On Mon, Nov 25, 2019 at 02:07:13PM +0100, Peter Krempa wrote: > On Mon, Nov 25, 2019 at 12:59:00 +0000, Daniel Berrange wrote: > > On Mon, Nov 25, 2019 at 01:53:47PM +0100, Peter Krempa wrote: > > > The redetection was originally added in 43c01d3838 as a way to recover > > > from libvirtd upgrade from the time when we didn't persist the qemu > > > capabilities in the status XML. Also this the oldest supported qemu by > > > more than two years. > > > > > > Even if somebody would have a running VM running at least qemu 1.5 with > > > such an old libvirt we certainly wouldn't do the right thing by > > > redetecting the capabilities and then trying to communicate with qemu. > > > > > > For now it will be the best to just stop considering this scenario any > > > more. > > > > > > Signed-off-by: Peter Krempa <pkrempa@xxxxxxxxxx> > > > --- > > > src/qemu/qemu_process.c | 7 ------- > > > 1 file changed, 7 deletions(-) > > > > > > diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c > > > index 1b88c471f4..a76a8da841 100644 > > > --- a/src/qemu/qemu_process.c > > > +++ b/src/qemu/qemu_process.c > > > @@ -8085,13 +8085,6 @@ qemuProcessReconnect(void *opaque) > > > goto error; > > > } > > > > > > - /* If upgrading from old libvirtd we won't have found any > > > - * caps in the domain status, so re-query them > > > - */ > > > - if (!priv->qemuCaps && > > > - (qemuDomainUpdateQEMUCaps(obj, driver->qemuCapsCache) < 0)) > > > - goto error; > > > > Shouldn't we be making missing qemuCaps into a fatal error > > when loading that VM. > > I thought about it for a bit. If we make it an error the VM will vanish > after upgrade (and continue running). If we don't make an error it will > not vanish and you'll be able to at least destroy it. > > Given that such situation is super-unlikely, I opted to remove it. > Nobody will probably run into this situation and if yes then the VM will > not vanish at least. > > I can add an error though, but to me it seems it's not worth. My concern is that pretty much all our later code will assume that priv->qemuCaps is non-NULL. So by ignoring the error, the VM might not vanish initially, but libvirtd may well crash shortly after. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
