Re: [RFC PATCH v4 14/28] Add support to access boot related data in the clear

[Dave Young]

On 02/16/17 at 09:45am, Tom Lendacky wrote:
[snip]
> + * This function determines if an address should be mapped encrypted.
> + * Boot setup data, EFI data and E820 areas are checked in making this
> + * determination.
> + */
> +static bool memremap_should_map_encrypted(resource_size_t phys_addr,
> +					  unsigned long size)
> +{
> +	/*
> +	 * SME is not active, return true:
> +	 *   - For early_memremap_pgprot_adjust(), returning true or false
> +	 *     results in the same protection value
> +	 *   - For arch_memremap_do_ram_remap(), returning true will allow
> +	 *     the RAM remap to occur instead of falling back to ioremap()
> +	 */
> +	if (!sme_active())
> +		return true;

>From the function name shouldn't above be return false? 

> +
> +	/* Check if the address is part of the setup data */
> +	if (memremap_is_setup_data(phys_addr, size))
> +		return false;
> +
> +	/* Check if the address is part of EFI boot/runtime data */
> +	switch (efi_mem_type(phys_addr)) {
> +	case EFI_BOOT_SERVICES_DATA:
> +	case EFI_RUNTIME_SERVICES_DATA:

Only these two types needed? I'm not sure about this, just bring up the
question.

> +		return false;
> +	default:
> +		break;
> +	}
> +
> +	/* Check if the address is outside kernel usable area */
> +	switch (e820__get_entry_type(phys_addr, phys_addr + size - 1)) {
> +	case E820_TYPE_RESERVED:
> +	case E820_TYPE_ACPI:
> +	case E820_TYPE_NVS:
> +	case E820_TYPE_UNUSABLE:
> +		return false;
> +	default:
> +		break;
> +	}
> +
> +	return true;
> +}
> +

Thanks
Dave