RE: [PATCH V5 12/12] net: netvsc: Add Isolation VM support for netvsc driver

[Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>]

> -----Original Message-----
> From: Tianyu Lan <ltykernel@xxxxxxxxx>
> Sent: Tuesday, September 14, 2021 9:39 AM
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> Subject: [PATCH V5 12/12] net: netvsc: Add Isolation VM support for
> netvsc driver
> 
> From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
> 
> In Isolation VM, all shared memory with host needs to mark visible
> to host via hvcall. vmbus_establish_gpadl() has already done it for
> netvsc rx/tx ring buffer. The page buffer used by vmbus_sendpacket_
> pagebuffer() stills need to be handled. Use DMA API to map/umap
> these memory during sending/receiving packet and Hyper-V swiotlb
> bounce buffer dma address will be returned. The swiotlb bounce buffer
> has been masked to be visible to host during boot up.
> 
> Allocate rx/tx ring buffer via alloc_pages() in Isolation VM and map
> these pages via vmap(). After calling vmbus_establish_gpadl() which
> marks these pages visible to host, unmap these pages to release the
> virtual address mapped with physical address below shared_gpa_boundary
> and map them in the extra address space via vmap_pfn().
> 
> Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
> ---
> Change since v4:
>       * Allocate rx/tx ring buffer via alloc_pages() in Isolation VM
>       * Map pages after calling vmbus_establish_gpadl().
>       * set dma_set_min_align_mask for netvsc driver.
> 
> Change since v3:
>       * Add comment to explain why not to use dma_map_sg()
>       * Fix some error handle.
> ---

Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>

Thank you!