MSI: also reject resource with flags all clear When resource assignment fails, things may end up this way, and we want to avoid using the resource in that case. Derived from an upstream patch by Yijing Wang . Signed-off-by: Jan Beulich --- a/drivers/pci/msi-xen.c +++ b/drivers/pci/msi-xen.c @@ -204,7 +204,9 @@ static u64 find_table_base(struct pci_de bar = reg & PCI_MSIX_FLAGS_BIRMASK; flags = pci_resource_flags(dev, bar); - if (flags & (IORESOURCE_DISABLED | IORESOURCE_UNSET | IORESOURCE_BUSY)) + if (!flags || + (flags & (IORESOURCE_DISABLED | IORESOURCE_UNSET | + IORESOURCE_BUSY))) return 0; return pci_resource_start(dev, bar);