@@ -1041,6 +1041,15 @@ static uint64_t vfio_legacy_read(void *opaque, hwaddr addr, unsigned size)
break;
}
+ /* XXX - Complete hardcoded hack, need to figure out how common this is and
+ * come up with a device quirk and match host phys to guest phys. This is
+ * only known to be needed for an ATI/AMD Radeon HD5450 which stores the
+ * upper byte of the I/O port address in this unused VGA I/O port register.
+ */
+ if (io->region_offset == 0x3c0 && addr == 3 && size == 1 && data == 0x40) {
+ data = 0xc0;
+ }
+
DPRINTF("%s(0x%"HWADDR_PRIx", %d) = 0x%"PRIx64"\n",
__func__, io->region_offset + addr, size, data);
This is a hack specific to my system which I haven't even attempted to generalize yet. The ATI/AMD Radeon HD5450 VGA BIOS appears to have a backdoor to determine the physical address of the device. It reads a value matching the top byte of the I/O Port BAR from a register in VGA I/O port space then uses in/out to that address during BIOS execution. On my setup the I/O port BAR is at 0x4000 physically and emulated for the guest at 0xc0000. So I simply look for this access and replace 0x40 with 0xc0. That's enough for it to get through BIOS init, but it's still only partially functional (no VGA text mode). Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- hw/vfio_pci.c | 9 +++++++++ 1 file changed, 9 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html