From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CC73C5479D for ; Thu, 5 Jan 2023 03:40:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230206AbjAEDjm (ORCPT ); Wed, 4 Jan 2023 22:39:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230241AbjAEDjP (ORCPT ); Wed, 4 Jan 2023 22:39:15 -0500 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B55E748CE6; Wed, 4 Jan 2023 19:39:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1672889954; x=1704425954; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=7+whF6O83FkAi7trCF9TEjov28V0K0S8cRinP/bHSI4=; b=ElbdV5eTGT0Yeh0HM7g0ELxfawM/y47UILcCEBkPM68kEcmsvpMG+yo2 cXyNaWIwr5t8fjT02RdsoajI+ciGPSFbNWp73UECvKAgpC7jDrabEqrBH EgVTKZeEapj7m8WNX4e00SdxMrrq2WYVewX2G0SVcSbWm/FrjexK91IXG 41WXjiJSG/GHmgk94LfsV1ZUi0KFQYzdg9w/KZtSHupwiikwFlSHYKxdS hNCtxMFuWG2qNqyDsnLN9xtVyKWNSROjcQ0k9l/cq+XlD/Gb+2ugG23W2 2O+SAOO4XgMQdA4ML+KfswJKuUmxX9tvfRWUSmQCxaOAeX5WaRqWLy4E+ g==; X-IronPort-AV: E=McAfee;i="6500,9779,10580"; a="349328871" X-IronPort-AV: E=Sophos;i="5.96,301,1665471600"; d="scan'208";a="349328871" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jan 2023 19:39:14 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10580"; a="829394357" X-IronPort-AV: E=Sophos;i="5.96,301,1665471600"; d="scan'208";a="829394357" Received: from chaop.bj.intel.com (HELO localhost) ([10.240.193.75]) by orsmga005.jf.intel.com with ESMTP; 04 Jan 2023 19:39:04 -0800 Date: Thu, 5 Jan 2023 11:34:51 +0800 From: Chao Peng To: Jarkko Sakkinen Cc: Michael Roth , kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, jroedel@suse.de, thomas.lendacky@amd.com, hpa@zytor.com, ardb@kernel.org, pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, luto@kernel.org, dave.hansen@linux.intel.com, slp@redhat.com, pgonda@google.com, peterz@infradead.org, srinivas.pandruvada@linux.intel.com, rientjes@google.com, dovmurik@linux.ibm.com, tobin@ibm.com, bp@alien8.de, vbabka@suse.cz, kirill@shutemov.name, ak@linux.intel.com, tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com, alpergun@google.com, dgilbert@redhat.com, ashish.kalra@amd.com, harald@profian.com, Nikunj A Dadhania Subject: Re: [PATCH RFC v7 01/64] KVM: Fix memslot boundary condition for large page Message-ID: <20230105033451.GA2251521@chaop.bj.intel.com> Reply-To: Chao Peng References: <20221214194056.161492-1-michael.roth@amd.com> <20221214194056.161492-2-michael.roth@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 04, 2023 at 12:01:05PM +0000, Jarkko Sakkinen wrote: > On Wed, Dec 14, 2022 at 01:39:53PM -0600, Michael Roth wrote: > > From: Nikunj A Dadhania > > > > Aligned end boundary causes a kvm crash, handle the case. > > > > Link: https://lore.kernel.org/kvm/20221202061347.1070246-8-chao.p.peng@linux.intel.com/ > > Chao, are you aware of this issue already? Thanks Jarkko adding me. I'm not aware of there is a fix. > > > Signed-off-by: Nikunj A Dadhania > > Signed-off-by: Michael Roth > > --- > > arch/x86/kvm/mmu/mmu.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > index b1953ebc012e..b3ffc61c668c 100644 > > --- a/arch/x86/kvm/mmu/mmu.c > > +++ b/arch/x86/kvm/mmu/mmu.c > > @@ -7159,6 +7159,9 @@ static void kvm_update_lpage_private_shared_mixed(struct kvm *kvm, > > for (gfn = first + pages; gfn < last; gfn += pages) > > linfo_set_mixed(gfn, slot, level, false); > > > > + if (gfn == last) > > + goto out; > > + Nikunj or Michael, could you help me understand in which case it causes a KVM crash? To me, even the end is aligned to huge page boundary, but: last = (end - 1) & mask; so 'last' is the base address for the last effective huage page. Even when gfn == last, it should still a valid page and needs to be updated for mem_attrs, correct? Thanks, Chao > > gfn = last; > > gfn_end = min(last + pages, slot->base_gfn + slot->npages); > > mixed = mem_attrs_mixed(kvm, slot, level, attrs, gfn, gfn_end); > > -- > > 2.25.1 > > > > > BR, Jarkko