From 8c28ef3f1c1c57b6f468343d5959e5125b30334d Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 25 Sep 2017 02:01:01 -0600 Subject: [PATCH] xen-pciback: relax BAR sizing write value check Just like done in d2bd05d88d ("xen-pciback: return proper values during BAR sizing") for the ROM BAR, ordinary ones also shouldn't compare the written value directly against ~0, but consider the r/o bits at the bottom (if any). Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Signed-off-by: Boris Ostrovsky --- drivers/xen/xen-pciback/conf_space_header.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/xen/xen-pciback/conf_space_header.c b/drivers/xen/xen-pciback/conf_space_header.c index 5fbfd9cfb6d6..5b3d57fc82d3 100644 --- a/drivers/xen/xen-pciback/conf_space_header.c +++ b/drivers/xen/xen-pciback/conf_space_header.c @@ -169,6 +169,9 @@ static int rom_write(struct pci_dev *dev, int offset, u32 value, void *data) static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data) { struct pci_bar_info *bar = data; + unsigned int pos = (offset - PCI_BASE_ADDRESS_0) / 4; + const struct resource *res = dev->resource; + u32 mask; if (unlikely(!bar)) { pr_warn(DRV_NAME ": driver data not found for %s\n", @@ -179,7 +182,13 @@ static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data) /* A write to obtain the length must happen as a 32-bit write. * This does not (yet) support writing individual bytes */ - if (value == ~0) + if (res[pos].flags & IORESOURCE_IO) + mask = ~PCI_BASE_ADDRESS_IO_MASK; + else if (pos && (res[pos - 1].flags & IORESOURCE_MEM_64)) + mask = 0; + else + mask = ~PCI_BASE_ADDRESS_MEM_MASK; + if ((value | mask) == ~0U) bar->which = 1; else { u32 tmpval;