From 962ae6892d8bd208b2d1e2b358f07551ddc8d32f Mon Sep 17 00:00:00 2001 From: "Anthony Pighin (Nokia)" Date: Fri, 16 Jan 2026 15:31:26 +0000 Subject: [PATCH] vfio/pci: Lock upstream bridge for vfio_pci_core_disable() The commit 7e89efc6e9e4 ("Lock upstream bridge for pci_reset_function()") added locking of the upstream bridge to the reset function. To catch paths that are not properly locked, the commit 920f6468924f ("Warn on missing cfg_access_lock during secondary bus reset") added a warning if the PCI configuration space was not locked during a secondary bus reset request. When a VFIO PCI device is released from userspace ownership, an attempt to reset the PCI device function may be made. If so, and the upstream bridge is not locked, the release request results in a warning: pcieport 0000:00:00.0: unlocked secondary bus reset via: pci_reset_bus_function+0x188/0x1b8 Add missing upstream bridge locking to vfio_pci_core_disable(). Fixes: 7e89efc6e9e4 ("PCI: Lock upstream bridge for pci_reset_function()") Signed-off-by: Anthony Pighin Link: https://lore.kernel.org/r/BN0PR08MB695171D3AB759C65B6438B5D838DA@BN0PR08MB6951.namprd08.prod.outlook.com Signed-off-by: Alex Williamson --- drivers/vfio/pci/vfio_pci_core.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 3a11e6f450f7..72c33b399800 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -588,6 +588,7 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_enable); void vfio_pci_core_disable(struct vfio_pci_core_device *vdev) { + struct pci_dev *bridge; struct pci_dev *pdev = vdev->pdev; struct vfio_pci_dummy_resource *dummy_res, *tmp; struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp; @@ -694,12 +695,20 @@ void vfio_pci_core_disable(struct vfio_pci_core_device *vdev) * We can not use the "try" reset interface here, which will * overwrite the previously restored configuration information. */ - if (vdev->reset_works && pci_dev_trylock(pdev)) { - if (!__pci_reset_function_locked(pdev)) - vdev->needs_reset = false; - pci_dev_unlock(pdev); + if (vdev->reset_works) { + bridge = pci_upstream_bridge(pdev); + if (bridge && !pci_dev_trylock(bridge)) + goto out_restore_state; + if (pci_dev_trylock(pdev)) { + if (!__pci_reset_function_locked(pdev)) + vdev->needs_reset = false; + pci_dev_unlock(pdev); + } + if (bridge) + pci_dev_unlock(bridge); } +out_restore_state: pci_restore_state(pdev); out: pci_disable_device(pdev); -- 2.47.3