On Tue, Nov 05, 2019 at 09:32:07PM +0000, Derrick, Jonathan wrote: > Without this patch, a /dev/mem, resource0, or third-party driver could > overwrite these values if they don't also restore them on close/unbind. > I imagine a kexec user would also overwrite these values. Don't you have the same problem with the in-kernel driver? It looks like pci core will clear the PCI_IO_BASE config registers in pci_setup_bridge_io() because VMD doesn't provide an IORESOURCE_IO resource. If you reload the driver, it'll read the wrong values on the second probing.
