The patch titled
Subject: kernel/dma/remap.c: align the size in dma_common_*_remap()
has been added to the -mm tree. Its filename is
dma-remap-align-the-size-in-dma_common__remap.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/dma-remap-align-the-size-in-dma_common__remap.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/dma-remap-align-the-size-in-dma_common__remap.patch
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------------------------------------------------------
From: Eric Auger <eric.auger@xxxxxxxxxx>
Subject: kernel/dma/remap.c: align the size in dma_common_*_remap()
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.
Link: http://lkml.kernel.org/r/20200622202320.1331-1-eric.auger@xxxxxxxxxx
Fixes: 515e5b6d90d4 ("dma-mapping: use vmap insted of reimplementing it")
Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
Cc: Bharat Bhushan <bbhushan2@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/dma/remap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/dma/remap.c~dma-remap-align-the-size-in-dma_common__remap
+++ a/kernel/dma/remap.c
@@ -24,7 +24,7 @@ void *dma_common_pages_remap(struct page
{
void *vaddr;
- vaddr = vmap(pages, size >> PAGE_SHIFT, VM_DMA_COHERENT, prot);
+ vaddr = vmap(pages, PAGE_ALIGN(size) >> PAGE_SHIFT, VM_DMA_COHERENT, prot);
if (vaddr)
find_vm_area(vaddr)->pages = pages;
return vaddr;
@@ -37,7 +37,7 @@ void *dma_common_pages_remap(struct page
void *dma_common_contiguous_remap(struct page *page, size_t size,
pgprot_t prot, const void *caller)
{
- int count = size >> PAGE_SHIFT;
+ int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct page **pages;
void *vaddr;
int i;
_
Patches currently in -mm which might be from eric.auger@xxxxxxxxxx are
dma-remap-align-the-size-in-dma_common__remap.patch
