From 9b788f32bee6b0b293a4bdfca4ad4bb0206407fb Mon Sep 17 00:00:00 2001 From: Brijesh Singh Date: Fri, 20 Jul 2018 10:28:46 +0900 Subject: [PATCH] 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 Signed-off-by: Ard Biesheuvel Reviewed-by: Tom Lendacky Cc: # 4.15.x Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner 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 --- 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;