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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6471CC433DB for ; Sat, 27 Mar 2021 00:20:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A15A61A10 for ; Sat, 27 Mar 2021 00:20:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231191AbhC0ATb (ORCPT ); Fri, 26 Mar 2021 20:19:31 -0400 Received: from mga03.intel.com ([134.134.136.65]:48252 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230299AbhC0AS5 (ORCPT ); Fri, 26 Mar 2021 20:18:57 -0400 IronPort-SDR: fXwo0yQhp1T9JE3RsciYIgc3Gz9ILaHSN3M+geh1gSWE/BgZZ29vuE/d0AU8oTT0+yDDnThFZu ViMDaI+e3WwQ== X-IronPort-AV: E=McAfee;i="6000,8403,9935"; a="191274076" X-IronPort-AV: E=Sophos;i="5.81,282,1610438400"; d="scan'208";a="191274076" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Mar 2021 17:18:56 -0700 IronPort-SDR: B87GfP4DtzqNdrNhYTI8yhd1qCp6G7jiybI53sCs37Wrmk2Tmy51Mll7Q5ZFYbJzZzT2qvPI7F TXXf4H3bMzzw== X-IronPort-AV: E=Sophos;i="5.81,282,1610438400"; d="scan'208";a="410128575" Received: from zcmahone-mobl1.amr.corp.intel.com (HELO skuppusw-mobl5.amr.corp.intel.com) ([10.255.231.203]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Mar 2021 17:18:55 -0700 From: Kuppuswamy Sathyanarayanan To: Peter Zijlstra , Andy Lutomirski , Dave Hansen Cc: Andi Kleen , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Dan Williams , Raj Ashok , Sean Christopherson , linux-kernel@vger.kernel.org, Kuppuswamy Sathyanarayanan Subject: [PATCH v1 1/1] x86/tdx: Handle MWAIT, MONITOR and WBINVD Date: Fri, 26 Mar 2021 17:18:22 -0700 Message-Id: <331b34e3d6153f0a7b0ab0a9a8cb5de71f0bfd93.1616803999.git.sathyanarayanan.kuppuswamy@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In non-root TDX guest mode, MWAIT, MONITOR and WBINVD instructions are not supported. So handle #VE due to these instructions as no ops. Signed-off-by: Kuppuswamy Sathyanarayanan Reviewed-by: Andi Kleen --- Changes since previous series: * Suppressed MWAIT feature as per Andi's comment. * Added warning debug log for MWAIT #VE exception. arch/x86/kernel/tdx.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c index e936b2f88bf6..fb7d22b846fc 100644 --- a/arch/x86/kernel/tdx.c +++ b/arch/x86/kernel/tdx.c @@ -308,6 +308,9 @@ void __init tdx_early_init(void) setup_force_cpu_cap(X86_FEATURE_TDX_GUEST); + /* MWAIT is not supported in TDX platform, so suppress it */ + setup_clear_cpu_cap(X86_FEATURE_MWAIT); + tdg_get_info(); pv_ops.irq.safe_halt = tdg_safe_halt; @@ -362,6 +365,26 @@ int tdg_handle_virtualization_exception(struct pt_regs *regs, case EXIT_REASON_EPT_VIOLATION: ve->instr_len = tdg_handle_mmio(regs, ve); break; + /* + * Per Guest-Host-Communication Interface (GHCI) for Intel Trust + * Domain Extensions (Intel TDX) specification, sec 2.4, + * some instructions that unconditionally cause #VE (such as WBINVD, + * MONITOR, MWAIT) do not have corresponding TDCALL + * [TDG.VP.VMCALL ] leaves, since the TD has been designed + * with no deterministic way to confirm the result of those operations + * performed by the host VMM. In those cases, the goal is for the TD + * #VE handler to increment the RIP appropriately based on the VE + * information provided via TDCALL. + */ + case EXIT_REASON_WBINVD: + pr_warn_once("WBINVD #VE Exception\n"); + case EXIT_REASON_MONITOR_INSTRUCTION: + /* Handle as nops. */ + break; + case EXIT_REASON_MWAIT_INSTRUCTION: + /* MWAIT is supressed, not supposed to reach here. */ + pr_warn("MWAIT unexpected #VE Exception\n"); + return -EFAULT; default: pr_warn("Unexpected #VE: %d\n", ve->exit_reason); return -EFAULT; -- 2.25.1