From 38eecccdf488e38ee93690cfe9ec1914b73f512f Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Mon, 17 Jul 2017 16:10:15 -0500 Subject: [PATCH] x86/efi: Update EFI pagetable creation to work with SME MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When SME is active, pagetable entries created for EFI need to have the encryption mask set as necessary. When the new pagetable pages are allocated they are mapped encrypted. So, update the efi_pgt value that will be used in CR3 to include the encryption mask so that the PGD table can be read successfully. The pagetable mapping as well as the kernel are also added to the pagetable mapping as encrypted. All other EFI mappings are mapped decrypted (tables, etc.). Signed-off-by: Tom Lendacky Reviewed-by: Thomas Gleixner Reviewed-by: Matt Fleming Reviewed-by: Borislav Petkov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brijesh Singh Cc: Dave Young Cc: Dmitry Vyukov Cc: Jonathan Corbet Cc: Konrad Rzeszutek Wilk Cc: Larry Woodman Cc: Linus Torvalds Cc: Michael S. Tsirkin Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Radim Krčmář Cc: Rik van Riel Cc: Toshimitsu Kani Cc: kasan-dev@googlegroups.com Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/9a8f4c502db4a84b09e2f0a1555bb75aa8b69785.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar --- arch/x86/platform/efi/efi_64.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 9bf72f5bfedb..12e83888e5b9 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -327,7 +327,7 @@ virt_to_phys_or_null_size(void *va, unsigned long size) int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) { - unsigned long pfn, text; + unsigned long pfn, text, pf; struct page *page; unsigned npages; pgd_t *pgd; @@ -335,7 +335,12 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) if (efi_enabled(EFI_OLD_MEMMAP)) return 0; - efi_scratch.efi_pgt = (pgd_t *)__pa(efi_pgd); + /* + * Since the PGD is encrypted, set the encryption mask so that when + * this value is loaded into cr3 the PGD will be decrypted during + * the pagetable walk. + */ + efi_scratch.efi_pgt = (pgd_t *)__sme_pa(efi_pgd); pgd = efi_pgd; /* @@ -345,7 +350,8 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) * phys_efi_set_virtual_address_map(). */ pfn = pa_memmap >> PAGE_SHIFT; - if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, _PAGE_NX | _PAGE_RW)) { + pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC; + if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) { pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap); return 1; } @@ -388,7 +394,8 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) text = __pa(_text); pfn = text >> PAGE_SHIFT; - if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, _PAGE_RW)) { + pf = _PAGE_RW | _PAGE_ENC; + if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) { pr_err("Failed to map kernel text 1:1\n"); return 1; } -- 2.20.1