6.12-stable review patch. If anyone has any objections, please let me know.
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From: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
[ Upstream commit 9ec19bfa78bd788945e2445b09de7b4482dee432 ]
__resource_resize_store() attempts to release all resources of the device before attempting the resize. The loop, however, only covers standard BARs (< PCI_STD_NUM_BARS). If a device has VF BARs that are assigned, pci_reassign_bridge_resources() finds the bridge window still has some assigned child resources and returns -NOENT which makes pci_resize_resource() to detect an error and abort the resize.
Change the release loop to cover all resources up to VF BARs which allows the resize operation to release the bridge windows and attempt to assigned them again with the different size.
If SR-IOV is enabled, disallow resize as it requires releasing also IOV resources.
Link: https://lore.kernel.org/r/20250320142837.8027-1-ilpo.jarvinen@linux.intel.co... Fixes: 91fa127794ac ("PCI: Expose PCIe Resizable BAR support via sysfs") Reported-by: Michał Winiarski michal.winiarski@intel.com Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/pci-sysfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 3e5a117f5b5d6..5af4a804a4f89 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1444,7 +1444,7 @@ static ssize_t __resource_resize_store(struct device *dev, int n, return -EINVAL;
device_lock(dev); - if (dev->driver) { + if (dev->driver || pci_num_vf(pdev)) { ret = -EBUSY; goto unlock; } @@ -1466,7 +1466,7 @@ static ssize_t __resource_resize_store(struct device *dev, int n,
pci_remove_resource_files(pdev);
- for (i = 0; i < PCI_STD_NUM_BARS; i++) { + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { if (pci_resource_len(pdev, i) && pci_resource_flags(pdev, i) == flags) pci_release_resource(pdev, i);