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;
Date:   Tue, 8 Aug 2023 12:02:23 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Tina Zhang <tina.zhang@intel.com>
Cc:     Kevin Tian <kevin.tian@intel.com>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        Michael Shavit <mshavit@google.com>, iommu@lists.linux.dev,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] iommu: Add mm_get_pasid() helper function
Message-ID: <ZNJY/9pwRxIkFEjD@ziepe.ca>
References: <20230808074944.7825-1-tina.zhang@intel.com>
 <20230808074944.7825-2-tina.zhang@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230808074944.7825-2-tina.zhang@intel.com>
Precedence: bulk

On Tue, Aug 08, 2023 at 03:49:40PM +0800, Tina Zhang wrote:
> mm_get_pasid() is for getting mm pasid value.
> 
> The motivation is to replace mm->pasid with an iommu private data
> structure that is introduced in a later patch.

Maybe we should start out by calling it what it actually is:

'mm_get_enqcmd_pasid()'

We can't actually have multiple SVA domains with different PASIDs
until the places wrongly calling this are removed :\

eg, I would expect this series to also come with removing
'pasid_private' from the Intel driver.

The mmu_notifier should be placed in the singular iommu_domain that is
the SVA domain for the mm. Drivers should not attempt to de-duplicate
this, the core code will do it like you are showing in this series.

Jason