vfio/pci: Expose shadow ROM as PCI option ROM
Integrated graphics may have their ROM shadowed at 0xc0000 rather than
implement a PCI option ROM. Make this ROM appear to the user using
the ROM BAR.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index 88dc646..142c533 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -475,14 +475,19 @@
bar = (__le32 *)&vdev->vconfig[PCI_ROM_ADDRESS];
/*
- * NB. we expose the actual BAR size here, regardless of whether
- * we can read it. When we report the REGION_INFO for the ROM
- * we report what PCI tells us is the actual ROM size.
+ * NB. REGION_INFO will have reported zero size if we weren't able
+ * to read the ROM, but we still return the actual BAR size here if
+ * it exists (or the shadow ROM space).
*/
if (pci_resource_start(pdev, PCI_ROM_RESOURCE)) {
mask = ~(pci_resource_len(pdev, PCI_ROM_RESOURCE) - 1);
mask |= PCI_ROM_ADDRESS_ENABLE;
*bar &= cpu_to_le32((u32)mask);
+ } else if (pdev->resource[PCI_ROM_RESOURCE].flags &
+ IORESOURCE_ROM_SHADOW) {
+ mask = ~(0x20000 - 1);
+ mask |= PCI_ROM_ADDRESS_ENABLE;
+ *bar &= cpu_to_le32((u32)mask);
} else
*bar = 0;