From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Brijesh Singh , Ard Biesheuvel , Tom Lendacky , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , linux-efi@vger.kernel.org, Ingo Molnar Subject: [PATCH 4.17 17/31] x86/efi: Access EFI MMIO data as unencrypted when SEV is active Date: Sat, 4 Aug 2018 11:00:52 +0200 Message-Id: <20180804082633.586381045@linuxfoundation.org> In-Reply-To: <20180804082632.304529527@linuxfoundation.org> References: <20180804082632.304529527@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Brijesh Singh 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 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 Signed-off-by: Greg Kroah-Hartman --- 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;