Re: [kvm-unit-tests PATCH v1 2/7] x86 UEFI: Refactor set up process

[Sean Christopherson <seanjc@google.com>]

On Sat, Oct 30, 2021, Zixuan Wang wrote:
> +efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo)
>  {
> +	efi_status_t status;
> +
> +	status = setup_memory_allocator(efi_bootinfo);
> +	if (status != EFI_SUCCESS) {
> +		printf("Failed to set up memory allocator: ");
> +		switch (status) {
> +		case EFI_OUT_OF_RESOURCES:
> +			printf("No free memory region\n");
> +			break;
> +		default:
> +			printf("Unknown error\n");
> +			break;
> +		}
> +		return status;
> +	}
> +	
> +	status = setup_rsdp(efi_bootinfo);
> +	if (status != EFI_SUCCESS) {
> +		printf("Cannot find RSDP in EFI system table\n");
> +		return status;
> +	}
> +
> +	status = setup_amd_sev();
> +	if (status != EFI_SUCCESS) {
> +		switch (status) {
> +		case EFI_UNSUPPORTED:
> +			/* Continue if AMD SEV is not supported */
> +			break;
> +		default:
> +			printf("Set up AMD SEV failed\n");
> +			return status;
> +		}
> +	}

Looks like this is pre-existing behavior, but the switch is quite gratuituous,
and arguably does the wrong thing for EFI_UNSUPPORTED here as attempting to setup
SEV-ES without SEV is guaranteed to fail.  And it'd be really nice if the printf()
actually provided the error (below might be wrong, I don't know the type of
efi_status-t).

	status = setup_amd_sev();

	/* Continue on if AMD SEV isn't supported, but skip SEV-ES setup. */
	if (status == EFI_UNSUPPORTED)
		goto continue_setup;

	if (status != EFI_SUCCESS) {
		printf("AMD SEV setup failed, error = %d\n", status);
		return status;
	}

	/* Same as above, lack of SEV-ES is not a fatal error. */
	status = setup_amd_sev_es();
	if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED) {
		printf("AMD SEV-ES setup failed, error = %d\n", status);
		return status;
	}

continue_setup:

> +
> +	status = setup_amd_sev_es();
> +	if (status != EFI_SUCCESS) {
> +		switch (status) {
> +		case EFI_UNSUPPORTED:
> +			/* Continue if AMD SEV-ES is not supported */
> +			break;
> +		default:
> +			printf("Set up AMD SEV-ES failed\n");
> +			return status;
> +		}
> +	}
> +
>  	reset_apic();
>  	setup_gdt_tss();
>  	setup_idt();
> @@ -343,9 +334,9 @@ void setup_efi(efi_bootinfo_t *efi_bootinfo)
>  	enable_apic();
>  	enable_x2apic();
>  	smp_init();
> -	phys_alloc_init(efi_bootinfo->free_mem_start, efi_bootinfo->free_mem_size);
> -	setup_efi_rsdp(efi_bootinfo->rsdp);
>  	setup_page_table();
> +
> +	return EFI_SUCCESS;
>  }
>  
>  #endif /* TARGET_EFI */
> -- 
> 2.33.0
>