vfio-pci: Add support for VGA region access
PCI defines display class VGA regions at I/O port address 0x3b0, 0x3c0
and MMIO address 0xa0000. As these are non-overlapping, we can ignore
the I/O port vs MMIO difference and expose them both in a single
region. We make use of the VGA arbiter around each access to
configure chipset access as necessary.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index bb8c8c2..8189cb6 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -84,6 +84,11 @@
} else
vdev->msix_bar = 0xFF;
+#ifdef CONFIG_VFIO_PCI_VGA
+ if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
+ vdev->has_vga = true;
+#endif
+
return 0;
}
@@ -285,6 +290,16 @@
info.flags = VFIO_REGION_INFO_FLAG_READ;
break;
}
+ case VFIO_PCI_VGA_REGION_INDEX:
+ if (!vdev->has_vga)
+ return -EINVAL;
+
+ info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
+ info.size = 0xc0000;
+ info.flags = VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE;
+
+ break;
default:
return -EINVAL;
}
@@ -386,6 +401,9 @@
case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
+
+ case VFIO_PCI_VGA_REGION_INDEX:
+ return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
}
return -EINVAL;