Re: [PATCH v11 42/45] virt: Add SEV-SNP guest driver

[Dave Hansen]

On 3/4/22 05:17, Brijesh Singh wrote:
>> BTW, this look like a generic allocator thingy.  But it's only ever used
>> to allocate a 'struct snp_guest_msg'.  Why all the trouble to allocate
>> and free one fixed-size structure?  The changelog and comments don't
>> shed any light.
> The GHCB specification says that a guest must use shared memory for
> request, response, and certificate blob. In this patch, you are seeing
> that {alloc,free}_shared_pages() used only to alloc/free the request and
> response page. In the last patch, we used the same generic function to
> allocate the certificate blob with a different size (~16K) than 'struct
> snp_guest_msg.'

It sounds like it's worth a sentence or two in the changelog to explain
this new "allocator" and its future uses.