At the moment the userspace tool is expected to request pinning of
the entire guest RAM when VFIO IOMMU SPAPR v2 driver is present.
When the userspace process finishes, all the pinned pages need to
be put; this is done as a part of the userspace memory context (MM)
destruction which happens on the very last mmdrop().
This approach has a problem that a MM of the userspace process
may live longer than the userspace process itself as kernel threads
use userspace process MMs which was runnning on a CPU where
the kernel thread was scheduled to. If this happened, the MM remains
referenced until this exact kernel thread wakes up again
and releases the very last reference to the MM, on an idle system this
can take even hours.
This moves preregistered regions tracking from MM to VFIO; insteads of
using mm_iommu_table_group_mem_t::used, tce_container::prereg_list is
added so each container releases regions which it has pre-registered.
This changes the userspace interface to return EBUSY if a memory
region is already registered in a container. However it should not
have any practical effect as the only userspace tool available now
does register memory region once per container anyway.
As tce_iommu_register_pages/tce_iommu_unregister_pages are called
under container->lock, this does not need additional locking.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We are going to get rid of @current references in mmu_context_boos3s64.c
and cache mm_struct in the VFIO container. Since mm_context_t does not
have reference counting, we will be using mm_struct which does have
the reference counter.
This changes mm_iommu_init/mm_iommu_cleanup to receive mm_struct rather
than mm_context_t (which is embedded into mm).
This should not cause any behavioral change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Update the PID switch as per ISA doc. slbia is needed in radix to
invalidate any implementation specific lookaside information.
We use the .long format due to build errors with the below compiler
version.
gcc (Ubuntu 5.3.1-14ubuntu2.1) 5.3.1 20160413
GNU assembler (GNU Binutils for Ubuntu) 2.26
CC arch/powerpc/mm//mmu_context_book3s64.o
{standard input}: Assembler messages:
{standard input}:506: Error: junk at end of line: `0x7'
scripts/Makefile.build:291: recipe for target 'arch/powerpc/mm//mmu_context_book3s64.o' failed
make[1]: *** [arch/powerpc/mm//mmu_context_book3s64.o] Error 1
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
ISA 3.0 updated it to be encoded as Radix tree size = 2^(RTS + 31). We
have it encoded as 2^(RTS + 28). Add a helper with the correct encoding
and use it instead of opencoding.
Fixes: 2bfd65e45e ("powerpc/mm/radix: Add radix callbacks for early init routines")
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As part of the radix support we switched Book3s64 to use a value of ~0
for MMU_NO_CONTEXT. That is because id 0 is special on radix.
However that broke the logic in init_new_context(). The code there needs
to differentiate between a newly allocated context and one inherited via
fork. Previously it worked because a newly allocated context has an id
of zero (because it was just memset() to zero), which used to match
MMU_NO_CONTEXT, and therefore slice_mm_new_context() did the right
thing.
Instead check against a context.id value of zero instead of using
slice_mm_new_context().
Without this patch we never call slice_set_user_psize(), and end up with
a slice psize value of zero and we always end up using 4K HPTE.
Fixes: 1a472c9dba ("powerpc/mm/radix: Add tlbflush routines")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This file now contains both hash and radix specific code. Rename it to
indicate this better.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Alexey Kardashevskiy
Aneesh Kumar K.V