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 0E584C001DE for ; Fri, 11 Aug 2023 14:09:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234343AbjHKOJo (ORCPT ); Fri, 11 Aug 2023 10:09:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229683AbjHKOJn (ORCPT ); Fri, 11 Aug 2023 10:09:43 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C00F5EA; Fri, 11 Aug 2023 07:09:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1691762982; x=1723298982; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=gcX2U+aKm/ntgbNmPwXB5cQkjSeRqXXyRXtp93z+H2c=; b=M4rj8asZGG+XS2AHSjtCEkl8DReiHfnjRgSly5eyKptanJqf+IggpNxz Hhw0UOmM6s1hweWZ0bP96F8jSVxlI1NwRgVqGaarJQ+fD4lp19iUliCQU Rqd9CAfOmnBjq26uRaOBLl0PTSY+pPc7e2gSmyvT/OBbYs/1DpEIH9w+8 8CoAD4sT4t62MgVW8823vmthNYn9SJna+dJShKKWSB/jnwVGktfUBZCI6 iZW3iiE7YegggoKfLaSDBBsfhw7wiUN+ceHEUDclzgLZ4IUjAO/tLk20g YD40VqFKVTw1u/PNczG2Doo+H2ZJuI3TrwaCP0p6i8jYK3O2nNFNRYW4l w==; X-IronPort-AV: E=McAfee;i="6600,9927,10799"; a="351285707" X-IronPort-AV: E=Sophos;i="6.01,165,1684825200"; d="scan'208";a="351285707" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Aug 2023 07:09:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10799"; a="762207995" X-IronPort-AV: E=Sophos;i="6.01,165,1684825200"; d="scan'208";a="762207995" Received: from swetabs-mobl2.amr.corp.intel.com (HELO [10.212.220.8]) ([10.212.220.8]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Aug 2023 07:09:41 -0700 Message-ID: <69b46bf3-40ab-c379-03d5-efd537ed44c7@intel.com> Date: Fri, 11 Aug 2023 07:09:40 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH RESEND v9 2/2] x86/tdx: Support vmalloc() for tdx_enc_status_changed() Content-Language: en-US To: Dexuan Cui , x86@kernel.org, ak@linux.intel.com, arnd@arndb.de, bp@alien8.de, brijesh.singh@amd.com, dan.j.williams@intel.com, dave.hansen@linux.intel.com, haiyangz@microsoft.com, hpa@zytor.com, jane.chu@oracle.com, kirill.shutemov@linux.intel.com, kys@microsoft.com, luto@kernel.org, mingo@redhat.com, peterz@infradead.org, rostedt@goodmis.org, sathyanarayanan.kuppuswamy@linux.intel.com, seanjc@google.com, tglx@linutronix.de, tony.luck@intel.com, wei.liu@kernel.org, Jason@zx2c4.com, nik.borisov@suse.com, mikelley@microsoft.com Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, Tianyu.Lan@microsoft.com, rick.p.edgecombe@intel.com, andavis@redhat.com, mheslin@redhat.com, vkuznets@redhat.com, xiaoyao.li@intel.com References: <20230811021246.821-1-decui@microsoft.com> <20230811021246.821-3-decui@microsoft.com> From: Dave Hansen In-Reply-To: <20230811021246.821-3-decui@microsoft.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 8/10/23 19:12, Dexuan Cui wrote: > + if (!is_vmalloc_addr((void *)start)) > + return tdx_enc_status_changed_phys(__pa(start), __pa(end), enc); > + > + while (start < end) { > + phys_addr_t start_pa = slow_virt_to_phys((void *)start); > + phys_addr_t end_pa = start_pa + PAGE_SIZE; > + > + if (!tdx_enc_status_changed_phys(start_pa, end_pa, enc)) > + return false; > + > + start += PAGE_SIZE; > + } This creates two different paths for vmalloc() and the direct map. There are two different ways to do va=>pa conversion, for instance. Here's a single loop that works for both cases: unsigned long step = end - start; unsigned long addr; /* Step through page-by-page for vmalloc() mappings: */ if (is_vmalloc_addr((void *)vaddr)) step = PAGE_SIZE; for (addr = start; addr < end; addr += step) { phys_addr_t start_pa = slow_virt_to_phys(addr); phys_addr_t end_pa = start_pa + step; if (!tdx_enc_status_changed_phys(start_pa, end_pa, enc)) return false; } Note that this also doesn't abuse 'start' by making it a loop variable. It also, uh, uses a for() loop. The only downside is that it costs a page table walk for direct map virt=>phys conversion. I can live with that.