Xen devel - Nov 2006 - [PATCH, resend] x86-64: change heap allocated from in some places

Since all memory is visible to Xen on x86-64, there is no need to allocate
from the special Xen heap for allocations specific to this subarch.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

Index: 2006-09-21/xen/arch/x86/domain.c
==================================================================---
2006-09-21.orig/xen/arch/x86/domain.c	2006-09-21 11:09:00.000000000 +0200
+++ 2006-09-21/xen/arch/x86/domain.c	2006-09-21 13:26:07.000000000 +0200
@@ -167,6 +167,9 @@ void free_vcpu_struct(struct vcpu *v)
 int arch_domain_create(struct domain *d)
 {
     l1_pgentry_t gdt_l1e;
+#ifdef __x86_64__
+    struct page_info *pg;
+#endif
     int vcpuid, pdpt_order;
     int i, rc = -ENOMEM;
 
@@ -194,19 +197,19 @@ int arch_domain_create(struct domain *d)
 
 #else /* __x86_64__ */
 
-    d->arch.mm_perdomain_l2 = alloc_xenheap_page();
-    d->arch.mm_perdomain_l3 = alloc_xenheap_page();
-    if ( (d->arch.mm_perdomain_l2 == NULL) ||
-         (d->arch.mm_perdomain_l3 == NULL) )
+    pg = alloc_domheap_page(NULL);
+    if ( !pg )
         goto fail;
-
-    memset(d->arch.mm_perdomain_l2, 0, PAGE_SIZE);
+    d->arch.mm_perdomain_l2 = clear_page(page_to_virt(pg));
     for ( i = 0; i < (1 << pdpt_order); i++ )
         d->arch.mm_perdomain_l2[l2_table_offset(PERDOMAIN_VIRT_START)+i]    
l2e_from_page(virt_to_page(d->arch.mm_perdomain_pt)+i,
                           __PAGE_HYPERVISOR);
 
-    memset(d->arch.mm_perdomain_l3, 0, PAGE_SIZE);
+    pg = alloc_domheap_page(NULL);
+    if ( !pg )
+        goto fail;
+    d->arch.mm_perdomain_l3 = clear_page(page_to_virt(pg));
     d->arch.mm_perdomain_l3[l3_table_offset(PERDOMAIN_VIRT_START)]         
l3e_from_page(virt_to_page(d->arch.mm_perdomain_l2),
                             __PAGE_HYPERVISOR);
@@ -240,8 +243,8 @@ int arch_domain_create(struct domain *d)
  fail:
     free_xenheap_page(d->shared_info);
 #ifdef __x86_64__
-    free_xenheap_page(d->arch.mm_perdomain_l2);
-    free_xenheap_page(d->arch.mm_perdomain_l3);
+    free_domheap_page(virt_to_page(d->arch.mm_perdomain_l2));
+    free_domheap_page(virt_to_page(d->arch.mm_perdomain_l3));
 #endif
     free_xenheap_pages(d->arch.mm_perdomain_pt, pdpt_order);
     return rc;
@@ -265,8 +268,8 @@ void arch_domain_destroy(struct domain *
         get_order_from_bytes(PDPT_L1_ENTRIES * sizeof(l1_pgentry_t)));
 
 #ifdef __x86_64__
-    free_xenheap_page(d->arch.mm_perdomain_l2);
-    free_xenheap_page(d->arch.mm_perdomain_l3);
+    free_domheap_page(virt_to_page(d->arch.mm_perdomain_l2));
+    free_domheap_page(virt_to_page(d->arch.mm_perdomain_l3));
 #endif
 
     free_xenheap_page(d->shared_info);
Index: 2006-09-21/xen/arch/x86/x86_64/mm.c
==================================================================---
2006-09-21.orig/xen/arch/x86/x86_64/mm.c	2006-09-18 11:37:57.000000000 +0200
+++ 2006-09-21/xen/arch/x86/x86_64/mm.c	2006-09-21 13:23:19.000000000 +0200
@@ -82,11 +82,10 @@ void __init paging_init(void)
     struct page_info *pg;
 
     /* Create user-accessible L2 directory to map the MPT for guests. */
-    l3_ro_mpt = alloc_xenheap_page();
-    clear_page(l3_ro_mpt);
+    pg = alloc_domheap_page(NULL);
+    l3_ro_mpt = clear_page(page_to_virt(pg));
     idle_pg_table[l4_table_offset(RO_MPT_VIRT_START)] -        l4e_from_page(
-            virt_to_page(l3_ro_mpt), __PAGE_HYPERVISOR | _PAGE_USER);
+        l4e_from_page(pg, __PAGE_HYPERVISOR | _PAGE_USER);
 
     /*
      * Allocate and map the machine-to-phys table.
@@ -107,12 +106,11 @@ void __init paging_init(void)
         if ( !((unsigned long)l2_ro_mpt & ~PAGE_MASK) )
         {
             unsigned long va = RO_MPT_VIRT_START + (i <<
L2_PAGETABLE_SHIFT);
+            struct page_info *pg = alloc_domheap_page(NULL);
 
-            l2_ro_mpt = alloc_xenheap_page();
-            clear_page(l2_ro_mpt);
+            l2_ro_mpt = clear_page(page_to_virt(pg));
             l3_ro_mpt[l3_table_offset(va)] -                l3e_from_page(
-                    virt_to_page(l2_ro_mpt), __PAGE_HYPERVISOR | _PAGE_USER);
+                l3e_from_page(pg, __PAGE_HYPERVISOR | _PAGE_USER);
             l2_ro_mpt += l2_table_offset(va);
         }
         /* NB. Cannot be GLOBAL as shadow_mode_translate reuses this area. */


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Jan,

Does this lift the dependency on the size of the Xen heap with regard to
the number of domains that can be created?

Aravindh
> -----Original Message-----
> From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-
> bounces@lists.xensource.com] On Behalf Of Jan Beulich
> Sent: Monday, November 13, 2006 7:25 AM
> To: xen-devel@lists.xensource.com
> Subject: [Xen-devel] [PATCH,resend] x86-64: change heap allocated from
in
> some places
> 
> Since all memory is visible to Xen on x86-64, there is no need to
allocate
> from the special Xen heap for allocations specific to this subarch.
> 
> Signed-off-by: Jan Beulich <jbeulich@novell.com>

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On 13/11/06 17:19, "Puthiyaparambil, Aravindh"
<aravindh.puthiyaparambil@unisys.com> wrote:
> Does this lift the dependency on the size of the Xen heap with regard to
> the number of domains that can be created?
Doesn''t remove the dependency, but it will certainly let you create
more.

 -- Keir


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