From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752592AbdCBRLQ (ORCPT <rfc822;w@1wt.eu>);
        Thu, 2 Mar 2017 12:11:16 -0500
Received: from mx1.redhat.com ([209.132.183.28]:45618 "EHLO mx1.redhat.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1753930AbdCBRLL (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Thu, 2 Mar 2017 12:11:11 -0500
Subject: Re: [RFC PATCH v4 19/28] swiotlb: Add warnings for use of bounce
 buffers with SME
To: Tom Lendacky <thomas.lendacky@amd.com>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
References: <20170216154158.19244.66630.stgit@tlendack-t1.amdoffice.net>
 <20170216154619.19244.76653.stgit@tlendack-t1.amdoffice.net>
 <20170217155955.GK30272@char.us.ORACLE.com>
 <17c8099a-5495-5f1d-4c8a-bd9f5d2c5e58@amd.com>
Cc: linux-arch@vger.kernel.org, linux-efi@vger.kernel.org,
        kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org,
        linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
        linux-mm@kvack.org, iommu@lists.linux-foundation.org,
        Rik van Riel <riel@redhat.com>,
        =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Toshimitsu Kani <toshi.kani@hpe.com>, Arnd Bergmann <arnd@arndb.de>,
        Jonathan Corbet <corbet@lwn.net>,
        Matt Fleming <matt@codeblueprint.co.uk>,
        "Michael S. Tsirkin" <mst@redhat.com>, Joerg Roedel <joro@8bytes.org>,
        Brijesh Singh <brijesh.singh@amd.com>, Ingo Molnar <mingo@redhat.com>,
        Alexander Potapenko <glider@google.com>,
        Andy Lutomirski <luto@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
        Borislav Petkov <bp@alien8.de>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Larry Woodman <lwoodman@redhat.com>,
        Dmitry Vyukov <dvyukov@google.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <ecc3f246-3626-3788-25f0-9178e38b92b1@redhat.com>
Date: Thu, 2 Mar 2017 18:01:26 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.7.0
MIME-Version: 1.0
In-Reply-To: <17c8099a-5495-5f1d-4c8a-bd9f5d2c5e58@amd.com>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 02 Mar 2017 17:01:35 +0000 (UTC)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org



On 17/02/2017 17:51, Tom Lendacky wrote:
> 
> It's meant just to notify the user about the condition. The user could
> then decide to use an alternative device that supports a greater DMA
> range (I can probably change it to a dev_warn_once() so that a device
> is identified).  I would be nice if I could issue this message once per
> device that experienced this.  I didn't see anything that would do
> that, though.

dev_warn_once would print once only, not once per device.  But if you
leave the dev_warn elsewhere, this can be just pr_warn_once.

Paolo