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 8DA9CC4743D for ; Tue, 8 Jun 2021 15:40:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7713861263 for ; Tue, 8 Jun 2021 15:40:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231947AbhFHPmd (ORCPT ); Tue, 8 Jun 2021 11:42:33 -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 S230460AbhFHPm2 (ORCPT ); Tue, 8 Jun 2021 11:42:28 -0400 IronPort-SDR: z6a/4M3uS3E648rmqolDWt4nCnOcuNmlNoizf/6MhpRswAoljn4hRjRbki17CcrLVfDCi+JZof BjelkoVfZJGw== X-IronPort-AV: E=McAfee;i="6200,9189,10009"; a="201849038" X-IronPort-AV: E=Sophos;i="5.83,258,1616482800"; d="scan'208";a="201849038" 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 08:40:30 -0700 IronPort-SDR: +GYRRZHink+JcLfuUobGYig3Syc9MAfdEbXVAH7BZvhhyjLQaoq8cRNiEH50I9nG4yikPkvJ5l ILOztZsQDImw== X-IronPort-AV: E=Sophos;i="5.83,258,1616482800"; d="scan'208";a="552314843" 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 08:40:30 -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 1/3] x86/tdx: Handle port I/O in decompression code Date: Tue, 8 Jun 2021 08:40:21 -0700 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add support to replace in/out instructions in decompression code with TDX IO hypercalls. TDX cannot do port IO directly. The TDX module triggers a #VE exception to let the guest kernel to emulate port I/O, by converting them into TDX hypercalls to call the host. But for the really early code in the decompressor, #VE cannot be used because the IDT needed for handling the exception is not set-up, and some other infrastructure needed by the handler is missing. So to support port IO in decompressor code, directly replace in/out instructions with TDX IO hypercalls. This can beeasily achieved by modifying __in/__out macros. Also, since TDX IO hypercall requires an IO size parameter, modify __in/__out macros to accept size as input parameter. Signed-off-by: Kuppuswamy Sathyanarayanan --- arch/x86/boot/compressed/Makefile | 1 + arch/x86/boot/compressed/tdcall.S | 3 ++ arch/x86/include/asm/io.h | 9 +++--- arch/x86/include/asm/tdx.h | 48 +++++++++++++++++++++++++++++++ 4 files changed, 57 insertions(+), 4 deletions(-) create mode 100644 arch/x86/boot/compressed/tdcall.S diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 22a2a6cc2ab4..1bfe30ebadbe 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -99,6 +99,7 @@ endif vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o +vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdcall.o vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a diff --git a/arch/x86/boot/compressed/tdcall.S b/arch/x86/boot/compressed/tdcall.S new file mode 100644 index 000000000000..aafadc136c88 --- /dev/null +++ b/arch/x86/boot/compressed/tdcall.S @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include "../../kernel/tdcall.S" diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index be96bf1e667a..391205dace98 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 @@ -272,25 +273,25 @@ static inline bool sev_key_active(void) { return false; } #endif /* CONFIG_AMD_MEM_ENCRYPT */ #ifndef __out -#define __out(bwl, bw) \ +#define __out(bwl, bw, sz) \ asm volatile("out" #bwl " %" #bw "0, %w1" : : "a"(value), "Nd"(port)) #endif #ifndef __in -#define __in(bwl, bw) \ +#define __in(bwl, bw, sz) \ asm volatile("in" #bwl " %w1, %" #bw "0" : "=a"(value) : "Nd"(port)) #endif #define BUILDIO(bwl, bw, type) \ static inline void out##bwl(unsigned type value, int port) \ { \ - __out(bwl, bw); \ + __out(bwl, bw, sizeof(type)); \ } \ \ static inline unsigned type in##bwl(int port) \ { \ unsigned type value; \ - __in(bwl, bw); \ + __in(bwl, bw, sizeof(type)); \ return value; \ } \ \ diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h index cbfe7479f2a3..ac38ed5b50db 100644 --- a/arch/x86/include/asm/tdx.h +++ b/arch/x86/include/asm/tdx.h @@ -9,6 +9,8 @@ #include #include +#include +#include /* * Used in __tdx_module_call() helper function to gather the @@ -73,6 +75,52 @@ u64 __tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15, bool tdx_protected_guest_has(unsigned long flag); +/* + * To support I/O port access in decompressor or early kernel init + * code, since #VE exception handler cannot be used, use paravirt + * model to implement __in/__out macros which will in turn be used + * by in{b,w,l}()/out{b,w,l} I/O helper macros used in kernel. You + * can find the __in/__out macro usage in arch/x86/include/asm/io.h + */ +#ifdef BOOT_COMPRESSED_MISC_H + +/* + * Helper function used for making hypercall for "in" + * instruction. It will be called from __in IO macro + * If IO is failed, it will return all 1s. + */ +static inline unsigned int tdg_in(int size, int port) +{ + struct tdx_hypercall_output out = {0}; + int err; + + err = __tdx_hypercall(EXIT_REASON_IO_INSTRUCTION, size, 0, + port, 0, &out); + + return err ? UINT_MAX : out.r11; +} + +#define __out(bwl, bw, sz) \ +do { \ + if (is_tdx_guest()) { \ + __tdx_hypercall(EXIT_REASON_IO_INSTRUCTION, sz, 1, \ + port, value, NULL); \ + } else { \ + asm volatile("out" #bwl " %" #bw "0, %w1" : : \ + "a"(value), "Nd"(port)); \ + } \ +} while (0) +#define __in(bwl, bw, sz) \ +do { \ + if (is_tdx_guest()) { \ + value = tdg_in(sz, port); \ + } else { \ + asm volatile("in" #bwl " %w1, %" #bw "0" : \ + "=a"(value) : "Nd"(port)); \ + } \ +} while (0) +#endif + #else // !CONFIG_INTEL_TDX_GUEST static inline bool is_tdx_guest(void) -- 2.25.1