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x86/efi: Access EFI data as encrypted when SEV is active

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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 <brijesh.singh@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: linux-efi@vger.kernel.org
Cc: kvm@vger.kernel.org
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20171020143059.3291-8-brijesh.singh@amd.com
This commit is contained in:
Tom Lendacky 2017-10-20 09:30:49 -05:00 committed by Thomas Gleixner
parent a72ec5a34d
commit 1379edd596
1 changed files with 15 additions and 1 deletions
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16
arch/x86/platform/efi/efi_64.c
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@ -33,6 +33,7 @@
#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>
@ -370,7 +371,11 @@ 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;
}
@ -413,6 +418,9 @@ 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",
@ -539,6 +547,9 @@ 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);
}
@ -590,6 +601,9 @@ 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);
}
}