From: Arnd Bergmann <[email protected]>
While system heap and system_cc_shared heap share a lot of code
and hence the same source file, their users have different needs.
system heap users need it to be a loadable module, while
system_cc_shared heap users don't.
Building as a loadable module breaks system_cc_shared heap on
powerpc and s390 due to un-exported set_memory_encrypted /
set_memory_decrypted functions.
Fix these by reorganising code to put the system_cc_shared heap
under a new Kconfig symbol, which allows either building both
into the kernel, or leave encryption up to the consumers of the
system heap.
Fixes: fd55edff8a0a ("dma-buf: heaps: system: Turn the heap into a module")
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Sumit Semwal <[email protected]>
---
drivers/dma-buf/heaps/Kconfig | 8 ++++++++
drivers/dma-buf/heaps/system_heap.c | 16 ++++++++++------
2 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index e273fb18feca..a39decdcf067 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -5,6 +5,14 @@ config DMABUF_HEAPS_SYSTEM
Choose this option to enable the system dmabuf heap. The system heap
is backed by pages from the buddy allocator. If in doubt, say Y.
+config DMABUF_HEAPS_CC_SYSTEM
+ bool "DMA-BUF System Heap for decrypted CoCo VMs"
+ depends on DMABUF_HEAPS && ARCH_HAS_MEM_ENCRYPT && DMABUF_HEAPS_SYSTEM=y
+ help
+ Choose this option to enable the system_cc_shared dmabuf heap. This
+ allows allocating shared (decrypted) memory for confidential computing
+ (CoCo) VMs.
+
config DMABUF_HEAPS_CMA
tristate "DMA-BUF CMA Heap"
depends on DMABUF_HEAPS && DMA_CMA
diff --git a/drivers/dma-buf/heaps/system_heap.c
b/drivers/dma-buf/heaps/system_heap.c
index c92bdec356fc..71d9028cc3df 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -48,6 +48,9 @@ struct dma_heap_attachment {
bool cc_shared;
};
+#define cc_shared_buffer(b) (IS_ENABLED(CONFIG_DMABUF_HEAPS_CC_SYSTEM) && \
+ (b)->cc_shared)
+
#define LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO)
#define HIGH_ORDER_GFP (((GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN \
| __GFP_NORETRY) & ~__GFP_RECLAIM) \
@@ -161,7 +164,7 @@ static struct sg_table *system_heap_map_dma_buf(struct
dma_buf_attachment *attac
unsigned long attrs;
int ret;
- attrs = a->cc_shared ? DMA_ATTR_CC_SHARED : 0;
+ attrs = cc_shared_buffer(a) ? DMA_ATTR_CC_SHARED : 0;
ret = dma_map_sgtable(attachment->dev, table, direction, attrs);
if (ret)
return ERR_PTR(ret);
@@ -233,7 +236,7 @@ static int system_heap_mmap(struct dma_buf *dmabuf, struct
vm_area_struct *vma)
int i, ret;
prot = vma->vm_page_prot;
- if (buffer->cc_shared)
+ if (cc_shared_buffer(buffer))
prot = pgprot_decrypted(prot);
for_each_sgtable_sg(table, sg, i) {
@@ -282,7 +285,7 @@ static void *system_heap_do_vmap(struct system_heap_buffer
*buffer)
}
prot = PAGE_KERNEL;
- if (buffer->cc_shared)
+ if (cc_shared_buffer(buffer))
prot = pgprot_decrypted(prot);
vaddr = vmap(pages, npages, VM_MAP, prot);
vfree(pages);
@@ -349,7 +352,7 @@ static void system_heap_dma_buf_release(struct dma_buf
*dmabuf)
* Intentionally leak pages that cannot be re-encrypted
* to prevent shared memory from being reused.
*/
- if (buffer->cc_shared &&
+ if (cc_shared_buffer(buffer) &&
system_heap_set_page_encrypted(page))
continue;
@@ -456,7 +459,7 @@ static struct dma_buf *system_heap_allocate(struct dma_heap
*heap,
list_del(&page->lru);
}
- if (cc_shared) {
+ if (cc_shared_buffer(buffer)) {
for_each_sgtable_sg(table, sg, i) {
ret = system_heap_set_page_decrypted(sg_page(sg));
if (ret)
@@ -485,7 +488,7 @@ static struct dma_buf *system_heap_allocate(struct dma_heap
*heap,
* Intentionally leak pages that cannot be re-encrypted
* to prevent shared memory from being reused.
*/
- if (buffer->cc_shared &&
+ if (cc_shared_buffer(buffer) &&
system_heap_set_page_encrypted(p))
continue;
__free_pages(p, compound_order(p));
@@ -525,6 +528,7 @@ static int __init system_heap_create(void)
return PTR_ERR(sys_heap);
if (IS_ENABLED(CONFIG_HIGHMEM) ||
+ !IS_ENABLED(CONFIG_DMABUF_HEAPS_CC_SYSTEM) ||
!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
return 0;
--
2.43.0
