Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH v2 08/10] iommufd/device: Use iommu_group_replace_domain() | Date | Wed, 15 Feb 2023 07:24:30 +0000 |
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> From: Nicolin Chen <nicolinc@nvidia.com> > Sent: Wednesday, February 15, 2023 3:15 PM > > But things will be out of control, if user space continues mapping > something onto domain1's iopt for idev2, even after it is attached > covertly to domain2's iopt by the replace routine. I wonder how > kernel should handle this and keep the consistency between IOMMUFD > objects and iommu_group. >
this is where I don't understand.
domain mapping just reflects what an address space has.
Take Qemu for example. w/o vIOMMU domain mappings is added/ removed according to the change in the GPA address space.
w/ vIOMMU then it is synced with guest page table.
why would userspace construct mappings for a specific device?
when device is moved from one domain to another domain, it just bears with whatever the new domain allows it to access.
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