[RFC,74/84] x86/pv: refactor how building dom0 in PV handles domheap mappings.

Commit Message

Xia, Hongyan Sept. 26, 2019, 9:46 a.m. UTC

From: Hongyan Xia <[e-mail]>

Building a PV dom0 is allocating from the domheap but uses it like the
xenheap. This is clearly wrong. Fix.

Signed-off-by: Hongyan Xia <[e-mail]>
---
 xen/arch/x86/pv/dom0_build.c | 40 ++++++++++++++++++++++++++----------
 xen/include/asm-x86/mm.h     |  1 +
 2 files changed, 30 insertions(+), 11 deletions(-)

Patch

diff --git a/xen/arch/x86/pv/dom0_build.c b/xen/arch/x86/pv/dom0_build.c
index 15b3ca2191..0ec30988b8 100644
--- a/xen/arch/x86/pv/dom0_build.c
+++ b/xen/arch/x86/pv/dom0_build.c
@@ -623,7 +623,10 @@  int __init dom0_construct_pv(struct domain *d,
     if ( !is_pv_32bit_domain(d) )
     {
         maddr_to_page(mpt_alloc)->u.inuse.type_info = PGT_l4_page_table;
-        l4start = l4tab = __va(mpt_alloc); mpt_alloc += PAGE_SIZE;
+        l4start = l4tab = __va(mpt_alloc);
+        map_pages_to_xen((unsigned long)l4start, maddr_to_mfn(mpt_alloc), 1,
+                PAGE_HYPERVISOR);
+        mpt_alloc += PAGE_SIZE;
         clear_page(l4tab);
         init_xen_l4_slots(l4tab, _mfn(virt_to_mfn(l4start)),
                           d, INVALID_MFN, true);
@@ -633,9 +636,12 @@  int __init dom0_construct_pv(struct domain *d,
     {
         /* Monitor table already created by switch_compat(). */
         l4start = l4tab = __va(pagetable_get_paddr(v->arch.guest_table));
+        map_pages_to_xen((unsigned long)l4start,
+                pagetable_get_mfn(v->arch.guest_table), 1, PAGE_HYPERVISOR);
         /* See public/xen.h on why the following is needed. */
         maddr_to_page(mpt_alloc)->u.inuse.type_info = PGT_l3_page_table;
-        l3start = __va(mpt_alloc); mpt_alloc += PAGE_SIZE;
+        l3start = map_xen_pagetable(maddr_to_mfn(mpt_alloc));
+        mpt_alloc += PAGE_SIZE;
     }
 
     l4tab += l4_table_offset(v_start);
@@ -645,14 +651,18 @@  int __init dom0_construct_pv(struct domain *d,
         if ( !((unsigned long)l1tab & (PAGE_SIZE-1)) )
         {
             maddr_to_page(mpt_alloc)->u.inuse.type_info = PGT_l1_page_table;
-            l1start = l1tab = __va(mpt_alloc); mpt_alloc += PAGE_SIZE;
+            UNMAP_XEN_PAGETABLE(l1start);
+            l1start = l1tab = map_xen_pagetable(maddr_to_mfn(mpt_alloc));
+            mpt_alloc += PAGE_SIZE;
             clear_page(l1tab);
             if ( count == 0 )
                 l1tab += l1_table_offset(v_start);
             if ( !((unsigned long)l2tab & (PAGE_SIZE-1)) )
             {
                 maddr_to_page(mpt_alloc)->u.inuse.type_info = PGT_l2_page_table;
-                l2start = l2tab = __va(mpt_alloc); mpt_alloc += PAGE_SIZE;
+                UNMAP_XEN_PAGETABLE(l2start);
+                l2start = l2tab = map_xen_pagetable(maddr_to_mfn(mpt_alloc));
+                mpt_alloc += PAGE_SIZE;
                 clear_page(l2tab);
                 if ( count == 0 )
                     l2tab += l2_table_offset(v_start);
@@ -662,19 +672,21 @@  int __init dom0_construct_pv(struct domain *d,
                     {
                         maddr_to_page(mpt_alloc)->u.inuse.type_info =
                             PGT_l3_page_table;
-                        l3start = __va(mpt_alloc); mpt_alloc += PAGE_SIZE;
+                        UNMAP_XEN_PAGETABLE(l3start);
+                        l3start = map_xen_pagetable(maddr_to_mfn(mpt_alloc));
+                        mpt_alloc += PAGE_SIZE;
                     }
                     l3tab = l3start;
                     clear_page(l3tab);
                     if ( count == 0 )
                         l3tab += l3_table_offset(v_start);
-                    *l4tab = l4e_from_paddr(__pa(l3start), L4_PROT);
+                    *l4tab = l4e_from_paddr(virt_to_maddr_walk(l3start), L4_PROT);
                     l4tab++;
                 }
-                *l3tab = l3e_from_paddr(__pa(l2start), L3_PROT);
+                *l3tab = l3e_from_paddr(virt_to_maddr_walk(l2start), L3_PROT);
                 l3tab++;
             }
-            *l2tab = l2e_from_paddr(__pa(l1start), L2_PROT);
+            *l2tab = l2e_from_paddr(virt_to_maddr_walk(l1start), L2_PROT);
             l2tab++;
         }
         if ( count < initrd_pfn || count >= initrd_pfn + PFN_UP(initrd_len) )
@@ -701,9 +713,11 @@  int __init dom0_construct_pv(struct domain *d,
             if ( !l3e_get_intpte(*l3tab) )
             {
                 maddr_to_page(mpt_alloc)->u.inuse.type_info = PGT_l2_page_table;
-                l2tab = __va(mpt_alloc); mpt_alloc += PAGE_SIZE;
-                clear_page(l2tab);
-                *l3tab = l3e_from_paddr(__pa(l2tab), L3_PROT);
+                UNMAP_XEN_PAGETABLE(l2start);
+                l2start = map_xen_pagetable(maddr_to_mfn(mpt_alloc));
+                mpt_alloc += PAGE_SIZE;
+                clear_page(l2start);
+                *l3tab = l3e_from_paddr(virt_to_maddr_walk(l2start), L3_PROT);
             }
             if ( i == 3 )
                 l3e_get_page(*l3tab)->u.inuse.type_info |= PGT_pae_xen_l2;
@@ -714,6 +728,10 @@  int __init dom0_construct_pv(struct domain *d,
         UNMAP_XEN_PAGETABLE(l2t);
     }
 
+    UNMAP_XEN_PAGETABLE(l1start);
+    UNMAP_XEN_PAGETABLE(l2start);
+    UNMAP_XEN_PAGETABLE(l3start);
+
     /* Pages that are part of page tables must be read only. */
     mark_pv_pt_pages_rdonly(d, l4start, vpt_start, nr_pt_pages);
 
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 76ba56bdc3..e5819cbfdf 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -645,6 +645,7 @@  void free_xen_pagetable(mfn_t mfn);
 l1_pgentry_t *virt_to_xen_l1e(unsigned long v);
 unsigned long virt_to_mfn_walk(void *va);
 struct page_info *virt_to_page_walk(void *va);
+#define virt_to_maddr_walk(va) mfn_to_maddr(_mfn(virt_to_mfn_walk(va)))
 
 DECLARE_PER_CPU(mfn_t, root_pgt_mfn);