Messages in this thread | | | Subject | Re: [PATCH v2 3/5] x86/mm: Centralize PMD flags in sme_encrypt_kernel() | From | Tom Lendacky <> | Date | Mon, 8 Jan 2018 17:18:26 -0600 |
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On 1/7/2018 10:28 AM, Borislav Petkov wrote: > On Thu, Dec 21, 2017 at 04:03:12PM -0600, Tom Lendacky wrote: >> In preparation for encrypting more than just the kernel during early >> boot processing, centralize the use of the PMD flag settings based >> on the type of mapping desired. When 4KB aligned encryption is added, >> this will allow either PTE flags or large page PMD flags to be used >> without requiring the caller to adjust. >> >> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> >> --- >> arch/x86/mm/mem_encrypt.c | 131 ++++++++++++++++++++++++++------------------- >> 1 file changed, 77 insertions(+), 54 deletions(-) >> >> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c >> index 5a20696..9b180f8 100644 >> --- a/arch/x86/mm/mem_encrypt.c >> +++ b/arch/x86/mm/mem_encrypt.c >> @@ -468,31 +468,40 @@ struct sme_populate_pgd_data { >> void *pgtable_area; >> pgd_t *pgd; >> >> - pmdval_t pmd_val; >> + pmdval_t pmd_flags; >> + unsigned long paddr; >> + >> unsigned long vaddr; >> + unsigned long vaddr_end; >> }; >> >> -static void __init sme_clear_pgd(pgd_t *pgd_base, unsigned long start, >> - unsigned long end) >> +static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd) >> { >> unsigned long pgd_start, pgd_end, pgd_size; >> pgd_t *pgd_p; >> >> - pgd_start = start & PGDIR_MASK; >> - pgd_end = end & PGDIR_MASK; >> + pgd_start = ppd->vaddr & PGDIR_MASK; >> + pgd_end = ppd->vaddr_end & PGDIR_MASK; >> >> pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1); >> pgd_size *= sizeof(pgd_t); > > This is a strange way of writing this. I'd expect: > > pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
Yup, clearer as one line. I can fix that up.
> >> >> - pgd_p = pgd_base + pgd_index(start); >> + pgd_p = ppd->pgd + pgd_index(ppd->vaddr); >> >> memset(pgd_p, 0, pgd_size); >> } >> >> -#define PGD_FLAGS _KERNPG_TABLE_NOENC >> -#define P4D_FLAGS _KERNPG_TABLE_NOENC >> -#define PUD_FLAGS _KERNPG_TABLE_NOENC >> -#define PMD_FLAGS (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL) >> +#define PGD_FLAGS _KERNPG_TABLE_NOENC >> +#define P4D_FLAGS _KERNPG_TABLE_NOENC >> +#define PUD_FLAGS _KERNPG_TABLE_NOENC >> + >> +#define PMD_FLAGS_LARGE (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL) >> + >> +#define PMD_FLAGS_DEC PMD_FLAGS_LARGE >> +#define PMD_FLAGS_DEC_WP ((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \ >> + (_PAGE_PAT | _PAGE_PWT)) >> + >> +#define PMD_FLAGS_ENC (PMD_FLAGS_LARGE | _PAGE_ENC) >> >> static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd) >> { >> @@ -561,7 +570,36 @@ static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd) >> >> pmd_p += pmd_index(ppd->vaddr); >> if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE)) >> - native_set_pmd(pmd_p, native_make_pmd(ppd->pmd_val)); >> + native_set_pmd(pmd_p, >> + native_make_pmd(ppd->paddr | ppd->pmd_flags)); > > Never do those ugly line breaks. Just let it stick out.
Will do.
Thanks, Tom
> > Otherwise, sme_encrypt_kernel() is starting to look quite readable :) >
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