Messages in this thread | | | Date | Mon, 10 May 2021 20:37:49 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v4 1/2] iommu/sva: Tighten SVA bind API with explicit flags |
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On Mon, May 10, 2021 at 06:25:07AM -0700, Jacob Pan wrote:
> +/* > + * The IOMMU_SVA_BIND_SUPERVISOR flag requests a PASID which can be used only > + * for access to kernel addresses. No IOTLB flushes are automatically done > + * for kernel mappings; it is valid only for access to the kernel's static > + * 1:1 mapping of physical memory — not to vmalloc or even module mappings. > + * A future API addition may permit the use of such ranges, by means of an > + * explicit IOTLB flush call (akin to the DMA API's unmap method). > + * > + * It is unlikely that we will ever hook into flush_tlb_kernel_range() to > + * do such IOTLB flushes automatically. > + */ > +#define IOMMU_SVA_BIND_SUPERVISOR BIT(0)
Huh? That isn't really SVA, can you call it something saner please?
Is it really a PASID that always has all of physical memory mapped into it? Sounds dangerous. What is it for?
Jason
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