Re: [PATCH v6 42/76] x86/sev-es: Setup early #VC handler

Lai Jiangshan
2021-09-04T09:39:55Z

> @@ -363,6 +370,33 @@ SYM_CODE_START_LOCAL(early_idt_handler_common)
> jmp restore_regs_and_return_to_kernel
> SYM_CODE_END(early_idt_handler_common)
>
> +#ifdef CONFIG_AMD_MEM_ENCRYPT
> +/*
> + * VC Exception handler used during very early boot. The
> + * early_idt_handler_array can't be used because it returns via the
> + * paravirtualized INTERRUPT_RETURN and pv-ops don't work that early.

Hello Joerg, Juergen

The commit ae755b5a4548 ("x86/paravirt: Switch iret pvops to ALTERNATIVE")
( https://lore.kernel.org/lkml/20210311142319.4723-12-jgross@suse.com/ )
had been merged and the paravirt_iret is deferenced based via %rip.

Can INTERRUPT_RETURN still be a problem if early_idt_handler_array
is used instead for bringup IDT?

Thanks
Lai