From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:47643) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R5gSB-0006C3-Dk for qemu-devel@nongnu.org; Mon, 19 Sep 2011 12:12:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R5gS5-0005Z9-Dw for qemu-devel@nongnu.org; Mon, 19 Sep 2011 12:12:19 -0400 Message-ID: <4E7769D0.3090909@freescale.com> Date: Mon, 19 Sep 2011 11:12:00 -0500 From: Scott Wood MIME-Version: 1.0 References: <1315989802-18753-1-git-send-email-agraf@suse.de> <1315989802-18753-25-git-send-email-agraf@suse.de> <14529F4D-D8AC-4097-8DF8-5F13EDCCC77F@suse.de> In-Reply-To: <14529F4D-D8AC-4097-8DF8-5F13EDCCC77F@suse.de> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 24/58] PPC: E500: Add PV spinning code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Blue Swirl , Yoder Stuart-B08248 , qemu-ppc@nongnu.org, qemu-devel Developers , Aurelien Jarno On 09/19/2011 06:35 AM, Alexander Graf wrote: > > On 17.09.2011, at 19:40, Blue Swirl wrote: > >> On Sat, Sep 17, 2011 at 5:15 PM, Alexander Graf wrote: >>> >>> Am 17.09.2011 um 18:58 schrieb Blue Swirl : >>> >>>> On Sparc32, there is no need for a PV device. The CPU is woken up from >>>> halted state with an IPI. Maybe you could use this approach? >>> >>> The way it's done here is defined by u-boot and now also nailed down in the ePAPR architecture spec. While alternatives might be more appealing, this is how guests work today :). >> >> OK. I hoped that there were no implementations yet. The header (btw >> missing) should point to the spec. The goal with the spin table stuff, suboptimal as it is, was something that would work on any powerpc implementation. Other implementation-specific release mechanisms are allowed, and are indicated by a property in the cpu node, but only if the loader knows that the OS supports it. > IIUC the spec that includes these bits is not finalized yet. It is however in use on all u-boot versions for e500 that I'm aware of and the method Linux uses to bring up secondary CPUs. It's in ePAPR 1.0, which has been out for a while now. ePAPR 1.1 was just released which clarifies some things such as WIMG. > Stuart / Scott, do you have any pointers to documentation where the spinning is explained? https://www.power.org/resources/downloads/Power_ePAPR_APPROVED_v1.1.pdf -Scott