Re: [PATCH v3 3/3] xsm: properly handle error from XSM init

[Jan Beulich <jbeulich@suse.com>]

On 31.05.2022 17:08, Daniel P. Smith wrote:
> @@ -1690,7 +1691,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
>  
>      open_softirq(NEW_TLBFLUSH_CLOCK_PERIOD_SOFTIRQ, new_tlbflush_clock_period);
>  
> -    if ( opt_watchdog ) 
> +    if ( opt_watchdog )
>          nmi_watchdog = NMI_LOCAL_APIC;
>  
>      find_smp_config();

Please omit formatting changes to entirely unrelated pieces of code.

> @@ -1700,7 +1701,11 @@ void __init noreturn __start_xen(unsigned long mbi_p)
>      mmio_ro_ranges = rangeset_new(NULL, "r/o mmio ranges",
>                                    RANGESETF_prettyprint_hex);
>  
> -    xsm_multiboot_init(module_map, mbi);
> +    if ( xsm_multiboot_init(module_map, mbi) )
> +        warning_add("WARNING: XSM failed to initialize.\n"
> +                    "This has implications on the security of the system,\n"
> +                    "as uncontrolled communications between trusted and\n"
> +                    "untrusted domains may occur.\n");

Uncontrolled communication isn't the only thing that could occur, aiui.
So at the very least "e.g." or some such would want adding imo.

Now that return values are checked, I think that in addition to what
you already do the two function declarations may want decorating with
__must_check.

Jan