4.17-stable review patch. If anyone has any objections, please let me know.
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From: Brijesh Singh brijesh.singh@amd.com
commit 9b788f32bee6b0b293a4bdfca4ad4bb0206407fb upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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;