[libvirt] [PATCH 1/2] util:mdev: Improve the error msg on non-existent mdev prior to VM start

[Erik Skultety]

On Fri, Mar 16, 2018 at 12:08:46PM +0100, Peter Krempa wrote:
> missing space in summary
>
> On Fri, Mar 16, 2018 at 11:50:01 +0100, Erik Skultety wrote:
> > What one currently gets is:
> > failed to read '/sys/bus/mdev/devices/<UUID>/mdev_type/device_api': No
> > such file or directory
> >
> > This indicates that something is missing within the device's sysfs tree
> > which likely might be not be the case here because the device simply
> > doesn't exist yet. So, when creating our internal mdev obj, let's check
> > whether the device exists first prior to trying to verify the
> > user-provided model within domain XML.
> >
> > Signed-off-by: Erik Skultety <eskultet at redhat.com>
> > ---
> >  src/util/virmdev.c | 16 +++++++++++++---
> >  1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/src/util/virmdev.c b/src/util/virmdev.c
> > index e4816cf20..2e3769aa6 100644
> > --- a/src/util/virmdev.c
> > +++ b/src/util/virmdev.c
> > @@ -150,13 +150,22 @@ virMediatedDeviceNew(const char *uuidstr, virMediatedDeviceModelType model)
> >  {
> >      virMediatedDevicePtr ret = NULL;
> >      virMediatedDevicePtr dev = NULL;
> > +    char *sysfspath = NULL;
> > +
> > +    if (!(sysfspath = virMediatedDeviceGetSysfsPath(uuidstr)))
> > +        goto cleanup;
> > +
> > +    if (!virFileExists(sysfspath)) {
> > +        virReportSystemError(errno, _("failed to read device '%s'"),
> > +                             sysfspath);
>
> You did not try to read the device at this point. It merely does not
> exist.

Would you like "device '%s' not found" better?

Erik