Re: [Xen-users] Firewire, PCI TV Tuner Card, PCI Wireless LAN Card, and USB Device Support Under Windows XP Xen Guest

["Teo En Ming" <space.time.universe@xxxxxxxxx>]

Oh dear, I've let the video card requirement in Windows guests slipped my mind. If I remember correctly, the virtual video card in Windows guest is somewhat backward/obsolete, and may not work with video editing software. Even if video editing software can be successfully installed in a windows guest, it may refuse to run/start due to an obsolete virtual video card.

Based on the same principle as AGP and PCI, I won't be able to use PCI Express x16 video cards in Windows guests too.

Sigh...

On 5/22/07, Petersson, Mats <Mats.Petersson@xxxxxxx> wrote:

> -----Original Message-----
> From: Teo En Ming [mailto:space.time.universe@xxxxxxxxx]
> Sent: 22 May 2007 15:55
> To: Petersson, Mats
> Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Xen-users] Firewire, PCI TV Tuner Card, PCI
> Wireless LAN Card, and USB Device Support Under Windows XP Xen Guest
>
> Hi
>
> Thank you for your reply.
>
> May I know when will IOMMU hardware be arriving? Any specific
> roadmap/dates?

I don't work for the right part of AMD to know the planned (or actual)
release-dates of new products, and I don't quite know which product(s)
the IOMMU will go into. It's not going to happen in the next few weeks,
I can assure you of that, but as I said, I don't really know much about
which parts will come out when - I usually know that some new product
has been released when it's announced by e-mail to all AMDers.
>
> I think I will still be going for current virtualization
> processors. I will still be able to install video editing
> software inside Windows XP guests and do all my video editing
> there, while I will move all other computing activities to my
> linux host operating system.

Yes, as far as I can determine, there's nothing in Video editing that
would be hardware specific, so it should work just fine in a virtual
Windows system. [Although if the graphics requirements are high for the
video editing software, you may still need to use a dedicated machine
for that, rather than a virtual machine, simply to get the graphics
performance].
>
> Will I be able to play Windows-based PC games inside Windows guests?

Short answer: No.
Long answer: Yes, as long as they don't require high-end 3D graphics.
You can't use 3D graphics cards for the same reason as any other PCI
device (AGP8x is PCI from software and most hardware standpoints, it's
just a different connector and somewhat different clock and signaling).

--
Mats
>
>
>
> On 5/22/07, Petersson, Mats < Mats.Petersson@xxxxxxx
> <mailto:Mats.Petersson@xxxxxxx > > wrote:
>
>
>
>       > -----Original Message-----
>       > From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
>       > [mailto: xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of
>       > Teo En Ming
>       > Sent: 22 May 2007 14:44
>       > To: xen-users@xxxxxxxxxxxxxxxxxxx
>       > Subject: [Xen-users] Firewire, PCI TV Tuner Card, PCI
>       > Wireless LAN Card, and USB Device Support Under
> Windows XP Xen Guest
>       >
>       > Dear All,
>       >
>       > Assuming that I buy a HVM compatible processor and
>       > motherboard, and having installed a linux host operating
>       > system with a Xen kernel, I proceed to install a Windows XP
>       > guest virtual machine. The question is:
>       >
>       > Will I be able to use the firewire ports, USB ports, TV Tuner
>       > program and wireless LAN card inside Windows XP guest VM?
>
>       Nope, none of these devices (aside from limited USB
> support, possibly),
>       will work under Xen, since (at present) there is no support to
>       hide/assign PCI devices to the HVM domain. This in turn
> is because of
>       the fact that PCI devices access memory directly, which
> isn't going to
>       work when Xen has told "lies" [1] to the Windows guest
> about where the
>       memory is. So when the guest OS tells the PCI device
> where in memory
>       something is, it will not know that this is not the
> ACTUAL physical
>       address. And there's no easy way to solve this in software only.
>
>       In future generations of processors/chipsets, there
> will be IOMMU
>       hardware that allows us to redirect the memory requests from a
>       particular PCI device, so that we can continue to hide
> the ACTUAL
>       physical address and still use the PCI devices within a
> guest. But
>       that's a little way out at this time.
>
>
>       [1] All operating systems want memory to start at
> address zero. Since
>       only one CAN have this address, guests in HVM-mode will
> get a fake
>       memory map that starts at zero and goes to whatever
> size it's configured
>       to. The fact that the ACTUAL physical address of the
> guest's memory is
>       somewhere else is completely hidden from the guest by
> using either
>       shadow-paging or hardware assisted paging (AMD Nested
> paging or Intel's
>       corresponding technology) [once this technology reaches
> customers,
>       sometime later this year or so].
>
>
>       > Will I be able to do video editing inside Windows XP guest
>       > VM? Or is networking the one and only feature that is
>       > supported under Windows XP guest operating system? And I
>       > won't be able to use anything else inside Windows XP guest?
>
>       You should be able to edit video in the guest, as long
> as you don't rely
>       on hardware features in PCI devices to do this.
>
>       Likewise, I don't see why you need to use Windows to
> connect to the
>       Wireless network, you can just as well hide the fact
> that it's wireless
>       from Windows, and just use virtual network device, and
> use the Linux
>       bridge setting to connect it to the physical Wireless device.
>
>       But you are correct, that the current technology only
> allows a limited
>       set of hardware features within the guest. This is a hardware
>       restriction, and it's nothing to do with Xen in itsels,
> but with the
>       current state of hardware. Future generations of
> hardware will remove
>       some or all of these restrictions (but leaving one remaining
>       restriction: each guest will HAVE to have it's own
> hardware to access -
>       no sharing of a single device without interfacing
> through a virtual
>       device - this is because all OS's requires that the
> hardware they
>       control is their own. There are hardware devices (such
> as network cards)
>       that support "multi-access" by providing multiple
> device-instances.
>       These of course can be shared, as they are from a
> software standpoint
>       multiple devices, and each device will thus have it's
> sole owner).
>
>       --
>       Mats
>       >
>       > Thank you.
>       >
>       >
>
>
>
>
>
>

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