Hi Alex,
When you say you had success with the
onboard igfx, how much success? Have you ever had a passthrough VGA display
from a DomU ?
I have also seen the write-up too although
a lot of work has been done on the VT-d support lately and I`m hoping to raise
this again on the developer list and start to document some of the
problems/issues so as we can find a way do solve it !
Thanks for the reply! It still leaves this
issue unsolved though ;(
Tim
Subject: Re: [Xen-devel] Memory mapping for PEG/PCIe
Graphics Passthrough to
<any> DomU
From: Alexia Benington <alexbenington@xxxxxxxxx>
To: Tim Moore <timothy.moore@xxxxxxxxxxx>
Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx"
<xen-devel@xxxxxxxxxxxxxxxxxxx>
Hi,
I've been trying to get this to work for some months, albeit
not
full-time. I concur that many would like to see it working.
Some have
posted that they managed to get it to work correctly,
however, they
almost always never reply to queries on how they got it to
work, or
their observations.
I did manage to get rid of the yellow exclamation mark.
You'll need to
disable the emulated VGA bios, pretty much as described here
http://lists.xensource.com/archives/html/xen-devel/2008-12/msg00474.html.
Even after doing so, some of the registers are not directly
passed
through. See
http://lists.xensource.com/archives/html/xen-devel/2009-02/msg=
01131.html.
I'm not sure if that may affect anything.
I've experimented with an Intel DQ45CB, nVidia Quadro NVS
290, nVidia
GF9500, ATI Radion HD 2600XT. The best results I get are
when using
the onboard igfx as the primary, which is also being passed
through.
There is also a writeup which you might want to take a look
http://staff.science.uva.nl/~delaat/sne-2008-2009/p22/report.pdf.
I'm also trying to get DomU's output to the display.
-Alex
2009/3/30 Tim Moore <timothy.moore@xxxxxxxxxxx>:
> Hi
>
>
>
> I have been testing xen-unstable.hg (29/03/09) over the
past few days ..
> trying to enable passthrough for VGA.
>
>
>
> I am using Debian 5.0 (lenny) x64 and compiling from
source each time. Tr=
ied
> both linux-2.6.18.8 and linux-2.6.27.5 from Xenbits =85
>
>
>
> Hardware is Nvidia Geforce 8800 512mb GTS PCIe on Intel
X58 (ASUS P6T
> Deluxe) with Core i7 920 CPU.
>
> (had to hack the xen/drviers/pci/passthrough/vtd/dmar.c
(line 388) and
> remove the DMAR bail because of bad RMRR tables.
>
> I also have ATI X300 PCIe for Dom0 Console.
>
>
>
> Using Xen parameter: iommu=3Dpassthrough,pv
>
> Using Dom) parameter: pciback.hide=3D(=91=85=92)
>
>
>
> I compiled pciback as embedded in the kernel and I have
tried many differ=
ent
> scenarios:
>
>
>
> 1) Nvidia Primary (hidden with pciback.hide=3D kernel
param) (no ATI card
> installed)
>
> 2) ATI Primary, with Nvidia hidden (with pciback.hide=3D
kernel param)
>
> 3) all scenarios with pciback as module and using echo
devn >
> /sys/bus/pci/drivers/pciback/new_slot and bind
>
>
>
> In all scenarios I can successfully see the correct PCI
device in the
> DomU(s), I have tried primarily Windows XP 32bit SP3
and also:
> linux-2.6.18.8 and linux-2.6.27.5 PV and non PV kernels
as DomU and
> (although I didn=92t load a driver) the lspci =96vvv
showed the devices.
>
>
>
> Now, I progressed to installing drivers under the Win32
DomU against the
> Nvidia card, windows correctly identified the device
and installed the
> driver! (latest from nvidia.com). As we all know =96
Windows wanted a reb=
oot-
> beforehand a quick check of the device and it has a
Yellow exclamation
> indicating reboot required and resources unavailable.
>
> Reboot and XP starts up =85 BSOD .. nv4 driver fails ..
L
>
>
>
> Tried with the ATI X300 Primary (no NVidia connected)
and went through th=
e
> same steps. Windows XP now boots without crash although
the ATI device st=
ill
> shows a yellow exclamation and insufficient resources.
>
>
>
> To summarise, pciback functions as expected for PCIe in
Dom0 and DomU see=
s
> the device. All tools work fine (xm pci-attach /
pci-detach / pci-list) a=
nd
> devid show and are managed correctly.
>
>
>
> I have read all that there is on this subject and have
come to the
> conclusion that this is a problem with qemu-dm and the
memory mapping for
> the new Video device, the Cirrus or stdvga card is
always present which I
> believe may be causing the problem. I have tried
nographics=3D1 but qemu-=
dm
> still maps the Video BIOS.
>
>
>
> Then I noticed that qemu-dm has the new options for
="" none=94 .. so=
I
> built a wrapper script for qemu-dm to launch with this
param. Unfortuntat=
ely
> the DomU doesn=92t startup and the qemu log does not
show any mention of =
the
> Video memory ! so I believe the switch works, but the
DomU then fails to
> boot L
>
>
>
> To solve this and make it usable I think some
development of qemu with
> regards to the Cirrus VGA and memory management when
using more than 1 vg=
a
> controller is necessary in order to remap the Cirrus or
secondary vga
> adapters in memory correctly. (its also difficult to
configure a Windows
> machine for a second vga when the primary is disabled
lol.)
>
>
>
> Also, I have run strace using a qemu-dm wrapper (very
verbose) and analys=
ed
> the results =96nothing seems obvious, but i`m not an
expert by far =85.
>
>
>
> Windows has been able to support multiple VGA cards for
a long time; I
> assume that MS is remapping these somehow?
>
>
>
> I have read in 2 different places that this has worked
for others before
> (without the legacy patch for igfx) and with
xen-unstable.hg .. why does =
it
> not work for me ?
>
>
>
> Any help / direction to further debug would be helpful
.. I think many
> people would like to get this one working once and for
all!
>
>
>
> Tim
>
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>
>
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