Commit-ID: 9b788f32bee6b0b293a4bdfca4ad4bb0206407fb
Gitweb: https://git.kernel.org/tip/9b788f32bee6b0b293a4bdfca4ad4bb0206407fb
Author: Brijesh Singh <brijesh.singh@xxxxxxx>
AuthorDate: Fri, 20 Jul 2018 10:28:46 +0900
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sun, 22 Jul 2018 14:10:38 +0200
x86/efi: Access EFI MMIO data as unencrypted when SEV is active
SEV guest fails to update the UEFI runtime variables stored in the
flash.
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 <brijesh.singh@xxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 4.15.x
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-efi@xxxxxxxxxxxxxxx
Fixes: 1379edd59673 ("x86/efi: Access EFI data as encrypted ...")
Link: http://lkml.kernel.org/r/20180720012846.23560-2-ard.biesheuvel@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/platform/efi/efi_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 77873ce700ae..5f2eb3231607 100644
--- 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_memory_desc_t *md, u64 va)
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;
--
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