Re: [Xen-devel] [PATCH 0 of 2] pci passthrough: support "managed" pci device in xend for libvirt usage

[George Dunlap <George.Dunlap@xxxxxxxxxxxxx>]

On Thu, Jan 17, 2013 at 5:29 AM, <cyliu@xxxxxxxx> wrote:

One of our customers requests parallel pci passthrough functionality between xen
(xend and libxl) and kvm, including support managed host pci devices. A
"managed" pci device will be made assignable before vm start  and reattach to
its original dirver after vm shut off.

Currently, libvirt supports "managed=yes/no" options in pci device definition.
Qemu driver already supports managed pci devices, libxl driver will add that
support in libvirt source code. For xend driver, since it's stateful, libvirt
can't do much things because libvirt doesn't store much informtion and most
work is done by calling xend directly. Even "managed" option won't be stored if
xend doesn't support it. For that reason, this patch series tries to add code in
xend toolstack to support managed pci devices first, then libvirt can call xend
operations directly to support "managed" host pci devices.

Syntax for managed pci device could be:
pci=['0000:00:1a.0,managed=1']

Please share your comments. Thanks!

The first question (before I look at the code closely) is whether we want to accept new features into xend.  It's not being actively maintained, and we would like to get rid of it at some point.

Given that you seem primarily to be using libvirt, after the 4.3 release, will there be a strong reason to use xend, instead of just using libxl?

Note I'm not rejecting it outright; I just think a case needs to be made. :-)

 -George

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel