Re: Fwd: Re: Xen 4.3 / 4.4 - concurrent APIs, VGA Passthru

[Gordan Bobic <gordan@bobich.net>]

On 2014-08-18 22:13, Richie wrote:
> On 8/18/2014 11:45 AM, Gordan Bobic wrote:
>> On 08/18/2014 04:26 PM, Georg Bege wrote:
>>> Hi
>>> 
>>> I simply wanted to tell my tale about the outcome of my experiments,
>>> I was occupied with certain other things (including exchanging some
>>> zpool's).
>>> For now I run an Vista x64 and it works pretty well, I never got the
>>> gplpv drivers running on
>>> acceptable levels (they are still quite slow) so I decided to pass
>>> onboard controller, sound and usb3.
>>> This decission seemed to be a wise one and everything works great as
>>> expected, the problem with gplpv
>>> well it might also be a result of my volume scheme since I only run 
>>> ZFS
>>> - now an raidz1 (on enterprise disks though).
>>> I also replaced the nvidia drivers from 331.65 to 337.88 - this 
>>> revision
>>> gave me a lot more performance but I can remember I had this issue on
>>> native Windows too.
>>> 
>>> So after a lot of testing, pain, time consuming days (and nights) its
>>> really working great - not perfect maybe.
>>> My next goal is to dedicate an SSD for that system volume, maybe try
>>> Win7 again as well -
>>> also I'd like to get an GTX690 and hardmod it so I get a lot more
>>> speed...
>> 
>> Modifying it won't get you more speed.
>> 
>> I was originally planning to use a GTX690 and pass one GPU to each of
>> my VMs, but I eventually replaced it with a pair of 780Tis.
>> 
>> I am running on a SSD backed zvol, with gplpv.
>> 
>> Gordan
>> 
> 
> Do you mind posting the specifics on your setups?  I read as many
> threads with this topic as I could find in the archives. It sounds
> like you are using Xen 4.3.2, Vista 64, nonmodded GTX as secondary
> passthrough and older nvidia drivers.

Xen 4.3.0 for me - I had to patch my hvmloader to mark most of
the RAM between 1GB and 4GB as reserved due to a bug in my PCIe
multiplexers which break IOMMU operation (Nvidia NF200). I saw
no reason to upgrade since it meant re-patching. I will upgrade
to 4.4.x when the patches that limit RAM below 4GB are incorporated
since I should be able to make do with those instead of my gross
hack job.

I have two VMs, one is XP/64, the other is Win7/64. I am using
_modified_ GTX780Ti cards. Previously I was running a modified
680, and before that a modified 480 (4xx series and older cards
can be modified with just a small BIOS patch).

Using secondary passthrough and the latest 331.xx driver (the
exact version escapes me at the moment).

> Did you have to do any vBAR patching?

No.

> Are you loading a copy of the VGA's rom bios?

No. No BIOS level output from the GPU being passed through
until the driver loads and initializes it.

Gordan