From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=53080 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OqR08-0001Iz-Vq for qemu-devel@nongnu.org; Tue, 31 Aug 2010 09:35:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OqR03-0001JA-RH for qemu-devel@nongnu.org; Tue, 31 Aug 2010 09:35:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23316) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OqR03-0001J2-LI for qemu-devel@nongnu.org; Tue, 31 Aug 2010 09:35:43 -0400 Date: Tue, 31 Aug 2010 16:35:39 +0300 From: Gleb Natapov Subject: Re: [Qemu-devel] Re: [PATCH 5/5] RFC: distinguish warm reset from cold reset. Message-ID: <20100831133539.GI10499@redhat.com> References: <0a460e01cca4fa24f446c7a715fe6df17d0be9ed.1283152674.git.yamahata@valinux.co.jp> <4C7BAB2A.30608@codemonkey.ws> <20100831025808.GA19374@valinux.co.jp> <4C7CFEC1.8040204@codemonkey.ws> <20100831131449.GG10499@redhat.com> <4C7D01B3.4030602@codemonkey.ws> <20100831132158.GH10499@redhat.com> <4C7D02FB.4030706@codemonkey.ws> <4C7D03C7.9090406@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C7D03C7.9090406@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: glommer@redhat.com, qemu-devel@nongnu.org, blauwirbel@gmail.com, Isaku Yamahata , alex.williamson@redhat.com On Tue, Aug 31, 2010 at 04:29:43PM +0300, Avi Kivity wrote: > On 08/31/2010 04:26 PM, Anthony Liguori wrote: > >On 08/31/2010 08:21 AM, Gleb Natapov wrote: > >>On Tue, Aug 31, 2010 at 08:20:51AM -0500, Anthony Liguori wrote: > >>>On 08/31/2010 08:14 AM, Gleb Natapov wrote: > >>>>System_reset should do cold reset like it does now. > >>>Why? > >>> > >>Because I should not be forced to restart qemu to bring devices to > >>initial state. > > > >IOW, you use system_reset for debugging purposes to reset the > >device model. > > > >Point taken but functionally speaking, system_reset should map to > >a RESET signal and from what I can tell in this thread, that's a > >warm reset. > > > > Note, for most devices there's no difference. x86 has INIT and > RESET, with the keyboard controller RESET signal sometimes wired to > INIT, and RAM doesn't have RESET. Otherwise most devices don't see > a difference. > Actually soft reset is defined as INIT in PIIX4 spec: Bits 1 and 2 in this register are used by PIIX4 to generate a hard reset or a soft reset. During a hard reset, PIIX4 asserts CPURST, PCIRST#, and RSTDRV, as well as reset its core and suspend well logic. During a soft reset, PIIX4 asserts INIT. -- Gleb.