From: Borislav Petkov bp@suse.de
stable inclusion from stable-5.10.57 commit 06a9092f6647e180bd738f6a862235de9b0adf56 bugzilla: 176179 https://gitee.com/openeuler/kernel/issues/I4DZ64
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 47e1e233e9d822dfda068383fb9a616451bda703 ]
One of the SUSE QA tests triggered:
localhost kernel: efi: Failed to lookup EFI memory descriptor for 0x000000003dcf8000
which comes from x86's version of efi_arch_mem_reserve() trying to reserve a memory region. Usually, that function expects EFI_BOOT_SERVICES_DATA memory descriptors but the above case is for the MOKvar table which is allocated in the EFI shim as runtime services.
That lead to a fix changing the allocation of that table to boot services.
However, that fix broke booting SEV guests with that shim leading to this kernel fix
8d651ee9c71b ("x86/ioremap: Map EFI-reserved memory as encrypted for SEV")
which extended the ioremap hint to map reserved EFI boot services as decrypted too.
However, all that wasn't needed, IMO, because that error message in efi_arch_mem_reserve() was innocuous in this case - if the MOKvar table is not in boot services, then it doesn't need to be reserved in the first place because it is, well, in runtime services which *should* be reserved anyway.
So do that reservation for the MOKvar table only if it is allocated in boot services data. I couldn't find any requirement about where that table should be allocated in, unlike the ESRT which allocation is mandated to be done in boot services data by the UEFI spec.
Signed-off-by: Borislav Petkov bp@suse.de Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- drivers/firmware/efi/mokvar-table.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/mokvar-table.c b/drivers/firmware/efi/mokvar-table.c index d8bc01340686..38722d2009e2 100644 --- a/drivers/firmware/efi/mokvar-table.c +++ b/drivers/firmware/efi/mokvar-table.c @@ -180,7 +180,10 @@ void __init efi_mokvar_table_init(void) pr_err("EFI MOKvar config table is not valid\n"); return; } - efi_mem_reserve(efi.mokvar_table, map_size_needed); + + if (md.type == EFI_BOOT_SERVICES_DATA) + efi_mem_reserve(efi.mokvar_table, map_size_needed); + efi_mokvar_table_size = map_size_needed; }