linux.git/kernel/dma, branch v5.8-rc3 Linux kernel source tree dma-remap: align the size in dma_common_*_remap() 2020-06-23T12:14:41+00:00 Eric Auger eric.auger@redhat.com 2020-06-23T12:07:55+00:00 8e36baf97b252cdcafa53589e8227cbb1e85f0b0 Running a guest with a virtio-iommu protecting virtio devices is broken since commit 515e5b6d90d4 ("dma-mapping: use vmap insted of reimplementing it"). Before the conversion, the size was page aligned in __get_vm_area_node(). Doing so fixes the regression. Fixes: 515e5b6d90d4 ("dma-mapping: use vmap insted of reimplementing it") Signed-off-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
Running a guest with a virtio-iommu protecting virtio devices
is broken since commit 515e5b6d90d4 ("dma-mapping: use vmap insted
of reimplementing it"). Before the conversion, the size was
page aligned in __get_vm_area_node(). Doing so fixes the
regression.

Fixes: 515e5b6d90d4 ("dma-mapping: use vmap insted of reimplementing it")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
dma-mapping: DMA_COHERENT_POOL should select GENERIC_ALLOCATOR 2020-06-23T12:13:58+00:00 Christoph Hellwig hch@lst.de 2020-06-18T15:23:31+00:00 d07ae4c486908615ab336b987c7c367d132fd844 The dma coherent pool code needs genalloc. Move the select over from DMA_REMAP, which doesn't actually need it. Fixes: dbed452a078d ("dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David Rientjes <rientjes@google.com> 
The dma coherent pool code needs genalloc.  Move the select over
from DMA_REMAP, which doesn't actually need it.

Fixes: dbed452a078d ("dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Rientjes <rientjes@google.com>
dma-direct: add missing set_memory_decrypted() for coherent mapping 2020-06-23T12:13:54+00:00 David Rientjes rientjes@google.com 2020-06-11T19:20:32+00:00 1a2b3357e860d890f8045367b179c7e7e802cd71 When a coherent mapping is created in dma_direct_alloc_pages(), it needs to be decrypted if the device requires unencrypted DMA before returning. Fixes: 3acac065508f ("dma-mapping: merge the generic remapping helpers into dma-direct") Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
When a coherent mapping is created in dma_direct_alloc_pages(), it needs
to be decrypted if the device requires unencrypted DMA before returning.

Fixes: 3acac065508f ("dma-mapping: merge the generic remapping helpers into dma-direct")
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
dma-direct: check return value when encrypting or decrypting memory 2020-06-17T07:29:38+00:00 David Rientjes rientjes@google.com 2020-06-11T19:20:30+00:00 56fccf21d1961a06e2a0c96ce446ebf036651062 __change_page_attr() can fail which will cause set_memory_encrypted() and set_memory_decrypted() to return non-zero. If the device requires unencrypted DMA memory and decryption fails, simply free the memory and fail. If attempting to re-encrypt in the failure path and that encryption fails, there is no alternative other than to leak the memory. Fixes: c10f07aa27da ("dma/direct: Handle force decryption for DMA coherent buffers in common code") Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
__change_page_attr() can fail which will cause set_memory_encrypted() and
set_memory_decrypted() to return non-zero.

If the device requires unencrypted DMA memory and decryption fails, simply
free the memory and fail.

If attempting to re-encrypt in the failure path and that encryption fails,
there is no alternative other than to leak the memory.

Fixes: c10f07aa27da ("dma/direct: Handle force decryption for DMA coherent buffers in common code")
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
dma-direct: re-encrypt memory if dma_direct_alloc_pages() fails 2020-06-17T07:29:38+00:00 David Rientjes rientjes@google.com 2020-06-11T19:20:29+00:00 96a539fa3bb71f443ae08e57b9f63d6e5bb2207c If arch_dma_set_uncached() fails after memory has been decrypted, it needs to be re-encrypted before freeing. Fixes: fa7e2247c572 ("dma-direct: make uncached_kernel_address more general") Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
If arch_dma_set_uncached() fails after memory has been decrypted, it needs
to be re-encrypted before freeing.

Fixes: fa7e2247c572 ("dma-direct: make uncached_kernel_address more general")
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
dma-direct: always align allocation size in dma_direct_alloc_pages() 2020-06-17T07:29:38+00:00 David Rientjes rientjes@google.com 2020-06-11T19:20:28+00:00 633d5fce78a61e8727674467944939f55b0bcfab dma_alloc_contiguous() does size >> PAGE_SHIFT and set_memory_decrypted() works at page granularity. It's necessary to page align the allocation size in dma_direct_alloc_pages() for consistent behavior. This also fixes an issue when arch_dma_prep_coherent() is called on an unaligned allocation size for dma_alloc_need_uncached() when CONFIG_DMA_DIRECT_REMAP is disabled but CONFIG_ARCH_HAS_DMA_SET_UNCACHED is enabled. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
dma_alloc_contiguous() does size >> PAGE_SHIFT and set_memory_decrypted()
works at page granularity.  It's necessary to page align the allocation
size in dma_direct_alloc_pages() for consistent behavior.

This also fixes an issue when arch_dma_prep_coherent() is called on an
unaligned allocation size for dma_alloc_need_uncached() when
CONFIG_DMA_DIRECT_REMAP is disabled but CONFIG_ARCH_HAS_DMA_SET_UNCACHED
is enabled.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
dma-direct: mark __dma_direct_alloc_pages static 2020-06-17T07:29:37+00:00 Christoph Hellwig hch@lst.de 2020-06-15T06:52:31+00:00 26749b3201ab05e288fbf78fbc8585dfa2da3218 Signed-off-by: Christoph Hellwig <hch@lst.de> 
Signed-off-by: Christoph Hellwig <hch@lst.de>
dma-direct: re-enable mmap for !CONFIG_MMU 2020-06-17T07:29:31+00:00 Christoph Hellwig hch@lst.de 2020-06-10T08:29:49+00:00 1fbf57d0530217b9f264eedc4867bf91479cdf3c nommu configfs can trivially map the coherent allocations to user space, as no actual page table setup is required and the kernel and the user space programs share the same address space. Fixes: 62fcee9a3bd7 ("dma-mapping: remove CONFIG_ARCH_NO_COHERENT_DMA_MMAP") Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: dillon min <dillon.minfei@gmail.com> Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: dillon min <dillon.minfei@gmail.com> 
nommu configfs can trivially map the coherent allocations to user space,
as no actual page table setup is required and the kernel and the user
space programs share the same address space.

Fixes: 62fcee9a3bd7 ("dma-mapping: remove CONFIG_ARCH_NO_COHERENT_DMA_MMAP")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: dillon min <dillon.minfei@gmail.com>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: dillon min <dillon.minfei@gmail.com>
dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL 2020-06-15T06:35:30+00:00 David Rientjes rientjes@google.com 2020-06-11T07:25:57+00:00 dbed452a078d56bc7f1abecc3edd6a75e8e4484e DMA_REMAP is an unnecessary requirement for AMD SEV, which requires DMA_COHERENT_POOL, so avoid selecting it when it is otherwise unnecessary. The only other requirement for DMA coherent pools is DMA_DIRECT_REMAP, so ensure that properly selects the config option when needed. Fixes: 82fef0ad811f ("x86/mm: unencrypted non-blocking DMA allocations use coherent pools") Reported-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca> Signed-off-by: David Rientjes <rientjes@google.com> Tested-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca> Signed-off-by: Christoph Hellwig <hch@lst.de> 
DMA_REMAP is an unnecessary requirement for AMD SEV, which requires
DMA_COHERENT_POOL, so avoid selecting it when it is otherwise unnecessary.

The only other requirement for DMA coherent pools is DMA_DIRECT_REMAP, so
ensure that properly selects the config option when needed.

Fixes: 82fef0ad811f ("x86/mm: unencrypted non-blocking DMA allocations use coherent pools")
Reported-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Signed-off-by: David Rientjes <rientjes@google.com>
Tested-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Signed-off-by: Christoph Hellwig <hch@lst.de>
dma-pool: fix too large DMA pools on medium memory size systems 2020-06-09T13:25:52+00:00 Geert Uytterhoeven geert@linux-m68k.org 2020-06-08T13:22:17+00:00 3ee06a6d532f75f20528ff4d2c473cda36c484fe On systems with at least 32 MiB, but less than 32 GiB of RAM, the DMA memory pools are much larger than intended (e.g. 2 MiB instead of 128 KiB on a 256 MiB system). Fix this by correcting the calculation of the number of GiBs of RAM in the system. Invert the order of the min/max operations, to keep on calculating in pages until the last step, which aids readability. Fixes: 1d659236fb43c4d2 ("dma-pool: scale the default DMA coherent pool size with memory capacity") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
On systems with at least 32 MiB, but less than 32 GiB of RAM, the DMA
memory pools are much larger than intended (e.g. 2 MiB instead of 128
KiB on a 256 MiB system).

Fix this by correcting the calculation of the number of GiBs of RAM in
the system.  Invert the order of the min/max operations, to keep on
calculating in pages until the last step, which aids readability.

Fixes: 1d659236fb43c4d2 ("dma-pool: scale the default DMA coherent pool size with memory capacity")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>