From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34662) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y1Cjl-0004ar-9t for qemu-devel@nongnu.org; Wed, 17 Dec 2014 06:25:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y1Cjd-0000tw-Ff for qemu-devel@nongnu.org; Wed, 17 Dec 2014 06:25:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55010) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y1Cjd-0000tm-30 for qemu-devel@nongnu.org; Wed, 17 Dec 2014 06:25:41 -0500 Message-ID: <54916829.3020200@redhat.com> Date: Wed, 17 Dec 2014 12:25:29 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1418721234-9588-1-git-send-email-fred.konrad@greensocs.com> <54915A76.3000408@greensocs.com> <54915AE8.3010809@suse.de> <54915EC6.2050708@suse.de> <8B6B4BF9-3400-4125-8571-F4EF9F12AA89@greensocs.com> <5491666A.7060001@suse.de> In-Reply-To: <5491666A.7060001@suse.de> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [RFC PATCH] target-arm: protect cpu_exclusive_*. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf , Mark Burton Cc: mttcg@greensocs.com, Peter Maydell , =?windows-1252?Q?Llu=EDs_Vilanova?= , QEMU Developers , =?windows-1252?Q?KONRAD_Fr=E9d=E9ric?= On 17/12/2014 12:18, Alexander Graf wrote: > > So I think the best way to go forward would be to add transaction_start > and transaction_end opcodes to TCG and implement them as mutex locks > today. When you get the chance to get yourself a machine that supports > actual TM, try to replace them with transaction start/end blocks and > have the normal mutex code as fallback if the transaction fails. Or implement load_locked/store_conditional TCG ops. They can be implemented as transactions, hardware ll/sc, or something slow that uses the MMU. Paolo