From patchwork Mon Nov 9 09:50:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Juergen Gross X-Patchwork-Id: 11890831 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A9CDF16C0 for ; Mon, 9 Nov 2020 09:51:18 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 699AF20657 for ; Mon, 9 Nov 2020 09:51:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="U584MBYl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 699AF20657 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.22269.48547 (Exim 4.92) (envelope-from ) id 1kc3om-00037W-S0; Mon, 09 Nov 2020 09:50:32 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 22269.48547; Mon, 09 Nov 2020 09:50:32 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kc3om-00037L-P0; Mon, 09 Nov 2020 09:50:32 +0000 Received: by outflank-mailman (input) for mailman id 22269; Mon, 09 Nov 2020 09:50:31 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kc3ok-00032y-UC for xen-devel@lists.xenproject.org; Mon, 09 Nov 2020 09:50:30 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 73627980-4f17-4a32-8c9f-f9554f50e3a6; Mon, 09 Nov 2020 09:50:24 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id AAA75AC23; Mon, 9 Nov 2020 09:50:23 +0000 (UTC) Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kc3ok-00032y-UC for xen-devel@lists.xenproject.org; Mon, 09 Nov 2020 09:50:30 +0000 X-Inumbo-ID: 73627980-4f17-4a32-8c9f-f9554f50e3a6 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 73627980-4f17-4a32-8c9f-f9554f50e3a6; Mon, 09 Nov 2020 09:50:24 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1604915423; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1OcADNeqtn5le1IW034CfnSXJe+7ZXbQ3qogiKRAU7Y=; b=U584MBYlyKA0OmO+EmQRpJWo3L6D/lC8U9IOmHtAp+DfmcF7sHcckrOBXW5j73Dj/CNL8H JxejBerXqH53Nfby8wCmFQa0d5wqFUjEdmM24QOY1UWJ4OipRn0ZbZGdMqiZFJu6tXsVWV MF2SZMlAuDBx0XMRyEWC8P3zomCk7Aw= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id AAA75AC23; Mon, 9 Nov 2020 09:50:23 +0000 (UTC) From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Jan Beulich , Andrew Cooper , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Wei Liu Subject: [PATCH v4 1/3] xen/x86: add nmi continuation framework Date: Mon, 9 Nov 2020 10:50:19 +0100 Message-Id: <20201109095021.9897-2-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201109095021.9897-1-jgross@suse.com> References: <20201109095021.9897-1-jgross@suse.com> MIME-Version: 1.0 Actions in NMI context are rather limited as e.g. locking is rather fragile. Add a framework to continue processing in normal interrupt context after leaving NMI processing. This is done by a high priority interrupt vector triggered via a self IPI from NMI context, which will then call the continuation function specified during NMI handling. Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich --- V4: - make the framework less generic V2: - add prototype for continuation function (Roger Pau Monné) - switch from softirq to explicit self-IPI (Jan Beulich) Signed-off-by: Juergen Gross --- xen/arch/x86/apic.c | 13 ++++++++++--- xen/arch/x86/traps.c | 19 +++++++++++++++++++ xen/include/asm-x86/nmi.h | 11 ++++++++++- 3 files changed, 39 insertions(+), 4 deletions(-) diff --git a/xen/arch/x86/apic.c b/xen/arch/x86/apic.c index 60627fd6e6..7497ddb5da 100644 --- a/xen/arch/x86/apic.c +++ b/xen/arch/x86/apic.c @@ -40,6 +40,7 @@ #include #include #include +#include #include static bool __read_mostly tdt_enabled; @@ -1376,16 +1377,22 @@ void spurious_interrupt(struct cpu_user_regs *regs) { /* * Check if this is a vectored interrupt (most likely, as this is probably - * a request to dump local CPU state). Vectored interrupts are ACKed; - * spurious interrupts are not. + * a request to dump local CPU state or to continue NMI handling). + * Vectored interrupts are ACKed; spurious interrupts are not. */ if (apic_isr_read(SPURIOUS_APIC_VECTOR)) { + bool is_spurious; + ack_APIC_irq(); + is_spurious = !nmi_check_continuation(); if (this_cpu(state_dump_pending)) { this_cpu(state_dump_pending) = false; dump_execstate(regs); - return; + is_spurious = false; } + + if ( !is_spurious ) + return; } /* see sw-dev-man vol 3, chapter 7.4.13.5 */ diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c index bc5b8f8ea3..5005ac6e6e 100644 --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -79,6 +79,7 @@ #include #include #include +#include #include #include @@ -1799,6 +1800,24 @@ void unset_nmi_callback(void) nmi_callback = dummy_nmi_callback; } +bool nmi_check_continuation(void) +{ + bool ret = false; + + return ret; +} + +void trigger_nmi_continuation(void) +{ + /* + * Issue a self-IPI. Handling is done in spurious_interrupt(). + * NMI could have happened in IPI sequence, so wait for ICR being idle + * again before leaving NMI handler. + */ + send_IPI_self(SPURIOUS_APIC_VECTOR); + apic_wait_icr_idle(); +} + void do_device_not_available(struct cpu_user_regs *regs) { #ifdef CONFIG_PV diff --git a/xen/include/asm-x86/nmi.h b/xen/include/asm-x86/nmi.h index a288f02a50..9a5da14162 100644 --- a/xen/include/asm-x86/nmi.h +++ b/xen/include/asm-x86/nmi.h @@ -33,5 +33,14 @@ nmi_callback_t *set_nmi_callback(nmi_callback_t *callback); void unset_nmi_callback(void); DECLARE_PER_CPU(unsigned int, nmi_count); - + +/** + * trigger_nmi_continuation + * + * Schedule continuation to be started in interrupt context after NMI handling. + */ +void trigger_nmi_continuation(void); + +/* Check for NMI continuation pending. */ +bool nmi_check_continuation(void); #endif /* ASM_NMI_H */