From: Jason Gunthorpe <jgg@nvidia.com>
To: Yi Liu <yi.l.liu@intel.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>,
Baolu Lu <baolu.lu@linux.intel.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"eric.auger@redhat.com" <eric.auger@redhat.com>,
"nicolinc@nvidia.com" <nicolinc@nvidia.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"chao.p.peng@linux.intel.com" <chao.p.peng@linux.intel.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"Duan, Zhenzhong" <zhenzhong.duan@intel.com>,
"Pan, Jacob jun" <jacob.jun.pan@intel.com>
Subject: Re: [PATCH v2 05/12] iommu: Allow iommu driver to populate the max_pasids
Date: Mon, 22 Apr 2024 08:52:43 -0300 [thread overview]
Message-ID: <20240422115243.GA45353@nvidia.com> (raw)
In-Reply-To: <fa27cf95-1be0-4d98-be72-8892f9cc003b@intel.com>
On Sat, Apr 20, 2024 at 01:45:57PM +0800, Yi Liu wrote:
> On 2024/4/17 16:49, Tian, Kevin wrote:
> > > From: Baolu Lu <baolu.lu@linux.intel.com>
> > > Sent: Monday, April 15, 2024 1:42 PM
> > >
> > > On 4/12/24 4:15 PM, Yi Liu wrote:
> > > > Today, the iommu layer gets the max_pasids by pci_max_pasids() or
> > > reading
> > > > the "pasid-num-bits" property. This requires the non-PCI devices to have a
> > > > "pasid-num-bits" property. Like the mock device used in iommufd selftest,
> > > > otherwise the max_pasids check would fail in iommu layer.
> > > >
> > > > While there is an alternative, the iommu layer can allow the iommu driver
> > > > to set the max_pasids in its probe_device() callback and populate it. This
> > > > is simpler and has no impact on the existing cases.
> > > >
> > > > Suggested-by: Jason Gunthorpe<jgg@nvidia.com>
> > > > Signed-off-by: Yi Liu<yi.l.liu@intel.com>
> > > > ---
> > > > drivers/iommu/iommu.c | 9 +++++----
> > > > 1 file changed, 5 insertions(+), 4 deletions(-)
> > >
> > > The code does not appear to match the commit message here.
> > >
> > > The code in change is a refactoring by folding the max_pasid assignment
> > > into its helper. However, the commit message suggests a desire to expose
> > > some kind of kAPI for device drivers.
> > >
> >
> > it's not about exposing a new kAPI. Instead it allows the driver to
> > manually set dev->iommu->max_pasids before calling
> > iommu_init_device(). kind of another contract to convey the
> > max pasid.
> >
> > But as how you are confused, I prefer to defining a "pasid-num-bits"
> > property in the mock driver. It's easier to understand.
>
> @Jason, how about your thought? :) Adding a "pasid-num-bits" may be
> more straightforward.
Sure, just make sure it doesn't leak memory...
Jason
next prev parent reply other threads:[~2024-04-22 11:52 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-12 8:15 [PATCH v2 00/12] iommufd support pasid attach/replace Yi Liu
2024-04-12 8:15 ` [PATCH v2 01/12] iommu: Pass old domain to set_dev_pasid op Yi Liu
2024-04-15 5:32 ` Baolu Lu
2024-04-15 11:54 ` Jason Gunthorpe
2024-04-16 2:07 ` Baolu Lu
2024-04-16 17:47 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 02/12] iommu: Introduce a replace API for device pasid Yi Liu
2024-04-16 3:01 ` Duan, Zhenzhong
2024-04-16 9:18 ` Yi Liu
2024-04-17 8:44 ` Tian, Kevin
2024-04-17 12:17 ` Jason Gunthorpe
2024-04-18 0:08 ` Tian, Kevin
2024-04-29 13:55 ` Jason Gunthorpe
2024-04-30 5:00 ` Yi Liu
2024-04-30 12:26 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 03/12] iommufd: replace attach_fn with a structure Yi Liu
2024-04-12 8:15 ` [PATCH v2 04/12] iommufd: Support attach/replace hwpt per pasid Yi Liu
2024-04-29 13:56 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 05/12] iommu: Allow iommu driver to populate the max_pasids Yi Liu
2024-04-15 5:41 ` Baolu Lu
2024-04-17 8:49 ` Tian, Kevin
2024-04-20 5:45 ` Yi Liu
2024-04-22 11:52 ` Jason Gunthorpe [this message]
2024-04-12 8:15 ` [PATCH v2 06/12] iommufd/selftest: Add set_dev_pasid and remove_dev_pasid in mock iommu Yi Liu
2024-04-12 8:15 ` [PATCH v2 07/12] iommufd/selftest: Add a helper to get test device Yi Liu
2024-04-12 8:15 ` [PATCH v2 08/12] iommufd/selftest: Add test ops to test pasid attach/detach Yi Liu
2024-04-12 8:15 ` [PATCH v2 09/12] iommufd/selftest: Add coverage for iommufd " Yi Liu
2024-04-12 8:15 ` [PATCH v2 10/12] iommu/vt-d: Return if no dev_pasid is found in domain Yi Liu
2024-04-15 6:04 ` Baolu Lu
2024-04-16 9:21 ` Yi Liu
2024-04-17 2:30 ` Baolu Lu
2024-04-17 3:48 ` Yi Liu
2024-04-17 9:03 ` Tian, Kevin
2024-04-17 9:36 ` Yi Liu
2024-04-12 8:15 ` [PATCH v2 11/12] iommu/vt-d: Make intel_iommu_set_dev_pasid() to handle domain replacement Yi Liu
2024-04-17 9:19 ` Tian, Kevin
2024-04-17 9:35 ` Yi Liu
2024-04-17 12:19 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 12/12] iommu/vt-d: Add set_dev_pasid callback for nested domain Yi Liu
2024-04-17 9:25 ` Tian, Kevin
2024-04-30 9:19 ` Yi Liu
2024-05-06 7:42 ` Baolu Lu
2024-05-06 13:36 ` Jason Gunthorpe
2024-05-07 2:28 ` Yi Liu
2024-05-07 15:18 ` Jason Gunthorpe
2024-05-08 6:10 ` Yi Liu
2024-05-08 12:25 ` Jason Gunthorpe
2024-05-08 13:26 ` Yi Liu
2024-05-08 14:11 ` Jason Gunthorpe
2024-05-09 14:22 ` Liu, Yi L
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=20240422115243.GA45353@nvidia.com \
--to=jgg@nvidia.com \
--cc=alex.williamson@redhat.com \
--cc=baolu.lu@linux.intel.com \
--cc=chao.p.peng@linux.intel.com \
--cc=eric.auger@redhat.com \
--cc=iommu@lists.linux.dev \
--cc=jacob.jun.pan@intel.com \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=nicolinc@nvidia.com \
--cc=robin.murphy@arm.com \
--cc=yi.l.liu@intel.com \
--cc=zhenzhong.duan@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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).