From: "Tian, Kevin" <kevin.tian@intel.com>
To: Baolu Lu <baolu.lu@linux.intel.com>, Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
"Robin Murphy" <robin.murphy@arm.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
Nicolin Chen <nicolinc@nvidia.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>,
"Joel Granados" <j.granados@samsung.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v5 5/9] iommufd: Add iommufd fault object
Date: Wed, 15 May 2024 07:57:28 +0000 [thread overview]
Message-ID: <BN9PR11MB5276F21755C883FE7EC784228CEC2@BN9PR11MB5276.namprd11.prod.outlook.com> (raw)
In-Reply-To: <a03d3bf6-0610-427c-bf2a-5f6c410e220e@linux.intel.com>
> From: Baolu Lu <baolu.lu@linux.intel.com>
> Sent: Wednesday, May 8, 2024 6:05 PM
>
> On 2024/5/8 8:11, Jason Gunthorpe wrote:
> > On Tue, Apr 30, 2024 at 10:57:06PM +0800, Lu Baolu wrote:
> >> diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h
> >> index ae65e0b85d69..1a0450a83bd0 100644
> >> --- a/drivers/iommu/iommu-priv.h
> >> +++ b/drivers/iommu/iommu-priv.h
> >> @@ -36,6 +36,10 @@ struct iommu_attach_handle {
> >> struct device *dev;
> >> refcount_t users;
> >> };
> >> + /* attach data for IOMMUFD */
> >> + struct {
> >> + void *idev;
> >> + };
> > We can use a proper type here, just forward declare it.
> >
> > But this sequence in the other patch:
> >
> > + ret = iommu_attach_group(hwpt->domain, idev->igroup->group);
> > + if (ret) {
> > + iommufd_fault_iopf_disable(idev);
> > + return ret;
> > + }
> > +
> > + handle = iommu_attach_handle_get(idev->igroup->group,
> IOMMU_NO_PASID, 0);
> > + handle->idev = idev;
> >
> > Is why I was imagining the caller would allocate, because now we have
> > the issue that a fault capable domain was installed into the IOMMU
> > before it's handle could be fully setup, so we have a race where a
> > fault could come in right between those things. Then what happens?
> > I suppose we can retry the fault and by the time it comes back the
> > race should resolve. A bit ugly I suppose.
>
> You are right. It makes more sense if the attached data is allocated and
> managed by the caller. I will go in this direction and update my series.
> I will also consider other review comments you have given in other
> places.
>
Does this direction imply a new iommu_attach_group_handle() helper
to pass in the caller-allocated handle pointer or exposing a new
iommu_group_set_handle() to set the handle to the group pasid_array
and then having iomm_attach_group() to update the domain info in
the handle?
next prev parent reply other threads:[~2024-05-15 7:57 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-30 14:57 [PATCH v5 0/9] IOMMUFD: Deliver IO page faults to user space Lu Baolu
2024-04-30 14:57 ` [PATCH v5 1/9] iommu: Introduce domain attachment handle Lu Baolu
2024-05-15 7:17 ` Tian, Kevin
2024-05-19 10:07 ` Baolu Lu
2024-04-30 14:57 ` [PATCH v5 2/9] iommu: Replace sva_iommu with iommu_attach_handle Lu Baolu
2024-05-07 23:58 ` Jason Gunthorpe
2024-05-15 7:21 ` Tian, Kevin
2024-05-19 10:14 ` Baolu Lu
2024-05-20 3:18 ` Tian, Kevin
2024-04-30 14:57 ` [PATCH v5 3/9] iommu: Add attachment handle to struct iopf_group Lu Baolu
2024-05-08 0:04 ` Jason Gunthorpe
2024-05-10 3:14 ` Baolu Lu
2024-05-10 13:38 ` Jason Gunthorpe
2024-05-10 14:30 ` Baolu Lu
2024-05-10 16:28 ` Jason Gunthorpe
2024-05-15 7:28 ` Tian, Kevin
2024-05-15 7:31 ` Tian, Kevin
2024-05-19 14:03 ` Baolu Lu
2024-05-20 3:20 ` Tian, Kevin
2024-04-30 14:57 ` [PATCH v5 4/9] iommufd: Add fault and response message definitions Lu Baolu
2024-05-15 7:43 ` Tian, Kevin
2024-05-19 14:37 ` Baolu Lu
2024-05-20 3:24 ` Tian, Kevin
2024-05-20 3:33 ` Baolu Lu
2024-05-20 4:59 ` Tian, Kevin
2024-05-24 14:15 ` Jason Gunthorpe
2024-05-27 1:27 ` Tian, Kevin
2024-04-30 14:57 ` [PATCH v5 5/9] iommufd: Add iommufd fault object Lu Baolu
2024-05-08 0:11 ` Jason Gunthorpe
2024-05-08 10:05 ` Baolu Lu
2024-05-15 7:57 ` Tian, Kevin [this message]
2024-05-20 0:41 ` Baolu Lu
2024-05-20 3:26 ` Tian, Kevin
2024-05-20 3:28 ` Baolu Lu
2024-05-08 0:22 ` Jason Gunthorpe
2024-05-10 9:13 ` Baolu Lu
2024-05-15 8:37 ` Tian, Kevin
2024-05-20 1:15 ` Baolu Lu
2024-05-20 1:24 ` Baolu Lu
2024-05-24 14:16 ` Jason Gunthorpe
2024-05-20 1:33 ` Baolu Lu
2024-05-20 3:33 ` Tian, Kevin
2024-05-20 1:38 ` Baolu Lu
2024-04-30 14:57 ` [PATCH v5 6/9] iommufd: Fault-capable hwpt attach/detach/replace Lu Baolu
2024-05-08 0:18 ` Jason Gunthorpe
2024-05-10 3:20 ` Baolu Lu
2024-05-10 13:39 ` Jason Gunthorpe
2024-05-15 8:43 ` Tian, Kevin
2024-05-20 2:10 ` Baolu Lu
2024-05-20 3:35 ` Tian, Kevin
2024-05-20 3:55 ` Baolu Lu
2024-04-30 14:57 ` [PATCH v5 7/9] iommufd: Associate fault object with iommufd_hw_pgtable Lu Baolu
2024-05-08 0:25 ` Jason Gunthorpe
2024-05-10 3:23 ` Baolu Lu
2024-05-15 8:50 ` Tian, Kevin
2024-05-20 2:18 ` Baolu Lu
2024-05-20 3:39 ` Tian, Kevin
2024-05-20 4:00 ` Baolu Lu
2024-05-24 14:24 ` Jason Gunthorpe
2024-05-27 1:33 ` Tian, Kevin
2024-05-27 3:16 ` Baolu Lu
2024-04-30 14:57 ` [PATCH v5 8/9] iommufd/selftest: Add IOPF support for mock device Lu Baolu
2024-04-30 14:57 ` [PATCH v5 9/9] iommufd/selftest: Add coverage for IOPF test Lu Baolu
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