Messages in this thread | | | Date | Tue, 21 Nov 2023 13:02:49 +0800 | Subject | Re: [PATCH v6 2/6] iommufd: Add IOMMU_HWPT_INVALIDATE | From | Baolu Lu <> |
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On 11/17/23 9:07 PM, Yi Liu wrote: > In nested translation, the stage-1 page table is user-managed but cached > by the IOMMU hardware, so an update on present page table entries in the > stage-1 page table should be followed with a cache invalidation. > > Add an IOMMU_HWPT_INVALIDATE ioctl to support such a cache invalidation. > It takes hwpt_id to specify the iommu_domain, and a multi-entry array to > support multiple invalidation requests in one ioctl. > > Check cache_invalidate_user op in the iommufd_hw_pagetable_alloc_nested, > since all nested domains need that. > > Co-developed-by: Nicolin Chen<nicolinc@nvidia.com> > Signed-off-by: Nicolin Chen<nicolinc@nvidia.com> > Signed-off-by: Yi Liu<yi.l.liu@intel.com> > --- > drivers/iommu/iommufd/hw_pagetable.c | 35 +++++++++++++++++++++++++ > drivers/iommu/iommufd/iommufd_private.h | 9 +++++++ > drivers/iommu/iommufd/main.c | 3 +++ > include/uapi/linux/iommufd.h | 35 +++++++++++++++++++++++++ > 4 files changed, 82 insertions(+) > > diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c > index 2abbeafdbd22..367459d92f69 100644 > --- a/drivers/iommu/iommufd/hw_pagetable.c > +++ b/drivers/iommu/iommufd/hw_pagetable.c > @@ -238,6 +238,11 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx, > rc = -EINVAL; > goto out_abort; > } > + /* Driver is buggy by missing cache_invalidate_user in domain_ops */ > + if (WARN_ON_ONCE(!hwpt->domain->ops->cache_invalidate_user)) { > + rc = -EINVAL; > + goto out_abort; > + } > return hwpt_nested;
The WARN message here may cause kernel regression when users bisect issues. Till this patch, there are no drivers support the cache_invalidation_user callback yet.
Best regards, baolu
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