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 C6A0DC32774 for ; Mon, 22 Aug 2022 22:31:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238207AbiHVWb3 (ORCPT ); Mon, 22 Aug 2022 18:31:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232069AbiHVWbY (ORCPT ); Mon, 22 Aug 2022 18:31:24 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51AF150733 for ; Mon, 22 Aug 2022 15:31:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1661207482; x=1692743482; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=gwgkmAh1m4dxY9h21mXik/a1rHa0oTuFFeRyk4XA4BM=; b=aSk/fiDPRheOdZYsfg6l38MhMV3XBDjK+poDbrNqW6ft8fsCEr68Hf+f 4Gt41zUJvlA8427o1AZOlnnlrTCfEpTX7sJBH3Vyy4T9A9hlamXounsNu Yjcv+Lfe61AHqRCqgoxltF41i5UuaIpTBByS1YW+k5NV/EV2KpHwHFfZb zCZB5ya32/IWl/vjLXeM6B48HWUBpJDb8W91JsLO6kjxKUs6GFqyxE9D4 RqlFBA6Ngud15/42dFle29cZ7rBpuPwswFemCMIdt5+sE49qa/TpuHMuE n//ZEjDVyzUpZLSejyWKN9bHDrcbHe0nJpgTPUbcISAXVB+AEW48nenTj A==; X-IronPort-AV: E=McAfee;i="6500,9779,10447"; a="355266571" X-IronPort-AV: E=Sophos;i="5.93,255,1654585200"; d="scan'208";a="355266571" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Aug 2022 15:31:21 -0700 X-IronPort-AV: E=Sophos;i="5.93,255,1654585200"; d="scan'208";a="751455019" Received: from jcsarker-mobl.amr.corp.intel.com (HELO [10.212.204.203]) ([10.212.204.203]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Aug 2022 15:31:21 -0700 Message-ID: <09bccb93-2c0e-4962-0c46-c84c22fa140d@intel.com> Date: Mon, 22 Aug 2022 15:31:20 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH 2/2] iommu: Use the user PGD for SVA if PTI is enabled Content-Language: en-US To: Jacob Pan , LKML , iommu@lists.linux.dev, x86@kernel.org, Joerg Roedel , Lu Baolu Cc: Raj Ashok , Thomas Gleixner , Borislav Petkov , Ingo Molnar , "Tian, Kevin" , Yi Liu References: <20220822201213.352289-1-jacob.jun.pan@linux.intel.com> <20220822201213.352289-3-jacob.jun.pan@linux.intel.com> From: Dave Hansen In-Reply-To: <20220822201213.352289-3-jacob.jun.pan@linux.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/22/22 13:12, Jacob Pan wrote: > @@ -394,7 +395,9 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, > sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ? > PASID_FLAG_SUPERVISOR_MODE : 0; > sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0; > - ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm->pasid, > + > + pgd = static_cpu_has(X86_FEATURE_PTI) ? kernel_to_user_pgdp(mm->pgd) : mm->pgd; > + ret = intel_pasid_setup_first_level(iommu, dev, pgd, mm->pasid, > FLPT_DEFAULT_DID, sflags); This X86_FEATURE_PTI should really be done within a helper. I'd probably do this with a *new* helper since all of the existing kernel_to_user_pgdp() users seem to be within a PTI #ifdef. Maybe something like: pgd_t *mm_user_pgd(struct mm_struct *mm) { #ifdef CONFIG_PAGE_TABLE_ISOLATION if (cpu_feature_enabled(X86_FEATURE_PTI)) return kernel_to_user_pgdp(mm->pgd); #endif return mm->pgd; } That #ifdef could even go away if your kernel_to_user_pgdp() stub from patch 1/2 was available. I'm not sure it's worth it though.