> +static dma_addr_t hyperv_map_page(struct device *dev, struct page *page,
> + unsigned long offset, size_t size,
> + enum dma_data_direction dir,
> + unsigned long attrs)
> +{
> + phys_addr_t map, phys = (page_to_pfn(page) << PAGE_SHIFT) + offset;
> +
> + if (!hv_is_isolation_supported())
> + return phys;
> +
> + map = swiotlb_tbl_map_single(dev, phys, size, HV_HYP_PAGE_SIZE, dir,
> + attrs);
> + if (map == (phys_addr_t)DMA_MAPPING_ERROR)
> + return DMA_MAPPING_ERROR;
> +
> + return map;
> +}
This largerly duplicates what dma-direct + swiotlb does. Please use
force_dma_unencrypted to force bounce buffering and just use the generic
code.
> + if (hv_isolation_type_snp()) {
> + ret = hv_set_mem_host_visibility(
> + phys_to_virt(hyperv_io_tlb_start),
> + hyperv_io_tlb_size,
> + VMBUS_PAGE_VISIBLE_READ_WRITE);
> + if (ret)
> + panic("%s: Fail to mark Hyper-v swiotlb buffer visible to host. err=%d\n",
> + __func__, ret);
> +
> + hyperv_io_tlb_remap = ioremap_cache(hyperv_io_tlb_start
> + + ms_hyperv.shared_gpa_boundary,
> + hyperv_io_tlb_size);
> + if (!hyperv_io_tlb_remap)
> + panic("%s: Fail to remap io tlb.\n", __func__);
> +
> + memset(hyperv_io_tlb_remap, 0x00, hyperv_io_tlb_size);
> + swiotlb_set_bounce_remap(hyperv_io_tlb_remap);
And this really needs to go into a common hook where we currently just
call set_memory_decrypted so that all the different schemes for these
trusted VMs (we have about half a dozen now) can share code rather than
reinventing it.
