On Wed, Dec 07, 2011 at 08:21:06AM +0200, Sasha Levin wrote: > 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? Yes, libvirt opens a /dev/tap device (or a macvtap device for VEPA mode), adds it to the neccessary bridge, and/or configures VEPA, etc and then passes the FD to the hypervisor, with a ARGV parameter to tell the HV which FD is being passed. > > > * 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? I presume that Osier is just comparing with the features QEMU has available for chardevs config, which include - PTYs - UNIX sockets - TCP sockets - UDP sockets - FIFO pipe - Plain file (output only obviously, but useful for logging) libvirt doesn't specifically need any of them, but it can support those options if they exist. > > > * 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) :) Ok, that sounds sufficient for the balloon info. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
