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

[Tobias Geiger <tobias.geiger@vido.info>]

Am Dienstag, 24. Januar 2012, 16:15:29 schrieb Likarpenkov Alexander:
> TG> I was a bit un-percice regarding the "reboot" issue:
> 
>  TG> The passing-through itself works even after a reboot of DomU - the
>  TG> rebooted System spits out its Graphics normaly through the
>  TG> passed-through Card (NVIDA or ATI doesnt matter here) ; BUT:
>  TG> After a reboot it doesn't work properly. Meaning:
>  TG> Slow 3d Performance, i.e.
>  TG> unsable for real 3d apps, even a 3d Desktop;
>  TG> For example, when the Card gives you 70fps in a Benchmark after a
> fresh TG> Cold Boot, it only gives you 5-10fps after a reboot, this will
> be that TG> low until you reboot Dom0 also, not only DomU;
>  TG> hopefully i described the scenario better now...
> 
> I'm sorry. Errors are highlighted in red.
> 
>  That is, situations as follows:
> - There is a certain group who are trying to make a vga pass, but not
> successed (unsuccessfully) - In the second group turned out, the
> performance on the second restart the deplorable
> 
> I belong to the first group, but I use a pci pass and after 10-20 reboots
> the system does not lose the 3D performance.
> 
> Question for Tobias Geiger:
> You do not deign to describe the process step by step is the setup and
> configuration xen-linux-systeM to a successful vga pass?


What i forgot was the cmdline for the xen hypervisor (not that important 
though):

watchdog dom0_mem=4096M dom0_max_vcpus=4 dom0_vcpus_pin 
cpufreq=xen:performance


it turned out to be a good idea to pin the vcpus not while running (with xl 
vcpu-pin) but as early as possible -  that way even a "make -j99 bzImage" 
within Dom0 doesnt really affect the DomU Performance (yes, otherwise i had the 
impression it was noticable)

Greetings again!
Tobias