Messages in this thread Patch in this message | | | From | Mario Limonciello <> | Subject | [PATCH 2/2] iommu: Don't use swiotlb unless it's active | Date | Mon, 4 Apr 2022 11:47:07 -0500 |
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The helper function `dev_use_swiotlb` is used for various decision making points for how to handle DMA mapping requests.
If the kernel doesn't have any memory allocated for swiotlb to use, then an untrusted device being connected to the system may fail to initialize when a request is made.
To avoid this situation, don't mark the use of swiotlb when it has not been set up.
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> --- drivers/iommu/dma-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 09f6e1c0f9c0..92ca136c8a12 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -504,7 +504,8 @@ static bool dev_is_untrusted(struct device *dev) static bool dev_use_swiotlb(struct device *dev) { - return IS_ENABLED(CONFIG_SWIOTLB) && dev_is_untrusted(dev); + return IS_ENABLED(CONFIG_SWIOTLB) && dev_is_untrusted(dev) \ + && is_swiotlb_active(dev); } /** -- 2.34.1
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