Re: Binary Windows guest drivers are released

[Kenni Lund <kenni@kelu.dk>]

2009/9/25 Vadim Rozenfeld <vrozenfe@redhat.com>:
> On 09/25/2009 12:07 AM, Dor Laor wrote:
>>
>> On 09/24/2009 11:59 PM, Javier Guerra wrote:
>>>
>>> On Thu, Sep 24, 2009 at 3:38 PM, Kenni Lund<kenni@kelu.dk>  wrote:
>>>>
>>>> I've done some benchmarking with the drivers on Windows XP SP3 32bit,
>>>> but it seems like using the VirtIO drivers are slower than the IDE
>>>> drivers in
>>>> (almost) all cases. Perhaps I've missed something or does the driver
>>>> still
>>>> need optimization?
>>>
>>> very interesting!
>>>
>>> it seems that IDE wins on all the performance numbers, but VirtIO
>>> always has lower CPU utilization.  i guess this is guest CPU %, right?
>>> it would also be interesting to compare the CPU usage from the host
>>> point of view, since a lower 'off-guest' CPU usage is very important
>>> for scaling to many guests doing I/O.
>>>
>> These drivers are mainly tweaked for win2k3 and win2k8. We once had queue
>> depth settings in the driver, not sure we still have it, Vadim, can you add
>> more info?
>> Dor
>
> Windows XP 32-bit virtio block driver was created from our mainline code
> almost for fun.
> Not like our mainline code, which is STORPORT oriented, it is a SCSIPORT
> (!!!!) mini-port driver.
> SCSIPORT has never been known as I/O optimized storage stack.
> SCSIPORT architecture is almost dead officially.
> Windows XP 32-bit has no support for STORPORT or virtual storage stack.

Ok, in that case, wouldn't it be better simply not to build the XP driver and
instead put a note somewhere (in the wiki?), saying that it doesn't make
sense to use VirtIO on XP due to these reasons?

> Developing monolithic disk driver, which will sit right on top of virtio-blk
> PCI device, looks like the one way
> to have some kind of high throughput storage for Windows XP 32-bit.

Ok, since these drivers are targeted Windows Server and XP is getting old,
I suppose no efforts will be put into developing such driver, or?

Best Regards,
Kenni