On 12/4/2017 5:23 AM, Kirill A. Shutemov wrote:
sme_populate_pgd() open-codes a lot of things that are not needed to be
open-coded.

Let's rewrite it in a more stream-lined way.

This would also buy us boot-time switching between support between
paging modes, when rest of the pieces will be upstream.

Hi Kirill,

Unfortunately, some of these can't be changed.  The use of p4d_offset(),
pud_offset(), etc., use non-identity mapped virtual addresses which cause
failures at this point of the boot process. Also, calls such as __p4d(),
__pud(), etc., are part of the paravirt support and can't be used yet,
either.  I can take a closer look at some of the others (p*d_none() and
p*d_large()) which make use of the native_ macros, but my worry would be
that these get changed in the future to the non-native calls and then
boot failures occur.

Thanks,
Tom


Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
---

The patch is only build tested. I don't have hardware. Tom, could you give it a 
try?

---
  arch/x86/mm/mem_encrypt.c | 89 +++++++++++++++--------------------------------
  1 file changed, 29 insertions(+), 60 deletions(-)

diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index d9a9e9fc75dd..16038f7472ca 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -489,73 +489,42 @@ static void __init sme_clear_pgd(pgd_t *pgd_base, 
unsigned long start,
  static void __init *sme_populate_pgd(pgd_t *pgd_base, void *pgtable_area,
                                     unsigned long vaddr, pmdval_t pmd_val)
  {
-       pgd_t *pgd_p;
-       p4d_t *p4d_p;
-       pud_t *pud_p;
-       pmd_t *pmd_p;
-
-       pgd_p = pgd_base + pgd_index(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);
-               else
-                       pud_p = (pud_t *)(native_pgd_val(*pgd_p) & 
~PTE_FLAGS_MASK);
-       } else {
-               pgd_t pgd;
-
-               if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-                       p4d_p = pgtable_area;
-                       memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
-                       pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
-
-                       pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
-               } else {
-                       pud_p = pgtable_area;
-                       memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-                       pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-                       pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
-               }
-               native_set_pgd(pgd_p, pgd);
+       pgd_t *pgd;
+       p4d_t *p4d;
+       pud_t *pud;
+       pmd_t *pmd;
+
+       pgd = pgd_base + pgd_index(vaddr);
+       if (pgd_none(*pgd)) {
+               p4d = pgtable_area;
+               memset(p4d, 0, sizeof(*p4d) * PTRS_PER_P4D);
+               pgtable_area += sizeof(*p4d) * PTRS_PER_P4D;
+               native_set_pgd(pgd, __pgd(PGD_FLAGS | __pa(p4d)));
        }
- if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-               p4d_p += p4d_index(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;
-                       memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-                       pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-                       p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
-                       native_set_p4d(p4d_p, p4d);
-               }
+       p4d = p4d_offset(pgd, vaddr);
+       if (p4d_none(*p4d)) {
+               pud = pgtable_area;
+               memset(pud, 0, sizeof(*pud) * PTRS_PER_PUD);
+               pgtable_area += sizeof(*pud) * PTRS_PER_PUD;
+               native_set_p4d(p4d, __p4d(P4D_FLAGS | __pa(pud)));
        }
- pud_p += pud_index(vaddr);
-       if (native_pud_val(*pud_p)) {
-               if (native_pud_val(*pud_p) & _PAGE_PSE)
-                       goto out;
-
-               pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
-       } else {
-               pud_t pud;
-
-               pmd_p = pgtable_area;
-               memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
-               pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
-
-               pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
-               native_set_pud(pud_p, pud);
+       pud = pud_offset(p4d, vaddr);
+       if (pud_none(*pud)) {
+               pmd = pgtable_area;
+               memset(pmd, 0, sizeof(*pmd) * PTRS_PER_PMD);
+               pgtable_area += sizeof(*pmd) * PTRS_PER_PMD;
+               native_set_pud(pud, __pud(PUD_FLAGS | __pa(pmd)));
        }
+       if (pud_large(*pud))
+               goto out;
- pmd_p += pmd_index(vaddr);
-       if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
-               native_set_pmd(pmd_p, native_make_pmd(pmd_val));
+       pmd = pmd_offset(pud, vaddr);
+       if (pmd_large(*pmd))
+               goto out;
+ native_set_pmd(pmd, native_make_pmd(pmd_val));
  out:
        return pgtable_area;
  }

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