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=-16.7 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 E5BDDC07E95 for ; Tue, 20 Jul 2021 03:53:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C29AC60041 for ; Tue, 20 Jul 2021 03:53:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348416AbhGTDMu (ORCPT ); Mon, 19 Jul 2021 23:12:50 -0400 Received: from mga03.intel.com ([134.134.136.65]:24180 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348361AbhGTDJg (ORCPT ); Mon, 19 Jul 2021 23:09:36 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10050"; a="211229339" X-IronPort-AV: E=Sophos;i="5.84,254,1620716400"; d="scan'208";a="211229339" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2021 20:49:26 -0700 X-IronPort-AV: E=Sophos;i="5.84,254,1620716400"; d="scan'208";a="661006641" Received: from ywei11-mobl1.amr.corp.intel.com (HELO skuppusw-desk1.amr.corp.intel.com) ([10.251.138.31]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2021 20:49:26 -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 , Sean Christopherson , Kuppuswamy Sathyanarayanan , x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 05/10] x86/tdx: Handle port I/O Date: Mon, 19 Jul 2021 20:48:56 -0700 Message-Id: <20210720034901.2120205-6-sathyanarayanan.kuppuswamy@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210720034901.2120205-1-sathyanarayanan.kuppuswamy@linux.intel.com> References: <20210720034901.2120205-1-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" TDX hypervisors cannot emulate instructions directly. This includes port IO which is normally emulated in the hypervisor. All port IO instructions inside TDX trigger the #VE exception in the guest and would be normally emulated there. Also string I/O is not supported in TDX guest. So, unroll the string I/O operation into a loop operating on one element at a time. This method is similar to AMD SEV, so just extend the support for TDX guest platform. Co-developed-by: Kuppuswamy Sathyanarayanan Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Kirill A. Shutemov Reviewed-by: Andi Kleen Reviewed-by: Dan Williams --- Changes since v2: * None Changes since v1: * Fixed comments for tdg_handle_io(). * Used _tdx_hypercall() instead of __tdx_hypercall() in tdg_handle_io(). arch/x86/include/asm/io.h | 7 +++++-- arch/x86/kernel/tdx.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 50f9eb17d364..b677f81168a0 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -40,6 +40,7 @@ #include #include +#include #include #include #include @@ -309,7 +310,8 @@ static inline unsigned type in##bwl##_p(int port) \ \ static inline void outs##bwl(int port, const void *addr, unsigned long count) \ { \ - if (sev_key_active()) { \ + if (sev_key_active() || \ + prot_guest_has(PR_GUEST_UNROLL_STRING_IO)) { \ unsigned type *value = (unsigned type *)addr; \ while (count) { \ out##bwl(*value, port); \ @@ -325,7 +327,8 @@ static inline void outs##bwl(int port, const void *addr, unsigned long count) \ \ static inline void ins##bwl(int port, void *addr, unsigned long count) \ { \ - if (sev_key_active()) { \ + if (sev_key_active() || \ + prot_guest_has(PR_GUEST_UNROLL_STRING_IO)) { \ unsigned type *value = (unsigned type *)addr; \ while (count) { \ *value = in##bwl(port); \ diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c index 549d10d1f27d..2bd596be70fd 100644 --- a/arch/x86/kernel/tdx.c +++ b/arch/x86/kernel/tdx.c @@ -177,6 +177,34 @@ static void tdg_handle_cpuid(struct pt_regs *regs) regs->dx = out.r15; } +/* + * tdx_handle_early_io() cannot be re-used in #VE handler for handling + * I/O because the way of handling string I/O is different between + * normal and early I/O case. Also, once trace support is enabled, + * tdg_handle_io() will be extended to use trace calls which is also + * not valid for early I/O cases. + */ +static void tdg_handle_io(struct pt_regs *regs, u32 exit_qual) +{ + struct tdx_hypercall_output outh; + int out = VE_IS_IO_OUT(exit_qual); + int size = VE_GET_IO_SIZE(exit_qual); + int port = VE_GET_PORT_NUM(exit_qual); + u64 mask = GENMASK(8 * size, 0); + bool string = VE_IS_IO_STRING(exit_qual); + int ret; + + /* I/O strings ops are unrolled at build time. */ + BUG_ON(string); + + ret = _tdx_hypercall(EXIT_REASON_IO_INSTRUCTION, size, out, port, + regs->ax, &outh); + if (!out) { + regs->ax &= ~mask; + regs->ax |= (ret ? UINT_MAX : outh.r11) & mask; + } +} + unsigned long tdg_get_ve_info(struct ve_info *ve) { u64 ret; @@ -223,6 +251,9 @@ int tdg_handle_virtualization_exception(struct pt_regs *regs, case EXIT_REASON_CPUID: tdg_handle_cpuid(regs); break; + case EXIT_REASON_IO_INSTRUCTION: + tdg_handle_io(regs, ve->exit_qual); + break; default: pr_warn("Unexpected #VE: %lld\n", ve->exit_reason); return -EFAULT; -- 2.25.1