From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35500) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XgDVE-0001Wg-TZ for qemu-devel@nongnu.org; Mon, 20 Oct 2014 10:00:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XgDV8-0008Hr-LL for qemu-devel@nongnu.org; Mon, 20 Oct 2014 10:00:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9819) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XgDV8-0008Hk-E7 for qemu-devel@nongnu.org; Mon, 20 Oct 2014 09:59:58 -0400 Date: Mon, 20 Oct 2014 15:59:55 +0200 From: Kevin Wolf Message-ID: <20141020135955.GL3585@noname.redhat.com> References: <201410202148499451733@sangfor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201410202148499451733@sangfor.com> Subject: Re: [Qemu-devel] [question] savevm/delvm: Is it neccesary to perform bdrv_drain_all before savevm and delvm? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Zhang Haoyu Cc: qemu-devel , Stefan Hajnoczi , Max Reitz Am 20.10.2014 um 15:48 hat Zhang Haoyu geschrieben: > Hi, > > I noticed that bdrv_drain_all is performed in load_vmstate before bdrv_snapshot_goto, > and bdrv_drain_all is performed in qmp_transaction before internal_snapshot_prepare, > so is it also neccesary to perform bdrv_drain_all in savevm and delvm? Definitely yes for savevm. do_savevm() calls it indirectly via vm_stop(), so that part looks okay. delvm doesn't affect the currently running VM, and therefore doesn't interfere with guest requests that are in flight. So I think that a bdrv_drain_all() isn't needed there. Kevin