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.
> + 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
