This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-users] Gigabit Interface - XEN Full Virtualization

if you compile the netfront drivers on your guest kernel and load them
as kernel module on your guests, you will have gigabit speed on a fully virtualized
virtual machine, hust use netfront and not ioemu then load
the kernel drivers on the virtual machine.
I have written something about it but it is in italian.
If you understand italian...


you should understand the way to do it even if it is written in italian.

I can translate in english if really it is needed


Artur Baruchi ha scritto:
Hi Mark,

Unfortunately, I did some tests, and even my nic being a giga and my
lan supporting giga, my full virtualized domain wasnt able to pass
100Mb/sec. My paravirtualized guests had a very good performance in
this environment.


Artur Baruchi

On Dec 2, 2007 12:34 AM, Mark Williamson <mark.williamson@xxxxxxxxxxxx> wrote:
I noted that the lspci output are different, and I would like to know,
how can I make my xen virtual machine see the same Hardware, so I can
force a 1000 Full speed.
You can't get Gigabit speed for your NIC in HVM.  Whatever network cards
you have on the physical system, it's emulated as a 10/100 mbps Realtek
card to the HVM.

Use paravirtualized drivers for HVMs to enhance the network card
performance and throughput, but don't expect 1000 mbps.  :-)
The virtual machine won't have hardware matching the physical system; it just
sees whatever hardware Xen is emulating.

Xen doesn't emulate a GigE network card so you won't be able to see one in the
guest.  However, I suspect that the 10/100mbps card will be able to transmit
above that speed if your machine can emulate the card fast enough: because
there's not a real hardware 100mbps ethernet card there, there actually
shouldn't be anything limiting the speed to that.

As Sadique mentioned, if you use paravirtualised drivers in your guest (either
by using a PV guest or by installing paravirt network drivers in an HVM
guest) you could potentially increase the throughput and decrease the CPU
overhead further.


Dave: Just a question. What use is a unicyle with no seat?  And no pedals!
Mark: To answer a question with a question: What use is a skateboard?
Dave: Skateboards have wheels.
Mark: My wheel has a wheel!

Xen-users mailing list

Xen-users mailing list