Messages in this thread Patch in this message | | | Date | Sun, 22 Jul 2018 08:19:02 -0700 | From | tip-bot for Brijesh Singh <> | Subject | [tip:efi/urgent] x86/efi: Access EFI MMIO data as unencrypted when SEV is active |
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Commit-ID: 9b788f32bee6b0b293a4bdfca4ad4bb0206407fb Gitweb: https://git.kernel.org/tip/9b788f32bee6b0b293a4bdfca4ad4bb0206407fb Author: Brijesh Singh <brijesh.singh@amd.com> AuthorDate: Fri, 20 Jul 2018 10:28:46 +0900 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Sun, 22 Jul 2018 14:10:38 +0200
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 <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> --- 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;
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