On 3/26/2024 3:57 AM, Andrew Jones wrote:
> On Mon, Mar 25, 2024 at 04:36:22PM -0500, Pavan Kumar Paluri wrote:
>> In some cases, KUT guest might fail to exit boot services due to a
>> possible memory map update that might have taken place between
>> efi_get_memory_map() and efi_exit_boot_services() calls. As per UEFI
>> spec 2.10 (Section 7.4.6 EFI_BOOT_SERVICES.ExitBootServices()), we need
>> to update the memory map and retry call to exit boot
>> services.
>>
>> Signed-off-by: Pavan Kumar Paluri <papaluri@xxxxxxx>
>> ---
>> lib/efi.c | 23 ++++++++++++++++++-----
>> 1 file changed, 18 insertions(+), 5 deletions(-)
>>
>> diff --git a/lib/efi.c b/lib/efi.c
>> index 124e77685230..9d066bfad0b6 100644
>> --- a/lib/efi.c
>> +++ b/lib/efi.c
>> @@ -458,14 +458,27 @@ efi_status_t efi_main(efi_handle_t handle, efi_system_table_t *sys_tab)
>> }
>> #endif
>>
>> - /*
>> + /*
>> * Exit EFI boot services, let kvm-unit-tests take full control of the
>> - * guest
>> + * guest.
>> */
>> status = efi_exit_boot_services(handle, &efi_bootinfo.mem_map);
>> - if (status != EFI_SUCCESS) {
>> - printf("Failed to exit boot services\n");
>> - goto efi_main_error;
>> +
>> + /*
>> + * There is a possibility that memory map might have changed
>> + * between efi_get_memory_map() and efi_exit_boot_services in
>> + * which case status is EFI_INVALID_PARAMETER. As per UEFI spec
>> + * 2.10, we need to get the updated memory map and try again.
>> + */
>> + if (status == EFI_INVALID_PARAMETER) {
>
> Shouldn't we loop on this? The spec doesn't make it clear that the second
> try should always work.
>
Indeed, will plug in a do-while to loop on it.
Thanks,
Pavan
>> + efi_get_memory_map(&efi_bootinfo.mem_map);
>> +
>> + status = efi_exit_boot_services(handle,
>> + &efi_bootinfo.mem_map);
>> + if (status != EFI_SUCCESS) {
>> + printf("Failed to exit boot services\n");
>> + goto efi_main_error;
>> + }
>> }
>>
>> /* Set up arch-specific resources */
>> --
>> 2.34.1
>>
>
> Thanks,
> drew
