From: Jason Gunthorpe <jgg@ziepe.ca>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Kevin Tian <kevin.tian@intel.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
Nicolin Chen <nicolinc@nvidia.com>, Yi Liu <yi.l.liu@intel.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>,
iommu@lists.linux.dev, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] iommu: Make pasid array per device
Date: Wed, 2 Aug 2023 11:15:33 -0300 [thread overview]
Message-ID: <ZMplBfgSb8Hh9jLt@ziepe.ca> (raw)
In-Reply-To: <20230801063125.34995-1-baolu.lu@linux.intel.com>
On Tue, Aug 01, 2023 at 02:31:23PM +0800, Lu Baolu wrote:
> The PCI PASID enabling interface guarantees that the address space used
> by each PASID is unique. This is achieved by checking that the PCI ACS
> path is enabled for the device. If the path is not enabled, then the
> PASID feature cannot be used.
>
> if (!pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
> return -EINVAL;
>
> The PASID array is not an attribute of the IOMMU group. It is more
> natural to store the PASID array in the per-device IOMMU data. This
> makes the code clearer and easier to understand. No functional changes
> are intended.
Is there a reason to do this?
*PCI* requires the ACS/etc because PCI kind of messed up how switches
handled PASID so PASID doesn't work otherwise.
But there is nothing that says other bus type can't have working
(non-PCI) PASID and still have device isolation issues.
So unless there is a really strong reason to do this we should keep
the PASID list in the group just like the domain.
Jason
next prev parent reply other threads:[~2023-08-02 14:15 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-01 6:31 [PATCH 0/2] iommu: Make pasid array per device Lu Baolu
2023-08-01 6:31 ` [PATCH 1/2] iommu: Consolidate pasid dma ownership check Lu Baolu
2023-08-01 7:03 ` Tian, Kevin
2023-08-01 7:43 ` Baolu Lu
2023-08-02 1:39 ` Tian, Kevin
2023-08-02 3:20 ` Baolu Lu
2023-08-01 6:31 ` [PATCH 2/2] iommu: Move pasid array from group to device Lu Baolu
[not found] ` <1254d61b-1f4e-2ef3-c3dc-95180f26f08c@intel.com>
2023-08-01 8:40 ` Baolu Lu
2023-08-02 14:15 ` Jason Gunthorpe [this message]
2023-08-03 0:44 ` [PATCH 0/2] iommu: Make pasid array per device Tian, Kevin
2023-08-03 15:18 ` Jason Gunthorpe
2023-08-04 0:57 ` Tian, Kevin
2023-08-04 2:20 ` Baolu Lu
2023-08-04 2:30 ` Baolu Lu
2023-08-04 13:12 ` Jason Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZMplBfgSb8Hh9jLt@ziepe.ca \
--to=jgg@ziepe.ca \
--cc=baolu.lu@linux.intel.com \
--cc=iommu@lists.linux.dev \
--cc=jacob.jun.pan@linux.intel.com \
--cc=jean-philippe@linaro.org \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=nicolinc@nvidia.com \
--cc=robin.murphy@arm.com \
--cc=will@kernel.org \
--cc=yi.l.liu@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox