From patchwork Mon Apr 10 08:14:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13206177 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 84446C76196 for ; Mon, 10 Apr 2023 08:41:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229835AbjDJIli (ORCPT ); Mon, 10 Apr 2023 04:41:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229732AbjDJIlJ (ORCPT ); Mon, 10 Apr 2023 04:41:09 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8196F422B; Mon, 10 Apr 2023 01:41:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1681116068; x=1712652068; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=8g9fYneHGWezeTK24y61/oxUFG9XbGt0W4kIun9/SEQ=; b=gLHoUALlm9pwg6IbV3YmKv8ICsHbyBpWJPuhHHTcdATcSRPq8unQikH8 L6zt4Ohz1o7JOeiN7mGZJuYfkprz7IPvzznHk1IHpW+SPrbRJ3cRDCnja uHRTcPKhjDG5iCXNflXANJi+oYEm8iGVmb8kxfovQN2P3XZcyST/tfyc6 bFXmGn2upMiLPaRxRKSClPMtWt3VKRCpSVtgJSfjYtZBG/QHhFGGXMwqg e0b/KKRY9kCZtaJIp2l7WBTF6ezalXcvqhZtxfNutXlZwyE8fQbCSdcwD RoszxfJMTYQ0G1dBD9FYt7pjrslycAQIs5j9eg27xT3awYYcL41T5iSGc Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10675"; a="342078058" X-IronPort-AV: E=Sophos;i="5.98,333,1673942400"; d="scan'208";a="342078058" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Apr 2023 01:41:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10675"; a="799436310" X-IronPort-AV: E=Sophos;i="5.98,333,1673942400"; d="scan'208";a="799436310" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga002.fm.intel.com with ESMTP; 10 Apr 2023 01:41:05 -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 v8 18/33] x86/fred: add a NMI entry stub for FRED Date: Mon, 10 Apr 2023 01:14:23 -0700 Message-Id: <20230410081438.1750-19-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230410081438.1750-1-xin3.li@intel.com> References: <20230410081438.1750-1-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++;