Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752175AbbKPUtK (ORCPT ); Mon, 16 Nov 2015 15:49:10 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:34040 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751205AbbKPUtG (ORCPT ); Mon, 16 Nov 2015 15:49:06 -0500 Subject: Re: [PATCH] xen/x86: Adjust stack pointer in xen_sysexit To: Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" References: <1447456706-24347-1-git-send-email-boris.ostrovsky@oracle.com> <56468D24.8030801@oracle.com> <564A0371.2040104@oracle.com> <20151116195906.GB20137@pd.tnic> <20151116202232.GC20137@pd.tnic> Cc: "linux-kernel@vger.kernel.org" , xen-devel , David Vrabel , Konrad Rzeszutek Wilk From: Boris Ostrovsky Message-ID: <564A4125.8000603@oracle.com> Date: Mon, 16 Nov 2015 15:48:37 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <20151116202232.GC20137@pd.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1206 Lines: 31 On 11/16/2015 03:22 PM, Borislav Petkov wrote: > On Mon, Nov 16, 2015 at 12:11:11PM -0800, Andy Lutomirski wrote: > >> Are there really multiple feature bits for this stuff? I'd like to >> imagine that the entry code is all either Xen PV or native/PVH/PVHVM >> -- i.e. I assumed that PVH works like native for all entries. Almost. For PVH we will have a small stub to set up bootparams and such but then we jump to startup_{32|64} code. > I just reacted to Boris' statement: > > "We don't currently have a Xen-specific CPU feature. We could, in > principle, add it but we can't replace all of current paravirt patching > with a single feature since PVH guests use a subset of existing pv ops > (and in the future it may become even more fine-grained)." Actually, nevermind this --- I was thinking about APIC ops and they are not pv ops. Note though that there are other users of pv ops --- lguest and looks like KVM (for one op) use them too. -boris -- 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/