[RFC,19/84] x86/mm: switch to new APIs in modify_xen_mappings

Commit Message

Xia, Hongyan Sept. 26, 2019, 9:45 a.m. UTC

From: Wei Liu <[e-mail]>

Page tables allocated in that function should be mapped and unmapped
now.

Signed-off-by: Wei Liu <[e-mail]>
---
 xen/arch/x86/mm.c | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

Patch

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 2333e93151..d2b873a958 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5564,6 +5564,7 @@  int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
         if ( l3e_get_flags(*pl3e) & _PAGE_PSE )
         {
             l2_pgentry_t *l2t;
+            mfn_t mfn;
 
             if ( l2_table_offset(v) == 0 &&
                  l1_table_offset(v) == 0 &&
@@ -5580,13 +5581,15 @@  int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
             }
 
             /* PAGE1GB: shatter the superpage and fall through. */
-            l2t = alloc_xen_pagetable();
-            if ( !l2t )
+            mfn = alloc_xen_pagetable_new();
+            if ( mfn_eq(mfn, INVALID_MFN) )
             {
                 ASSERT(rc == -ENOMEM);
                 goto out;
             }
 
+            l2t = map_xen_pagetable_new(mfn);
+
             for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ )
                 l2e_write(l2t + i,
                           l2e_from_pfn(l3e_get_pfn(*pl3e) +
@@ -5597,14 +5600,17 @@  int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
             if ( (l3e_get_flags(*pl3e) & _PAGE_PRESENT) &&
                  (l3e_get_flags(*pl3e) & _PAGE_PSE) )
             {
-                l3e_write_atomic(pl3e, l3e_from_mfn(virt_to_mfn(l2t),
-                                                    __PAGE_HYPERVISOR));
+                l3e_write_atomic(pl3e, l3e_from_mfn(mfn, __PAGE_HYPERVISOR));
+                UNMAP_XEN_PAGETABLE_NEW(l2t);
                 l2t = NULL;
             }
             if ( locking )
                 spin_unlock(&map_pgdir_lock);
             if ( l2t )
-                free_xen_pagetable(l2t);
+            {
+                UNMAP_XEN_PAGETABLE_NEW(l2t);
+                free_xen_pagetable_new(mfn);
+            }
         }
 
         /*
@@ -5639,15 +5645,18 @@  int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
             else
             {
                 l1_pgentry_t *l1t;
+                mfn_t mfn;
 
                 /* PSE: shatter the superpage and try again. */
-                l1t = alloc_xen_pagetable();
-                if ( !l1t )
+                mfn = alloc_xen_pagetable_new();
+                if ( mfn_eq(mfn, INVALID_MFN) )
                 {
                     ASSERT(rc == -ENOMEM);
                     goto out;
                 }
 
+                l1t = map_xen_pagetable_new(mfn);
+
                 for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
                     l1e_write(&l1t[i],
                               l1e_from_pfn(l2e_get_pfn(*pl2e) + i,
@@ -5657,14 +5666,18 @@  int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
                 if ( (l2e_get_flags(*pl2e) & _PAGE_PRESENT) &&
                      (l2e_get_flags(*pl2e) & _PAGE_PSE) )
                 {
-                    l2e_write_atomic(pl2e, l2e_from_mfn(virt_to_mfn(l1t),
+                    l2e_write_atomic(pl2e, l2e_from_mfn(mfn,
                                                         __PAGE_HYPERVISOR));
+                    UNMAP_XEN_PAGETABLE_NEW(l1t);
                     l1t = NULL;
                 }
                 if ( locking )
                     spin_unlock(&map_pgdir_lock);
                 if ( l1t )
-                    free_xen_pagetable(l1t);
+                {
+                    UNMAP_XEN_PAGETABLE_NEW(l1t);
+                    free_xen_pagetable_new(mfn);
+                }
             }
         }
         else