From nobody Mon Feb 9 11:33:29 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=quarantine dis=none) header.from=suse.com ARC-Seal: i=1; a=rsa-sha256; t=1613749266; cv=none; d=zohomail.com; s=zohoarc; b=oEzZmLgoXEoRd/602XbecctOl+TWhB8m9HUeubKvqZ4Cf10116FiGwIwc+/zd8M8eJ43DEL9WSPa75yAzT5NSfwZ5f4sr1R0fixnK94zajWx2RH0Rnis6ShWhLgQdedRCmdrNh1pukOTNrozE+YMVd4TF8zxAe2TjWPqb85EN7o= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1613749266; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=nYiBLOOS0jKaGXZR/xdp5WHTi+5sOW1v2m88NDrZNbI=; b=U5ltbnW4z37Otz7ULsTFJqmG64Cy2I43A2HJdZzl8rcsCFA6uwY63vfnSdI/bFa0aAUR0F9/W73risuh+AFo0CECEfznLwotY2428t7xI17vZR+IWTvo2yZ4W+xHELUo4nIvzG9UGPwNJYrG+fOp/Q2fxt2oI/b9Ks7FR/bFLwg= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=quarantine dis=none) header.from= Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1613749265775821.199198147273; Fri, 19 Feb 2021 07:41:05 -0800 (PST) Received: from list by lists.xenproject.org with outflank-mailman.86935.163595 (Exim 4.92) (envelope-from ) id 1lD7tk-0002R3-FH; Fri, 19 Feb 2021 15:40:52 +0000 Received: by outflank-mailman (output) from mailman id 86935.163595; Fri, 19 Feb 2021 15:40:52 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lD7tk-0002Qo-7w; Fri, 19 Feb 2021 15:40:52 +0000 Received: by outflank-mailman (input) for mailman id 86935; Fri, 19 Feb 2021 15:40:50 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lD7th-0002F7-Vq for xen-devel@lists.xenproject.org; Fri, 19 Feb 2021 15:40:50 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 17195ed2-3ee0-4ae2-ad36-57118e02a687; Fri, 19 Feb 2021 15:40:40 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 8FC36B114; Fri, 19 Feb 2021 15:40:39 +0000 (UTC) X-Outflank-Mailman: Message body and most headers restored to incoming version 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: 17195ed2-3ee0-4ae2-ad36-57118e02a687 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=1613749239; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nYiBLOOS0jKaGXZR/xdp5WHTi+5sOW1v2m88NDrZNbI=; b=mqlyaLZe/YgvYSsQIvPpN9XoaMOuiHW3Pbur9d3Wz3NOMHY4Oy4s66u3aQWq9fxarixX/O Ey3afn8U9k0KK6JKqUCXGc1zWME5EppFL1W/JOkfTp3ilVzkPrWMZUrxql+Y+EqqtO2aWl dpSxPChifLttkm90i7WQkWP8NL1KFr4= From: Juergen Gross To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Juergen Gross , Boris Ostrovsky , Stefano Stabellini , Andrew Cooper , Jan Beulich Subject: [PATCH v3 7/8] xen/evtchn: use smp barriers for user event ring Date: Fri, 19 Feb 2021 16:40:29 +0100 Message-Id: <20210219154030.10892-8-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210219154030.10892-1-jgross@suse.com> References: <20210219154030.10892-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @suse.com) Content-Type: text/plain; charset="utf-8" The ring buffer for user events is local to the given kernel instance, so smp barriers are fine for ensuring consistency. Reported-by: Andrew Cooper Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich --- drivers/xen/evtchn.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c index a7a85719a8c8..421382c73d88 100644 --- a/drivers/xen/evtchn.c +++ b/drivers/xen/evtchn.c @@ -173,7 +173,7 @@ static irqreturn_t evtchn_interrupt(int irq, void *data) =20 if ((u->ring_prod - u->ring_cons) < u->ring_size) { *evtchn_ring_entry(u, u->ring_prod) =3D evtchn->port; - wmb(); /* Ensure ring contents visible */ + smp_wmb(); /* Ensure ring contents visible */ if (u->ring_cons =3D=3D u->ring_prod++) { wake_up_interruptible(&u->evtchn_wait); kill_fasync(&u->evtchn_async_queue, @@ -245,7 +245,7 @@ static ssize_t evtchn_read(struct file *file, char __us= er *buf, } =20 rc =3D -EFAULT; - rmb(); /* Ensure that we see the port before we copy it. */ + smp_rmb(); /* Ensure that we see the port before we copy it. */ if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) || ((bytes2 !=3D 0) && copy_to_user(&buf[bytes1], &u->ring[0], bytes2))) --=20 2.26.2