[fedora-virt] guestfish, libguestfs, ext4 and bad perms on /dev/kvm

[Richard W.M. Jones]

On Wed, Apr 22, 2009 at 03:20:14PM -0400, Robert P. J. Day wrote:
>   in short, ext4 filesystem support now appears to work, but there's
> still the issue (perhaps addressed earlier) that non-root users don't
> have access to KVM support but, from the perspective of libguestfs,
> does that really matter?

KVM makes things do a lot faster, which is always nice.  You can
do the following:

  # chmod o+rw /dev/kvm

You have to do (just) that command as root, but after that qemu-kvm and
guestfish itself can all be run as non-root, and will benefit from KVM
acceleration.

There is the question of whether it's safe to allow non-root users to
use KVM.  Generally the answer seems to be that it's OK.  But if you
are running a production service, or have lots of untrusted users or
guests, then maybe it's better not to turn this on just yet.

>   anyway, ext4 support is in there so things are working, at least to
> the extent that i've tested it.

> p.s.  i could have sworn i didn't get that /dev/kvm perms error
> yesterday. did something about that change since version 1.0.4?

Yes, libguestfs changed to detect and enable KVM by default.  Before
today it wasn't using KVM at all.

Rich.

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