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path: root/drivers/vfio
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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/pci: Have all VFIO PCI drivers store the vfio_pci_core_device in drvdataJason Gunthorpe
Having a consistent pointer in the drvdata will allow the next patch to make use of the drvdata from some of the core code helpers. Use a WARN_ON inside vfio_pci_core_register_device() to detect drivers that miss this. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/1-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>
2022-05-11Merge tag 'gvt-next-2022-04-29' into v5.19/vfio/nextAlex Williamson
Merge GVT-g dependencies for vfio. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-11Merge tag 'mlx5-lm-parallel' of ↵Alex Williamson
https://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux into v5.19/vfio/next Improve mlx5 live migration driver From Yishai: This series improves mlx5 live migration driver in few aspects as of below. Refactor to enable running migration commands in parallel over the PF command interface. To achieve that we exposed from mlx5_core an API to let the VF be notified before that the PF command interface goes down/up. (e.g. PF reload upon health recovery). Once having the above functionality in place mlx5 vfio doesn't need any more to obtain the global PF lock upon using the command interface but can rely on the above mechanism to be in sync with the PF. This can enable parallel VFs migration over the PF command interface from kernel driver point of view. In addition, Moved to use the PF async command mode for the SAVE state command. This enables returning earlier to user space upon issuing successfully the command and improve latency by let things run in parallel. Alex, as this series touches mlx5_core we may need to send this in a pull request format to VFIO to avoid conflicts before acceptance. Link: https://lore.kernel.org/all/20220510090206.90374-1-yishaih@nvidia.com Signed-of-by: Leon Romanovsky <leonro@nvidia.com>
2022-05-11vfio/mlx5: Run the SAVE state command in an async modeYishai Hadas
Use the PF asynchronous command mode for the SAVE state command. This enables returning earlier to user space upon issuing successfully the command and improve latency by let things run in parallel. Link: https://lore.kernel.org/r/20220510090206.90374-5-yishaih@nvidia.com Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
2022-05-11vfio/mlx5: Refactor to enable VFs migration in parallelYishai Hadas
Refactor to enable different VFs to run their commands over the PF command interface in parallel and to not block one each other. This is done by not using the global PF lock that was used before but relying on the VF attach/detach mechanism to sync. Link: https://lore.kernel.org/r/20220510090206.90374-4-yishaih@nvidia.com Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
2022-05-11vfio/mlx5: Manage the VF attach/detach callback from the PFYishai Hadas
Manage the VF attach/detach callback from the PF. This lets the driver to enable parallel VFs migration as will be introduced in the next patch. As part of this, reorganize the VF is migratable code to be in a separate function and rename it to be set_migratable() to match its functionality. Link: https://lore.kernel.org/r/20220510090206.90374-3-yishaih@nvidia.com Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
2022-05-11Merge tag 'drm-intel-next-2022-05-06' of ↵Dave Airlie
git://anongit.freedesktop.org/drm/drm-intel into drm-next drm/i915 feature pull #2 for v5.19: Features and functionality: - Add first set of DG2 PCI IDs for "motherboard down" designs (Matt Roper) - Add initial RPL-P PCI IDs as ADL-P subplatform (Matt Atwood) Refactoring and cleanups: - Power well refactoring and cleanup (Imre) - GVT-g refactor and mdev API cleanup (Christoph, Jason, Zhi) - DPLL refactoring and cleanup (Ville) - VBT panel specific data parsing cleanup (Ville) - Use drm_mode_init() for on-stack modes (Ville) Fixes: - Fix PSR state pipe A/B confusion by clearing more state on disable (José) - Fix FIFO underruns caused by not taking DRAM channel into account (Vinod) - Fix FBC flicker on display 11+ by enabling a workaround (José) - Fix VBT seamless DRRS min refresh rate check (Ville) - Fix panel type assumption on bogus VBT data (Ville) - Fix panel data parsing for VBT that misses panel data pointers block (Ville) - Fix spurious AUX timeout/hotplug handling on LTTPR links (Imre) Merges: - Backmerge drm-next (Jani) - GVT changes (Jani) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/87bkwbkkdo.fsf@intel.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: Move the Intel no-snoop control off of IOMMU_CACHEJason Gunthorpe
IOMMU_CACHE means "normal DMA to this iommu_domain's IOVA should be cache coherent" and is used by the DMA API. The definition allows for special non-coherent DMA to exist - ie processing of the no-snoop flag in PCIe TLPs - so long as this behavior is opt-in by the device driver. The flag is mainly used by the DMA API to synchronize the IOMMU setting with the expected cache behavior of the DMA master. eg based on dev_is_dma_coherent() in some case. For Intel IOMMU IOMMU_CACHE was redefined to mean 'force all DMA to be cache coherent' which has the practical effect of causing the IOMMU to ignore the no-snoop bit in a PCIe TLP. x86 platforms are always IOMMU_CACHE, so Intel should ignore this flag. Instead use the new domain op enforce_cache_coherency() which causes every IOPTE created in the domain to have the no-snoop blocking behavior. Reconfigure VFIO to always use IOMMU_CACHE and call enforce_cache_coherency() to operate the special Intel behavior. Remove the IOMMU_CACHE test from Intel IOMMU. Ultimately VFIO plumbs the result of enforce_cache_coherency() back into the x86 platform code through kvm_arch_register_noncoherent_dma() which controls if the WBINVD instruction is available in the guest. No other archs implement kvm_arch_register_noncoherent_dma() nor are there any other known consumers of VFIO_DMA_CC_IOMMU that might be affected by the user visible result change on non-x86 archs. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Lu Baolu <baolu.lu@linux.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/2-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>
2022-04-21vfio/mdev: Use the driver core to create the 'remove' fileJason Gunthorpe
The device creator is supposed to use the dev.groups value to add sysfs files before device_add is called, not call sysfs_create_files() after device_add() returns. This creates a race with uevent delivery where the extra attribute will not be visible. This was being done because the groups had been co-opted by the mdev driver, now that prior patches have moved the driver's groups to the struct device_driver the dev.group is properly free for use here. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Zhi Wang <zhi.a.wang@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-34-hch@lst.de Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
2022-04-21vfio/mdev: Remove mdev_parent_opsJason Gunthorpe
The last useful member in this struct is the supported_type_groups, move it to the mdev_driver and delete mdev_parent_ops. Replace it with mdev_driver as an argument to mdev_register_device() Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Zhi Wang <zhi.a.wang@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-33-hch@lst.de Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
2022-04-21vfio/mdev: Remove mdev_parent_ops dev_attr_groupsJason Gunthorpe
This is only used by one sample to print a fixed string that is pointless. In general, having a device driver attach sysfs attributes to the parent is horrific. This should never happen, and always leads to some kind of liftime bug as it become very difficult for the sysfs attribute to go back to any data owned by the device driver. Remove the general mechanism to create this abuse. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Zhi Wang <zhi.a.wang@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-32-hch@lst.de Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
2022-04-21vfio/mdev: Remove vfio_mdev.cJason Gunthorpe
Now that all mdev drivers directly create their own mdev_device driver and directly register with the vfio core's vfio_device_ops this is all dead code. Delete vfio_mdev.c and the mdev_parent_ops members that are connected to it. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Zhi Wang <zhi.a.wang@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-31-hch@lst.de Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
2022-04-13vfio/pci: Fix vf_token mechanism when device-specific VF drivers are usedJason Gunthorpe
get_pf_vdev() tries to check if a PF is a VFIO PF by looking at the driver: if (pci_dev_driver(physfn) != pci_dev_driver(vdev->pdev)) { However now that we have multiple VF and PF drivers this is no longer reliable. This means that security tests realted to vf_token can be skipped by mixing and matching different VFIO PCI drivers. Instead of trying to use the driver core to find the PF devices maintain a linked list of all PF vfio_pci_core_device's that we have called pci_enable_sriov() on. When registering a VF just search the list to see if the PF is present and record the match permanently in the struct. PCI core locking prevents a PF from passing pci_disable_sriov() while VF drivers are attached so the VFIO owned PF becomes a static property of the VF. In common cases where vfio does not own the PF the global list remains empty and the VF's pointer is statically NULL. This also fixes a lockdep splat from recursive locking of the vfio_group::device_lock between vfio_device_get_from_name() and vfio_device_get_from_dev(). If the VF and PF share the same group this would deadlock. Fixes: ff53edf6d6ab ("vfio/pci: Split the pci_driver code out of vfio_pci_core.c") Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/0-v3-876570980634+f2e8-vfio_vf_token_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-03-15hisi_acc_vfio_pci: Use its own PCI reset_done error handlerShameer Kolothum
Register private handler for pci_error_handlers.reset_done and update state accordingly. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Longfang Liu <liulongfang@huawei.com> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Link: https://lore.kernel.org/r/20220308184902.2242-10-shameerali.kolothum.thodi@huawei.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-03-15hisi_acc_vfio_pci: Add support for VFIO live migrationLongfang Liu
VMs assigned with HiSilicon ACC VF devices can now perform live migration if the VF devices are bind to the hisi_acc_vfio_pci driver. Just like ACC PF/VF drivers this VFIO driver also make use of the HiSilicon QM interface. QM stands for Queue Management which is a generic IP used by ACC devices. It provides a generic PCIe interface for the CPU and the ACC devices to share a group of queues. QM integrated into an accelerator provides queue management service. Queues can be assigned to PF and VFs, and queues can be controlled by unified mailboxes and doorbells. The QM driver (drivers/crypto/hisilicon/qm.c) provides generic interfaces to ACC drivers to manage the QM. Signed-off-by: Longfang Liu <liulongfang@huawei.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Link: https://lore.kernel.org/r/20220308184902.2242-9-shameerali.kolothum.thodi@huawei.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-03-15hisi_acc_vfio_pci: Restrict access to VF dev BAR2 migration regionShameer Kolothum
HiSilicon ACC VF device BAR2 region consists of both functional register space and migration control register space. Unnecessarily exposing the migration BAR region to the Guest has the potential to prevent/corrupt the Guest migration. Hence, introduce a separate struct vfio_device_ops for migration support which will override the ioctl/read/write/mmap methods to hide the migration region and limit the Guest access only to the functional register space. This will be used in subsequent patches when we add migration support to the driver. Please note that it is OK to export the entire VF BAR if migration is not supported or required as this cannot affect the PF configurations. Reviewed-by: Longfang Liu <liulongfang@huawei.com> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20220308184902.2242-6-shameerali.kolothum.thodi@huawei.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-03-15hisi_acc_vfio_pci: add new vfio_pci driver for HiSilicon ACC devicesShameer Kolothum
Add a vendor-specific vfio_pci driver for HiSilicon ACC devices. This will be extended in subsequent patches to add support for VFIO live migration feature. Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20220308184902.2242-5-shameerali.kolothum.thodi@huawei.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-03-09vfio/mlx5: Fix to not use 0 as NULL pointerYishai Hadas
Fix sparse warning to not use plain integer (i.e. 0) as NULL pointer. Reported-by: kernel test robot <lkp@intel.com> Fixes: 6fadb021266d ("vfio/mlx5: Implement vfio_pci driver for mlx5 devices") Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Link: https://lore.kernel.org/r/202203090703.kxvZumJg-lkp@intel.com Link: https://lore.kernel.org/r/20220309080217.94274-1-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-03-03Merge branches 'v5.18/vfio/next/mlx5-migration-v10', ↵Alex Williamson
'v5.18/vfio/next/pm-fixes' and 'v5.18/vfio/next/uml-build-fix' into v5.18/vfio/next/next
2022-03-03vfio/mlx5: Use its own PCI reset_done error handlerYishai Hadas
Register its own handler for pci_error_handlers.reset_done and update state accordingly. Link: https://lore.kernel.org/all/20220224142024.147653-16-yishaih@nvidia.com Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
2022-03-03vfio/pci: Expose vfio_pci_core_aer_err_detected()Yishai Hadas
Expose vfio_pci_core_aer_err_detected() to be used by drivers as part of their pci_error_handlers structure. Next patch for mlx5 driver will use it. Link: https://lore.kernel.org/all/20220224142024.147653-15-yishaih@nvidia.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/mlx5: Implement vfio_pci driver for mlx5 devicesYishai Hadas
This patch adds support for vfio_pci driver for mlx5 devices. It uses vfio_pci_core to register to the VFIO subsystem and then implements the mlx5 specific logic in the migration area. The migration implementation follows the definition from uapi/vfio.h and uses the mlx5 VF->PF command channel to achieve it. This patch implements the suspend/resume flows. Link: https://lore.kernel.org/all/20220224142024.147653-14-yishaih@nvidia.com Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
2022-03-03vfio/mlx5: Expose migration commands over mlx5 deviceYishai Hadas
Expose migration commands over the device, it includes: suspend, resume, get vhca id, query/save/load state. As part of this adds the APIs and data structure that are needed to manage the migration data. Link: https://lore.kernel.org/all/20220224142024.147653-13-yishaih@nvidia.com Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
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>
2022-02-22vfio/pci: wake-up devices around reset functionsAbhishek Sahu
If 'vfio_pci_core_device::needs_pm_restore' is set (PCI device does not have No_Soft_Reset bit set in its PMCSR config register), then the current PCI state will be saved locally in 'vfio_pci_core_device::pm_save' during D0->D3hot transition and same will be restored back during D3hot->D0 transition. For reset-related functionalities, vfio driver uses PCI reset API's. These API's internally change the PCI power state back to D0 first if the device power state is non-D0. This state change to D0 will happen without the involvement of vfio driver. Let's consider the following example: 1. The device is in D3hot. 2. User invokes VFIO_DEVICE_RESET ioctl. 3. pci_try_reset_function() will be called which internally invokes pci_dev_save_and_disable(). 4. pci_set_power_state(dev, PCI_D0) will be called first. 5. pci_save_state() will happen then. Now, for the devices which has NoSoftRst-, the pci_set_power_state() can trigger soft reset and the original PCI config state will be lost at step (4) and this state cannot be restored again. This original PCI state can include any setting which is performed by SBIOS or host linux kernel (for example LTR, ASPM L1 substates, etc.). When this soft reset will be triggered, then all these settings will be reset, and the device state saved at step (5) will also have this setting cleared so it cannot be restored. Since the vfio driver only exposes limited PCI capabilities to its user, so the vfio driver user also won't have the option to save and restore these capabilities state either and these original settings will be permanently lost. For pci_reset_bus() also, we can have the above situation. The other functions/devices can be in D3hot and the reset will change the power state of all devices to D0 without the involvement of vfio driver. So, before calling any reset-related API's, we need to make sure that the device state is D0. This is mainly to preserve the state around soft reset. For vfio_pci_core_disable(), we use __pci_reset_function_locked() which internally can use pci_pm_reset() for the function reset. pci_pm_reset() requires the device power state to be in D0, otherwise it returns error. This patch changes the device power state to D0 by invoking vfio_pci_set_power_state() explicitly before calling any reset related API's. Fixes: 51ef3a004b1e ("vfio/pci: Restore device state on PM transition") Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com> Link: https://lore.kernel.org/r/20220217122107.22434-3-abhsahu@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-02-22vfio/pci: fix memory leak during D3hot to D0 transitionAbhishek Sahu
If 'vfio_pci_core_device::needs_pm_restore' is set (PCI device does not have No_Soft_Reset bit set in its PMCSR config register), then the current PCI state will be saved locally in 'vfio_pci_core_device::pm_save' during D0->D3hot transition and same will be restored back during D3hot->D0 transition. For saving the PCI state locally, pci_store_saved_state() is being used and the pci_load_and_free_saved_state() will free the allocated memory. But for reset related IOCTLs, vfio driver calls PCI reset-related API's which will internally change the PCI power state back to D0. So, when the guest resumes, then it will get the current state as D0 and it will skip the call to vfio_pci_set_power_state() for changing the power state to D0 explicitly. In this case, the memory pointed by 'pm_save' will never be freed. In a malicious sequence, the state changing to D3hot followed by VFIO_DEVICE_RESET/VFIO_DEVICE_PCI_HOT_RESET can be run in a loop and it can cause an OOM situation. This patch frees the earlier allocated memory first before overwriting 'pm_save' to prevent the mentioned memory leak. Fixes: 51ef3a004b1e ("vfio/pci: Restore device state on PM transition") Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com> Link: https://lore.kernel.org/r/20220217122107.22434-2-abhsahu@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-02-22vfio/pci: Stub vfio_pci_vga_rw when !CONFIG_VFIO_PCI_VGAAlex Williamson
Resolve build errors reported against UML build for undefined ioport_map() and ioport_unmap() functions. Without this config option a device cannot have vfio_pci_core_device.has_vga set, so the existing function would always return -EINVAL anyway. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/20220123125737.2658758-1-geert@linux-m68k.org Link: https://lore.kernel.org/r/164306582968.3758255.15192949639574660648.stgit@omen Signed-off-by: Alex Williamson <alex.williamson@redhat.com>