On 07.03.2022 21:53, Andrew Cooper wrote:
> --- a/xen/arch/x86/machine_kexec.c
> +++ b/xen/arch/x86/machine_kexec.c
> @@ -156,6 +156,16 @@ void machine_kexec(struct kexec_image *image)
> */
> local_irq_disable();
>
> + /* Reset CPUID masking and faulting to the host's default. */
> + ctxt_switch_levelling(NULL);
> +
> + /* Disable CET. */
> + if ( read_cr4() & X86_CR4_CET )
> + {
> + wrmsrl(MSR_S_CET, 0);
> + write_cr4(read_cr4() & ~X86_CR4_CET);
> + }
> +
> /* Now regular interrupts are disabled, we need to reduce the impact
> * of interrupts not disabled by 'cli'.
> *
Besides introducing somewhat of a disconnect between the comment in
context here and the earlier local_irq_disable(), is it really
necessary to do both actions with IRQs off?
Jan
