From patchwork Mon Apr 15 06:47:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Liao, Chang" X-Patchwork-Id: 13629507 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F39A2C00A94 for ; Mon, 15 Apr 2024 06:55:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gHVlVXDbzQxWINGY8K7BsqzSUUcoUM7ir4qz09wsh4g=; b=yIpGUK0Q+e6uJv QFTd/X68IiQzuFqUbFohZTabMhaSXf77BIcdX0CG8COvFEOoVe3Gvh5hQQiqO2BZAyuqJdCRnn3Q1 5U/t6y5b7Zv4/Jkd2k4/C++upPQ4jUWjbHIL8kMn2NohOSfmktWIAXGwsonuUe+96tu6SPe3Qsybe 1A27dmOjt7L5/wLicruJssg27kocbQL231mKpOEvn4i6c5iwbNI7R6Nvl7ysOsHJUJmgGt5OWnVi+ AEguaGIABIqRQHMHrllxkvoDm360V1NJlJ+Odm4TWQ6EQgOHcR+vHyycwgw/CDVLF+MExWdtktiaq IXZg+FiQALVD2xe0EGfw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwGEy-00000007EQq-3uPW; Mon, 15 Apr 2024 06:54:56 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwGEn-00000007EGw-1tJz for linux-arm-kernel@lists.infradead.org; Mon, 15 Apr 2024 06:54:48 +0000 Received: from mail.maildlp.com (unknown [172.19.163.174]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4VHyYZ1NKbzYdgg; Mon, 15 Apr 2024 14:53:22 +0800 (CST) Received: from kwepemd200013.china.huawei.com (unknown [7.221.188.133]) by mail.maildlp.com (Postfix) with ESMTPS id 8A2AE1400CD; Mon, 15 Apr 2024 14:54:22 +0800 (CST) Received: from huawei.com (10.67.174.28) by kwepemd200013.china.huawei.com (7.221.188.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Mon, 15 Apr 2024 14:54:21 +0800 From: Liao Chang To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: , , Subject: [PATCH v3 2/8] arm64/cpufeature: Detect PE support for FEAT_NMI Date: Mon, 15 Apr 2024 06:47:52 +0000 Message-ID: <20240415064758.3250209-3-liaochang1@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240415064758.3250209-1-liaochang1@huawei.com> References: <20240415064758.3250209-1-liaochang1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.28] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemd200013.china.huawei.com (7.221.188.133) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240414_235446_028757_D750FB1B X-CRM114-Status: GOOD ( 20.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Mark Brown Use of FEAT_NMI requires that all the PEs in the system and the GIC have NMI support. This patch implements the PE part of that detection. In order to avoid problematic interactions between real and pseudo NMIs we disable the architected feature if the user has enabled pseudo NMIs on the command line. If this is done on a system where support for the architected feature is detected then a warning is printed during boot in order to help users spot what is likely to be a misconfiguration. In order to allow KVM to offer the feature to guests even if pseudo NMIs are in use by the host we have a separate feature for the raw feature which is used in KVM. Signed-off-by: Mark Brown Signed-off-by: Liao Chang Signed-off-by: Jinjie Ruan --- arch/arm64/include/asm/cpufeature.h | 6 +++ arch/arm64/kernel/cpufeature.c | 58 ++++++++++++++++++++++++++++- arch/arm64/tools/cpucaps | 2 + 3 files changed, 65 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 8b904a757bd3..4c35565ad656 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -800,6 +800,12 @@ static __always_inline bool system_uses_irq_prio_masking(void) return alternative_has_cap_unlikely(ARM64_HAS_GIC_PRIO_MASKING); } +static __always_inline bool system_uses_nmi(void) +{ + return IS_ENABLED(CONFIG_ARM64_NMI) && + alternative_has_cap_likely(ARM64_USES_NMI); +} + static inline bool system_supports_mte(void) { return alternative_has_cap_unlikely(ARM64_MTE); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 56583677c1f2..99c3bc74008d 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -85,6 +85,7 @@ #include #include #include +#include #include #include #include @@ -291,6 +292,7 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { }; static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = { + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_NMI_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME), FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_SME_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_MPAM_frac_SHIFT, 4, 0), @@ -1076,9 +1078,11 @@ static void init_32bit_cpu_features(struct cpuinfo_32bit *info) init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2); } -#ifdef CONFIG_ARM64_PSEUDO_NMI +#if IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) || IS_ENABLED(CONFIG_ARM64_NMI) static bool enable_pseudo_nmi; +#endif +#ifdef CONFIG_ARM64_PSEUDO_NMI static int __init early_enable_pseudo_nmi(char *p) { return kstrtobool(p, &enable_pseudo_nmi); @@ -2263,6 +2267,41 @@ static bool has_gic_prio_relaxed_sync(const struct arm64_cpu_capabilities *entry } #endif +#ifdef CONFIG_ARM64_NMI +static bool use_nmi(const struct arm64_cpu_capabilities *entry, int scope) +{ + if (!has_cpuid_feature(entry, scope)) + return false; + + /* + * Having both real and pseudo NMIs enabled simultaneously is + * likely to cause confusion. Since pseudo NMIs must be + * enabled with an explicit command line option, if the user + * has set that option on a system with real NMIs for some + * reason assume they know what they're doing. + */ + if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && enable_pseudo_nmi) { + pr_info("Pseudo NMI enabled, not using architected NMI\n"); + return false; + } + + return true; +} + +static void nmi_enable(const struct arm64_cpu_capabilities *__unused) +{ + /* + * Enable use of NMIs controlled by ALLINT, SPINTMASK should + * be clear by default but make it explicit that we are using + * this mode. Ensure that ALLINT is clear first in order to + * avoid leaving things masked. + */ + _allint_clear(); + sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPINTMASK, SCTLR_EL1_NMI); + isb(); +} +#endif + #ifdef CONFIG_ARM64_BTI static void bti_enable(const struct arm64_cpu_capabilities *__unused) { @@ -2861,6 +2900,23 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_nv1, ARM64_CPUID_FIELDS_NEG(ID_AA64MMFR4_EL1, E2H0, NI_NV1) }, +#ifdef CONFIG_ARM64_NMI + { + .desc = "Non-maskable Interrupts present", + .capability = ARM64_HAS_NMI, + .type = ARM64_CPUCAP_BOOT_CPU_FEATURE, + .matches = has_cpuid_feature, + ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, NMI, IMP) + }, + { + .desc = "Non-maskable Interrupts enabled", + .capability = ARM64_USES_NMI, + .type = ARM64_CPUCAP_BOOT_CPU_FEATURE, + .matches = use_nmi, + .cpu_enable = nmi_enable, + ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, NMI, IMP) + }, +#endif {}, }; diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 62b2838a231a..bb62c487ef99 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -43,6 +43,7 @@ HAS_LPA2 HAS_LSE_ATOMICS HAS_MOPS HAS_NESTED_VIRT +HAS_NMI HAS_PAN HAS_S1PIE HAS_RAS_EXTN @@ -71,6 +72,7 @@ SPECTRE_BHB SSBS SVE UNMAP_KERNEL_AT_EL0 +USES_NMI WORKAROUND_834220 WORKAROUND_843419 WORKAROUND_845719