From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <maxime.coquelin@redhat.com>
Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28])
 by dpdk.org (Postfix) with ESMTP id C3E861B1BF;
 Mon,  8 Jan 2018 16:54:58 +0100 (CET)
Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com
 [10.5.11.14])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by mx1.redhat.com (Postfix) with ESMTPS id 03FBEC0567A2;
 Mon,  8 Jan 2018 15:54:58 +0000 (UTC)
Received: from [10.36.112.43] (ovpn-112-43.ams2.redhat.com [10.36.112.43])
 by smtp.corp.redhat.com (Postfix) with ESMTPS id E19365D72B;
 Mon,  8 Jan 2018 15:54:50 +0000 (UTC)
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: dev@dpdk.org, stable@dpdk.org, jianfeng.tan@intel.com,
 santosh.shukla@caviumnetworks.com, anatoly.burakov@intel.com,
 thomas@monjalon.net, peterx@redhat.com
References: <20180108135127.25869-1-maxime.coquelin@redhat.com>
 <20180108073841.43c15072@xeon-e3>
From: Maxime Coquelin <maxime.coquelin@redhat.com>
Message-ID: <62b32cc7-68a8-806c-d4fb-e15addbeabfb@redhat.com>
Date: Mon, 8 Jan 2018 16:54:48 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.5.0
MIME-Version: 1.0
In-Reply-To: <20180108073841.43c15072@xeon-e3>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16
 (mx1.redhat.com [10.5.110.32]); Mon, 08 Jan 2018 15:54:58 +0000 (UTC)
Subject: Re: [dpdk-dev] [PATCH] bus/pci: forbid VA as IOVA mode if IOMMU
 address width too small
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Mon, 08 Jan 2018 15:54:59 -0000



On 01/08/2018 04:38 PM, Stephen Hemminger wrote:
> On Mon,  8 Jan 2018 14:51:27 +0100
> Maxime Coquelin <maxime.coquelin@redhat.com> wrote:
> 
>> +static inline bool
>> +pci_one_device_iommu_support_va(struct rte_pci_device *dev)
>> +{
>> +#if defined(RTE_ARCH_PPC_64)
>> +	return false;
>> +#elif defined(RTE_ARCH_X86)
>> +
> 
> The cleaner way to handle this kind of ifdef is:
> 
> #ifdef RTE_ARCH_X86
> static bool
> pci_one_device_iommu_support_va(struct rte_pci_device *dev)
> {
> ....
> }
> #elif defined(RTE_ARCH_PPC_64)
> static inline bool
> pci_one_device_iommu_support_va(struct rte_pci_device *dev)
> {
> 	return false;
> }
> #endif

Ok, thanks. I do this in v2.

> What about AMD64?

I haven't checked AMD64 spec yet.

> Do all ARM processors have IOMMU, I think not.

No, not all have an IOMMU, and I don't know if those which have one have 
such limitations.
But if they don't, they cannot use VFIO without noiommu enabled.

This patch only change behavior for Intel, and could be extended to
other HW if needed.

Regards,
Maxime