Re: [Xen-users] VGA passthough still not working

["Pavel Matěja" <pavel@netsafe.cz>]

On Wed 25. of January 2012 17:52:11 Doug Magee wrote:
> Also, i believe you said the card you're trying to pass through is not
> the primary card in your host system.  If that's the case, don't use
> gfx_passthru or expect to get the video bios working.  The 'primary'
> video adapter owns certain io ports and memory areas that are consitent
> from machine to machine.  Also, the system will copy the vbios from the
> card to a location in memory (0xc0000) so it can execute at boot time.
> 
> Xen's gfx_passthru code depends on all of these factors.  As the code
> stands, if you use gfx_passthru on a secondary card, it will still copy
> the vbios from the primary card (as it simply reads memory from
> 0xc0000), and directly map io ports and low memory areas to those used
> by the primary card in the host system.  In this case the guest will
> almost certainly never get past executing ROMBIOS, and the host may or
> may not lock up or experience 'issues'.

This will do the trick with secondary card (replace path to VGA BIOS):

--- xen-unstable.hg.working/tools/ioemu-remote/hw/pt-graphics.c 2012-01-25 
20:26:37.927654890 +0100
+++ xen-unstable.hg.working.generic/tools/ioemu-remote/hw/pt-graphics.c 
2011-07-30 13:57:57.347396095 +0200
@@ -487,10 +487,10 @@
 {
     int fd;
     uint32_t bios_size = 0;
-    uint32_t start = 0;
+    uint32_t start = 0xC0000;
     uint16_t magic = 0;
 
-    if ( (fd = open("/lib/firmware/ASUS.HD6850.1024.101007.bin", O_RDONLY)) < 
0 )
+    if ( (fd = open("/dev/mem", O_RDONLY)) < 0 )
     {
         PT_LOG("Error: Can't open /dev/mem: %s\n", strerror(errno));
         return 0;
-- 
Pavel Mateja