A value of efi.runtime_version is checked before calling
update_capsule()/query_variable_info() as follows.
But it isn't initialized anywhere.
<snip>
static efi_status_t virt_efi_query_variable_info(u32 attr,
                                                 u64 *storage_space,
                                                 u64 *remaining_space,
                                                 u64 *max_variable_size)
{
        if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
                return EFI_UNSUPPORTED;
<snip>
This patch initializes a value of efi.runtime_version at boot time.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
         *
         * Call EFI services through wrapper functions.
         */
+       efi.runtime_version = efi_systab.fw_revision;
        efi.get_time = virt_efi_get_time;
        efi.set_time = virt_efi_set_time;
        efi.get_wakeup_time = virt_efi_get_wakeup_time;