Re: xl and GFX passthrough

[Daniel De Graaf <dgdegra@tycho.nsa.gov>]

On 01/25/2011 09:49 PM, Kay, Allen M wrote:
> Sergey,
> 
> Did you get gfx_passthru to work with xl?  I found the latest source still does not seems to pass gfx_passthru to qemu correctly.
> 
> By the way, how to output debug messages to xl*.log file?  I tried LOG() and fprintf(stderr...) neither worked for me.
> 
> Allen
> 
> -----Original Message-----
> From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of Sergey Tovpeko
> Sent: Thursday, January 13, 2011 3:18 AM
> To: Ian Campbell; Daniel De Graaf
> Cc: xen-devel@lists.xensource.com
> Subject: Re: [Xen-devel] xl and GFX passthrough
> 
> 
>>
>> I just noticed that this appears to have been fixed by Daniel De Graf
>> just a few days ago, see 22711:4f6fee3a456e, which may only be in the
>> staging tree at http://xenbits.xen.org/staging/xen-unstable.hg since we
>> are waiting for a test pass.
>>
>>   
> 
> Ian, Daniel
>  
>   my patch is almost like Daniel's one.  Thank you for pointing to it.
> 
> And there's one absent thing in Daniel's commit (4f6fee3a456e). To 
> complete the gfx passthrough issue for xl we should pass this option to 
> qemu-dm, like this :
> 
> +        if (info->gfx_passthru) {
> +            flexarray_set(dm_args, num++, "-gfx_passthru");
> +            flexarray_set(dm_args, num++, libxl__sprintf(gc, "%d", 
> info->gfx_passthru));
> +        }
> 
> I suppose, without it 'qemu-dm' won't  know about gfx_passthru mode and 
> won't load passthru'ed vga bios.
> 
> Daniel might plan to add this code or added it already?
> 

Actually, I hadn't noticed that gfx_passthru takes an (apparently optional)
numeric parameter. This change is more correct than the one I posted,
although it also needs gfx_passthru to be changed from bool to int in the
IDL (assuming that -gfx_passthru 2 is still useful, I hadn't heard of it
until recently).

Kay: sounds like you have this fixed in your tree, I'll let you or Ian
fix it.

-- 
Daniel De Graaf
National Security Agency