From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758335AbcLRIpD (ORCPT ); Sun, 18 Dec 2016 03:45:03 -0500 Received: from mail-wj0-f195.google.com ([209.85.210.195]:36709 "EHLO mail-wj0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751532AbcLRIpC (ORCPT ); Sun, 18 Dec 2016 03:45:02 -0500 Date: Sun, 18 Dec 2016 09:44:57 +0100 From: Ingo Molnar To: Boris Ostrovsky Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, matt@codeblueprint.co.uk, Linus Torvalds , Andy Lutomirski , Borislav Petkov , Peter Zijlstra , Josh Poimboeuf , Denys Vlasenko , Brian Gerst Subject: Re: [PATCH] x86/head: Refactor 32-bit pgtable setup Message-ID: <20161218084457.GA19538@gmail.com> References: <1481215471-9639-1-git-send-email-boris.ostrovsky@oracle.com> <20161209043347.GB2595@gmail.com> <17b4298e-f073-d323-3a3f-1974ed3ec62f@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <17b4298e-f073-d323-3a3f-1974ed3ec62f@oracle.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Boris Ostrovsky wrote: > On 12/08/2016 11:33 PM, Ingo Molnar wrote: > > * Boris Ostrovsky wrote: > > > >> The new Xen PVH entry point requires page tables to be setup by the > >> kernel since it is entered with paging disabled. > >> > >> Pull the common code out of head_32.S so that mk_early_pgtbl_32 can be > >> invoked from both the new Xen entry point and the existing startup_32 > >> code. > >> > >> Convert resulting common code to C. > >> > >> Signed-off-by: Boris Ostrovsky > >> --- > >> This is replacement for https://lkml.org/lkml/2016/10/14/434, with > >> assembly code re-written in C as requested by Ingo. > >> > >> > >> arch/x86/include/asm/pgtable_32.h | 32 ++++++++++ > >> arch/x86/kernel/head32.c | 62 +++++++++++++++++++ > >> arch/x86/kernel/head_32.S | 122 +++----------------------------------- > >> 3 files changed, 101 insertions(+), 115 deletions(-) > > Whee, I love it! And the code is so much more readable! > > > > Did you have any particular robustness problems (difficult to resolve crashes) > > while developing it, or was it reasonably straightforward to do? > > There was nothing particularly difficult beyond understanding current > code. That, of course, is not to say that there were no crashes but > developing this on a guest gives you pretty good insight into why/where > you crashed. > > This was tested on bare-metal (in case you are wondering), but obviously > more testing is always good. Ok, cool! Would you like to carry this with your other Xen dependencies? If yes: Acked-by: Ingo Molnar If not then I can pick it up and get it to Linus in v4.10. Thanks, Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH] x86/head: Refactor 32-bit pgtable setup Date: Sun, 18 Dec 2016 09:44:57 +0100 Message-ID: <20161218084457.GA19538@gmail.com> References: <1481215471-9639-1-git-send-email-boris.ostrovsky@oracle.com> <20161209043347.GB2595@gmail.com> <17b4298e-f073-d323-3a3f-1974ed3ec62f@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cIX5a-0007Au-5i for xen-devel@lists.xenproject.org; Sun, 18 Dec 2016 08:45:02 +0000 Received: by mail-wj0-f193.google.com with SMTP id xy5so19702506wjc.1 for ; Sun, 18 Dec 2016 00:45:00 -0800 (PST) Content-Disposition: inline In-Reply-To: <17b4298e-f073-d323-3a3f-1974ed3ec62f@oracle.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Boris Ostrovsky Cc: Denys Vlasenko , Peter Zijlstra , Josh Poimboeuf , matt@codeblueprint.co.uk, Brian Gerst , x86@kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, Borislav Petkov , Andy Lutomirski , hpa@zytor.com, xen-devel@lists.xenproject.org, tglx@linutronix.de, Linus Torvalds List-Id: xen-devel@lists.xenproject.org CiogQm9yaXMgT3N0cm92c2t5IDxib3Jpcy5vc3Ryb3Zza3lAb3JhY2xlLmNvbT4gd3JvdGU6Cgo+ IE9uIDEyLzA4LzIwMTYgMTE6MzMgUE0sIEluZ28gTW9sbmFyIHdyb3RlOgo+ID4gKiBCb3JpcyBP c3Ryb3Zza3kgPGJvcmlzLm9zdHJvdnNreUBvcmFjbGUuY29tPiB3cm90ZToKPiA+Cj4gPj4gVGhl IG5ldyBYZW4gUFZIIGVudHJ5IHBvaW50IHJlcXVpcmVzIHBhZ2UgdGFibGVzIHRvIGJlIHNldHVw IGJ5IHRoZQo+ID4+IGtlcm5lbCBzaW5jZSBpdCBpcyBlbnRlcmVkIHdpdGggcGFnaW5nIGRpc2Fi bGVkLgo+ID4+Cj4gPj4gUHVsbCB0aGUgY29tbW9uIGNvZGUgb3V0IG9mIGhlYWRfMzIuUyBzbyB0 aGF0IG1rX2Vhcmx5X3BndGJsXzMyIGNhbiBiZQo+ID4+IGludm9rZWQgZnJvbSBib3RoIHRoZSBu ZXcgWGVuIGVudHJ5IHBvaW50IGFuZCB0aGUgZXhpc3Rpbmcgc3RhcnR1cF8zMgo+ID4+IGNvZGUu Cj4gPj4KPiA+PiBDb252ZXJ0IHJlc3VsdGluZyBjb21tb24gY29kZSB0byBDLgo+ID4+Cj4gPj4g U2lnbmVkLW9mZi1ieTogQm9yaXMgT3N0cm92c2t5IDxib3Jpcy5vc3Ryb3Zza3lAb3JhY2xlLmNv bT4KPiA+PiAtLS0KPiA+PiBUaGlzIGlzIHJlcGxhY2VtZW50IGZvciBodHRwczovL2xrbWwub3Jn L2xrbWwvMjAxNi8xMC8xNC80MzQsIHdpdGgKPiA+PiBhc3NlbWJseSBjb2RlIHJlLXdyaXR0ZW4g aW4gQyBhcyByZXF1ZXN0ZWQgYnkgSW5nby4KPiA+Pgo+ID4+Cj4gPj4gIGFyY2gveDg2L2luY2x1 ZGUvYXNtL3BndGFibGVfMzIuaCB8ICAzMiArKysrKysrKysrCj4gPj4gIGFyY2gveDg2L2tlcm5l bC9oZWFkMzIuYyAgICAgICAgICB8ICA2MiArKysrKysrKysrKysrKysrKysrCj4gPj4gIGFyY2gv eDg2L2tlcm5lbC9oZWFkXzMyLlMgICAgICAgICB8IDEyMiArKystLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLQo+ID4+ICAzIGZpbGVzIGNoYW5nZWQsIDEwMSBpbnNlcnRpb25zKCsp LCAxMTUgZGVsZXRpb25zKC0pCj4gPiBXaGVlLCBJIGxvdmUgaXQhIEFuZCB0aGUgY29kZSBpcyBz byBtdWNoIG1vcmUgcmVhZGFibGUhCj4gPgo+ID4gRGlkIHlvdSBoYXZlIGFueSBwYXJ0aWN1bGFy IHJvYnVzdG5lc3MgcHJvYmxlbXMgKGRpZmZpY3VsdCB0byByZXNvbHZlIGNyYXNoZXMpIAo+ID4g d2hpbGUgZGV2ZWxvcGluZyBpdCwgb3Igd2FzIGl0IHJlYXNvbmFibHkgc3RyYWlnaHRmb3J3YXJk IHRvIGRvPwo+IAo+IFRoZXJlIHdhcyBub3RoaW5nIHBhcnRpY3VsYXJseSBkaWZmaWN1bHQgYmV5 b25kIHVuZGVyc3RhbmRpbmcgY3VycmVudAo+IGNvZGUuIFRoYXQsIG9mIGNvdXJzZSwgaXMgbm90 IHRvIHNheSB0aGF0IHRoZXJlIHdlcmUgbm8gY3Jhc2hlcyBidXQKPiBkZXZlbG9waW5nIHRoaXMg b24gYSBndWVzdCBnaXZlcyB5b3UgcHJldHR5IGdvb2QgaW5zaWdodCBpbnRvIHdoeS93aGVyZQo+ IHlvdSBjcmFzaGVkLgo+IAo+IFRoaXMgd2FzIHRlc3RlZCBvbiBiYXJlLW1ldGFsIChpbiBjYXNl IHlvdSBhcmUgd29uZGVyaW5nKSwgYnV0IG9idmlvdXNseQo+IG1vcmUgdGVzdGluZyBpcyBhbHdh eXMgZ29vZC4KCk9rLCBjb29sIQoKV291bGQgeW91IGxpa2UgdG8gY2FycnkgdGhpcyB3aXRoIHlv dXIgb3RoZXIgWGVuIGRlcGVuZGVuY2llcz8gSWYgeWVzOgoKICAgQWNrZWQtYnk6IEluZ28gTW9s bmFyIDxtaW5nb0BrZXJuZWwub3JnPgoKSWYgbm90IHRoZW4gSSBjYW4gcGljayBpdCB1cCBhbmQg Z2V0IGl0IHRvIExpbnVzIGluIHY0LjEwLgoKVGhhbmtzLAoKCUluZ28KCl9fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClhlbi1kZXZlbCBtYWlsaW5nIGxpc3QK WGVuLWRldmVsQGxpc3RzLnhlbi5vcmcKaHR0cHM6Ly9saXN0cy54ZW4ub3JnL3hlbi1kZXZlbAo=