From: Jason Gunthorpe <jgg@nvidia.com>
To: Baolu Lu <baolu.lu@linux.intel.com>
Cc: Yi Liu <yi.l.liu@intel.com>,
joro@8bytes.org, kevin.tian@intel.com,
alex.williamson@redhat.com, robin.murphy@arm.com,
eric.auger@redhat.com, nicolinc@nvidia.com, kvm@vger.kernel.org,
chao.p.peng@linux.intel.com, iommu@lists.linux.dev,
zhenzhong.duan@intel.com, jacob.jun.pan@intel.com
Subject: Re: [PATCH v2 01/12] iommu: Pass old domain to set_dev_pasid op
Date: Tue, 16 Apr 2024 14:47:49 -0300 [thread overview]
Message-ID: <20240416174749.GI3637727@nvidia.com> (raw)
In-Reply-To: <4f570287-cd11-4c89-9dd2-9bb106e343c1@linux.intel.com>
On Tue, Apr 16, 2024 at 10:07:49AM +0800, Baolu Lu wrote:
> On 4/15/24 7:54 PM, Jason Gunthorpe wrote:
> > On Mon, Apr 15, 2024 at 01:32:03PM +0800, Baolu Lu wrote:
> > > On 4/12/24 4:15 PM, Yi Liu wrote:
> > > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > > > index 40dd439307e8..1e5e9249c93f 100644
> > > > --- a/include/linux/iommu.h
> > > > +++ b/include/linux/iommu.h
> > > > @@ -631,7 +631,7 @@ struct iommu_ops {
> > > > struct iommu_domain_ops {
> > > > int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
> > > > int (*set_dev_pasid)(struct iommu_domain *domain, struct device *dev,
> > > > - ioasid_t pasid);
> > > > + ioasid_t pasid, struct iommu_domain *old);
> > > Is it possible to add another op to replace a domain for pasid? For
> > > example,
> > >
> > > int (*replace_dev_pasid)(domain, dev, pasid, old_domain)
> > We haven't needed that in the normal case, what would motivate it
> > here?
>
> My understanding of the difference between set_dev_pasid and
> replace_dev_pasid is that the former assumes that there is no domain
> attached to the pasid yet, so it sets the passed domain to it. For the
> latter, it simply replaces the existing domain with a new one.
>
> The set_dev_pasid doesn't need an old domain because it's assumed that
> the existing domain is NULL. The replace_dev_pasid could have an
> existing domain as its input.
I would just pass in the NULL domain for set than make another
op. iommu drivers should be exactly the same implementation for both
> Replace also implies an atomic switch between different domains. This
> makes it subtly different from a set operation.
Well, not necessarily hitless, but at least old/new/blocked - not
something corrupt.
Jason
next prev parent reply other threads:[~2024-04-16 17:47 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 [this message]
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
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
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