Re: [PATCH v2 2/3] xen: Add an unsecure Taint type

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Mon, 26 Oct 2020, Bertrand Marquis wrote:
> Define a new Unsecure taint type to be used to signal a system tainted
> due to an unsecure configuration or hardware feature/errata.
> 
> Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
>  xen/common/kernel.c   | 4 +++-
>  xen/include/xen/lib.h | 1 +
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/xen/common/kernel.c b/xen/common/kernel.c
> index c3a943f077..7a345ae45e 100644
> --- a/xen/common/kernel.c
> +++ b/xen/common/kernel.c
> @@ -326,6 +326,7 @@ unsigned int tainted;
>   *  'E' - An error (e.g. a machine check exceptions) has been injected.
>   *  'H' - HVM forced emulation prefix is permitted.
>   *  'M' - Machine had a machine check experience.
> + *  'U' - Platform is unsecure (usually due to an errata on the platform).
>   *
>   *      The string is overwritten by the next call to print_taint().
>   */
> @@ -333,7 +334,8 @@ char *print_tainted(char *str)
>  {
>      if ( tainted )
>      {
> -        snprintf(str, TAINT_STRING_MAX_LEN, "Tainted: %c%c%c%c",
> +        snprintf(str, TAINT_STRING_MAX_LEN, "Tainted: %c%c%c%c%c",
> +                 tainted & TAINT_MACHINE_UNSECURE ? 'U' : ' ',
>                   tainted & TAINT_MACHINE_CHECK ? 'M' : ' ',
>                   tainted & TAINT_SYNC_CONSOLE ? 'C' : ' ',
>                   tainted & TAINT_ERROR_INJECT ? 'E' : ' ',
> diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
> index 1983bd6b86..a9679c913d 100644
> --- a/xen/include/xen/lib.h
> +++ b/xen/include/xen/lib.h
> @@ -193,6 +193,7 @@ uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c);
>  #define TAINT_MACHINE_CHECK             (1u << 1)
>  #define TAINT_ERROR_INJECT              (1u << 2)
>  #define TAINT_HVM_FEP                   (1u << 3)
> +#define TAINT_MACHINE_UNSECURE          (1u << 4)
>  extern unsigned int tainted;
>  #define TAINT_STRING_MAX_LEN            20
>  extern char *print_tainted(char *str);
> -- 
> 2.17.1
>