From: Jason Gunthorpe <jgg@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: "Liu, Yi L" <yi.l.liu@intel.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>,
"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 02/12] iommu: Introduce a replace API for device pasid
Date: Wed, 17 Apr 2024 09:17:00 -0300 [thread overview]
Message-ID: <20240417121700.GL3637727@nvidia.com> (raw)
In-Reply-To: <BN9PR11MB52761DF58AE1C9AAD4C3A46E8C0F2@BN9PR11MB5276.namprd11.prod.outlook.com>
On Wed, Apr 17, 2024 at 08:44:11AM +0000, Tian, Kevin wrote:
> > From: Liu, Yi L <yi.l.liu@intel.com>
> > Sent: Friday, April 12, 2024 4:15 PM
> >
> > @@ -3332,11 +3333,34 @@ static int __iommu_set_group_pasid(struct
> > iommu_domain *domain,
> > err_revert:
> > last_gdev = device;
> > for_each_group_device(group, device) {
> > - const struct iommu_ops *ops = dev_iommu_ops(device-
> > >dev);
> > + /*
> > + * If no old domain, just undo all the devices/pasid that
> > + * have attached to the new domain.
> > + */
> > + if (!old) {
> > + const struct iommu_ops *ops =
> > + dev_iommu_ops(device-
> > >dev);
> > +
> > + if (device == last_gdev)
> > + break;
> > + ops = dev_iommu_ops(device->dev);
>
> 'ops' is already assigned
>
> > + ops->remove_dev_pasid(device->dev, pasid, domain);
> > + continue;
> > + }
> >
> > - if (device == last_gdev)
> > + /*
> > + * Rollback the devices/pasid that have attached to the new
> > + * domain. And it is a driver bug to fail attaching with a
> > + * previously good domain.
> > + */
> > + if (device == last_gdev) {
> > + WARN_ON(old->ops->set_dev_pasid(old, device-
> > >dev,
> > + pasid, NULL));
>
> do we have a clear definition that @set_dev_pasid callback should
> leave the device detached (as 'NULL' indicates) or we just don't
> care the currently-attached domain at this point?
If set_dev_pasid fails I would expect to to have done nothing so the
failing device should be left in the old config and we should just not
call it at all.
The RID path is wonky here because so many drivers don't do that, so
we poke them again to hopefully get it right. I think for PASID we
should try to make the drivers work properly from the start. Failure
means no change.
I would summarize this in a comment..
Jason
next prev parent reply other threads:[~2024-04-17 12:17 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 [this message]
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
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=20240417121700.GL3637727@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).