SEV guest fails to update the UEFI runtime variables stored in the flash. 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.
Fixes: 1379edd59673 (x86/efi: Access EFI data as encrypted ...) Cc: Tom Lendacky thomas.lendacky@amd.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Borislav Petkov bp@suse.de Cc: linux-efi@vger.kernel.org Cc: kvm@vger.kernel.org Cc: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: Matt Fleming matt@codeblueprint.co.uk Cc: Andy Lutomirski luto@kernel.org Cc: stable@vger.kernel.org # 4.15.x Signed-off-by: Brijesh Singh brijesh.singh@amd.com --- 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 77873ce..5f2eb32 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;