On Thu, Mar 20, 2025 at 04:28:37PM +0200, Ilpo Järvinen wrote:
> __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.
>
> Fixes: 91fa127794ac ("PCI: Expose PCIe Resizable BAR support via sysfs")
> Reported-by: Michał Winiarski <michal.winiarski@xxxxxxxxx>
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Replaced the v2 patch [1] on pci/resource, headed for v6.15, thanks!
[1] https://lore.kernel.org/r/20250307140349.5634-1-ilpo.jarvinen@xxxxxxxxxxxxxxx
> ---
>
> v3:
> - Check that SR-IOV is not enabled before resizing
>
> v2:
> - Removed language about expansion ROMs
>
> 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 b46ce1a2c554..0e7eb2a42d88 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -1556,7 +1556,7 @@ 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;
> }
> @@ -1578,7 +1578,7 @@ 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);
>
> base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
> --
> 2.39.5
>
