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 99A3FC433FE for ; Mon, 21 Nov 2022 00:31:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229836AbiKUAbO (ORCPT ); Sun, 20 Nov 2022 19:31:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229934AbiKUAa2 (ORCPT ); Sun, 20 Nov 2022 19:30:28 -0500 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F3F035E9F5; Sun, 20 Nov 2022 16:28:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668990537; x=1700526537; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=3LwZ/2jAQ0M9UrYz1pvBJwdZZg6HBZnO8RRBVvS9No4=; b=MEWNWzv7JAUBF48uSWNG2sSZ3wzkfCIr540XtHyg5JHJDcgYWp9O7RDR q9Jgh7t58bqjgrnVtkf9e1wOyU7CetgPLG3bso9IjTH/IeVBgksl8dzmp Cfb72x7Uu1ZNlmR2gsG48uFzMhfg4sRyYbbrrLP2RL4NfGbD7IO2v+2de zw2j9eD0kB4hi0MmD1o4LlF1L1iX2k5/UFLYUo6yVPMnW62uzdpOPanhq u4xy1gYyVEPhb/wgPxHXVI5UGQmDQYdfL68E7z7MOn4ZLax52oTjf1d0V K7vWjSTaguOAgf/OmifHTjidF0Za9wU9r1eKCB7VOAYwfnObwLHxmjrys Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10537"; a="377705762" X-IronPort-AV: E=Sophos;i="5.96,180,1665471600"; d="scan'208";a="377705762" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Nov 2022 16:28:13 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10537"; a="729825550" X-IronPort-AV: E=Sophos;i="5.96,180,1665471600"; d="scan'208";a="729825550" Received: from tomnavar-mobl.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.209.176.15]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Nov 2022 16:28:09 -0800 From: Kai Huang To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: linux-mm@kvack.org, seanjc@google.com, pbonzini@redhat.com, dave.hansen@intel.com, dan.j.williams@intel.com, rafael.j.wysocki@intel.com, kirill.shutemov@linux.intel.com, ying.huang@intel.com, reinette.chatre@intel.com, len.brown@intel.com, tony.luck@intel.com, peterz@infradead.org, ak@linux.intel.com, isaku.yamahata@intel.com, chao.gao@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, bagasdotme@gmail.com, sagis@google.com, imammedo@redhat.com, kai.huang@intel.com Subject: [PATCH v7 18/20] x86/virt/tdx: Initialize all TDMRs Date: Mon, 21 Nov 2022 13:26:40 +1300 Message-Id: <2337c8e9086a006aaa2c4b99caf478420d1fc640.1668988357.git.kai.huang@intel.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Initialize TDMRs via TDH.SYS.TDMR.INIT as the last step to complete the TDX initialization. All TDMRs need to be initialized using TDH.SYS.TDMR.INIT SEAMCALL before the memory pages can be used by the TDX module. The time to initialize TDMR is proportional to the size of the TDMR because TDH.SYS.TDMR.INIT internally initializes the PAMT entries using the global KeyID. To avoid long latency caused in one SEAMCALL, TDH.SYS.TDMR.INIT only initializes an (implementation-specific) subset of PAMT entries of one TDMR in one invocation. The caller needs to call TDH.SYS.TDMR.INIT iteratively until all PAMT entries of the given TDMR are initialized. TDH.SYS.TDMR.INITs can run concurrently on multiple CPUs as long as they are initializing different TDMRs. To keep it simple, just initialize all TDMRs one by one. On a 2-socket machine with 2.2G CPUs and 64GB memory, each TDH.SYS.TDMR.INIT roughly takes couple of microseconds on average, and it takes roughly dozens of milliseconds to complete the initialization of all TDMRs while system is idle. Reviewed-by: Isaku Yamahata Signed-off-by: Kai Huang --- v6 -> v7: - Removed need_resched() check. -- Andi. --- arch/x86/virt/vmx/tdx/tdx.c | 69 ++++++++++++++++++++++++++++++++++--- arch/x86/virt/vmx/tdx/tdx.h | 1 + 2 files changed, 65 insertions(+), 5 deletions(-) diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index 99d1be5941a7..9bcdb30b7a80 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -1066,6 +1066,65 @@ static int config_global_keyid(void) return seamcall_on_each_package_serialized(&sc); } +/* Initialize one TDMR */ +static int init_tdmr(struct tdmr_info *tdmr) +{ + u64 next; + + /* + * Initializing PAMT entries might be time-consuming (in + * proportion to the size of the requested TDMR). To avoid long + * latency in one SEAMCALL, TDH.SYS.TDMR.INIT only initializes + * an (implementation-defined) subset of PAMT entries in one + * invocation. + * + * Call TDH.SYS.TDMR.INIT iteratively until all PAMT entries + * of the requested TDMR are initialized (if next-to-initialize + * address matches the end address of the TDMR). + */ + do { + struct tdx_module_output out; + int ret; + + ret = seamcall(TDH_SYS_TDMR_INIT, tdmr->base, 0, 0, 0, NULL, + &out); + if (ret) + return ret; + /* + * RDX contains 'next-to-initialize' address if + * TDH.SYS.TDMR.INT succeeded. + */ + next = out.rdx; + /* Allow scheduling when needed */ + cond_resched(); + } while (next < tdmr->base + tdmr->size); + + return 0; +} + +/* Initialize all TDMRs */ +static int init_tdmrs(struct tdmr_info *tdmr_array, int tdmr_num) +{ + int i; + + /* + * Initialize TDMRs one-by-one for simplicity, though the TDX + * architecture does allow different TDMRs to be initialized in + * parallel on multiple CPUs. Parallel initialization could + * be added later when the time spent in the serialized scheme + * becomes a real concern. + */ + for (i = 0; i < tdmr_num; i++) { + int ret; + + ret = init_tdmr(tdmr_array_entry(tdmr_array, i)); + if (ret) + return ret; + } + + return 0; +} + /* * Detect and initialize the TDX module. * @@ -1172,11 +1231,11 @@ static int init_tdx_module(void) if (ret) goto out_free_pamts; - /* - * Return -EINVAL until all steps of TDX module initialization - * process are done. - */ - ret = -EINVAL; + /* Initialize TDMRs to complete the TDX module initialization */ + ret = init_tdmrs(tdmr_array, tdmr_num); + if (ret) + goto out_free_pamts; + out_free_pamts: if (ret) { /* diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h index 768d097412ab..891691b1ea50 100644 --- a/arch/x86/virt/vmx/tdx/tdx.h +++ b/arch/x86/virt/vmx/tdx/tdx.h @@ -19,6 +19,7 @@ #define TDH_SYS_INFO 32 #define TDH_SYS_INIT 33 #define TDH_SYS_LP_INIT 35 +#define TDH_SYS_TDMR_INIT 36 #define TDH_SYS_LP_SHUTDOWN 44 #define TDH_SYS_CONFIG 45 -- 2.38.1