On Tue, Jun 14, 2016 at 05:57:00PM +0100, Ian Jackson wrote: > Wei Liu writes ("Re: [Xen-devel] "xl vcpu-set" not persistent across > reboot?"): > > What Andrew means is that QEMU shouldn't have kept the CPU state > > structures in the first place. My response explains why that is not > > possible from a QEMU upstream point of view. > > I don't think it addresses my point. > > > Hence the unfortunate fact is that we need to live with it for now. To > > start QEMU we need to create a bunch of dummy CPUs to keep QEMU happy. > > All those dummy states need to be kept. > > Why do we need one dummy state per actual vcpu rather than just one > dummy state no matter how many vcpus ? > > Or is qemu involved in hvm cpu hotplug ?
It is, QEMU does the notification to the guest of a newly available CPU via an ACPI GPE or something like that. I think QEMU manage the bitfield of online CPUs then notify the guest about changes. -- Anthony PERARD _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel