[lkml]   [2018]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 4.17 17/31] x86/efi: Access EFI MMIO data as unencrypted when SEV is active
4.17-stable review patch.  If anyone has any objections, please let me know.


From: Brijesh Singh <>

commit 9b788f32bee6b0b293a4bdfca4ad4bb0206407fb upstream.

SEV guest fails to update the UEFI runtime variables stored in the

The following commit:

1379edd59673 ("x86/efi: Access EFI data as encrypted when SEV is active")

unconditionally maps all the UEFI runtime data as 'encrypted' (C=1).

When SEV is active the UEFI runtime data marked as EFI_MEMORY_MAPPED_IO
should be mapped as 'unencrypted' so that both guest and hypervisor can
access the data.

Signed-off-by: Brijesh Singh <>
Signed-off-by: Ard Biesheuvel <>
Reviewed-by: Tom Lendacky <>
Cc: <> # 4.15.x
Cc: Linus Torvalds <>
Cc: Peter Zijlstra <>
Cc: Thomas Gleixner <>
Fixes: 1379edd59673 ("x86/efi: Access EFI data as encrypted ...")
Signed-off-by: Ingo Molnar <>
Signed-off-by: Greg Kroah-Hartman <>

arch/x86/platform/efi/efi_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -417,7 +417,7 @@ static void __init __map_region(efi_memo
if (!(md->attribute & EFI_MEMORY_WB))
flags |= _PAGE_PCD;

- if (sev_active())
+ if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO)
flags |= _PAGE_ENC;

pfn = md->phys_addr >> PAGE_SHIFT;

 \ /
  Last update: 2018-08-04 11:24    [W:0.099 / U:4.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site