On 16.01.2021 00:10, Andrew Cooper wrote:
> --- a/xen/arch/x86/cpu/common.c
> +++ b/xen/arch/x86/cpu/common.c
> @@ -834,6 +834,29 @@ void load_system_tables(void)
> BUG_ON(system_state != SYS_STATE_early_boot && (stack_bottom & 0xf));
> }
>
> +static void skinit_enable_intr(void)
> +{
> + uint64_t val;
> +
> + /*
> + * If the platform is performing a Secure Launch via SKINIT
> + * INIT_REDIRECTION flag will be active.
> + */
> + if ( !cpu_has_skinit || rdmsr_safe(MSR_K8_VM_CR, val) ||
> + !(val & VM_CR_INIT_REDIRECTION) )
> + return;
> +
> + ap_boot_method = AP_BOOT_SKINIT;
> +
> + /*
> + * We don't yet handle #SX. Disable INIT_REDIRECTION first, before
> + * enabling GIF, so a pending INIT resets us, rather than causing a
> + * panic due to an unknown exception.
> + */
> + wrmsr_safe(MSR_K8_VM_CR, val & ~VM_CR_INIT_REDIRECTION);
Why wrmsr_safe() without checking its return value? If the write
faults, we're hosed anyway, aren't we, so we may as well crash on
the offending WRMSR rather than some time later?
Jan
