Re: [PATCH] Add I/O hypercalls for i386 paravirt

Zachary Amsden
2007-08-22T21:46:50Z

Alan Cox wrote:
>> I still think it's preferable to change some drivers than everybody.
>>
>> AFAIK BusLogic as real hardware is pretty much dead anyways,
>> so you're probably the only primary user of it anyways.
>> Go wild on it!
>>
>
> I don't believe anyone is materially maintaining the buslogic driver and
> in time its going to break completely.
>

I think I was actually the last person to touch it ;)

>
>> Well that might be. I just think it would be a mistake
>> to design paravirt_ops based on someone's short term release engineering
>> considerations.
>>
>
> Agreed, especially as an interface where each in or out traps into the
> hypervisor is broken even for the model of virtualising hardware.
>

Well, it's not necessarily broken, it's just a different model. At some
point the cost of maintaining a whole suite of virtual drivers becomes
greater than leveraging a bunch of legacy drivers. If you can eliminate
most of the performance cost of that by changing something at a layer
below (port I/O), it is a win even if it is not a perfect solution.

But I think I've lost the argument anyways; it doesn't seem to be for
the greater good of Linux, and there are alternatives we can take.
Unfortunately for me, they require a lot more work.

Zach