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 58015C47082 for ; Tue, 8 Jun 2021 15:40:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 39F1361263 for ; Tue, 8 Jun 2021 15:40:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232153AbhFHPmi (ORCPT ); Tue, 8 Jun 2021 11:42:38 -0400 Received: from mga11.intel.com ([192.55.52.93]:7767 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231842AbhFHPmc (ORCPT ); Tue, 8 Jun 2021 11:42:32 -0400 IronPort-SDR: f4Xb2iTbYEyD86EXa9N9wdRhiq9Polnfp9+e5AhWRqpxgXnY8+2rTQRg9Z5vG0O/VevBPx0f68 krIev1oHwOyw== X-IronPort-AV: E=McAfee;i="6200,9189,10009"; a="201849045" X-IronPort-AV: E=Sophos;i="5.83,258,1616482800"; d="scan'208";a="201849045" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2021 08:40:31 -0700 IronPort-SDR: jDvZnNXmv7ZMEwvDTvkHrWl1QyyKdNEA3gnGhH1PDQ/+1yBzxlSkZwCLnze7JIhc7H/jHpmwiy rdqhmuD5DNXA== X-IronPort-AV: E=Sophos;i="5.83,258,1616482800"; d="scan'208";a="552314854" Received: from ticela-az-103.amr.corp.intel.com (HELO skuppusw-desk1.amr.corp.intel.com) ([10.254.36.77]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2021 08:40:31 -0700 From: Kuppuswamy Sathyanarayanan To: Peter Zijlstra , Andy Lutomirski , Dave Hansen , Tony Luck , Dan Williams Cc: Andi Kleen , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Raj Ashok , Sean Christopherson , linux-kernel@vger.kernel.org, Kuppuswamy Sathyanarayanan Subject: [RFC v2-fix-v2 3/3] x86/tdx: Handle port I/O Date: Tue, 8 Jun 2021 08:40:23 -0700 Message-Id: <369a29afba9bb561afa1b77e113a9dae4921fe53.1623165571.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 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 --- Changes since RFC v2-fix-v1: * Fixed commit log to adapt to decompression support code split. arch/x86/include/asm/io.h | 6 ++++-- arch/x86/kernel/tdx.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 391205dace98..e01d8bf2b37a 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -310,7 +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() || \ + protected_guest_has(VM_UNROLL_STRING_IO)) { \ unsigned type *value = (unsigned type *)addr; \ while (count) { \ out##bwl(*value, port); \ @@ -326,7 +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() || \ + protected_guest_has(VM_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 3410cfc8a988..48a0cc2663ea 100644 --- a/arch/x86/kernel/tdx.c +++ b/arch/x86/kernel/tdx.c @@ -201,6 +201,31 @@ static void tdg_handle_cpuid(struct pt_regs *regs) regs->dx = out.r15; } +/* + * Since the way we fail for string case is different we cannot + * reuse tdx_handle_early_io(). + */ +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; @@ -247,6 +272,9 @@ 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