Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <c0de76f1-6b8e-2fc0-a7e7-5d2c29df4509@linux.intel.com>
Date:   Thu, 18 Aug 2022 19:55:28 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.11.0
Cc:     baolu.lu@linux.intel.com, Joerg Roedel <joro@8bytes.org>,
        Christoph Hellwig <hch@infradead.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Kevin Tian <kevin.tian@intel.com>,
        Ashok Raj <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Vinod Koul <vkoul@kernel.org>,
        Eric Auger <eric.auger@redhat.com>,
        Liu Yi L <yi.l.liu@intel.com>,
        Jacob jun Pan <jacob.jun.pan@intel.com>,
        Zhangfei Gao <zhangfei.gao@linaro.org>,
        Zhu Tony <tony.zhu@intel.com>, iommu@lists.linux.dev,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v11 04/13] PCI: Allow PASID only when ACS enforced on
 upstreaming path
Content-Language: en-US
To:     Jason Gunthorpe <jgg@nvidia.com>,
        Bjorn Helgaas <helgaas@kernel.org>
References: <20220817012024.3251276-5-baolu.lu@linux.intel.com>
 <20220817211743.GA2274788@bhelgaas> <Yv1wVfCWHnTdvPOc@nvidia.com>
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <Yv1wVfCWHnTdvPOc@nvidia.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 2022/8/18 06:48, Jason Gunthorpe wrote:
> On Wed, Aug 17, 2022 at 04:17:43PM -0500, Bjorn Helgaas wrote:
> 
>> Does the PCIe spec really allow TLPs with PASID to be routed anywhere
>> except upstream?
> I think yes:
> 
>   2.2.10.2 End-End TLP Prefix Processing:
> 
>   The presence of an End-End TLP Prefix does not alter the routing of a
>   TLP. TLPs are routed based on the routing rules covered in Section
>   2.2.4 .
> 
> Which I read as saying that routing is done after stripping all the
> prefixes. PASID is a prefix.
> 
> Lu, you may want to quote the spec in the commit message to make it
> clear.

Yes. Sure thing. Thank you!

Best regards,
baolu