From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55837) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VToUL-0003WE-3Q for qemu-devel@nongnu.org; Wed, 09 Oct 2013 03:47:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VToUC-0008KV-Aq for qemu-devel@nongnu.org; Wed, 09 Oct 2013 03:47:21 -0400 Received: from mail-ea0-x22e.google.com ([2a00:1450:4013:c01::22e]:55520) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VToUC-0008KK-2u for qemu-devel@nongnu.org; Wed, 09 Oct 2013 03:47:12 -0400 Received: by mail-ea0-f174.google.com with SMTP id z15so191170ead.33 for ; Wed, 09 Oct 2013 00:47:11 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <525509FA.1070105@redhat.com> Date: Wed, 09 Oct 2013 09:47:06 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <5253C514.6090103@ozlabs.ru> <5253CAB5.7040708@redhat.com> <20131008092330.GB25109@dhcp-200-207.str.redhat.com> <5253D174.1060200@redhat.com> <52550275.7000007@ozlabs.ru> In-Reply-To: <52550275.7000007@ozlabs.ru> Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] savevm/loadvm List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: Kevin Wolf , "qemu-devel@nongnu.org" Il 09/10/2013 09:15, Alexey Kardashevskiy ha scritto: > Sorry for my ignorance (I never ever touched this part of qemu) but how can > you possibly avoid block.c while doing savevm? The qcow2 driver must not > use posix read()/write(), right? So no matter how, all writes end up in > bdrv_co_do_writev() which changes blocks number. Or use > raw_aio_readv()/raw_aio_writev() API directly? Please give some more hints. > Thanks. I think Kevin was suggesting using qcow_aio_writev directly, or something like that. But it is not trivial, especially because save_vm_state takes byte offsets instead of sectors. So for now I'd still go for the more hacky solution. Paolo