Messages in this thread | | | From | Tianyu Lan <> | Subject | [PATCH V2 0/2] x86/hyperv/Swiotlb: Add swiotlb_set_alloc_from_low_pages() switch function. | Date | Wed, 9 Feb 2022 07:23:00 -0500 |
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From: Tianyu Lan <Tianyu.Lan@microsoft.com>
Hyper-V Isolation VM may fail to allocate swiotlb bounce buffer due to there is no enough contiguous memory from 0 to 4G in some cases. Current swiotlb code allocates bounce buffer in the low end memory. This patchset adds a new function swiotlb_set_alloc_from_low_pages() to control swiotlb bounce buffer from low pages or no limitation. Devices in Hyper-V Isolation VM may use memory above 4G as DMA memory and switch swiotlb allocation in order to avoid no enough contiguous memory in low pages.
Tianyu Lan (2): Swiotlb: Add swiotlb_alloc_from_low_pages switch x86/hyperv: Make swiotlb bounce buffer allocation not just from low pages
arch/x86/kernel/cpu/mshyperv.c | 1 + include/linux/swiotlb.h | 1 + kernel/dma/swiotlb.c | 18 ++++++++++++++++-- 3 files changed, 18 insertions(+), 2 deletions(-)
-- 2.25.1
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