From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:38254) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R8b2p-0006BQ-IN for qemu-devel@nongnu.org; Tue, 27 Sep 2011 13:02:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R8b2o-0000h6-OS for qemu-devel@nongnu.org; Tue, 27 Sep 2011 13:02:11 -0400 Sender: Richard Henderson Message-ID: <4E820186.3090505@twiddle.net> Date: Tue, 27 Sep 2011 10:01:58 -0700 From: Richard Henderson 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> <4E7769D0.3090909@freescale.com> <1CECB54D-1FED-4AC2-B86B-8082CCFE001F@suse.de> <4E810883.4010405@freescale.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 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: Blue Swirl Cc: Alexander Graf , qemu-devel Developers , Yoder Stuart-B08248 , qemu-ppc@nongnu.org, Scott Wood , Aurelien Jarno On 09/27/2011 09:53 AM, Blue Swirl wrote: >> > So how would you emulate cache lines with line locking on KVM? > The cache would be a MMIO device which registers to handle all memory > space. Configuring the cache controller changes how the device > operates. Put this device between CPU and memory and other devices. > Performance would probably be horrible, so CPU should disable the > device automatically after some time. > Seems like a better alternative would be to add an mmio device when a line is actually locked. And the device would cover *only* the locked line. I assume that following the boot process these lines are unlocked, and the normal running state of the system would have none of these mmio devices active. r~