From bacf6b499e11760aef73a3bb5ce4e5eea74a3fd4 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Wed, 10 Jan 2018 13:26:05 -0600 Subject: [PATCH] x86/mm: Use a struct to reduce parameters for SME PGD mapping In preparation for follow-on patches, combine the PGD mapping parameters into a struct to reduce the number of function arguments and allow for direct updating of the next pagetable mapping area pointer. Tested-by: Gabriel Craciunescu Signed-off-by: Tom Lendacky Reviewed-by: Borislav Petkov Cc: Borislav Petkov Cc: Brijesh Singh Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180110192605.6026.96206.stgit@tlendack-t1.amdoffice.net Signed-off-by: Ingo Molnar --- arch/x86/mm/mem_encrypt.c | 90 ++++++++++++++++++++------------------- 1 file changed, 46 insertions(+), 44 deletions(-) diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index 391b13402e40..5a20696c5440 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -464,6 +464,14 @@ void swiotlb_set_mem_attributes(void *vaddr, unsigned long size) set_memory_decrypted((unsigned long)vaddr, size >> PAGE_SHIFT); } +struct sme_populate_pgd_data { + void *pgtable_area; + pgd_t *pgd; + + pmdval_t pmd_val; + unsigned long vaddr; +}; + static void __init sme_clear_pgd(pgd_t *pgd_base, unsigned long start, unsigned long end) { @@ -486,15 +494,14 @@ static void __init sme_clear_pgd(pgd_t *pgd_base, unsigned long start, #define PUD_FLAGS _KERNPG_TABLE_NOENC #define PMD_FLAGS (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL) -static void __init *sme_populate_pgd(pgd_t *pgd_base, void *pgtable_area, - unsigned long vaddr, pmdval_t pmd_val) +static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd) { pgd_t *pgd_p; p4d_t *p4d_p; pud_t *pud_p; pmd_t *pmd_p; - pgd_p = pgd_base + pgd_index(vaddr); + pgd_p = ppd->pgd + pgd_index(ppd->vaddr); if (native_pgd_val(*pgd_p)) { if (IS_ENABLED(CONFIG_X86_5LEVEL)) p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK); @@ -504,15 +511,15 @@ static void __init *sme_populate_pgd(pgd_t *pgd_base, void *pgtable_area, pgd_t pgd; if (IS_ENABLED(CONFIG_X86_5LEVEL)) { - p4d_p = pgtable_area; + p4d_p = ppd->pgtable_area; memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D); - pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D; + ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D; pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS); } else { - pud_p = pgtable_area; + pud_p = ppd->pgtable_area; memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD); - pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD; + ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD; pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS); } @@ -520,44 +527,41 @@ static void __init *sme_populate_pgd(pgd_t *pgd_base, void *pgtable_area, } if (IS_ENABLED(CONFIG_X86_5LEVEL)) { - p4d_p += p4d_index(vaddr); + p4d_p += p4d_index(ppd->vaddr); if (native_p4d_val(*p4d_p)) { pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK); } else { p4d_t p4d; - pud_p = pgtable_area; + pud_p = ppd->pgtable_area; memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD); - pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD; + ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD; p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS); native_set_p4d(p4d_p, p4d); } } - pud_p += pud_index(vaddr); + pud_p += pud_index(ppd->vaddr); if (native_pud_val(*pud_p)) { if (native_pud_val(*pud_p) & _PAGE_PSE) - goto out; + return; pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK); } else { pud_t pud; - pmd_p = pgtable_area; + pmd_p = ppd->pgtable_area; memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD); - pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD; + ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD; pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS); native_set_pud(pud_p, pud); } - pmd_p += pmd_index(vaddr); + 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(pmd_val)); - -out: - return pgtable_area; + native_set_pmd(pmd_p, native_make_pmd(ppd->pmd_val)); } static unsigned long __init sme_pgtable_calc(unsigned long len) @@ -615,11 +619,10 @@ void __init sme_encrypt_kernel(void) unsigned long workarea_start, workarea_end, workarea_len; unsigned long execute_start, execute_end, execute_len; unsigned long kernel_start, kernel_end, kernel_len; + struct sme_populate_pgd_data ppd; unsigned long pgtable_area_len; unsigned long paddr, pmd_flags; unsigned long decrypted_base; - void *pgtable_area; - pgd_t *pgd; if (!sme_active()) return; @@ -683,18 +686,18 @@ void __init sme_encrypt_kernel(void) * pagetables and when the new encrypted and decrypted kernel * mappings are populated. */ - pgtable_area = (void *)execute_end; + ppd.pgtable_area = (void *)execute_end; /* * Make sure the current pagetable structure has entries for * addressing the workarea. */ - pgd = (pgd_t *)native_read_cr3_pa(); + ppd.pgd = (pgd_t *)native_read_cr3_pa(); paddr = workarea_start; while (paddr < workarea_end) { - pgtable_area = sme_populate_pgd(pgd, pgtable_area, - paddr, - paddr + PMD_FLAGS); + ppd.pmd_val = paddr + PMD_FLAGS; + ppd.vaddr = paddr; + sme_populate_pgd_large(&ppd); paddr += PMD_PAGE_SIZE; } @@ -708,17 +711,17 @@ void __init sme_encrypt_kernel(void) * populated with new PUDs and PMDs as the encrypted and decrypted * kernel mappings are created. */ - pgd = pgtable_area; - memset(pgd, 0, sizeof(*pgd) * PTRS_PER_PGD); - pgtable_area += sizeof(*pgd) * PTRS_PER_PGD; + ppd.pgd = ppd.pgtable_area; + memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD); + ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD; /* Add encrypted kernel (identity) mappings */ pmd_flags = PMD_FLAGS | _PAGE_ENC; paddr = kernel_start; while (paddr < kernel_end) { - pgtable_area = sme_populate_pgd(pgd, pgtable_area, - paddr, - paddr + pmd_flags); + ppd.pmd_val = paddr + pmd_flags; + ppd.vaddr = paddr; + sme_populate_pgd_large(&ppd); paddr += PMD_PAGE_SIZE; } @@ -736,9 +739,9 @@ void __init sme_encrypt_kernel(void) pmd_flags = (PMD_FLAGS & ~_PAGE_CACHE_MASK) | (_PAGE_PAT | _PAGE_PWT); paddr = kernel_start; while (paddr < kernel_end) { - pgtable_area = sme_populate_pgd(pgd, pgtable_area, - paddr + decrypted_base, - paddr + pmd_flags); + ppd.pmd_val = paddr + pmd_flags; + ppd.vaddr = paddr + decrypted_base; + sme_populate_pgd_large(&ppd); paddr += PMD_PAGE_SIZE; } @@ -746,30 +749,29 @@ void __init sme_encrypt_kernel(void) /* Add decrypted workarea mappings to both kernel mappings */ paddr = workarea_start; while (paddr < workarea_end) { - pgtable_area = sme_populate_pgd(pgd, pgtable_area, - paddr, - paddr + PMD_FLAGS); + ppd.pmd_val = paddr + PMD_FLAGS; + ppd.vaddr = paddr; + sme_populate_pgd_large(&ppd); - pgtable_area = sme_populate_pgd(pgd, pgtable_area, - paddr + decrypted_base, - paddr + PMD_FLAGS); + ppd.vaddr = paddr + decrypted_base; + sme_populate_pgd_large(&ppd); paddr += PMD_PAGE_SIZE; } /* Perform the encryption */ sme_encrypt_execute(kernel_start, kernel_start + decrypted_base, - kernel_len, workarea_start, (unsigned long)pgd); + kernel_len, workarea_start, (unsigned long)ppd.pgd); /* * At this point we are running encrypted. Remove the mappings for * the decrypted areas - all that is needed for this is to remove * the PGD entry/entries. */ - sme_clear_pgd(pgd, kernel_start + decrypted_base, + sme_clear_pgd(ppd.pgd, kernel_start + decrypted_base, kernel_end + decrypted_base); - sme_clear_pgd(pgd, workarea_start + decrypted_base, + sme_clear_pgd(ppd.pgd, workarea_start + decrypted_base, workarea_end + decrypted_base); /* Flush the TLB - no globals so cr3 is enough */