Re: [libvirt] (no subject)

On Tue, 2011-12-06 at 14:38 +0000, Daniel P. Berrange wrote: > On Fri, Nov 11, 2011 at 07:56:58PM +0800, Osier Yang wrote: > > * KVM tool manages the network completely itself (with DHCP support?), > > no way to configure, except specify the modes (user|tap|none). I > > have not test it yet, but it should need explicit script to setup > > the network rules(e.g. NAT) for the guest access outside world. > > Anyway, there is no way for libvirt to control the guest network. > > If KVM tool support TAP devices, can't be do whatever we like with > that just by passing in a configured TAP device from libvir ? KVM tool currently creates and configures the TAP devices it uses, it shouldn't be an issue to have it use a TAP fd passed to it either. How does libvirt do it? Create a /dev/tapX on it's own and pass the fd to the hypervisor?

> > * console connection is implemented by setup ptys in libvirt, stdout/stderr > > of kvm tool process is redirected to the master pty, and libvirt connects > > to the slave pty. This works fine now, but it might be better if kvm > > tool could provide more advanced console mechanisms. Just like QEMU > > does? > > This sounds good enough for now. KVM tools does a redirection to a PTY, which at that point could be redirected to anywhere the user wants. What features might be interesting to do on top of that?

> > * Not much ways existed yet for external apps or user to query the guest > > informations. But this might be changed soon per KVM tool grows up > > quickly. > > What sort of guest info are you thinking about ? The most immediate > pieces of info I can imagine we need are > > - Mapping between PIDs and vCPU threads > - Current balloon driver value Those are pretty easily added using the IPC interface I've mentioned above. For example, 'kvm balloon' and 'kvm stat' will return a lot of info out of the balloon driver (including the memory stats VQ - which afaik we're probably the only ones who actually do that (but I might be wrong) :)