From: David Stevens <stevensd@chromium.org>
To: Robin Murphy <robin.murphy@arm.com>, Christoph Hellwig <hch@lst.de>
Cc: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Lu Baolu <baolu.lu@linux.intel.com>, Tom Murphy <murphyt7@tcd.ie>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
David Stevens <stevensd@chromium.org>
Subject: [PATCH v6 6/7] swiotlb: support aligned swiotlb buffers
Date: Tue, 17 Aug 2021 10:38:51 +0900 [thread overview]
Message-ID: <20210817013852.3222824-7-stevensd@google.com> (raw)
In-Reply-To: <20210817013852.3222824-1-stevensd@google.com>
From: David Stevens <stevensd@chromium.org>
Add an argument to swiotlb_tbl_map_single that specifies the desired
alignment of the allocated buffer. This is used by dma-iommu to ensure
the buffer is aligned to the iova granule size when using swiotlb with
untrusted sub-granule mappings. This addresses an issue where adjacent
slots could be exposed to the untrusted device if IO_TLB_SIZE < iova
granule < PAGE_SIZE.
Signed-off-by: David Stevens <stevensd@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
drivers/iommu/dma-iommu.c | 4 ++--
drivers/xen/swiotlb-xen.c | 2 +-
include/linux/swiotlb.h | 3 ++-
kernel/dma/swiotlb.c | 11 +++++++----
4 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 49a0d4de5f6c..6738420fc081 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -800,8 +800,8 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
size_t padding_size;
aligned_size = iova_align(iovad, size);
- phys = swiotlb_tbl_map_single(dev, phys, size,
- aligned_size, dir, attrs);
+ phys = swiotlb_tbl_map_single(dev, phys, size, aligned_size,
+ iova_mask(iovad), dir, attrs);
if (phys == DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 24d11861ac7d..8b03d2c93428 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -382,7 +382,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
*/
trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);
- map = swiotlb_tbl_map_single(dev, phys, size, size, dir, attrs);
+ map = swiotlb_tbl_map_single(dev, phys, size, size, 0, dir, attrs);
if (map == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 216854a5e513..93d82e43eb3a 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -44,7 +44,8 @@ extern void __init swiotlb_update_mem_attributes(void);
phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t phys,
size_t mapping_size, size_t alloc_size,
- enum dma_data_direction dir, unsigned long attrs);
+ unsigned int alloc_aligned_mask, enum dma_data_direction dir,
+ unsigned long attrs);
extern void swiotlb_tbl_unmap_single(struct device *hwdev,
phys_addr_t tlb_addr,
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index e50df8d8f87e..d4c45d8cd1fa 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -427,7 +427,7 @@ static unsigned int wrap_index(struct io_tlb_mem *mem, unsigned int index)
* allocate a buffer from that IO TLB pool.
*/
static int find_slots(struct device *dev, phys_addr_t orig_addr,
- size_t alloc_size)
+ size_t alloc_size, unsigned int alloc_align_mask)
{
struct io_tlb_mem *mem = io_tlb_default_mem;
unsigned long boundary_mask = dma_get_seg_boundary(dev);
@@ -450,6 +450,7 @@ static int find_slots(struct device *dev, phys_addr_t orig_addr,
stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1;
if (alloc_size >= PAGE_SIZE)
stride = max(stride, stride << (PAGE_SHIFT - IO_TLB_SHIFT));
+ stride = max(stride, (alloc_align_mask >> IO_TLB_SHIFT) + 1);
spin_lock_irqsave(&mem->lock, flags);
if (unlikely(nslots > mem->nslabs - mem->used))
@@ -504,7 +505,8 @@ static int find_slots(struct device *dev, phys_addr_t orig_addr,
phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
size_t mapping_size, size_t alloc_size,
- enum dma_data_direction dir, unsigned long attrs)
+ unsigned int alloc_align_mask, enum dma_data_direction dir,
+ unsigned long attrs)
{
struct io_tlb_mem *mem = io_tlb_default_mem;
unsigned int offset = swiotlb_align_offset(dev, orig_addr);
@@ -524,7 +526,8 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
return (phys_addr_t)DMA_MAPPING_ERROR;
}
- index = find_slots(dev, orig_addr, alloc_size + offset);
+ index = find_slots(dev, orig_addr,
+ alloc_size + offset, alloc_align_mask);
if (index == -1) {
if (!(attrs & DMA_ATTR_NO_WARN))
dev_warn_ratelimited(dev,
@@ -636,7 +639,7 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,
trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size,
swiotlb_force);
- swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, dir,
+ swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, 0, dir,
attrs);
if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;
--
2.33.0.rc1.237.g0d66db33f3-goog
next prev parent reply other threads:[~2021-08-17 1:39 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-17 1:38 [PATCH v6 0/7] Fixes for dma-iommu swiotlb bounce buffers David Stevens
2021-08-17 1:38 ` [PATCH v6 1/7] dma-iommu: fix sync_sg with swiotlb David Stevens
2021-08-17 1:38 ` [PATCH v6 2/7] dma-iommu: fix arch_sync_dma for map David Stevens
2021-08-19 8:59 ` Robin Murphy
2021-08-17 1:38 ` [PATCH v6 3/7] dma-iommu: skip extra sync during unmap w/swiotlb David Stevens
2021-08-19 8:59 ` Robin Murphy
2021-08-17 1:38 ` [PATCH v6 4/7] dma-iommu: fold _swiotlb helpers into callers David Stevens
2021-08-19 9:00 ` Robin Murphy
2021-08-17 1:38 ` [PATCH v6 5/7] dma-iommu: Check CONFIG_SWIOTLB more broadly David Stevens
2021-08-17 1:38 ` David Stevens [this message]
2021-08-17 1:38 ` [PATCH v6 7/7] dma-iommu: account for min_align_mask David Stevens
2021-08-19 9:03 ` Robin Murphy
2021-08-19 10:05 ` David Stevens
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