From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A414CC43218 for ; Fri, 26 Apr 2019 01:49:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81333206BF for ; Fri, 26 Apr 2019 01:49:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727415AbfDZBtW (ORCPT ); Thu, 25 Apr 2019 21:49:22 -0400 Received: from mga18.intel.com ([134.134.136.126]:22462 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726402AbfDZBtW (ORCPT ); Thu, 25 Apr 2019 21:49:22 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Apr 2019 18:49:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,395,1549958400"; d="scan'208";a="152463897" Received: from genxtest-ykzhao.sh.intel.com (HELO [10.239.143.71]) ([10.239.143.71]) by FMSMGA003.fm.intel.com with ESMTP; 25 Apr 2019 18:49:19 -0700 Subject: Re: [RFC PATCH v5 3/4] x86/acrn: Use HYPERVISOR_CALLBACK_VECTOR for ACRN guest upcall vector To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de, bp@alien8.de, Jason Chen CJ References: <1556067260-9128-1-git-send-email-yakui.zhao@intel.com> <1556067260-9128-4-git-send-email-yakui.zhao@intel.com> <20190425071700.GB57256@gmail.com> <20190425194527.GA52659@gmail.com> From: "Zhao, Yakui" Message-ID: <12c00f28-a1a8-8642-6912-ec9b706b589e@intel.com> Date: Fri, 26 Apr 2019 09:46:50 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20190425194527.GA52659@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019年04月26日 03:45, Ingo Molnar wrote: > > * Zhao, Yakui wrote: > >>>> + alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, >>>> + acrn_hv_callback_vector); >>> >>> Why is this on two lines, not a single line? >> >> At first it used the long function name for acrn_hv_callback_vector. >> As it exceeds 80 columns, it is split into two lines. > > No, it doesn't exceed 80 columns - the last character of that line is on > column 71. Thanks for the helps. It will be fixed. > >>> Does the hypervisor model the APIC EOI command, i.e. does it require the >>> APIC to be acked? I.e. would not acking the APIC create an IRQ storm? >> >> The hypervisor requires that the APIC EOI should be acked. If the EOI APIC >> is not acked, the APIC ISR bit for the HYPERVISOR_CALLBACK_VECTOR will not >> be cleared and then it will block the interrupt whose vector is lower than >> HYPERVISOR_CALLBACK_VECTOR. > > Ok! > I will add some comments for calling entering_ack_irq in acrn_hv_callback_handler. Is this ok to you? > Thanks, > > Ingo >