From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54711) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UD1Jw-0004uj-W5 for qemu-devel@nongnu.org; Tue, 05 Mar 2013 18:30:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UD1Ju-0004zH-0y for qemu-devel@nongnu.org; Tue, 05 Mar 2013 18:30:56 -0500 Received: from mx1.redhat.com ([209.132.183.28]:26985) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UD1Jt-0004z9-Oi for qemu-devel@nongnu.org; Tue, 05 Mar 2013 18:30:53 -0500 Message-ID: <513680A6.4090804@redhat.com> Date: Wed, 06 Mar 2013 00:32:54 +0100 From: Laszlo Ersek MIME-Version: 1.0 References: <1362435597-20018-1-git-send-email-lersek@redhat.com> <1362435597-20018-2-git-send-email-lersek@redhat.com> <51365EC2.8050903@redhat.com> <51367A50.6040405@redhat.com> <51367BEC.2070502@redhat.com> In-Reply-To: <51367BEC.2070502@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/3] qga: introduce guest-get-vcpus / guest-set-vcpus with stubs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: Drew Jones , qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com, pbonzini@redhat.com, lcapitulino@redhat.com, Karen Noel On 03/06/13 00:12, Eric Blake wrote: > The old cpu_set HMP command "worked" in something like qemu 0.10, and > was ripped out when we realized it didn't actually work in a way that > was guaranteed to be safe to the guest. Since then, the libvirt command > has been a guaranteed failure on qemu, although it continues to work on > xen (and since it has been several YEARS now of not working, people are > laughing at qemu for not getting cpu hotplug working when xen has had it > for so long). Under xen there's a separate comms method for requesting this (dom0 side massaging of a specific node in xenstore + xenstore watch in the guest kernel on that node). http://wiki.xen.org/wiki/XenBus http://wiki.xen.org/wiki/Event_Channel_Internals >> I'll have to test this in RHEL-6. If it doesn't work, I should check >> why. If it does, I'll have to figure out if I should continue to work on >> this. > > Yes, PLEASE continue to work on this - having the guest agent as an > alternative to ACPI has proven useful in other respects (for example, we > wired up virDomainShutdownFlags() to let the user choose between > guest-agent, ACPI, or hypervisor choice). OK. Laszlo