Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932504AbdIFOEE (ORCPT ); Wed, 6 Sep 2017 10:04:04 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:18281 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932171AbdIFOED (ORCPT ); Wed, 6 Sep 2017 10:04:03 -0400 Subject: Re: SME/32-bit regression To: Thomas Gleixner References: <4c07148a-5d97-0fc2-aa9b-1db31429736d@oracle.com> <20170906092618.fkvzrqx32z6iqf2t@pd.tnic> <86bcf09d-255d-3ad7-ecfe-497e3f57c4eb@oracle.com> Cc: Borislav Petkov , thomas.lendacky@amd.com, X86 ML , "linux-kernel@vger.kernel.org" , Ingo Molnar , "H. Peter Anvin" From: Boris Ostrovsky Message-ID: <49cfbec8-df6f-5eed-0639-53c6bb3eaab2@oracle.com> Date: Wed, 6 Sep 2017 10:03:27 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1186 Lines: 26 On 09/06/2017 09:57 AM, Thomas Gleixner wrote: > On Wed, 6 Sep 2017, Boris Ostrovsky wrote: >> On 09/06/2017 05:26 AM, Borislav Petkov wrote: >>> On Tue, Sep 05, 2017 at 11:45:07PM -0400, Boris Ostrovsky wrote: >>>> It appears there is a regression for 32-bit kernels due to SME changes. >>>> >>>> I bisected my particular problem >>> It being? Doesn't boot, splats? >> Xen guest crashes very early, before a splat can can be generated. >> >>>> (Xen PV guest) to >>>> 21729f81ce8ae76a6995681d40e16f7ce8075db4 but I also saw pmd_clear_bad() >>>> errors on baremetal. This seems to be caused by sme_me_mask being an >>>> unsigned long as opposed to phys_addr_t (the actual problem is that >>>> __PHYSICAL_MASK is truncated). When I declare it as u64 and drop unsigned >>>> long cast in __sme_set()/__sme_clr() the problem goes way. (This presumably >>>> won't work for non-PAE which I haven't tried). >>> Right, so I think we should do this because those macros should not have >>> any effect on !CONFIG_AMD_MEM_ENCRYPT setups. >> This won't help though if kernel is built with SME support. > Which is not the case for 32bit. SME depends on 64bit Oh, OK, I didn't realize that. -boris