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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 1B6BAC43467 for ; Thu, 8 Oct 2020 09:12:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BC4E217BA for ; Thu, 8 Oct 2020 09:12:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="b6J+u0Xh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728931AbgJHJMl (ORCPT ); Thu, 8 Oct 2020 05:12:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725852AbgJHJMl (ORCPT ); Thu, 8 Oct 2020 05:12:41 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6937C061755; Thu, 8 Oct 2020 02:12:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=iYkgmBFwBFTGLh4X6+sAeZSb4T2DgVQdFEDy9/+a90o=; b=b6J+u0XhcBjH42FDZ6+k0NTFvd PVj+PGjbsQ8c+Xog+CESns9qI9/H3+dqxAWg2Zk4ZOmx3iI0yRsoIFOr/aKC9ETzKQD9724tWdd2M sx8qzhDqsfjeDK0ayKnmlgmqZcSgeX6kfX1aDVOvwzwg8RJwrBz4nhTH5mCaM3lkOhSeFvgCCWqy1 2uVz0mAi0Ud3r3GAChUbhdrktZaCne0lTqSR9bLa34Zvu+QfyQ3v8kbgQjSNBeKMfBlv4L4KfYmy/ mogZoTOSdZUKgblsvH/YdzcxUAg8qQFj/XVpZERbAhpv/760DnSqlk0VE8XbcRwzODQUVZcAwREX8 AF7+pORQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kQRyP-0000ve-TJ; Thu, 08 Oct 2020 09:12:30 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D33CC300455; Thu, 8 Oct 2020 11:12:25 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id B8C1320C2330C; Thu, 8 Oct 2020 11:12:25 +0200 (CEST) Date: Thu, 8 Oct 2020 11:12:25 +0200 From: Peter Zijlstra To: David Woodhouse Cc: x86@kernel.org, kvm , Thomas Gleixner , Paolo Bonzini , linux-kernel Subject: Re: [PATCH 3/5] x86/ioapic: Handle Extended Destination ID field in RTE Message-ID: <20201008091225.GV2628@hirez.programming.kicks-ass.net> References: <803bb6b2212e65c568c84ff6882c2aa8a0ee03d5.camel@infradead.org> <20201007122046.1113577-1-dwmw2@infradead.org> <20201007122046.1113577-3-dwmw2@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201007122046.1113577-3-dwmw2@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 07, 2020 at 01:20:44PM +0100, David Woodhouse wrote: > @@ -1861,7 +1863,8 @@ static void ioapic_configure_entry(struct irq_data *irqd) > * ioapic chip to verify that. > */ > if (irqd->chip == &ioapic_chip) { > - mpd->entry.dest = cfg->dest_apicid; > + mpd->entry.dest = cfg->dest_apicid & 0xff; > + mpd->entry.ext_dest = cfg->dest_apicid >> 8; > mpd->entry.vector = cfg->vector; > } > for_each_irq_pin(entry, mpd->irq_2_pin) All the other sites did memset(0) before the assignment, and this the extra unconditional write of 0 to ext_dest is harmless. This might be true for this site too, but it wasn't immediately obvious.