Subject: Re: [GIT PULL] AlacrityVM guest drivers for 2.6.33

From: Avi Kivity <[email-masked]>
Date: Sun, 27 Dec 2009 11:33:33 +0200

On 12/24/2009 11:36 AM, Gregory Haskins wrote:
>> As a twist on this, the VMware paravirt driver interface is so
>> hardware-like that they're getting hardware vendors to supply cards that
>> implement it.  Try that with a pure software approach.
>>      
> Any hardware engineer (myself included) will tell you that, generally
> speaking, what you can do in hardware you can do in software (think of
> what QEMU does today, for instance).  It's purely a cost/performance
> tradeoff.
>
> I can at least tell you that is true of vbus.  Anything on the vbus side
> would be equally eligible for a hardware implementation, though there is
> not reason to do this today since we have equivalent functionality in
> baremetal already.

There's a huge difference in the probability of vmware getting cards to 
their spec, or x86 vendors improving interrupt delivery to guests, 
compared to vbus being implemented in hardware.

> The only motiviation is if you wanted to preserve
> ABI etc, which is what vmware is presumably after.  However, I am not
> advocating this as necessary at this juncture.
>    

Maybe AlacrityVM users don't care about compatibility, but my users do.

-- 
error compiling committee.c: too many arguments to function