From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 20AD96B0005 for ; Fri, 9 Feb 2018 08:35:10 -0500 (EST) Received: by mail-wm0-f69.google.com with SMTP id b193so3680507wmd.7 for ; Fri, 09 Feb 2018 05:35:10 -0800 (PST) Received: from theia.8bytes.org (8bytes.org. [2a01:238:4383:600:38bc:a715:4b6d:a889]) by mx.google.com with ESMTPS id d46si1807995edb.88.2018.02.09.05.35.08 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 09 Feb 2018 05:35:08 -0800 (PST) Date: Fri, 9 Feb 2018 14:35:07 +0100 From: Joerg Roedel Subject: Re: [PATCH 00/31 v2] PTI support for x86_32 Message-ID: <20180209133507.GD16484@8bytes.org> References: <1518168340-9392-1-git-send-email-joro@8bytes.org> <35f19c79-7277-3ad8-50bf-8def929377b6@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <35f19c79-7277-3ad8-50bf-8def929377b6@suse.com> Sender: owner-linux-mm@kvack.org List-ID: To: Juergen Gross Cc: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Andrea Arcangeli , Waiman Long , Pavel Machek , jroedel@suse.de Hi Juergen, On Fri, Feb 09, 2018 at 01:11:42PM +0100, Juergen Gross wrote: > On 09/02/18 10:25, Joerg Roedel wrote: > > XENPV is also untested from my side, but I added checks to > > not do the stack switches in the entry-code when XENPV is > > enabled, so hopefully it works. But someone should test it, > > of course. > > That's unfortunate. 32 bit XENPV kernel is vulnerable to Meltdown, too. > I'll have a look whether 32 bit XENPV is still working, though. > > Adding support for KPTI with Xen PV should probably be done later. :-) Not sure how much is missing to make it work there, one point is certainly to write the right stack into tss.sp0 for xenpv on 32bit. This write has a check to only happen for !xenpv. But let's first test the code as-is on XENPV and see if it still boots :) Thanks, Joerg -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org