Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754850Ab2BOTSJ (ORCPT ); Wed, 15 Feb 2012 14:18:09 -0500 Received: from tx2ehsobe004.messaging.microsoft.com ([65.55.88.14]:44093 "EHLO TX2EHSOBE004.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754693Ab2BOTSG (ORCPT ); Wed, 15 Feb 2012 14:18:06 -0500 X-SpamScore: -11 X-BigFish: VS-11(zzbb2dI9371I1432N98dKzz1202hzzz2dh2a8h668h839h) X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI Message-ID: <4F3C04E4.4090708@freescale.com> Date: Wed, 15 Feb 2012 13:17:56 -0600 From: Scott Wood User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:6.0.2) Gecko/20110906 Thunderbird/6.0.2 MIME-Version: 1.0 To: Alexander Graf CC: Avi Kivity , Anthony Liguori , KVM list , linux-kernel , qemu-devel , kvm-ppc Subject: Re: [Qemu-devel] [RFC] Next gen kvm api References: <4F2AB552.2070909@redhat.com> <4F2B41D6.8020603@codemonkey.ws> <51470503-DEE0-478D-8D01-020834AF6E8C@suse.de> <4F3117E5.6000105@redhat.com> <4F31241C.70404@redhat.com> <4F313354.4080401@redhat.com> <4B03190C-1B6B-48EC-92C7-C27F6982018A@suse.de> <4F3B9497.4020700@redhat.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1245 Lines: 30 On 02/15/2012 05:57 AM, Alexander Graf wrote: > > On 15.02.2012, at 12:18, Avi Kivity wrote: > >> Well the real reason is we have an extra bit reported by page faults >> that we can control. Can't you set up a hashed pte that is configured >> in a way that it will fault, no matter what type of access the guest >> does, and see it in your page fault handler? > > I might be able to synthesize a PTE that is !readable and might throw > a permission exception instead of a miss exception. I might be able > to synthesize something similar for booke. I don't however get any > indication on why things failed. On booke with ISA 2.06 hypervisor extensions, there's MAS8[VF] that will trigger a DSI that gets sent to the hypervisor even if normal DSIs go directly to the guest. You'll still need to zero out the execute permission bits. For other booke, you could use one of the user bits in MAS3 (along with zeroing out all the permission bits), which you could get to by doing a tlbsx. -Scott -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/