From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53347) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VoBdx-0007rX-HE for qemu-devel@nongnu.org; Wed, 04 Dec 2013 07:33:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VoBdn-0005Np-NT for qemu-devel@nongnu.org; Wed, 04 Dec 2013 07:33:29 -0500 Received: from mailout4.w1.samsung.com ([210.118.77.14]:40220) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VoBdn-0005Jo-HQ for qemu-devel@nongnu.org; Wed, 04 Dec 2013 07:33:19 -0500 Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout4.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MXA00IN987GLH60@mailout4.w1.samsung.com> for qemu-devel@nongnu.org; Wed, 04 Dec 2013 12:33:16 +0000 (GMT) Message-id: <529F210B.8020108@samsung.com> Date: Wed, 04 Dec 2013 16:33:15 +0400 From: Fedorov Sergey MIME-version: 1.0 References: <1386060535-15908-1-git-send-email-s.fedorov@samsung.com> <1386060535-15908-6-git-send-email-s.fedorov@samsung.com> <529EFD75.7020208@samsung.com> In-reply-to: Content-type: text/plain; charset=UTF-8; format=flowed Content-transfer-encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH 05/21] target-arm: add CPU Monitor mode List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , Peter Crosthwaite Cc: Johannes Winter , a.basov@samsung.com, "qemu-devel@nongnu.org Developers" , Svetlana Fedoseeva On 12/04/2013 03:18 PM, Peter Maydell wrote: > On 4 December 2013 10:58, Peter Crosthwaite > wrote: >> So what im proposing is just a slightly more general patch. Is it >> really any more complicated than just applying your change pattern for >> the hyp mode? > I think it would be, because of the wrinkle that hyp mode doesn't > have a banked LR, so the existing "assume we can just translate > the mode into a single index good for both LR and SP" logic > would break. > > The minimal change if we wanted to keep VMSD bumps to a > minimum would be to increase the size of the banked_spsr[] > and banked_r13[] arrays to allow for Hyp mode but do nothing > else (except add a comment about it I guess). If we want to bump VMSD just once for monitor + hypervisor mode then we need to add ELR_hyp register definition too. I think then it would be better to implement hypervisor mode and its special banking scheme, too. But I doubt it worth to combine these two things into one patch. > >> The motiviation is less VMSD version bumps in ARM CPU (a place where I >> expect assume such version bumps to be considerable annoyance). > Well, they're only a problem at the point where we start trying > to support cross-version migration; we're not at that point yet... > > thanks > -- PMM > Best regards, Sergey Fedorov