From b8c0f6d1b04cdf07eda31cb643eea1a1410b551f Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 13 Apr 2022 10:10:36 -0300 Subject: vfio/pci: Fix vf_token mechanism when device-specific VF drivers are used [ Upstream commit 1ef3342a934e235aca72b4bcc0d6854d80a65077 ] 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 Link: https://lore.kernel.org/r/0-v3-876570980634+f2e8-vfio_vf_token_jgg@nvidia.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin --- include/linux/vfio_pci_core.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h index ae6f4838ab75..6e5db4edc335 100644 --- a/include/linux/vfio_pci_core.h +++ b/include/linux/vfio_pci_core.h @@ -133,6 +133,8 @@ struct vfio_pci_core_device { struct mutex ioeventfds_lock; struct list_head ioeventfds_list; struct vfio_pci_vf_token *vf_token; + struct list_head sriov_pfs_item; + struct vfio_pci_core_device *sriov_pf_core_dev; struct notifier_block nb; struct mutex vma_lock; struct list_head vma_list; -- cgit v1.2.3