From patchwork Tue Apr 4 10:27:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13199597 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 47259C761AF for ; Tue, 4 Apr 2023 10:55:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234768AbjDDKzI (ORCPT ); Tue, 4 Apr 2023 06:55:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234816AbjDDKyV (ORCPT ); Tue, 4 Apr 2023 06:54:21 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA2C130DA; Tue, 4 Apr 2023 03:53:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1680605615; x=1712141615; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=8g9fYneHGWezeTK24y61/oxUFG9XbGt0W4kIun9/SEQ=; b=cPMrKTd6DG1w8kdIqrV6UxP5PwQv2LeZaedgAUFgYFezdNUe/A7onH3B mfbwt9ggmeEew4rzOG1ltd7HcSU2Hl9BRjzMYg3//dxBZgdtoh74k0P2m eSkz2DkGXsDkM45Vaq2UppYWtN2OU7HADQ9lAcjASsu2VUKVXnYImavui en4z4Fm04Z0E/YE1JS+CvA+34FgmoKRygL0dwVBZDFBxgUvjAhr96IpUY /LwztCyiEVntlceuGV5Ec8Lle07F+OhJauCbKIBtZXeeaz4dWk+yWQD3H r1CWNxrXLBmAWrjp+N7ljTmOzzQ1OsfvRsdypJbDt+HRsQrsYWGXMiTRo A==; X-IronPort-AV: E=McAfee;i="6600,9927,10669"; a="330734108" X-IronPort-AV: E=Sophos;i="5.98,317,1673942400"; d="scan'208";a="330734108" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Apr 2023 03:53:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10669"; a="775597832" X-IronPort-AV: E=Sophos;i="5.98,317,1673942400"; d="scan'208";a="775597832" Received: from unknown (HELO fred..) ([172.25.112.68]) by FMSMGA003.fm.intel.com with ESMTP; 04 Apr 2023 03:53:04 -0700 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com, jiangshanlai@gmail.com, shan.kang@intel.com Subject: [PATCH v7 18/33] x86/fred: add a NMI entry stub for FRED Date: Tue, 4 Apr 2023 03:27:01 -0700 Message-Id: <20230404102716.1795-19-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230404102716.1795-1-xin3.li@intel.com> References: <20230404102716.1795-1-xin3.li@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: "H. Peter Anvin (Intel)" On a FRED system, NMIs nest both with themselves and faults, transient information is saved into the stack frame, and NMI unblocking only happens when the stack frame indicates that so should happen. Thus, the NMI entry stub for FRED is really quite small... Signed-off-by: H. Peter Anvin (Intel) Tested-by: Shan Kang Signed-off-by: Xin Li --- arch/x86/include/asm/fred.h | 1 + arch/x86/kernel/nmi.c | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index f670430aaa54..9ce2a6439091 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -99,6 +99,7 @@ static __always_inline unsigned long fred_event_data(struct pt_regs *regs) #define DEFINE_FRED_HANDLER(f) noinstr DECLARE_FRED_HANDLER(f) typedef DECLARE_FRED_HANDLER((*fred_handler)); +DECLARE_FRED_HANDLER(fred_exc_nmi); DECLARE_FRED_HANDLER(fred_exc_debug); DECLARE_FRED_HANDLER(fred_exc_page_fault); diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 776f4b1e395b..e7b2abe42583 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -34,6 +34,7 @@ #include #include #include +#include #define CREATE_TRACE_POINTS #include @@ -643,6 +644,24 @@ void nmi_backtrace_stall_check(const struct cpumask *btp) #endif +#ifdef CONFIG_X86_FRED +DEFINE_FRED_HANDLER(fred_exc_nmi) +{ + /* + * With FRED, CR2 and DR6 are pushed atomically on faults, + * so we don't have to worry about saving and restoring them. + * Breakpoint faults nest, so assume it is OK to leave DR7 + * enabled. + */ + irqentry_state_t irq_state = irqentry_nmi_enter(regs); + + inc_irq_stat(__nmi_count); + default_do_nmi(regs); + + irqentry_nmi_exit(regs, irq_state); +} +#endif + void stop_nmi(void) { ignore_nmis++;