From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony PERARD Subject: Re: [PATCH] libxl: Use -vcpu_avail with qemu-xen. Date: Mon, 3 Jun 2013 14:49:48 +0100 Message-ID: <51AC9EFC.4040902@citrix.com> References: <1370017993-13437-1-git-send-email-anthony.perard@citrix.com> <1370018361-14556-1-git-send-email-anthony.perard@citrix.com> <1370248648.404.5.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1370248648.404.5.camel@zakaz.uk.xensource.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: Ian Campbell Cc: Stefano Stabellini , Xen Devel List-Id: xen-devel@lists.xenproject.org On 03/06/13 09:37, Ian Campbell wrote: > On Fri, 2013-05-31 at 17:39 +0100, Anthony PERARD wrote: >> > This require the series CPU hotplug for qemu-xen. >> > >> > Note: this patch is valid only for 4.3 as the -vcpu_avail will >> > probably not be upstream to Qemu. > Ugh. So how are we going to handle this in the future? libxl ideally > needs to work with upstream qemu or our qemu seamlessly, which would > mean needed to know whether to use -vcpu_avail vs. whatever upstream > has. I'd much prefer to make our qemu export the same interface and use > that... It could maybe be removed all together. QEMU already know how many initial CPUs there is. The only difference is the bitmap. -vcpu_avail is giving to QEMU a bitmap of the running CPUs. But I don't know if it useful to have a bitmap, or if a number is enough. With QEMU upstream, we could actually pass the bitmap through several QMP command "cpu-add CPUx", if a number is not enough. -- Anthony PERARD