Re: [Qemu-devel] [PATCH v12 11/28] sev/i386: add command to initialize the memory encryption context

["Daniel P. Berrangé" <berrange@redhat.com>]

On Thu, Mar 08, 2018 at 06:48:44AM -0600, Brijesh Singh wrote:
> When memory encryption is enabled, KVM_SEV_INIT command is used to
> initialize the platform. The command loads the SEV related persistent
> data from non-volatile storage and initializes the platform context.
> This command should be first issued before invoking any other guest
> commands provided by the SEV firmware.
> 
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Richard Henderson <rth@twiddle.net>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
>  accel/kvm/kvm-all.c       |  16 ++++
>  include/sysemu/sev.h      |  22 +++++
>  stubs/Makefile.objs       |   1 +
>  stubs/sev.c               |  21 +++++
>  target/i386/Makefile.objs |   2 +-
>  target/i386/monitor.c     |  11 ++-
>  target/i386/sev-stub.c    |  41 +++++++++
>  target/i386/sev.c         | 224 ++++++++++++++++++++++++++++++++++++++++++++++
>  target/i386/sev_i386.h    |  24 +++++
>  target/i386/trace-events  |   3 +
>  10 files changed, 362 insertions(+), 3 deletions(-)
>  create mode 100644 include/sysemu/sev.h
>  create mode 100644 stubs/sev.c
>  create mode 100644 target/i386/sev-stub.c
> 

> +static const char *const sev_fw_errlist[] = {
> +    "",
> +    "Platform state is invalid",
> +    "Guest state is invalid",
> +    "Platform configuration is invalid",
> +    "Buffer too small",
> +    "Platform is already owned",
> +    "Certificate is invalid",
> +    "Policy is not allowed",
> +    "Guest is not active",
> +    "Invalid address",
> +    "Bad signature",
> +    "Bad measurement",
> +    "Asid is already owned",
> +    "Invalid ASID",
> +    "WBINVD is required",
> +    "DF_FLUSH is required",
> +    "Guest handle is invalid",
> +    "Invalid command",
> +    "Guest is active",
> +    "Hardware error",
> +    "Hardware unsafe",
> +    "Feature not supported",
> +    "Invalid parameter"
> +};
> +
> +#define SEV_FW_MAX_ERROR      ARRAY_SIZE(sev_fw_errlist)
> +

> +static const char *
> +fw_error_to_str(int code)
> +{
> +    if (code >= SEV_FW_MAX_ERROR) {
> +        return "unknown error";

Seems '0' is not an error, and negative numbers are invalid
too, so augment this with   '|| code <= 0' to avoid bad array
access on negative numbers

> +    }
> +
> +    return sev_fw_errlist[code];
> +}

Regards,
Daniel
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