Re: help? need to enable VT-d for 2.6.27

[Chris Friesen <chris.friesen@genband.com>]

On 08/30/2011 12:31 PM, David Ahern wrote:

> In my case I am setting the MAC address for the VFs in the host at boot;
> they are getting reset on passthrough so the VM driver creates a random
> one. A backport of commit a6b5ea3 fixes one aspect. Looking at the code
> for the igb driver I think commit 8fa7e0f fixes the other reset problem.
>
> On the plus side I can tell you that the VF driver for the VM
>    http://sourceforge.net/projects/e1000/files/igbvf%20stable/
>
> compiles cleaning against WRL3 and appears to work fine (limited testing
> with benchmarks).
>
> kernel module wise I ran some basic KVM tests with kvm-kmod-2.6.32.27; I
> have not tried VF passthrough. This is on my radar as well, so I would
> be interested in what you learn.

I downloaded the latest kvm-kmod release.  It looks interesting, but it 
has some issues:

1) I use separate source and build output directories.  kvm-kmod assumes 
that there is a "source" link in my build output directory pointing back 
to the source directory.  This doesn't exist, so the build breaks.

2) If I create such a link, it builds a few files, and then gives the 
following:

/home/cfriesen/Download/kvm-kmod-3.0b/x86/x86.c: In function 
‘vcpu_enter_guest’:
/home/cfriesen/Download/kvm-kmod-3.0b/x86/x86.c:5539:26: error: 
‘prof_on’ undeclared (first use in this function)
/home/cfriesen/Download/kvm-kmod-3.0b/x86/x86.c:5539:26: note: each 
undeclared identifier is reported only once for each function it appears in


This appears to be due to the fact that KVM_PROFILING is defined 
unconditionally in my kernel, but "prof_on" is only defined if 
CONFIG_PROFILING is enabled.  Commenting out that chunk of code in x86.c 
lets everything build.

I haven't tried actually loading it yet, that will be next.

Thanks for the pointer.
Chris


-- 
Chris Friesen
Software Developer
GENBAND
chris.friesen@genband.com
www.genband.com