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

Borislav Petkov
2020-08-31T09:45:50Z

On Mon, Aug 24, 2020 at 10:54:37AM +0200, Joerg Roedel wrote:
> +#ifdef CONFIG_AMD_MEM_ENCRYPT
> +static void set_early_idt_handler(gate_desc *idt, int n, void *handler)
> +{
> + struct idt_data data;
> + gate_desc desc;
> +
> + init_idt_data(&data, n, handler);
> + idt_init_desc(&desc, &data);
> + native_write_idt_entry(idt, n, &desc);
> +}
> +#endif
> +
> +static struct desc_ptr early_idt_descr __initdata = {
> + .size = IDT_TABLE_SIZE - 1,
> + .address = 0 /* Needs physical address of idt_table - initialized at runtime. */,
> +};
> +
> +void __init early_idt_setup(unsigned long physbase)
> +{
> + void __maybe_unused *handler;
> + gate_desc *idt;
> +
> + idt = fixup_pointer(idt_table, physbase);
> +
> +#ifdef CONFIG_AMD_MEM_ENCRYPT
> + /* VMM Communication Exception */
> + handler = fixup_pointer(vc_no_ghcb, physbase);
> + set_early_idt_handler(idt, X86_TRAP_VC, handler);

This function is used only once AFAICT - you might just as well add its
three-lined body here and save yourself the function definition and
ifdeffery above...

> +#endif
> +
> + /* Initialize IDT descriptor and load IDT */
> + early_idt_descr.address = (unsigned long)idt;
> + native_load_idt(&early_idt_descr);
> +}
> --
> 2.28.0
>

--
Regards/Gruss,
Boris.