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 BAD52C47080 for ; Wed, 2 Jun 2021 02:22:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1012613BE for ; Wed, 2 Jun 2021 02:22:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230475AbhFBCXv (ORCPT ); Tue, 1 Jun 2021 22:23:51 -0400 Received: from mga07.intel.com ([134.134.136.100]:26376 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230311AbhFBCXd (ORCPT ); Tue, 1 Jun 2021 22:23:33 -0400 IronPort-SDR: TUq1LvvOgFN2PrVKu06JeKo5W9D8Owusi+utdwjSF0Te9PYyy4nNRi4dOm81iqwTGTcRtvTl5+ d22zAj+pJT+w== X-IronPort-AV: E=McAfee;i="6200,9189,10002"; a="267560434" X-IronPort-AV: E=Sophos;i="5.83,241,1616482800"; d="scan'208";a="267560434" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2021 19:21:50 -0700 IronPort-SDR: wVYhzber/HAjpBqX0tvlGfcslu7E+4JI5ohQ55hzStysAvdvZNOz6DUS2Ln8JiB0Qzm3n0Q6Ao zOoSUZw3EKIw== X-IronPort-AV: E=Sophos;i="5.83,241,1616482800"; d="scan'208";a="633069227" Received: from mjdelaro-mobl.amr.corp.intel.com (HELO skuppusw-desk1.amr.corp.intel.com) ([10.254.3.23]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2021 19:21:49 -0700 From: Kuppuswamy Sathyanarayanan To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Peter Zijlstra , Andy Lutomirski Cc: Peter H Anvin , Dave Hansen , Tony Luck , Dan Williams , Andi Kleen , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Sean Christopherson , Kuppuswamy Sathyanarayanan , linux-kernel@vger.kernel.org, x86@kernel.org Subject: [PATCH v1 08/11] x86/tdx: Add HLT support for TDX guest Date: Tue, 1 Jun 2021 19:21:33 -0700 Message-Id: <20210602022136.2186759-9-sathyanarayanan.kuppuswamy@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210602022136.2186759-1-sathyanarayanan.kuppuswamy@linux.intel.com> References: <20210602022136.2186759-1-sathyanarayanan.kuppuswamy@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Kirill A. Shutemov" Per Guest-Host-Communication Interface (GHCI) for Intel Trust Domain Extensions (Intel TDX) specification, sec 3.8, TDVMCALL[Instruction.HLT] provides HLT operation. Use it to implement halt() and safe_halt() paravirtualization calls. The same TDX hypercall is used to handle #VE exception due to EXIT_REASON_HLT. Signed-off-by: Kirill A. Shutemov Reviewed-by: Andi Kleen Reviewed-by: Tony Luck Signed-off-by: Kuppuswamy Sathyanarayanan --- arch/x86/kernel/tdx.c | 50 +++++++++++++++++++++++++++++++++++++------ 1 file changed, 43 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c index 527d2638ddae..76b71bf56b81 100644 --- a/arch/x86/kernel/tdx.c +++ b/arch/x86/kernel/tdx.c @@ -88,6 +88,33 @@ static void tdg_get_info(void) td_info.attributes = out.rdx; } +static __cpuidle void tdg_halt(void) +{ + u64 ret; + + ret = __tdx_hypercall(EXIT_REASON_HLT, irqs_disabled(), 0, 0, 0, NULL); + + /* It should never fail */ + BUG_ON(ret); +} + +static __cpuidle void tdg_safe_halt(void) +{ + u64 ret; + + /* + * Enable interrupts next to the TDVMCALL to avoid + * performance degradation. + */ + local_irq_enable(); + + /* IRQ is enabled, So set R12 as 0 */ + ret = __tdx_hypercall(EXIT_REASON_HLT, 0, 0, 0, 0, NULL); + + /* It should never fail */ + BUG_ON(ret); +} + unsigned long tdg_get_ve_info(struct ve_info *ve) { u64 ret; @@ -114,13 +141,19 @@ unsigned long tdg_get_ve_info(struct ve_info *ve) int tdg_handle_virtualization_exception(struct pt_regs *regs, struct ve_info *ve) { - /* - * TODO: Add handler support for various #VE exit - * reasons. It will be added by other patches in - * the series. - */ - pr_warn("Unexpected #VE: %lld\n", ve->exit_reason); - return -EFAULT; + switch (ve->exit_reason) { + case EXIT_REASON_HLT: + tdg_halt(); + break; + default: + pr_warn("Unexpected #VE: %lld\n", ve->exit_reason); + return -EFAULT; + } + + /* After successful #VE handling, move the IP */ + regs->ip += ve->instr_len; + + return 0; } void __init tdx_early_init(void) @@ -132,5 +165,8 @@ void __init tdx_early_init(void) tdg_get_info(); + pv_ops.irq.safe_halt = tdg_safe_halt; + pv_ops.irq.halt = tdg_halt; + pr_info("TDX guest is initialized\n"); } -- 2.25.1