[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] pci: fix locking around vPCI removal in pci_remove_device()
commit 635dd1120a01961a39dce6ad3f09692681379378 Author: Roger Pau Monné <roger.pau@xxxxxxxxxx> AuthorDate: Thu Feb 29 17:00:40 2024 +0100 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Thu Feb 29 17:00:40 2024 +0100 pci: fix locking around vPCI removal in pci_remove_device() Currently vpci_deassign_device() is called without holding the per-domain pci_lock in pci_remove_device(), which leads to: Assertion 'rw_is_write_locked(&pdev->domain->pci_lock)' failed at ../drivers/vpci/vpci.c:47 [...] Xen call trace: [<ffff82d040260eac>] R vpci_deassign_device+0x10d/0x1b9 [<ffff82d04027932f>] S pci_remove_device+0x2b1/0x380 [<ffff82d040260bd0>] F pci_physdev_op+0x197/0x19e [<ffff82d04032272d>] F do_physdev_op+0x342/0x12aa [<ffff82d0402f067a>] F pv_hypercall+0x58e/0x62b [<ffff82d0402012ba>] F lstar_enter+0x13a/0x140 Move the existing block that removes the device from the domain pdev_list ahead and also issue the call to vpci_deassign_device() there. It's fine to remove the device from the domain list of assigned devices, as further functions only care that the pdev domain field is correctly set to the owner of the device about to be removed. Moving the vpci_deassign_device() past the pci_cleanup_msi() call can be dangerous, as doing the MSI cleanup ahead of having removed the vPCI handlers could lead to stale data in vPCI MSI(-X) internal structures. Fixes: 4f78438b45e2 ('vpci: use per-domain PCI lock to protect vpci structure') Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Stewart Hildebrand <stewart.hildebrand@xxxxxxx> --- xen/drivers/passthrough/pci.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c index 4c0a836486..194701c913 100644 --- a/xen/drivers/passthrough/pci.c +++ b/xen/drivers/passthrough/pci.c @@ -817,15 +817,15 @@ int pci_remove_device(u16 seg, u8 bus, u8 devfn) list_for_each_entry ( pdev, &pseg->alldevs_list, alldevs_list ) if ( pdev->bus == bus && pdev->devfn == devfn ) { - vpci_deassign_device(pdev); - pci_cleanup_msi(pdev); - ret = iommu_remove_device(pdev); if ( pdev->domain ) { write_lock(&pdev->domain->pci_lock); + vpci_deassign_device(pdev); list_del(&pdev->domain_list); write_unlock(&pdev->domain->pci_lock); } + pci_cleanup_msi(pdev); + ret = iommu_remove_device(pdev); printk(XENLOG_DEBUG "PCI remove device %pp\n", &pdev->sbdf); free_pdev(pseg, pdev); break; -- generated by git-patchbot for /home/xen/git/xen.git#staging
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |