[vfio-users] Questions for all who have gotten this to work

[Zycorax Tokoroa]

> Zycorax:
>> I take that it's recommended, in order to have other configurations
>> available, such as both GPUs working in parallel on the same (host) OS,
>> to avoid using both NVidia and ATI, and the graphic cards have to be the
>> same model (although different OCs are theoretically allowed) in case of
>> SLI.
> 
> No I don't think so. There are dozens of examples of people using one card mfg for the host and another for the guest. In fact, it can be even easier to have different mfgs, because then blacklisting kernel modules is simpler.
> Last I checked, neither SLI nor crossfire worked on the guest with VGA passthrough.
I am not interested in having SLI on the guest, but it could be a
fallback alternative for the same hardware if I for some reason stop
using one card for a guest. Crossfire seemed to be obtainable from a
previous thread in this mailing list - then again, I can't say anything
about it.
I am aware of the google doc with mixed NVidia and ATI card
configurations working, and of the Code 43 error which is triggered with
recent guest drivers.

This said, I'd ask again for the suggestion of which card is recommended.

>> I suppose that this should restrict the best choice between another 970
>> and a 960
> 
> No not at all. The 970 you have would be a great candidate for passing through to a guest. So you can get just about anything for the host -- you could even replace your i7-5930K for a CPU with integrated Intel graphics. This last suggestion might be the one most compatible with your "power drain and heat generated" concerns.
Changing the current hardware is not a possibility for me, and I can
only add new one. Getting a Xeon E5 and a card is out of my
possibilities. I understand that any card is probably going to work for
the host, and I intend to use the 970 for the guest if I get a weaker one.

>> I hope no one minds if I add my own question at this. I'd like to hear
>> suggestions on the second GPU to take, keeping an eye on the power drain
>> and the heat generated.
>>
>> The current hardware configuration is this:
>> Corsair Cx750M
>> ASUS X99-Deluxe (which seems to support ACS and hence need no patch?)
> 
> Depends on where you install the card.  We have quirks for the X99
> chipset (and in fact most Intel chipsets, except the latest) to enforce
> isolation of the PCH root ports, but Intel client processors (Core
> i7/i5) and Xeon E3 do not support ACS on the processor root ports.
> You'd need a Xeon E5 platform to be completely clear of the ACS issues.
My assumption was only based on the motherboard's "BIOS" menu, which has
an "enable ACS" option. I read from your blog already that any processor
aside the E5 series has issues. I'd like to know more over possible
quirks and issues that may appear on the X99.



Thanks to all for the help,
 - Zycorax