Re: [RFC PATCH 5/6] i386/sev: add support to encrypt BIOS when SEV-SNP is enabled

[Connor Kuehl]

On 7/9/21 3:55 PM, Brijesh Singh wrote:
> The KVM_SEV_SNP_LAUNCH_UPDATE command is used for encrypting the bios
> image used for booting the SEV-SNP guest.
> 
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
>  target/i386/sev.c        | 33 ++++++++++++++++++++++++++++++++-
>  target/i386/trace-events |  1 +
>  2 files changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/target/i386/sev.c b/target/i386/sev.c
> index 259408a8f1..41dcb084d1 100644
> --- a/target/i386/sev.c
> +++ b/target/i386/sev.c
> @@ -883,6 +883,30 @@ out:
>      return ret;
>  }
>  
> +static int
> +sev_snp_launch_update(SevGuestState *sev, uint8_t *addr, uint64_t len, int 
> type)
> +{
> +    int ret, fw_error;
> +    struct kvm_sev_snp_launch_update update = {};
> +
> +    if (!addr || !len) {
> +        return 1;

Should this be a -1? It looks like the caller checks if this function
returns < 0, but doesn't check for res == 1.

Alternatively, invoking error_report might provide more useful
information that the preconditions to this function were violated.

Connor