| Message ID | 148846760142.2349.8522516472305792434.stgit@brijesh-build-machine (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
On Thu, Mar 02, 2017 at 10:13:21AM -0500, Brijesh Singh wrote: > 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 <brijesh.singh@amd.com> This SOB chain looks good. > --- > 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 2d8674d..9a76ed8 100644 > --- a/arch/x86/platform/efi/efi_64.c > +++ b/arch/x86/platform/efi/efi_64.c > @@ -45,6 +45,7 @@ > #include <asm/realmode.h> > #include <asm/time.h> > #include <asm/pgalloc.h> > +#include <asm/mem_encrypt.h> > > /* > * We allocate runtime services regions bottom-up, starting from -4G, i.e. > @@ -286,7 +287,10 @@ 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; > + 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; > } > @@ -329,6 +333,9 @@ 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; > + So I'm wondering if we could avoid this sprinkling of _PAGE_ENC in the EFI code by defining something like __supported_pte_mask but called __efi_base_page_flags or so which has _PAGE_ENC cleared in the SME case, i.e., when baremetal and has it set in the SEV case. Then we could simply OR in __efi_base_page_flags which the SME/SEV code will set appropriately early enough. Hmm. Matt, what do you think?
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 2d8674d..9a76ed8 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -45,6 +45,7 @@ #include <asm/realmode.h> #include <asm/time.h> #include <asm/pgalloc.h> +#include <asm/mem_encrypt.h> /* * We allocate runtime services regions bottom-up, starting from -4G, i.e. @@ -286,7 +287,10 @@ 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; + 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; } @@ -329,6 +333,9 @@ 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", @@ -455,6 +462,9 @@ 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); } @@ -506,6 +516,9 @@ 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); } }