Re: [Qemu-devel] Re: [PATCH] qemu: make virtio-blk PCI compliant by default

[john cooper]

Avi Kivity wrote:
> On 09/21/2009 06:47 PM, john cooper wrote:
>> Rusty Russell wrote:
>>
>>   
>>> Too late, but no big deal.  We just add another feature bit for the
>>> new method.  We can have a command virtqueue for queries such as this.
>>>
>>> (Interestingly, this same issue broke lguest, with the 8-bit limit on
>>> configuration space sizes).
>>>      
>> I believe the existing guest visible interface
>> is preservable as-is without introducing any
>> ATA specific knowledge into the driver.  A
>> trivial alternate R/O mapping for the page
>> into the guest is all that is required.
>>
>> I ran out of time last week to tie this off
>> but hopefully will do so shortly.
>>
>>    
> 
> Can we just read this page as a virtqueue command instead of having it
> mapped permanently?

Probably although I hadn't looked specifically
at doing so.   Mapping the data via an unused
pci bar is pretty trivial and seemed minimally
intrusive to the existing driver.

-john

-- 
address@hidden