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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 167A4C433F5 for ; Fri, 18 Mar 2022 15:33:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238262AbiCRPeu (ORCPT ); Fri, 18 Mar 2022 11:34:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238147AbiCRPcw (ORCPT ); Fri, 18 Mar 2022 11:32:52 -0400 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E5E81B694F for ; Fri, 18 Mar 2022 08:31:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647617466; x=1679153466; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=GPsonxD2SH/VQBEfitQ+ooyvb6UrqdA98KPm1ddBE5M=; b=Lxx20Sm2WDXNnX+1F4DCXwbi8XIcB5kXIdXcX9ZhmPw4V8YPG/AuepMC xyRNKJRR0386Ab5QfdnCNrQMNB9KimbWCmsD9LCMXmFqLBVvAUQlI5NLe Maof7eAPncXfgaglVaOHFHDblDohWCQ1mbHOrq5PgpMCzxFGdZ20wcCPs gJ2QFBIu35+3EimSbLyDdjWTW4MHE/ibJGV87PvnFfdwknPK0TGfYF51W JS625+/TDRdEd6xNLZHEOER3mqs6LBquMW6kvNpzsWp8gnbzV3Q/30byg nOHJ5YWlFTmF3ZB+PTBLMVJldsS+Mr+BEeVNlcg8m0O1xOHLnCr1We5eI A==; X-IronPort-AV: E=McAfee;i="6200,9189,10290"; a="257344036" X-IronPort-AV: E=Sophos;i="5.90,192,1643702400"; d="scan'208";a="257344036" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2022 08:30:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,192,1643702400"; d="scan'208";a="784269845" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga006.fm.intel.com with ESMTP; 18 Mar 2022 08:30:44 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 73E5876F; Fri, 18 Mar 2022 17:30:50 +0200 (EET) From: "Kirill A. Shutemov" To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@intel.com, luto@kernel.org, peterz@infradead.org Cc: sathyanarayanan.kuppuswamy@linux.intel.com, aarcange@redhat.com, ak@linux.intel.com, dan.j.williams@intel.com, david@redhat.com, hpa@zytor.com, jgross@suse.com, jmattson@google.com, joro@8bytes.org, jpoimboe@redhat.com, knsathya@kernel.org, pbonzini@redhat.com, sdeep@vmware.com, seanjc@google.com, tony.luck@intel.com, vkuznets@redhat.com, wanpengli@tencent.com, thomas.lendacky@amd.com, brijesh.singh@amd.com, x86@kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Dave Hansen Subject: [PATCHv7 15/30] x86/boot: Port I/O: allow to hook up alternative helpers Date: Fri, 18 Mar 2022 18:30:33 +0300 Message-Id: <20220318153048.51177-16-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220318153048.51177-1-kirill.shutemov@linux.intel.com> References: <20220318153048.51177-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Port I/O instructions trigger #VE in the TDX environment. In response to the exception, kernel emulates these instructions using hypercalls. But during early boot, on the decompression stage, it is cumbersome to deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE handling. Add a way to hook up alternative port I/O helpers in the boot stub with a new pio_ops structure. For now, set the ops structure to just call the normal I/O operation functions. out*()/in*() macros redefined to use pio_ops callbacks. It eliminates need in changing call sites. io_delay() changed to use port I/O helper instead of inline assembly. Signed-off-by: Kirill A. Shutemov Reviewed-by: Dave Hansen --- arch/x86/boot/boot.h | 4 ++-- arch/x86/boot/compressed/misc.c | 4 ++++ arch/x86/boot/compressed/misc.h | 2 +- arch/x86/boot/io.h | 41 +++++++++++++++++++++++++++++++++ arch/x86/boot/main.c | 4 ++++ arch/x86/realmode/rm/wakemain.c | 4 ++++ 6 files changed, 56 insertions(+), 3 deletions(-) create mode 100644 arch/x86/boot/io.h diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h index 22a474c5b3e8..b42b91606ca8 100644 --- a/arch/x86/boot/boot.h +++ b/arch/x86/boot/boot.h @@ -23,10 +23,10 @@ #include #include #include -#include #include "bitops.h" #include "ctype.h" #include "cpuflags.h" +#include "io.h" /* Useful macros */ #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x))) @@ -39,7 +39,7 @@ extern struct boot_params boot_params; static inline void io_delay(void) { const u16 DELAY_PORT = 0x80; - asm volatile("outb %%al,%0" : : "dN" (DELAY_PORT)); + outb(0, DELAY_PORT); } /* These functions are used to reference data in other segments. */ diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 2b1169869b96..9fdef6af20a1 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -47,6 +47,8 @@ void *memmove(void *dest, const void *src, size_t n); */ struct boot_params *boot_params; +struct port_io_ops pio_ops; + memptr free_mem_ptr; memptr free_mem_end_ptr; @@ -370,6 +372,8 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, lines = boot_params->screen_info.orig_video_lines; cols = boot_params->screen_info.orig_video_cols; + init_default_io_ops(); + /* * Detect TDX guest environment. * diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 8a253e85f990..ea71cf3d64e1 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -26,7 +26,6 @@ #include #include #include -#include #include "tdx.h" @@ -35,6 +34,7 @@ #define BOOT_BOOT_H #include "../ctype.h" +#include "../io.h" #ifdef CONFIG_X86_64 #define memptr long diff --git a/arch/x86/boot/io.h b/arch/x86/boot/io.h new file mode 100644 index 000000000000..fd589ebcbd05 --- /dev/null +++ b/arch/x86/boot/io.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BOOT_IO_H +#define BOOT_IO_H + +#include + +#undef inb +#undef inw +#undef inl +#undef outb +#undef outw +#undef outl + +struct port_io_ops { + u8 (*inb)(u16 port); + void (*outb)(u8 v, u16 port); + void (*outw)(u16 v, u16 port); +}; + +extern struct port_io_ops pio_ops; + +/* + * Use the normal I/O instructions by default. + * TDX guests override these to use hypercalls. + */ +static inline void init_default_io_ops(void) +{ + pio_ops.inb = __inb; + pio_ops.outb = __outb; + pio_ops.outw = __outw; +} + +/* + * Redirect port I/O operations via pio_ops callbacks. + * TDX guests override these callbacks with TDX-specific helpers. + */ +#define inb pio_ops.inb +#define outb pio_ops.outb +#define outw pio_ops.outw + +#endif diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c index e3add857c2c9..1202d4f8a390 100644 --- a/arch/x86/boot/main.c +++ b/arch/x86/boot/main.c @@ -17,6 +17,8 @@ struct boot_params boot_params __attribute__((aligned(16))); +struct port_io_ops pio_ops; + char *HEAP = _end; char *heap_end = _end; /* Default end of heap = no heap */ @@ -133,6 +135,8 @@ static void init_heap(void) void main(void) { + init_default_io_ops(); + /* First, copy the boot header into the "zeropage" */ copy_boot_params(); diff --git a/arch/x86/realmode/rm/wakemain.c b/arch/x86/realmode/rm/wakemain.c index 1d6437e6d2ba..a6f4d8388ad8 100644 --- a/arch/x86/realmode/rm/wakemain.c +++ b/arch/x86/realmode/rm/wakemain.c @@ -62,8 +62,12 @@ static void send_morse(const char *pattern) } } +struct port_io_ops pio_ops; + void main(void) { + init_default_io_ops(); + /* Kill machine if structures are wrong */ if (wakeup_header.real_magic != 0x12345678) while (1) -- 2.34.1