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=-7.9 required=3.0 tests=BAYES_00, 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 BB60CC433DF for ; Tue, 25 Aug 2020 08:36:17 +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 9304520706 for ; Tue, 25 Aug 2020 08:36:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9304520706 Authentication-Results: mail.kernel.org; dmarc=none (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 localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kAUQi-0001ki-H2; Tue, 25 Aug 2020 08:35:44 +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 1kAUQh-0001kd-HI for xen-devel@lists.xenproject.org; Tue, 25 Aug 2020 08:35:43 +0000 X-Inumbo-ID: a3e13ad0-0a37-4ccf-8c2f-bacef622aaf8 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id a3e13ad0-0a37-4ccf-8c2f-bacef622aaf8; Tue, 25 Aug 2020 08:35:42 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 2A462ACA0; Tue, 25 Aug 2020 08:36:12 +0000 (UTC) Subject: Re: [PATCH 5/5] x86/vioapic: switch to use the EOI callback mechanism To: Roger Pau Monne Cc: xen-devel@lists.xenproject.org, Andrew Cooper , Wei Liu References: <20200812124709.4165-1-roger.pau@citrix.com> <20200812124709.4165-6-roger.pau@citrix.com> From: Jan Beulich Message-ID: Date: Tue, 25 Aug 2020 10:35:42 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200812124709.4165-6-roger.pau@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 12.08.2020 14:47, Roger Pau Monne wrote: > --- a/xen/arch/x86/hvm/vioapic.c > +++ b/xen/arch/x86/hvm/vioapic.c > @@ -375,6 +375,50 @@ static const struct hvm_mmio_ops vioapic_mmio_ops = { > .write = vioapic_write > }; > > +static void eoi_callback(struct vcpu *v, unsigned int vector, void *data) > +{ > + struct domain *d = v->domain; > + struct hvm_irq *hvm_irq = hvm_domain_irq(d); > + union vioapic_redir_entry *ent; While you move the code, could you restrict this variable's scope? > + unsigned int i; > + > + ASSERT(has_vioapic(d)); > + > + spin_lock(&d->arch.hvm.irq_lock); > + > + for ( i = 0; i < d->arch.hvm.nr_vioapics; i++ ) > + { > + struct hvm_vioapic *vioapic = domain_vioapic(d, i); > + unsigned int pin; > + > + for ( pin = 0; pin < vioapic->nr_pins; pin++ ) > + { > + ent = &vioapic->redirtbl[pin]; > + if ( ent->fields.vector != vector ) > + continue; > + > + ent->fields.remote_irr = 0; > + > + if ( is_iommu_enabled(d) ) > + { > + spin_unlock(&d->arch.hvm.irq_lock); > + hvm_dpci_eoi(d, vioapic->base_gsi + pin, ent); > + spin_lock(&d->arch.hvm.irq_lock); > + } Just as a remark (simply because of it catching my attention) - this intermediate dropping of the lock can't really be good. We may want (need?) to think about ways to avoid this. Jan