Drivers: hv: Explicitly request decrypted in vmap_pfn() calls

Update vmap_pfn() calls to explicitly request that the mapping
be for decrypted access to the memory.  There's no change in
functionality since the PFNs passed to vmap_pfn() are above the
shared_gpa_boundary, implicitly producing a decrypted mapping.
But explicitly requesting "decrypted" allows the code to work
before and after changes that cause vmap_pfn() to mask the
PFNs to being below the shared_gpa_boundary.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/1679838727-87310-4-git-send-email-mikelley@microsoft.com

arch/x86/hyperv/ivm.c

@@ -343,7 +343,7 @@ void *hv_map_memory(void *addr, unsigned long size)
 		pfns[i] = vmalloc_to_pfn(addr + i * PAGE_SIZE) +
 			(ms_hyperv.shared_gpa_boundary >> PAGE_SHIFT);
 
-	vaddr = vmap_pfn(pfns, size / PAGE_SIZE, PAGE_KERNEL_IO);
+	vaddr = vmap_pfn(pfns, size / PAGE_SIZE, pgprot_decrypted(PAGE_KERNEL));
 	kfree(pfns);
 
 	return vaddr;

drivers/hv/ring_buffer.c

@@ -211,7 +211,7 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 
 		ring_info->ring_buffer = (struct hv_ring_buffer *)
 			vmap_pfn(pfns_wraparound, page_cnt * 2 - 1,
-				 PAGE_KERNEL);
+				 pgprot_decrypted(PAGE_KERNEL));
 		kfree(pfns_wraparound);
 
 		if (!ring_info->ring_buffer)