From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony PERARD Subject: Re: [PATCH 0/4] CPU hotplug port from qemu-traditionnal to qemu-xen for 4.3. Date: Fri, 31 May 2013 18:20:01 +0100 Message-ID: <51A8DBC1.5030202@citrix.com> References: <1370017993-13437-1-git-send-email-anthony.perard@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1370017993-13437-1-git-send-email-anthony.perard@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Anthony PERARD Cc: Stefano Stabellini , Xen Devel List-Id: xen-devel@lists.xenproject.org On 31/05/13 17:33, Anthony PERARD wrote: > Hi all, > > This series ports few patches from qemu-xen-traditionnal to qemu-xen > (upstream). There is as little modification as possible on those patches so > they *can not* be upstream as is. So this is only for 4.3. A proper series will > be done for 4.4. > > There make possible to have CPU hotplug on qemu-xen. > > A patch for libxl will follow, which make use of the old command line > -vcpu_avail with qemu-xen. This command line will probably not be upstream. > > BUG: There is an issue with SeaBIOS (used with qemu-xen). At SMP > initialisation, SeaBIOS will count the number of CPU running, and the number is > always equal to maxvcpu when SeaBIOS expect less. This happen when we have > something like: > vcpus = 2 > maxvcpus = 8 > in the VM config file. Linux is fine with this and will use only $vcpus. So > the probleme is: an infinit loop in SeaBIOS. To let you know, I just realize that QEMU 1.5 (we are using 1.3, I think) already have everything needed for CPU hotplug. It will just be a matter of plumbing libxl to use the cpu-add QMP command. But cpu-remove QMP command seams to be missing from QEMU. Regards, -- Anthony PERARD