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

-----Original Message-----
From: Tianyu Lan <redacted>
Sent: Tuesday, September 14, 2021 9:39 AM
To: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
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Subject: [PATCH V5 12/12] net: netvsc: Add Isolation VM support for
netvsc driver

From: Tianyu Lan <redacted>

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 <redacted>
---
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@microsoft.com>

Thank you!