permissive, which is what Jason had been after, AFAICT)" * tag 'pull-work.lseek' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: remove no_llseek fs: check FMODE_LSEEK to control internal pipe splicing vfio: do not set FMODE_LSEEK flag dma-buf: remove useless FMODE_LSEEK flag fs: do not compare against ->llseek fs: clear or set FMODE_LSEEK based on llseek function
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>
2022-07-16vfio: do not set FMODE_LSEEK flagJason A. Donenfeld
This file does not support llseek, so don't set the flag advertising it. Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-07-05vfio: Move IOMMU_CAP_CACHE_COHERENCY test to after we know we have a groupJason Gunthorpe
The test isn't going to work if a group doesn't exist. Normally this isn't a problem since VFIO isn't going to create a device if there is no group, but the special CONFIG_VFIO_NOIOMMU behavior allows bypassing this prevention. The new cap test effectively forces a group and breaks this config option. Move the cap test to vfio_group_find_or_alloc() which is the earliest time we know we have a group available and thus are not running in noiommu mode. Fixes: e8ae0e140c05 ("vfio: Require that devices support DMA cache coherence") Reported-by: Xiang Chen <chenxiang66@hisilicon.com> Tested-by: Xiang Chen <chenxiang66@hisilicon.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/0-v1-e8934b490f36+f4-vfio_cap_fix_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-06-30Merge branches 'v5.20/vfio/migration-enhancements-v3', ↵Alex Williamson
'v5.20/vfio/simplify-bus_type-determination-v3', 'v5.20/vfio/check-vfio_register_iommu_driver-return-v2', 'v5.20/vfio/check-iommu_group_set_name_return-v1', 'v5.20/vfio/clear-caps-buf-v3', 'v5.20/vfio/remove-useless-judgement-v1' and 'v5.20/vfio/move-device_open-count-v2' into v5.20/vfio/next
2022-06-30vfio: Move "device->open_count--" out of group_rwsem in vfio_device_open()Yi Liu
We do not protect the vfio_device::open_count with group_rwsem elsewhere (see vfio_device_fops_release as a comparison, where we already drop group_rwsem before open_count--). So move the group_rwsem unlock prior to open_count--. This change now also drops group_rswem before setting device->kvm = NULL, but that's also OK (again, just like vfio_device_fops_release). The setting of device->kvm before open_device is technically done while holding the group_rwsem, this is done to protect the group kvm value we are copying from, and we should not be relying on that to protect the contents of device->kvm; instead we assume this value will not change until after the device is closed and while under the dev_set->lock. Cc: Matthew Rosato <mjrosato@linux.ibm.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20220627074119.523274-1-yi.l.liu@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-06-30vfio: Clear the caps->buf to NULL after freeSchspa Shi
On buffer resize failure, vfio_info_cap_add() will free the buffer, report zero for the size, and return -ENOMEM. As additional hardening, also clear the buffer pointer to prevent any chance of a double free. Signed-off-by: Schspa Shi <schspa@gmail.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20220629022948.55608-1-schspa@gmail.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-06-30vfio: check iommu_group_set_name() return valueLiam Ni
As iommu_group_set_name() can fail, we should check the return value. Signed-off-by: Liam Ni <zhiguangni01@gmail.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20220625114239.9301-1-zhiguangni01@gmail.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: check vfio_register_iommu_driver() return valueBo Liu
As vfio_register_iommu_driver() can fail, we should check the return value. Signed-off-by: Bo Liu <liubo03@inspur.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20220622045651.5416-1-liubo03@inspur.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-06-27vfio: Use device_iommu_capable()Robin Murphy
Use the new interface to check the capabilities for our device specifically. Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/4ea5eb64246f1ee188d1a61c3e93b37756932eb7.1656092606.git.robin.murphy@arm.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-06-01Merge tag 'vfio-v5.19-rc1' of https://github.com/awilliam/linux-vfioLinus Torvalds
Pull vfio updates from Alex Williamson: - Improvements to mlx5 vfio-pci variant driver, including support for parallel migration per PF (Yishai Hadas) - Remove redundant iommu_present() check (Robin Murphy) - Ongoing refactoring to consolidate the VFIO driver facing API to use vfio_device (Jason Gunthorpe) - Use drvdata to store vfio_device among all vfio-pci and variant drivers (Jason Gunthorpe) - Remove redundant code now that IOMMU core manages group DMA ownership (Jason Gunthorpe) - Remove vfio_group from external API handling struct file ownership (Jason Gunthorpe) - Correct typo in uapi comments (Thomas Huth) - Fix coccicheck detected deadlock (Wan Jiabing) - Use rwsem to remove races and simplify code around container and kvm association to groups (Jason Gunthorpe) - Harden access to devices in low power states and use runtime PM to enable d3cold support for unused devices (Abhishek Sahu) - Fix dma_owner handling of fake IOMMU groups (Jason Gunthorpe) - Set driver_managed_dma on vfio-pci variant drivers (Jason Gunthorpe) - Pass KVM pointer directly rather than via notifier (Matthew Rosato) * tag 'vfio-v5.19-rc1' of https://github.com/awilliam/linux-vfio: (38 commits) vfio: remove VFIO_GROUP_NOTIFY_SET_KVM vfio/pci: Add driver_managed_dma to the new vfio_pci drivers vfio: Do not manipulate iommu dma_owner for fake iommu groups vfio/pci: Move the unused device into low power state with runtime PM vfio/pci: Virtualize PME related registers bits and initialize to zero vfio/pci: Change the PF power state to D0 before enabling VFs vfio/pci: Invalidate mmaps and block the access in D3hot power state vfio: Change struct vfio_group::container_users to a non-atomic int vfio: Simplify the life cycle of the group FD vfio: Fully lock struct vfio_group::container vfio: Split up vfio_group_get_device_fd() vfio: Change struct vfio_group::opened from an atomic to bool vfio: Add missing locking for struct vfio_group::kvm kvm/vfio: Fix potential deadlock problem in vfio include/uapi/linux/vfio.h: Fix trivial typo - _IORW should be _IOWR instead vfio/pci: Use the struct file as the handle not the vfio_group kvm/vfio: Remove vfio_group from kvm vfio: Change vfio_group_set_kvm() to vfio_file_set_kvm() vfio: Change vfio_external_check_extension() to vfio_file_enforced_coherent() vfio: Remove vfio_external_group_match_file() ...
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>
2022-05-23vfio: Do not manipulate iommu dma_owner for fake iommu groupsJason Gunthorpe
Since asserting dma ownership now causes the group to have its DMA blocked the iommu layer requires a working iommu. This means the dma_owner APIs cannot be used on the fake groups that VFIO creates. Test for this and avoid calling them. Otherwise asserting dma ownership will fail for VFIO mdev devices as a BLOCKING iommu_domain cannot be allocated due to the NULL iommu ops. Fixes: 0286300e6045 ("iommu: iommu_group_claim_dma_owner() must always assign a domain") Reported-by: Eric Farman <farman@linux.ibm.com> Tested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/0-v1-9cfc47edbcd4+13546-vfio_dma_owner_fix_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-20Merge branches 'apple/dart', 'arm/mediatek', 'arm/msm', 'arm/smmu', ↵Joerg Roedel
'ppc/pamu', 'x86/vt-d', 'x86/amd' and 'vfio-notifier-fix' into next
2022-05-17vfio: Change struct vfio_group::container_users to a non-atomic intJason Gunthorpe
Now that everything is fully locked there is no need for container_users to remain as an atomic, change it to an unsigned int. Use 'if (group->container)' as the test to determine if the container is present or not instead of using container_users. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/6-v2-d035a1842d81+1bf-vfio_group_locking_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-17vfio: Simplify the life cycle of the group FDJason Gunthorpe
Once userspace opens a group FD it is prevented from opening another instance of that same group FD until all the prior group FDs and users of the container are done. The first is done trivially by checking the group->opened during group FD open. However, things get a little weird if userspace creates a device FD and then closes the group FD. The group FD still cannot be re-opened, but this time it is because the group->container is still set and container_users is elevated by the device FD. Due to this mismatched lifecycle we have the vfio_group_try_dissolve_container() which tries to auto-free a container after the group FD is closed but the device FD remains open. Instead have the device FD hold onto a reference to the single group FD. This directly prevents vfio_group_fops_release() from being called when any device FD exists and makes the lifecycle model more understandable. vfio_group_try_dissolve_container() is removed as the only place a container is auto-deleted is during vfio_group_fops_release(). At this point the container_users is either 1 or 0 since all device FDs must be closed. Change group->opened to group->opened_file which points to the single struct file * that is open for the group. If the group->open_file is NULL then group->container == NULL. If all device FDs have closed then the group's notifier list must be empty. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/5-v2-d035a1842d81+1bf-vfio_group_locking_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-17vfio: Fully lock struct vfio_group::containerJason Gunthorpe
This is necessary to avoid various user triggerable races, for instance racing SET_CONTAINER/UNSET_CONTAINER: ioctl(VFIO_GROUP_SET_CONTAINER) ioctl(VFIO_GROUP_UNSET_CONTAINER) vfio_group_unset_container int users = atomic_cmpxchg(&group->container_users, 1, 0); // users == 1 container_users == 0 __vfio_group_unset_container(group); container = group->container; vfio_group_set_container() if (!atomic_read(&group->container_users)) down_write(&container->group_lock); group->container = container; up_write(&container->group_lock); down_write(&container->group_lock); group->container = NULL; up_write(&container->group_lock); vfio_container_put(container); /* woops we lost/leaked the new container */ This can then go on to NULL pointer deref since container == 0 and container_users == 1. Wrap all touches of container, except those on a performance path with a known open device, with the group_rwsem. The only user of vfio_group_add_container_user() holds the user count for a simple operation, change it to just hold the group_lock over the operation and delete vfio_group_add_container_user(). Containers now only gain a user when a device FD is opened. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/4-v2-d035a1842d81+1bf-vfio_group_locking_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-17vfio: Split up vfio_group_get_device_fd()Jason Gunthorpe
The split follows the pairing with the destroy functions: - vfio_group_get_device_fd() destroyed by close() - vfio_device_open() destroyed by vfio_device_fops_release() - vfio_device_assign_container() destroyed by vfio_group_try_dissolve_container() The next patch will put a lock around vfio_device_assign_container(). Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/3-v2-d035a1842d81+1bf-vfio_group_locking_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-17vfio: Change struct vfio_group::opened from an atomic to boolJason Gunthorpe
This is not a performance path, just use the group_rwsem to protect the value. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/2-v2-d035a1842d81+1bf-vfio_group_locking_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-17vfio: Add missing locking for struct vfio_group::kvmJason Gunthorpe
Without locking userspace can trigger a UAF by racing KVM_DEV_VFIO_GROUP_DEL with VFIO_GROUP_GET_DEVICE_FD: CPU1 CPU2 ioctl(KVM_DEV_VFIO_GROUP_DEL) ioctl(VFIO_GROUP_GET_DEVICE_FD) vfio_group_get_device_fd open_device() intel_vgpu_open_device() vfio_register_notifier() vfio_register_group_notifier() blocking_notifier_call_chain(&group->notifier, VFIO_GROUP_NOTIFY_SET_KVM, group->kvm); set_kvm() group->kvm = NULL close() kfree(kvm) intel_vgpu_group_notifier() vdev->kvm = data [..] kvm_get_kvm(vgpu->kvm); // UAF! Add a simple rwsem in the group to protect the kvm while the notifier is using it. Note this doesn't fix the race internal to i915 where userspace can trigger two VFIO_GROUP_NOTIFY_SET_KVM's before we reach a consumer of vgpu->kvm and trigger this same UAF, it just makes the notifier self-consistent. Fixes: ccd46dbae77d ("vfio: support notifier chain in vfio_group") Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/1-v2-d035a1842d81+1bf-vfio_group_locking_jgg@nvidia.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>
2022-05-13vfio: Delete container_qJason Gunthorpe
Now that the iommu core takes care of isolation there is no race between driver attach and container unset. Once iommu_group_release_dma_owner() returns the device can immediately be re-used. Remove this mechanism. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/0-v1-a1e8791d795b+6b-vfio_container_q_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-13Merge remote-tracking branch 'iommu/vfio-notifier-fix' into v5.19/vfio/nextAlex Williamson
Merge IOMMU dependencies for vfio. 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 calls to vfio_group_add_container_user()Jason Gunthorpe
When the open_device() op is called the container_users is incremented and held incremented until close_device(). Thus, so long as drivers call functions within their open_device()/close_device() region they do not need to worry about the container_users. These functions can all only be called between open_device() and close_device(): vfio_pin_pages() vfio_unpin_pages() vfio_dma_rw() vfio_register_notifier() vfio_unregister_notifier() Eliminate the calls to vfio_group_add_container_user() and add vfio_assert_device_open() to detect driver mis-use. This causes the close_device() op to check device->open_count so always leave it elevated while calling the op. 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/7-v4-8045e76bf00b+13d-vfio_mdev_no_group_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>
2022-05-11vfio: Stop using iommu_present()Robin Murphy
IOMMU groups have been mandatory for some time now, so a device without one is necessarily a device without any usable IOMMU, therefore the iommu_present() check is redundant (or at best unhelpful). Signed-off-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/537103bbd7246574f37f2c88704d7824a3a889f2.1649160714.git.robin.murphy@arm.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-04-28vfio: Require that devices support DMA cache coherenceJason Gunthorpe
IOMMU_CACHE means that normal DMAs do not require any additional coherency mechanism and is the basic uAPI that VFIO exposes to userspace. For instance VFIO applications like DPDK will not work if additional coherency operations are required. Therefore check IOMMU_CAP_CACHE_COHERENCY like vdpa & usnic do before allowing an IOMMU backed VFIO device to be created. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/4-v3-2cf356649677+a32-intel_no_snoop_jgg@nvidia.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2022-04-28vfio: Remove iommu group notifierLu Baolu
The iommu core and driver core have been enhanced to avoid unsafe driver binding to a live group after iommu_group_set_dma_owner(PRIVATE_USER) has been called. There's no need to register iommu group notifier. This removes the iommu group notifer which contains BUG_ON() and WARN(). Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Link: https://lore.kernel.org/r/20220418005000.897664-11-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2022-04-28vfio: Delete the unbound_listJason Gunthorpe
commit 60720a0fc646 ("vfio: Add device tracking during unbind") added the unbound list to plug a problem with KVM where KVM_DEV_VFIO_GROUP_DEL relied on vfio_group_get_external_user() succeeding to return the vfio_group from a group file descriptor. The unbound list allowed vfio_group_get_external_user() to continue to succeed in edge cases. However commit 5d6dee80a1e9 ("vfio: New external user group/file match") deleted the call to vfio_group_get_external_user() during KVM_DEV_VFIO_GROUP_DEL. Instead vfio_external_group_match_file() is used to directly match the file descriptor to the group pointer. This in turn avoids the call down to vfio_dev_viable() during KVM_DEV_VFIO_GROUP_DEL and also avoids the trouble the first commit was trying to fix. There are no other users of vfio_dev_viable() that care about the time after vfio_unregister_group_dev() returns, so simply delete the unbound_list entirely. Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Link: https://lore.kernel.org/r/20220418005000.897664-10-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2022-04-28vfio: Remove use of vfio_group_viable()Lu Baolu
As DMA ownership is claimed for the iommu group when a VFIO group is added to a VFIO container, the VFIO group viability is guaranteed as long as group->container_users > 0. Remove those unnecessary group viability checks which are only hit when group->container_users is not zero. The only remaining reference is in GROUP_GET_STATUS, which could be called at any time when group fd is valid. Here we just replace the vfio_group_viable() by directly calling IOMMU core to get viability status. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Link: https://lore.kernel.org/r/20220418005000.897664-9-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2022-04-28vfio: Set DMA ownership for VFIO devicesLu Baolu
Claim group dma ownership when an IOMMU group is set to a container, and release the dma ownership once the iommu group is unset from the container. This change disallows some unsafe bridge drivers to bind to non-ACS bridges while devices under them are assigned to user space. This is an intentional enhancement and possibly breaks some existing configurations. The recommendation to such an affected user would be that the previously allowed host bridge driver was unsafe for this use case and to continue to enable assignment of devices within that group, the driver should be unbound from the bridge device or replaced with the pci-stub driver. For any bridge driver, we consider it unsafe if it satisfies any of the following conditions: 1) The bridge driver uses DMA. Calling pci_set_master() or calling any kernel DMA API (dma_map_*() and etc.) is an indicate that the driver is doing DMA. 2) If the bridge driver uses MMIO, it should be tolerant to hostile userspace also touching the same MMIO registers via P2P DMA attacks. If the bridge driver turns out to be a safe one, it could be used as before by setting the driver's .driver_managed_dma field, just like what we have done in the pcieport driver. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Link: https://lore.kernel.org/r/20220418005000.897664-8-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
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>
generated by cgit (git 2.34.1) at 2024-06-26 08:55:20 +0000