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vfio/spapr: Postpone allocation of userspace version of TCE table

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[ Upstream commit 39701e56f5 ]

The iommu_table struct manages a hardware TCE table and a vmalloc'd
table with corresponding userspace addresses. Both are allocated when
the default DMA window is created and this happens when the very first
group is attached to a container.

As we are going to allow the userspace to configure container in one
memory context and pas container fd to another, we have to postpones
such allocations till a container fd is passed to the destination
user process so we would account locked memory limit against the actual
container user constrainsts.

This postpones the it_userspace array allocation till it is used first
time for mapping. The unmapping patch already checks if the array is
allocated.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexey Kardashevskiy 2017-03-17 00:48:26 +00:00 committed by Greg Kroah-Hartman
parent 3c0cbb47a8
commit 5d8b3e7559
1 changed files with 7 additions and 13 deletions
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20
drivers/vfio/vfio_iommu_spapr_tce.c
View file

@ -509,6 +509,12 @@ static long tce_iommu_build_v2(struct tce_container *container,
unsigned long hpa;
enum dma_data_direction dirtmp;
if (!tbl->it_userspace) {
ret = tce_iommu_userspace_view_alloc(tbl);
if (ret)
return ret;
}
for (i = 0; i < pages; ++i) {
struct mm_iommu_table_group_mem_t *mem = NULL;
unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl,
@ -582,15 +588,6 @@ static long tce_iommu_create_table(struct tce_container *container,
WARN_ON(!ret && !(*ptbl)->it_ops->free);
WARN_ON(!ret && ((*ptbl)->it_allocated_size != table_size));
if (!ret && container->v2) {
ret = tce_iommu_userspace_view_alloc(*ptbl);
if (ret)
(*ptbl)->it_ops->free(*ptbl);
}
if (ret)
decrement_locked_vm(table_size >> PAGE_SHIFT);
return ret;
}
@ -1062,10 +1059,7 @@ static int tce_iommu_take_ownership(struct tce_container *container,
if (!tbl || !tbl->it_map)
continue;
rc = tce_iommu_userspace_view_alloc(tbl);
if (!rc)
rc = iommu_take_ownership(tbl);
rc = iommu_take_ownership(tbl);
if (rc) {
for (j = 0; j < i; ++j)
iommu_release_ownership(