Alexey Kardashevskiy 58629c0dc3 powerpc/powernv/npu: Fault user page into the hypervisor's pagetable
When a page fault happens in a GPU, the GPU signals the OS and the GPU
driver calls the fault handler which populated a page table; this allows
the GPU to complete an ATS request.

On the bare metal get_user_pages() is enough as it adds a pte to
the kernel page table but under KVM the partition scope tree does not get
updated so ATS will still fail.

This reads a byte from an effective address which causes HV storage
interrupt and KVM updates the partition scope tree.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 16:20:46 +11:00
..
2018-08-10 22:12:39 +10:00
2018-07-16 11:37:21 +10:00