Re: [PATCH] efi: Reallocate memory map if ExitBootServices() fails

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 29/05/15 08:48, Ross Lagerwall wrote:
> If calling ExitBootServices() fails, the memory map size may have
> increased, so determine the new size and reallocate the memory map
> before calling GetMemoryMap() again.
>
> This was seen on the following machine when using the iscsidxe UEFI
> driver. The machine would consistently fail the first call to
> ExitBootServices().
> System Information
>         Manufacturer: Supermicro
>         Product Name: X10SLE-F/HF
> BIOS Information
>         Vendor: American Megatrends Inc.
>         Version: 2.00
>         Release Date: 04/24/2014
>
> Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

> ---
>  xen/common/efi/boot.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
> index ef8476c..078f9b8 100644
> --- a/xen/common/efi/boot.c
> +++ b/xen/common/efi/boot.c
> @@ -1053,14 +1053,14 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
>              efi_arch_video_init(gop, info_size, mode_info);
>      }
>  
> -    efi_bs->GetMemoryMap(&efi_memmap_size, NULL, &map_key,
> -                         &efi_mdesc_size, &mdesc_ver);
> -    efi_memmap = efi_arch_allocate_mmap_buffer(&efi_memmap_size);
> -    if ( !efi_memmap )
> -        blexit(L"Unable to allocate memory for EFI memory map");
> -
>      for ( retry = 0; ; retry = 1 )
>      {
> +        efi_bs->GetMemoryMap(&efi_memmap_size, NULL, &map_key,
> +                             &efi_mdesc_size, &mdesc_ver);
> +        efi_memmap = efi_arch_allocate_mmap_buffer(&efi_memmap_size);
> +        if ( !efi_memmap )
> +            blexit(L"Unable to allocate memory for EFI memory map");
> +
>          status = efi_bs->GetMemoryMap(&efi_memmap_size, efi_memmap, &map_key,
>                                        &efi_mdesc_size, &mdesc_ver);
>          if ( EFI_ERROR(status) )