[lkml]   [2008]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 0/16 v6] PCI: Linux kernel SR-IOV support
Greg KH wrote:
> On Sun, Nov 09, 2008 at 02:44:06PM +0200, Avi Kivity wrote:
>> Greg KH wrote:
>>> It's that "second" part that I'm worried about. How is that going to
>>> happen? Do you have any patches that show this kind of "assignment"?
>> For kvm, this is in 2.6.28-rc.
> Where? I just looked and couldn't find anything, but odds are I was
> looking in the wrong place :(

arch/x86/kvm/vtd.c: iommu integration (allows assigning the device's
memory resources)
virt/kvm/irq*: interrupt redirection (allows assigning the device's
interrupt resources)

the rest (pci config space, pio redirection) are in userspace.

>> Note there are two ways to assign a device to a guest:
>> - run the VF driver in the guest: this has the advantage of best
>> performance, but requires pinning all guest memory, makes live migration a
>> tricky proposition, and ties the guest to the underlying hardware.
> Is this what you would prefer for kvm?

It's not my personal preference, but it is a supported configuration.
For some use cases it is the only one that makes sense.

Again, VF-in-guest and VF-in-host both have their places. And since
Linux can be both guest and host, it's best if the VF driver knows
nothing about SR-IOV; it's just a pci driver. The PF driver should
emulate anything that SR-IOV does not provide (like missing pci config

I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

 \ /
  Last update: 2008-11-09 20:41    [W:0.113 / U:5.164 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site