Messages in this thread | | | Date | Tue, 15 Aug 2023 11:34:35 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH] iommu/vt-d: Atomic breakdown of IOPT into finer granularity |
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On Mon, Aug 14, 2023 at 08:10:16PM +0800, Jie Ji wrote: > With the addition of IOMMU support for IO page fault, it's now possible > to unpin the memory which DMA remapping. However, the lack of support > for unmapping a subrange of the I/O page table (IOPT) in IOMMU can lead > to some issues. > > For instance, a virtual machine can establish IOPT of 2M/1G for better > performance, while the host system enable swap and attempts to swap out > some 4K pages. Unfortunately, unmap subrange of the large-page mapping > will make IOMMU page walk to error level, and finally cause kernel crash.
Nothing in-kernel does something like this.
Jason
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