On Mon, Aug 22, 2016 at 07:25:25PM -0400, Brijesh Singh wrote:
> From: Tom Lendacky <thomas.lendacky@xxxxxxx>
>
> EFI data is encrypted when the kernel is run under SEV. Update the
> page table references to be sure the EFI memory areas are accessed
> encrypted.
>
> Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
> ---
> arch/x86/platform/efi/efi_64.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
> index 0871ea4..98363f3 100644
> --- a/arch/x86/platform/efi/efi_64.c
> +++ b/arch/x86/platform/efi/efi_64.c
> @@ -213,7 +213,7 @@ void efi_sync_low_kernel_mappings(void)
>
> int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
> {
> - unsigned long pfn, text;
> + unsigned long pfn, text, flags;
> efi_memory_desc_t *md;
> struct page *page;
> unsigned npages;
> @@ -230,6 +230,10 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
> efi_scratch.efi_pgt = (pgd_t *)__sme_pa(efi_pgd);
> pgd = efi_pgd;
>
> + flags = _PAGE_NX | _PAGE_RW;
> + if (sev_active)
> + flags |= _PAGE_ENC;
So this is confusing me. There's this patch which says EFI data is
accessed in the clear:
https://lkml.kernel.org/r/20160822223738.29880.6909.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx
but now here it is encrypted when SEV is enabled.
Do you mean, it is encrypted here because we're in the guest kernel?
Thanks.
--
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--
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