From patchwork Wed Feb 23 05:21:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junaid Shahid X-Patchwork-Id: 12756408 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 BF683C4332F for ; Wed, 23 Feb 2022 05:23:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237826AbiBWFYV (ORCPT ); Wed, 23 Feb 2022 00:24:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237725AbiBWFYS (ORCPT ); Wed, 23 Feb 2022 00:24:18 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37904692AD for ; Tue, 22 Feb 2022 21:23:51 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id w1-20020a05690204e100b006244315a721so15100815ybs.0 for ; Tue, 22 Feb 2022 21:23:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=w8tfMjRpTHBn0meL0Ch0aZ7WXP9rbXxYNEO8B63hsno=; b=davxLdvboa7AnosMDU4YZaonHOXc2mWvmXUYJD5HKzin8o36/qY50HjsjugGaI/D5l Ru80WqGe/FnLjt+8HnlGtPjt4Zi6YBsphfykkNdK7xrLMzwOVzFL31vs2n/ZZ0O/HnpI LOgi7W6aQ+4Zmn4Z1cOc+jbXsnCew4XJAl85YB5PRtJ03TFKlpmUqcnmAJ1Qg9xnXjcb 4yfUNHBaaQoJYVar5RgqzCzuUxniA1Jjald3axQoDsLvTOuO9FNS+ARVJ1i5nxUMdGko 1OO6tdOVImcBTLT1zhrx+dYQEI4jcgxd4WQZmhlrRvv7dBLxB4zea6BzNV1mQ4MyCUUD fnQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=w8tfMjRpTHBn0meL0Ch0aZ7WXP9rbXxYNEO8B63hsno=; b=y2krTEA+q3DurwCqr4WWU2pNRH8HHWvKDTbdt0SAanwmgUse7HOnjVCcp1cfQ9f0rF 76g7/X76C4lILHcV/n8SQVA0uUsrXHQpSMMtmo3bZ86wbXD81q4JXkhe7YX5GcfwOwsX J5eH4CeU2eLMBkhNohv7V2qkcGwTIqmpciwSMe68jLhlv6JA3HosrM/2+XdM2AUD1QB6 UuEsHpwI1ajG1+XUdldPaZ69Y51T0A90ydmhhYvsFz2LG3EF17ee+Kiq2cN2FGx2Yyag lBE61AnmntIldxFms1PJwiw4z2fK6XM176CoxwMe6SAPsCFYW6ZZCmHFtJGCN5VQse3i MlTA== X-Gm-Message-State: AOAM532p1+LWAv5XO2Gpw4qJ76jtyJgI0pRYIBkr2Nnte7USUGfNBEmu Qzy3HnZ2NyWzIbTboZc0ESwLKjd2irhE X-Google-Smtp-Source: ABdhPJxbYNkojrkaLjILQ8n9XN/i4xd/c0tZZOEcEinUXddidcFfUTlIca2QMtLlpZBc7xT9Yey+F1gwDIpI X-Received: from js-desktop.svl.corp.google.com ([2620:15c:2cd:202:ccbe:5d15:e2e6:322]) (user=junaids job=sendgmr) by 2002:a25:2551:0:b0:613:2017:b879 with SMTP id l78-20020a252551000000b006132017b879mr26593133ybl.557.1645593830476; Tue, 22 Feb 2022 21:23:50 -0800 (PST) Date: Tue, 22 Feb 2022 21:21:38 -0800 In-Reply-To: <20220223052223.1202152-1-junaids@google.com> Message-Id: <20220223052223.1202152-3-junaids@google.com> Mime-Version: 1.0 References: <20220223052223.1202152-1-junaids@google.com> X-Mailer: git-send-email 2.35.1.473.g83b2b277ed-goog Subject: [RFC PATCH 02/47] mm: asi: Add command-line parameter to enable/disable ASI From: Junaid Shahid To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, pbonzini@redhat.com, jmattson@google.com, pjt@google.com, oweisse@google.com, alexandre.chartre@oracle.com, rppt@linux.ibm.com, dave.hansen@linux.intel.com, peterz@infradead.org, tglx@linutronix.de, luto@kernel.org, linux-mm@kvack.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org A parameter named "asi" is added, disabled by default. A feature flag X86_FEATURE_ASI is set if ASI is enabled. Signed-off-by: Junaid Shahid --- arch/x86/include/asm/asi.h | 17 ++++++++++---- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/disabled-features.h | 8 ++++++- arch/x86/mm/asi.c | 29 ++++++++++++++++++++++++ arch/x86/mm/init.c | 2 +- include/asm-generic/asi.h | 2 ++ 6 files changed, 53 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/asi.h b/arch/x86/include/asm/asi.h index f9fc928a555d..0a4af23ed0eb 100644 --- a/arch/x86/include/asm/asi.h +++ b/arch/x86/include/asm/asi.h @@ -6,6 +6,7 @@ #include #include +#include #ifdef CONFIG_ADDRESS_SPACE_ISOLATION @@ -52,18 +53,24 @@ void asi_exit(void); static inline void asi_set_target_unrestricted(void) { - barrier(); - this_cpu_write(asi_cpu_state.target_asi, NULL); + if (static_cpu_has(X86_FEATURE_ASI)) { + barrier(); + this_cpu_write(asi_cpu_state.target_asi, NULL); + } } static inline struct asi *asi_get_current(void) { - return this_cpu_read(asi_cpu_state.curr_asi); + return static_cpu_has(X86_FEATURE_ASI) + ? this_cpu_read(asi_cpu_state.curr_asi) + : NULL; } static inline struct asi *asi_get_target(void) { - return this_cpu_read(asi_cpu_state.target_asi); + return static_cpu_has(X86_FEATURE_ASI) + ? this_cpu_read(asi_cpu_state.target_asi) + : NULL; } static inline bool is_asi_active(void) @@ -76,6 +83,8 @@ static inline bool asi_is_target_unrestricted(void) return !asi_get_target(); } +#define static_asi_enabled() cpu_feature_enabled(X86_FEATURE_ASI) + #endif /* CONFIG_ADDRESS_SPACE_ISOLATION */ #endif diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index d5b5f2ab87a0..0b0ead3cdd48 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -295,6 +295,7 @@ #define X86_FEATURE_PER_THREAD_MBA (11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */ #define X86_FEATURE_SGX1 (11*32+ 8) /* "" Basic SGX */ #define X86_FEATURE_SGX2 (11*32+ 9) /* "" SGX Enclave Dynamic Memory Management (EDMM) */ +#define X86_FEATURE_ASI (11*32+10) /* Kernel Address Space Isolation */ /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */ #define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI instructions */ diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index 8f28fafa98b3..9659cd9f867d 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -56,6 +56,12 @@ # define DISABLE_PTI (1 << (X86_FEATURE_PTI & 31)) #endif +#ifdef CONFIG_ADDRESS_SPACE_ISOLATION +# define DISABLE_ASI 0 +#else +# define DISABLE_ASI (1 << (X86_FEATURE_ASI & 31)) +#endif + /* Force disable because it's broken beyond repair */ #define DISABLE_ENQCMD (1 << (X86_FEATURE_ENQCMD & 31)) @@ -79,7 +85,7 @@ #define DISABLED_MASK8 0 #define DISABLED_MASK9 (DISABLE_SMAP|DISABLE_SGX) #define DISABLED_MASK10 0 -#define DISABLED_MASK11 0 +#define DISABLED_MASK11 (DISABLE_ASI) #define DISABLED_MASK12 0 #define DISABLED_MASK13 0 #define DISABLED_MASK14 0 diff --git a/arch/x86/mm/asi.c b/arch/x86/mm/asi.c index 9928325f3787..d274c86f89b7 100644 --- a/arch/x86/mm/asi.c +++ b/arch/x86/mm/asi.c @@ -1,5 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 +#include + #include #include #include @@ -18,6 +20,9 @@ int asi_register_class(const char *name, uint flags, { int i; + if (!boot_cpu_has(X86_FEATURE_ASI)) + return 0; + VM_BUG_ON(name == NULL); spin_lock(&asi_class_lock); @@ -43,6 +48,9 @@ EXPORT_SYMBOL_GPL(asi_register_class); void asi_unregister_class(int index) { + if (!boot_cpu_has(X86_FEATURE_ASI)) + return; + spin_lock(&asi_class_lock); WARN_ON(asi_class[index].name == NULL); @@ -52,10 +60,22 @@ void asi_unregister_class(int index) } EXPORT_SYMBOL_GPL(asi_unregister_class); +static int __init set_asi_param(char *str) +{ + if (strcmp(str, "on") == 0) + setup_force_cpu_cap(X86_FEATURE_ASI); + + return 0; +} +early_param("asi", set_asi_param); + int asi_init(struct mm_struct *mm, int asi_index) { struct asi *asi = &mm->asi[asi_index]; + if (!boot_cpu_has(X86_FEATURE_ASI)) + return 0; + /* Index 0 is reserved for special purposes. */ WARN_ON(asi_index == 0 || asi_index >= ASI_MAX_NUM); WARN_ON(asi->pgd != NULL); @@ -79,6 +99,9 @@ EXPORT_SYMBOL_GPL(asi_init); void asi_destroy(struct asi *asi) { + if (!boot_cpu_has(X86_FEATURE_ASI)) + return; + free_pages((ulong)asi->pgd, PGD_ALLOCATION_ORDER); memset(asi, 0, sizeof(struct asi)); } @@ -109,6 +132,9 @@ static void __asi_enter(void) void asi_enter(struct asi *asi) { + if (!static_cpu_has(X86_FEATURE_ASI)) + return; + VM_WARN_ON_ONCE(!asi); this_cpu_write(asi_cpu_state.target_asi, asi); @@ -123,6 +149,9 @@ void asi_exit(void) u64 unrestricted_cr3; struct asi *asi; + if (!static_cpu_has(X86_FEATURE_ASI)) + return; + preempt_disable(); VM_BUG_ON(this_cpu_read(cpu_tlbstate.loaded_mm) == diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 000cbe5315f5..dfff17363365 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -240,7 +240,7 @@ static void __init probe_page_size_mask(void) __default_kernel_pte_mask = __supported_pte_mask; /* Except when with PTI or ASI where the kernel is mostly non-Global: */ if (cpu_feature_enabled(X86_FEATURE_PTI) || - IS_ENABLED(CONFIG_ADDRESS_SPACE_ISOLATION)) + cpu_feature_enabled(X86_FEATURE_ASI)) __default_kernel_pte_mask &= ~_PAGE_GLOBAL; /* Enable 1 GB linear kernel mappings if available: */ diff --git a/include/asm-generic/asi.h b/include/asm-generic/asi.h index e5ba51d30b90..dae1403ee1d0 100644 --- a/include/asm-generic/asi.h +++ b/include/asm-generic/asi.h @@ -44,6 +44,8 @@ static inline struct asi *asi_get_target(void) { return NULL; } static inline struct asi *asi_get_current(void) { return NULL; } +#define static_asi_enabled() false + #endif /* !_ASSEMBLY_ */ #endif /* !CONFIG_ADDRESS_SPACE_ISOLATION */