iommu/amd: Fix race in increase_address_space()
After the conversion to lock-less dma-api call the increase_address_space() function can be called without any locking. Multiple CPUs could potentially race for increasing the address space, leading to invalid domain->mode settings and invalid page-tables. This has been happening in the wild under high IO load and memory pressure. Fix the race by locking this operation. The function is called infrequently so that this does not introduce a performance regression in the dma-api path again. Reported-by: NQian Cai <cai@lca.pw> Fixes: 256e4621 ('iommu/amd: Make use of the generic IOVA allocator') Signed-off-by: NJoerg Roedel <jroedel@suse.de>
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