From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [RFC Part1 PATCH v3 08/17] x86/efi: Access EFI data as encrypted when SEV is active Date: Fri, 28 Jul 2017 12:31:52 +0200 Message-ID: <20170728103152.GE1889@nazgul.tnic> References: <20170724190757.11278-1-brijesh.singh@amd.com> <20170724190757.11278-9-brijesh.singh@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20170724190757.11278-9-brijesh.singh-5C7GfCeVMHo@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Brijesh Singh Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andy Lutomirski , Tony Luck , Piotr Luc , Tom Lendacky , Fenghua Yu , Lu Baolu , Reza Arbab , David Howells , Matt Fleming , "Kirill A . Shutemov" , Laura Abbott , Ard Biesheuvel , Andrew Morton , Eric List-Id: linux-efi@vger.kernel.org On Mon, Jul 24, 2017 at 02:07:48PM -0500, Brijesh Singh wrote: > From: Tom Lendacky > > 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 > Signed-off-by: Brijesh Singh > --- > arch/x86/platform/efi/efi_64.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c > index 12e8388..1ecb3f6 100644 > --- a/arch/x86/platform/efi/efi_64.c > +++ b/arch/x86/platform/efi/efi_64.c > @@ -32,6 +32,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -369,7 +370,10 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) > * as trim_bios_range() will reserve the first page and isolate it away > * from memory allocators anyway. > */ > - if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, _PAGE_RW)) { > + pf = _PAGE_RW; > + if (sev_active()) > + pf |= _PAGE_ENC; \n here > + if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) { > pr_err("Failed to create 1:1 mapping for the first page!\n"); > return 1; > } > @@ -412,6 +416,9 @@ static void __init __map_region(efi_memory_desc_t *md, u64 va) > if (!(md->attribute & EFI_MEMORY_WB)) > flags |= _PAGE_PCD; > > + if (sev_active()) > + flags |= _PAGE_ENC; > + > pfn = md->phys_addr >> PAGE_SHIFT; > if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags)) > pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n", > @@ -511,6 +518,9 @@ static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf) > pgd_t *pgd = efi_pgd; > int err1, err2; > > + if (sev_active()) > + pf |= _PAGE_ENC; Move this assignment to the caller efi_update_mem_attr() where pf is being set... > + > /* Update the 1:1 mapping */ > pfn = md->phys_addr >> PAGE_SHIFT; > err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf); > @@ -589,6 +599,9 @@ void __init efi_runtime_update_mappings(void) > (md->type != EFI_RUNTIME_SERVICES_CODE)) > pf |= _PAGE_RW; > > + if (sev_active()) > + pf |= _PAGE_ENC; ... just like here. > + > efi_update_mappings(md, pf); In general, I'm not totally excited about that sprinkling of if (sev_active())... :-\ -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --