Re: [libvirt] [PATCH] Don't list capabilities entries if emulators can't be accessed
"Daniel P. Berrange" <berrange(a)redhat.com> wrote:
On Wed, Aug 20, 2008 at 12:51:05PM -0400, Cole Robinson wrote:
> The patch below fixes capabilities xml generation for
> the qemu driver if the emulators aren't found in the
> hardcoded paths. Current behavior will add a <guest>
> entry for the emulator even if it does not exist, patch
> fixes this to check that we actually have access.
>
> This brings up another issue, that hardcoded paths
> aren't exactly distro friendly. I'm not really familiar
> with what options we have to allow specifying these
> at build time (or something else). Anyone have an
> idea?
Ideally we'd just list the binary names, and search in $PATH for them.
Patches for this welcome...
The gnulib "findprog" module can be used to do this, but
there are two obstacles:
- it's GPL (probably just because...
- it exits on an out of memory error
However, it's not a big deal to rewrite it not to exit,
and make dependent modules will be LGPLv2+. Will require
pulling the mfile_name_cat function out into its own module.
I'm working on this.
> diff --git a/src/qemu_conf.c b/src/qemu_conf.c
> index dc9e42a..0328cc1 100644
> --- a/src/qemu_conf.c
> +++ b/src/qemu_conf.c
> @@ -230,6 +230,10 @@ qemudCapsInitGuest(virCapsPtr caps,
> virCapsGuestPtr guest;
> int i;
>
> + /* Check for existance of base emulator */
> + if (access(info->binary, X_OK) == -1)
> + return 0;
> +
This isn't right - this means that if KVM is installed, but QEMU is
not installed you won't get any capabilities.
Basically we need todo all the access() checks for QEMU, KVM, /dev/kvm
up-front. And then generated the capabilites if either QEMU or KVM is
available.
Daniel