Re: [RFC PATCH 2/6] i386/sev: extend sev-guest property to include SEV-SNP

[Dov Murik]

On 10/07/2021 0:55, Brijesh Singh wrote:
> To launch the SEV-SNP guest, a user can specify up to 8 parameters.
> Passing all parameters through command line can be difficult. To simplify
> the launch parameter passing, introduce a .ini-like config file that can be
> used for passing the parameters to the launch flow.
> 
> The contents of the config file will look like this:
> 
> $ cat snp-launch.init
> 
> # SNP launch parameters
> [SEV-SNP]
> init_flags = 0
> policy = 0x1000
> id_block = "YWFhYWFhYWFhYWFhYWFhCg=="
> 
> 
> Add 'snp' property that can be used to indicate that SEV guest launch
> should enable the SNP support.
> 
> SEV-SNP guest launch examples:
> 
> 1) launch without additional parameters
> 
>   $(QEMU_CLI) \
>     -object sev-guest,id=sev0,snp=on
> 
> 2) launch with optional parameters
>   $(QEMU_CLI) \
>     -object sev-guest,id=sev0,snp=on,launch-config=<file>
> 

Not directly SNP-related, but in an internal communication Connor told
me he wants to allow the SEV configuration (like dh-cert-file etc.) to
be set using QMP commands when the machine launches instead (or in
addition to) setting them via QEMU command-line parameters.

Whatever the configuration solution decided for the SEV parameters
should also apply to these new SNP settings (policy, id_block, etc.).

-Dov