[Part1 PATCH v7 07/17] x86/efi: Access EFI data as encrypted when SEV is active
From: Brijesh Singh <hidden>
Date: 2017-10-20 14:37:07
Also in:
kvm, lkml
Subsystem:
extensible firmware interface (efi), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Ard Biesheuvel, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Tom Lendacky <thomas.lendacky@amd.com> 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@amd.com> Signed-off-by: Brijesh Singh <redacted> Reviewed-by: Borislav Petkov <redacted> Tested-by: Borislav Petkov <redacted> Cc: Thomas Gleixner <redacted> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <redacted> Cc: Andy Lutomirski <luto@kernel.org> Cc: Matt Fleming <redacted> Cc: Ard Biesheuvel <redacted> Cc: linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: x86@kernel.org --- arch/x86/platform/efi/efi_64.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 12e83888e5b9..5469c9319f43 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c@@ -32,6 +32,7 @@ #include <linux/reboot.h> #include <linux/slab.h> #include <linux/ucs2_string.h> +#include <linux/mem_encrypt.h> #include <asm/setup.h> #include <asm/page.h>
@@ -369,7 +370,11 @@ 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; + + 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 +417,9 @@ 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",
@@ -538,6 +546,9 @@ static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *m if (!(md->attribute & EFI_MEMORY_RO)) pf |= _PAGE_RW; + if (sev_active()) + pf |= _PAGE_ENC; + return efi_update_mappings(md, pf); }
@@ -589,6 +600,9 @@ void __init efi_runtime_update_mappings(void) (md->type != EFI_RUNTIME_SERVICES_CODE)) pf |= _PAGE_RW; + if (sev_active()) + pf |= _PAGE_ENC; + efi_update_mappings(md, pf); } }
--
2.9.5