From: Jason Gunthorpe <jgg@nvidia.com>
To: Baolu Lu <baolu.lu@linux.intel.com>
Cc: iommu@lists.linux.dev, Kevin Tian <kevin.tian@intel.com>,
linux-kselftest@vger.kernel.org, kvm@vger.kernel.org,
Nicolin Chen <nicolinc@nvidia.com>, Yi Liu <yi.l.liu@intel.com>
Subject: Re: [PATCH v2 09/17] iommufd: Add enforced_cache_coherency to iommufd_hw_pagetable_alloc()
Date: Wed, 8 Mar 2023 11:06:28 -0400 [thread overview]
Message-ID: <ZAikdKoQkSfqxMxc@nvidia.com> (raw)
In-Reply-To: <07b337da-e215-434b-b84f-8fadd07e3020@linux.intel.com>
On Wed, Mar 08, 2023 at 09:04:47PM +0800, Baolu Lu wrote:
> > + /* Try to upgrade the domain we have */
> > + if (idev->enforce_cache_coherency) {
> > + rc = iommufd_hw_pagetable_enforce_cc(hwpt);
> > + if (rc)
> > + return rc;
>
> As "HWPT should have the coherency set properly for the device that it
> is being created for when it is created", is it an incompatible case if
>
> idev->enforce_cache_coherency && !hwpt->enforce_cache_coherency
>
> ?
>
> If so, why not,
>
> if (idev->enforce_cache_coherency && !hwpt->enforce_cache_coherency)
> return -EINVAL;
In principle you can create a HWPT for device A and then later attach
it to device B
If B requires coherency then we try to upgrade the existing domain.
This is an effort to try an minimize the number of domains that we
need to have for simpe IOAS based cases where we don't want to spawn
two auto domains
Jason
next prev parent reply other threads:[~2023-03-08 15:07 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-08 0:35 [PATCH v2 00/17] Add iommufd physical device operations for replace and alloc hwpt Jason Gunthorpe
2023-03-08 0:35 ` [PATCH v2 01/17] iommufd: Move isolated msi enforcement to iommufd_device_bind() Jason Gunthorpe
2023-03-08 2:55 ` Baolu Lu
2023-03-09 12:53 ` Jason Gunthorpe
2023-03-08 0:35 ` [PATCH v2 02/17] iommufd: Add iommufd_group Jason Gunthorpe
2023-03-08 3:18 ` Baolu Lu
2023-03-09 15:51 ` Jason Gunthorpe
2023-03-10 10:30 ` Tian, Kevin
2023-03-08 0:35 ` [PATCH v2 03/17] iommufd: Replace the hwpt->devices list with iommufd_group Jason Gunthorpe
2023-03-08 11:56 ` Baolu Lu
2023-03-10 10:36 ` Tian, Kevin
2023-03-10 14:16 ` Jason Gunthorpe
2023-03-08 0:35 ` [PATCH v2 04/17] iommu: Export iommu_get_resv_regions() Jason Gunthorpe
2023-03-08 12:06 ` Baolu Lu
2023-03-08 14:54 ` Jason Gunthorpe
2023-03-10 10:40 ` Tian, Kevin
2023-03-08 0:35 ` [PATCH v2 05/17] iommufd: Keep track of each device's reserved regions instead of groups Jason Gunthorpe
2023-03-08 12:32 ` Baolu Lu
2023-03-08 15:02 ` Jason Gunthorpe
2023-03-09 1:43 ` Baolu Lu
2023-03-10 10:42 ` Tian, Kevin
2023-03-08 0:35 ` [PATCH v2 06/17] iommufd: Use the iommufd_group to avoid duplicate MSI setup Jason Gunthorpe
2023-03-10 10:42 ` Tian, Kevin
2023-03-08 0:35 ` [PATCH v2 07/17] iommufd: Make sw_msi_start a group global Jason Gunthorpe
2023-03-10 10:45 ` Tian, Kevin
2023-03-08 0:35 ` [PATCH v2 08/17] iommufd: Move putting a hwpt to a helper function Jason Gunthorpe
2023-03-08 12:42 ` Baolu Lu
2023-03-10 10:45 ` Tian, Kevin
2023-03-08 0:35 ` [PATCH v2 09/17] iommufd: Add enforced_cache_coherency to iommufd_hw_pagetable_alloc() Jason Gunthorpe
2023-03-08 13:04 ` Baolu Lu
2023-03-08 15:06 ` Jason Gunthorpe [this message]
2023-03-09 2:03 ` Baolu Lu
2023-03-09 2:05 ` Baolu Lu
2023-03-08 0:35 ` [PATCH v2 10/17] iommufd: Reorganize iommufd_device_attach into iommufd_device_change_pt Jason Gunthorpe
2023-03-08 13:46 ` Baolu Lu
2023-03-10 11:26 ` Tian, Kevin
2023-03-10 15:01 ` Jason Gunthorpe
2023-03-08 0:35 ` [PATCH v2 11/17] iommu: Introduce a new iommu_group_replace_domain() API Jason Gunthorpe
2023-03-08 13:48 ` Baolu Lu
2023-03-08 0:35 ` [PATCH v2 12/17] iommufd: Add iommufd_device_replace() Jason Gunthorpe
2023-03-09 1:14 ` Baolu Lu
2023-03-10 11:48 ` Tian, Kevin
2023-03-10 15:04 ` Jason Gunthorpe
2023-03-08 0:35 ` [PATCH v2 13/17] iommufd: Make destroy_rwsem use a lock class per object type Jason Gunthorpe
2023-03-08 0:35 ` [PATCH v2 14/17] iommufd/selftest: Test iommufd_device_replace() Jason Gunthorpe
2023-03-08 0:35 ` [PATCH v2 15/17] iommufd: Add IOMMU_HWPT_ALLOC Jason Gunthorpe
2023-03-09 1:21 ` Baolu Lu
2023-03-08 0:35 ` [PATCH v2 16/17] iommufd/selftest: Return the real idev id from selftest mock_domain Jason Gunthorpe
2023-03-08 0:35 ` [PATCH v2 17/17] iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC 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=ZAikdKoQkSfqxMxc@nvidia.com \
--to=jgg@nvidia.com \
--cc=baolu.lu@linux.intel.com \
--cc=iommu@lists.linux.dev \
--cc=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=nicolinc@nvidia.com \
--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