From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1GJbNA-0000iV-Bx for qemu-devel@nongnu.org; Sat, 02 Sep 2006 15:41:44 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1GJbN8-0000hC-H9 for qemu-devel@nongnu.org; Sat, 02 Sep 2006 15:41:43 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1GJbN8-0000h2-1y for qemu-devel@nongnu.org; Sat, 02 Sep 2006 15:41:42 -0400 Received: from [65.74.133.4] (helo=mail.codesourcery.com) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA:32) (Exim 4.52) id 1GJbXG-00064s-7u for qemu-devel@nongnu.org; Sat, 02 Sep 2006 15:52:10 -0400 From: Paul Brook Subject: Re: [Qemu-devel] AIO and savevm Date: Sat, 2 Sep 2006 20:34:38 +0100 References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200609022034.38863.paul@codesourcery.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org > I don't think savevm works reliably together with current AIO. At least > some kind of AIO flushing or completion waiting should happen and then this > should be done before any devices have started saving their state. Is this > correct? Correct. Implementing it this way does mean savevm can effect the guest VM state (it causes all pending IO to complete immediately). However this should be safe, ie. it could occur be chance anyway, and qemu isn't deterministic to start with. Trying to make async AIO restartable is IMHO not worth the effort at this point. Paul