Hi all!
I''ve used xen for a while and now I want to use this obscure Intel
technology called Vanderpool.
If is correct what I''ve heard and read then Xen 3.0 should virtualize
any x86 OS without modification. But if so I have some question...
A. Based on the information in the german Wikipedia
(
http://de.wikipedia.org/wiki/Vanderpool#Prozessoren_mit_Vanderpool-Unterst.C3.BCtzung
) I want to buy a Pentium D 920.
Is this a "good" cpu for using Vanderpool with Xen?
B. If I obtain a Pentium D 920...
Do I need a Mainboard with special chipset?
C. I know that I can''t assign one ore more graphicadapters to a domU
with paravirtualisation. But...
Is it possible to assign one ore more graphicadapters to one
guestmaschine in Xen 3.0 with a Vanderpool capable machine?
I hope the questions are clear enough. If not just ask...
Bye
Goran
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On 4/19/06, Goran <xamiw@arcor.de> wrote:> Hi all! > > I''ve used xen for a while and now I want to use this obscure Intel > technology called Vanderpool. > > If is correct what I''ve heard and read then Xen 3.0 should virtualize > any x86 OS without modification. But if so I have some question... > > A. Based on the information in the german Wikipedia > ( http://de.wikipedia.org/wiki/Vanderpool#Prozessoren_mit_Vanderpool-Unterst.C3.BCtzung ) I want to buy a Pentium D 920. > > Is this a "good" cpu for using Vanderpool with Xen?I use this CPU here, and it works just fine. Overclocked to 3.5 GHz without any extra cooling, even :)> > B. If I obtain a Pentium D 920... > > Do I need a Mainboard with special chipset?You need a motherboard that supports the Intel VT in the BIOS. I use an ASUS P5WD2-E Premium (http://usa.asus.com/products4.aspx?l1=3&l2=11&l3=0&model=981&modelmenu=1) here.> > C. I know that I can''t assign one ore more graphicadapters to a domU > with paravirtualisation. But... > > Is it possible to assign one ore more graphicadapters to one > guestmaschine in Xen 3.0 with a Vanderpool capable machine?You can''t do PCI passthrough to an hvm guest, no :( I had wanted to do this as well, but it is not possible due to memory addressing problems.> > > I hope the questions are clear enough. If not just ask... > > Bye > > Goran > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >Good luck :) Dave -- Dave Goodlad dgoodlad@gmail.com or dave@goodlad.ca http://david.goodlad.ca/ _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thank you Dave for answering my questions. ...> > C. I know that I can''t assign one ore more graphicadapters to a domU > > with paravirtualisation. But... > > > > Is it possible to assign one ore more graphicadapters to one > > guestmaschine in Xen 3.0 with a Vanderpool capable machine? > > You can''t do PCI passthrough to an hvm guest, no :( I had wanted to > do this as well, but it is not possible due to memory addressing > problems.... So there''s still no IOMMU available in a PC to restrict the access for DMA capable devices. Hmph.... But maybe the unsure alternative with "physdev_dom0_hide" work for the second or third graphicadapter. Did you get Windows installed in a Xen/linux environment? (Shame on me but some customers want some Windows based network-services) ...> -- > Dave Goodlad > dgoodlad@gmail.com or dave@goodlad.ca > http://david.goodlad.ca/Goran _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> -----Original Message----- > From: xen-users-bounces@lists.xensource.com > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of > Goran Vukoman > Sent: 20 April 2006 15:01 > To: xen-users@lists.xensource.com > Subject: Re: [Xen-users] Vanderpool Hardware Question > > Thank you Dave for answering my questions. > > ... > > > C. I know that I can''t assign one ore more > graphicadapters to a domU > > > with paravirtualisation. But... > > > > > > Is it possible to assign one ore more graphicadapters to one > > > guestmaschine in Xen 3.0 with a Vanderpool capable machine? > > > > You can''t do PCI passthrough to an hvm guest, no :( I had > wanted to > > do this as well, but it is not possible due to memory addressing > > problems. > ... > > So there''s still no IOMMU available in a PC to restrict the > access for DMA capable devices. Hmph....It''s not as simple as "restricting access" (we can do that in AMD''s devices, but unfortunately, it just aborts the cycle). The need for an IOMMU is there also because we map the memory differently than what the guest actually thinks. The guest will think that memory starts at address 0 and ends at, say, 512MB. The Hypervisor knows that this is not actually the case, memory starts at 512MB, and ends at 1024MB. But we hide this by "modifying the page-tables" in the hypervisor. So when the graphics card tries to bit-copy from somewhere around 256MB (guest physical address) to some place in the frame-buffer, it actually should say copy from 768MB to the frame-buffer. This can only be solved with two approaches: 1. The graphics driver understands that the REAL physical memory isn''t the same as what the OS thinks it is - this is the para-virtual driver approach (meaning driver is aware of virtualization). 2. All direct memory accesses goes through a IOMMU - the memory map of the guest is translated before the actual hardware gets to see the memory, so when the graphics card says "I''d like to read at 256MB" it actually gets memory located at 512MB. It may be possible (on AMD processors) to use the GART to achieve this - it has been used on Linux x86-64 to support 32-bit-only hardware accessing > 4GB RAM. But I don''t know if/when such support may be available in Xen. -- Mats> > But maybe the unsure alternative with "physdev_dom0_hide" > work for the second or third graphicadapter. > > Did you get Windows installed in a Xen/linux environment? > (Shame on me but some customers want some Windows based > network-services) > > ... > > -- > > Dave Goodlad > > dgoodlad@gmail.com or dave@goodlad.ca > > http://david.goodlad.ca/ > > > Goran > > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On 4/20/06, Goran Vukoman <vukoman@web.de> wrote:> Thank you Dave for answering my questions. > > ... > > > C. I know that I can''t assign one ore more graphicadapters to a domU > > > with paravirtualisation. But... > > > > > > Is it possible to assign one ore more graphicadapters to one > > > guestmaschine in Xen 3.0 with a Vanderpool capable machine? > > > > You can''t do PCI passthrough to an hvm guest, no :( I had wanted to > > do this as well, but it is not possible due to memory addressing > > problems. > ... > > So there''s still no IOMMU available in a PC to restrict the access for > DMA capable devices. Hmph.... > > But maybe the unsure alternative with "physdev_dom0_hide" work for the > second or third graphicadapter. > > Did you get Windows installed in a Xen/linux environment? (Shame on me > but some customers want some Windows based network-services)Yes, I was able to install Windows succesfully. It runs great (great being a relative term, this IS windows hehe); I had it running Prime95 for a week straight without a hitch. Dave> > ... > > -- > > Dave Goodlad > > dgoodlad@gmail.com or dave@goodlad.ca > > http://david.goodlad.ca/ > > > Goran > > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- Dave Goodlad dgoodlad@gmail.com or dave@goodlad.ca http://david.goodlad.ca/ _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users