On Thu, Sep 08, 2016 at 11:12:16AM +0200, Greg Kurz wrote: > On Thu, 8 Sep 2016 10:59:26 +0200 > Cornelia Huck <cornelia.h...@de.ibm.com> wrote: > > > On Wed, 07 Sep 2016 19:19:24 +0200 > > Greg Kurz <gr...@kaod.org> wrote: > > > > > Calling assert() really makes sense when hitting a genuine bug, which > > > calls > > > for a fix in QEMU. However, when something goes wrong because the guest > > > sends a malformed message, it is better to write down a more meaningul > > > error message and exit. > > > > > > Signed-off-by: Greg Kurz <gr...@kaod.org> > > > --- > > > hw/9pfs/virtio-9p-device.c | 20 ++++++++++++++++++-- > > > 1 file changed, 18 insertions(+), 2 deletions(-) > > > > While this is an improvement over the current state, I don't think the > > guest should be able to kill qemu just by doing something stupid. > > > > Hi Connie, > > I'm glad you're pointing this out... this was also my impression, but > since there are a bunch of sanity checks in the virtio code that cause > QEMU to exit (even recently added like 1e7aed70144b), I did not dare > stand up :)
It's true that it's broken in many places but we should just fix them all. A separate question is how to log such hardware/guest bugs generally. People already complained about disk filling up because of us printing errors on each such bug. Maybe print each message only N times, and then set a flag to skip the log until management tells us to restart logging again. > > The right way to go is to mark the virtio device as broken and stop > > doing any processing until the guest resets it. I think Stefan had a > > patch series doing that for some base virtio errors, but I'd have to > > search for it. > > > > I'd be glad to have a look and try to address this issue. > > Thanks ! > > -- > Greg