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path: root/drivers/vfio/vfio.h (follow)
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2022-10-07vfio: Make the group FD disassociate from the iommu_groupJason Gunthorpe1-1/+0
Allow the vfio_group struct to exist with a NULL iommu_group pointer. When the pointer is NULL the vfio_group users promise not to touch the iommu_group. This allows a driver to be hot unplugged while userspace is keeping the group FD open. Remove all the code waiting for the group FD to close. This fixes a userspace regression where we learned that virtnodedevd leaves a group FD open even though the /dev/ node for it has been deleted and all the drivers for it unplugged. Fixes: ca5f21b25749 ("vfio: Follow a strict lifetime for struct iommu_group") Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Tested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/3-v2-15417f29324e+1c-vfio_group_disassociate_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04vfio: Change vfio_group->group_rwsem to a mutexJason Gunthorpe1-1/+1
These days not much is using the read side: - device first open - ioctl_get_status - device FD release - check enforced_coherent None of this is performance, so just make it into a normal mutex. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/2-v1-917e3647f123+b1a-vfio_group_users_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04vfio: Remove the vfio_group->users and users_compJason Gunthorpe1-2/+1
Kevin points out that the users is really just tracking if group->opened_file is set, so we can simplify this code to a wait_queue that looks for !opened_file under the group_rwsem. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/1-v1-917e3647f123+b1a-vfio_group_users_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-27vfio: Follow a strict lifetime for struct iommu_groupJason Gunthorpe1-0/+8
The iommu_group comes from the struct device that a driver has been bound to and then created a struct vfio_device against. To keep the iommu layer sane we want to have a simple rule that only an attached driver should be using the iommu API. Particularly only an attached driver should hold ownership. In VFIO's case since it uses the group APIs and it shares between different drivers it is a bit more complicated, but the principle still holds. Solve this by waiting for all users of the vfio_group to stop before allowing vfio_unregister_group_dev() to complete. This is done with a new completion to know when the users go away and an additional refcount to keep track of how many device drivers are sharing the vfio group. The last driver to be unregistered will clean up the group. This solves crashes in the S390 iommu driver that come because VFIO ends up racing releasing ownership (which attaches the default iommu_domain to the device) with the removal of that same device from the iommu driver. This is a side case that iommu drivers should not have to cope with. iommu driver failed to attach the default/blocking domain WARNING: CPU: 0 PID: 5082 at drivers/iommu/iommu.c:1961 iommu_detach_group+0x6c/0x80 Modules linked in: macvtap macvlan tap vfio_pci vfio_pci_core irqbypass vfio_virqfd kvm nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables nfnetlink mlx5_ib sunrpc ib_uverbs ism smc uvdevice ib_core s390_trng eadm_sch tape_3590 tape tape_class vfio_ccw mdev vfio_iommu_type1 vfio zcrypt_cex4 sch_fq_codel configfs ghash_s390 prng chacha_s390 libchacha aes_s390 mlx5_core des_s390 libdes sha3_512_s390 nvme sha3_256_s390 sha512_s390 sha256_s390 sha1_s390 sha_common nvme_core zfcp scsi_transport_fc pkey zcrypt rng_core autofs4 CPU: 0 PID: 5082 Comm: qemu-system-s39 Tainted: G W 6.0.0-rc3 #5 Hardware name: IBM 3931 A01 782 (LPAR) Krnl PSW : 0704c00180000000 000000095bb10d28 (iommu_detach_group+0x70/0x80) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000001 0000000900000027 0000000000000039 000000095c97ffe0 00000000fffeffff 00000009fc290000 00000000af1fda50 00000000af590b58 00000000af1fdaf0 0000000135c7a320 0000000135e52258 0000000135e52200 00000000a29e8000 00000000af590b40 000000095bb10d24 0000038004b13c98 Krnl Code: 000000095bb10d18: c020003d56fc larl %r2,000000095c2bbb10 000000095bb10d1e: c0e50019d901 brasl %r14,000000095be4bf20 #000000095bb10d24: af000000 mc 0,0 >000000095bb10d28: b904002a lgr %r2,%r10 000000095bb10d2c: ebaff0a00004 lmg %r10,%r15,160(%r15) 000000095bb10d32: c0f4001aa867 brcl 15,000000095be65e00 000000095bb10d38: c004002168e0 brcl 0,000000095bf3def8 000000095bb10d3e: eb6ff0480024 stmg %r6,%r15,72(%r15) Call Trace: [<000000095bb10d28>] iommu_detach_group+0x70/0x80 ([<000000095bb10d24>] iommu_detach_group+0x6c/0x80) [<000003ff80243b0e>] vfio_iommu_type1_detach_group+0x136/0x6c8 [vfio_iommu_type1] [<000003ff80137780>] __vfio_group_unset_container+0x58/0x158 [vfio] [<000003ff80138a16>] vfio_group_fops_unl_ioctl+0x1b6/0x210 [vfio] pci 0004:00:00.0: Removing from iommu group 4 [<000000095b5b62e8>] __s390x_sys_ioctl+0xc0/0x100 [<000000095be5d3b4>] __do_syscall+0x1d4/0x200 [<000000095be6c072>] system_call+0x82/0xb0 Last Breaking-Event-Address: [<000000095be4bf80>] __warn_printk+0x60/0x68 It indicates that domain->ops->attach_dev() failed because the driver has already passed the point of destructing the device. Fixes: 9ac8545199a1 ("iommu: Fix use-after-free in iommu_release_device") Reported-by: Matthew Rosato <mjrosato@linux.ibm.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/0-v2-a3c5f4429e2a+55-iommu_group_lifetime_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-22vfio: Move container code into drivers/vfio/container.cJason Gunthorpe1-0/+46
All the functions that dereference struct vfio_container are moved into container.c. Simple code motion, no functional change. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/8-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-22vfio: Add header guards and includes to drivers/vfio/vfio.hJason Gunthorpe1-0/+10
As is normal for headers. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/1-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-25vfio: Replace phys_pfn with pages for vfio_pin_pages()Nicolin Chen1-1/+1
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: Pass in starting IOVA to vfio_pin/unpin_pages APINicolin Chen1-2/+2
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 Chen1-1/+1
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 Gunthorpe1-8/+4
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 Gunthorpe1-0/+3
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>
2021-09-30vfio: clean up the check for mediated device in vfio_iommu_type1Christoph Hellwig1-1/+26
Pass the group flags to ->attach_group and remove the messy check for the bus type. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-12-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-09-30vfio: move the vfio_iommu_driver_ops interface out of <linux/vfio.h>Christoph Hellwig1-0/+47
Create a new private drivers/vfio/vfio.h header for the interface between the VFIO core and the iommu drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-10-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>