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@amd.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@vger.kernel.org> # 4.15.x
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes:
1379edd59673 ("x86/efi: Access EFI data as encrypted ...")
Link: http://lkml.kernel.org/r/20180720012846.23560-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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;