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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 8B1A9C433ED for ; Thu, 8 Apr 2021 14:32:18 +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 3F42F610C7 for ; Thu, 8 Apr 2021 14:32:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F42F610C7 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine 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.107381.205279 (Exim 4.92) (envelope-from ) id 1lUVhY-0001uk-1T; Thu, 08 Apr 2021 14:32:08 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 107381.205279; Thu, 08 Apr 2021 14:32:08 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lUVhX-0001ud-UX; Thu, 08 Apr 2021 14:32:07 +0000 Received: by outflank-mailman (input) for mailman id 107381; Thu, 08 Apr 2021 14:32:07 +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 1lUVhW-0001uW-Tl for xen-devel@lists.xenproject.org; Thu, 08 Apr 2021 14:32:06 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id d06d7b27-0037-4351-9f92-b90a3c057ea0; Thu, 08 Apr 2021 14:32:06 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 768DBB49D; Thu, 8 Apr 2021 14:32:04 +0000 (UTC) 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" X-Inumbo-ID: d06d7b27-0037-4351-9f92-b90a3c057ea0 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=1617892325; h=from:from:reply-to: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=32e+c7Ksex1CseVidA3EDRgcwsU9vvrltZpKcXhBZ/M=; b=IosULcaKy5TYHMuE1L0M+A1WSX+a+M5QzJVsLty+D1w2Xq5lsUDtBOHUbASv93mIp+uejD wjAgyW1jNLcjLd8v2jsCrePDhs2lxN14kri01d7uFdCbGFHFqxNLndQE3yaT2yF9k+FKE1 vhaDBp9Q+j/KCsm5Uym8fpUWhpChfgc= Subject: Re: [PATCH v3 06/11] x86/hvm: allowing registering EOI callbacks for GSIs To: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Cc: Andrew Cooper , Wei Liu , xen-devel@lists.xenproject.org References: <20210331103303.79705-1-roger.pau@citrix.com> <20210331103303.79705-7-roger.pau@citrix.com> From: Jan Beulich Message-ID: <8d088ae2-e8a7-7818-5ee8-5ed95ac260c1@suse.com> Date: Thu, 8 Apr 2021 16:31:59 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit On 08.04.2021 14:52, Roger Pau Monné wrote: > On Wed, Apr 07, 2021 at 05:51:14PM +0200, Jan Beulich wrote: >> On 31.03.2021 12:32, Roger Pau Monne wrote: >>> --- a/xen/arch/x86/hvm/irq.c >>> +++ b/xen/arch/x86/hvm/irq.c >>> +void hvm_gsi_unregister_callback(struct domain *d, unsigned int gsi, >>> + struct hvm_gsi_eoi_callback *cb) >>> +{ >>> + struct hvm_irq *hvm_irq = hvm_domain_irq(d); >>> + const struct list_head *tmp; >>> + >>> + if ( gsi >= hvm_irq->nr_gsis ) >>> + { >>> + ASSERT_UNREACHABLE(); >>> + return; >>> + } >>> + >>> + write_lock(&hvm_irq->gsi_callbacks_lock); >>> + list_for_each ( tmp, &hvm_irq->gsi_callbacks[gsi] ) >>> + if ( tmp == &cb->list ) >>> + { >>> + list_del(&cb->list); >>> + break; >>> + } >>> + write_unlock(&hvm_irq->gsi_callbacks_lock); >>> +} >> >> Perhaps somehow flag, at least in debug builds, if the callback >> wasn#t found? > > I've added a debug printf here to warn if the callback is not found, > but I see it triggering because hpet_set_timer will call > destroy_periodic_time and create_periodic_time and thus two calls will > be made to hvm_gsi_unregister_callback. This is fine, but adding a > message there gets too verbose, so I will drop it and leave the code > as-is. > > I don't see a problem with calling destroy_periodic_time multiple > times even if the timer was not active, and that shouldn't result in a > message being printed. If destroy_periodic_time() is to remain the only caller, I guess I agree. Other (future) callers may then need this function to gain a return value indicating whether the callback was actually found. Jan