[Xen-users] PCI Passthrough

[Paul Schulze <avlex@xxxxxxx>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello everyone,

I am currently in the planning phase for a new HTPC system, I want to  
set up and there are several questions related to Xen that I was not  
able to find answers to. The goal of that system in the long run is  
to replace not only my server and TV receiver, but also my primary  
desktop and access point for several LAN and Wifi clients. Though  
this might sound rather simple, the solution I am hoping for has to  
separate all these tasks in virtual machines, leaving the Dom0  
strictly as a controller for those and only accessible by SSH from  
one virtual machine (probably the Desktop). This would ensure that I  
can work on one instance (which might need tinkering with the kernel  
for example) while all other services are still available and it  
would help me sandbox all the components, so none of them directly  
influences the other. The system would be an AMD Athlon X2 4850e CPU  
on an Asus M3A-H mainboard (AMD 780G chipset).
The questions I have now are:
1. Is it possible to successfully pass through a graphics adapter, in  
this case probably an onboard ATI HD 3200 PCIe (currently only  
supported with the non-free fglrx driver), so that the Desktop/TV  
virtual machine has exclusive use of the hardware including (future)  
3D support? I would also like to try other systems that can not be  
paravirtualized, while the other services have to still be running.  
In some of these systems I would like to have 3D hardware  
acceleration support (Desktop VM would have to be shut down as I  
understand it), since they heavily depend on it (like Vista or maybe  
Mac OS X). Is that possible? I already read that it is rather  
problematic to pass through the primary VGA adapter, because Xen  
itself will always claim it for console output at boot time, but  
wouldn't it be possible to use a serial port for that instead? Are  
there any other pitfalls that will not permit me to achieve this?
2. Is it possible to have a virtual machine hosting a MythTV backend,  
that has exclusive use of a PCI(e) or PCMCIA DVB-T/S/S2 adapter. This  
backend should not run in the Desktop instance, because I would  
prefer it if the Desktop doesn't have to be running for other clients  
to use it. This would also come in handy, because not running a full  
blown desktop while using the MythTV backend from another client  
could possibly save a bit on the energy bill (and the whole system is  
supposed to help me reduce that at least a bit)
3. I would like to pass 3 NICs (HP 4 port gbit switch pci card, D- 
Link 4x T100Base card and a Ralink pci 802.11n draft 2.0 adapter)  
directly to an AP/Router virtual maschine, so the Dom0 is not  
connected directly to the network, but only to the Desktop VM by a  
separate bridge and the onboard gbit adapter (for backups/failover).
Is that possible and am I really gaining security for the whole  
system or is this just my imagination and doesn't make any sense at  
all? How about the performance, especially for the graphics adapter,  
do I have to factor in bigger losses there (maybe because PCI  
passthrough doesn't support the full PCIe 16x speed)? Has anyone  
tried something similar yet or am I the first to think this might be  
a good idea?
I hope someone can give me an answer or at least a hint on how far I  
am from reality.
Thanks,


Paul.

- --
Paul Schulze
avlex@xxxxxxx
Public Key: http://solaris-net.dyndns.org/keys/key_avlex.asc

"Making mistakes is human,
but to really fuck things up you need Computers"


-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.1 (Darwin)

iD8DBQFIN4QuYDWOGtiChoARAn2yAJ9RsIf7zLpGWhHQ1JJcb+cX739jAQCeNgRg
tP8MXF4wMjaauElDH/oboz8=
=LHN/
-----END PGP SIGNATURE-----

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users