From: Bill Burns <bburns@redhat.com>
Date: Tue, 18 Dec 2007 15:56:03 -0500
Subject: [xen] domain address-size clamping
Message-id: 20071218205603.15371.18136.sendpatchset@localhost.localdomain
O-Subject: [RHEL5.2 PATCH 2/3] Domain address-size clamping
Bugzilla: 227614

32-on-64: Fix domain address-size clamping, implement
copy-on-grant-transfer, and eliminate 166GB memory limit for x86/64
Xen.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
xen-unstable changeset: 16548:cd5e1e76d0bc66440a04122baa27860f5d763b5b
xen-unstable date: Thu Dec 06 13:39:19 2007 +0000

32-on-64: Fixes to previous changeset.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
xen-unstable changeset: 16549:baf90ee3c1dab65f4a386521be6e108920622866
xen-unstable date: Thu Dec 06 13:56:00 2007 +0000

Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: "Stephen C. Tweedie" <sct@redhat.com>

diff --git a/arch/x86/domain.c b/arch/x86/domain.c
index 9a0ba98..215d4f2 100644
--- a/arch/x86/domain.c
+++ b/arch/x86/domain.c
@@ -296,8 +296,6 @@ int switch_native(struct domain *d)
             release_compat_l4(d->vcpu[vcpuid]);
     }
 
-    d->arch.physaddr_bitsize = 64;
-
     return 0;
 }
 
diff --git a/arch/x86/domain_build.c b/arch/x86/domain_build.c
index f3eeb76..e053334 100644
--- a/arch/x86/domain_build.c
+++ b/arch/x86/domain_build.c
@@ -363,7 +363,7 @@ int __init construct_dom0(
 #ifdef CONFIG_COMPAT
         HYPERVISOR_COMPAT_VIRT_START(d) =
             max_t(unsigned int, m2p_compat_vstart, value);
-        d->arch.physaddr_bitsize = !is_pv_32on64_domain(d) ? 64 :
+        d->arch.physaddr_bitsize =
             fls((1UL << 32) - HYPERVISOR_COMPAT_VIRT_START(d)) - 1
             + (PAGE_SIZE - 2);
         if ( value > (!is_pv_32on64_domain(d) ?
diff --git a/arch/x86/x86_64/mm.c b/arch/x86/x86_64/mm.c
index 2df1c6c..2c6d462 100644
--- a/arch/x86/x86_64/mm.c
+++ b/arch/x86/x86_64/mm.c
@@ -428,7 +428,7 @@ int check_descriptor(const struct domain *dom, struct desc_struct *d)
 
 unsigned int domain_clamp_alloc_bitsize(struct domain *d, unsigned int bits)
 {
-    if ( d == NULL )
+    if ( (d == NULL) || !is_pv_32on64_domain(d) )
         return bits;
     return min(d->arch.physaddr_bitsize, bits);
 }
diff --git a/common/grant_table.c b/common/grant_table.c
index b6a16d5..dc14f5a 100644
--- a/common/grant_table.c
+++ b/common/grant_table.c
@@ -809,6 +809,7 @@ gnttab_transfer(
     grant_entry_t *sha;
     struct gnttab_transfer gop;
     unsigned long mfn;
+    unsigned int max_bitsize;
 
     for ( i = 0; i < count; i++ )
     {
@@ -857,6 +858,34 @@ gnttab_transfer(
             goto copyback;
         }
 
+        max_bitsize = domain_clamp_alloc_bitsize(
+            e, BITS_PER_LONG+PAGE_SHIFT-1);
+        if ( (1UL << (max_bitsize - PAGE_SHIFT)) <= mfn )
+        {
+            struct page_info *new_page;
+            void *sp, *dp;
+
+            new_page = alloc_domheap_pages(NULL, 0, MEMF_bits(max_bitsize));
+            if ( new_page == NULL )
+            {
+                rcu_unlock_domain(e);
+                page->count_info &= ~(PGC_count_mask|PGC_allocated);
+                free_domheap_page(page);
+                gop.status = GNTST_address_too_big;
+                goto copyback;
+            }
+
+            sp = map_domain_page(mfn);
+            dp = map_domain_page(page_to_mfn(new_page));
+            memcpy(dp, sp, PAGE_SIZE);
+            unmap_domain_page(dp);
+            unmap_domain_page(sp);
+
+            page->count_info &= ~(PGC_count_mask|PGC_allocated);
+            free_domheap_page(page);
+            page = new_page;
+        }
+
         spin_lock(&e->page_alloc_lock);
 
         /*
diff --git a/common/memory.c b/common/memory.c
index 311c5ae..1c2f2a8 100644
--- a/common/memory.c
+++ b/common/memory.c
@@ -309,18 +309,6 @@ static long memory_exchange(XEN_GUEST_HANDLE(xen_memory_exchange_t) arg)
         goto fail_early;
     }
 
-    if ( (exch.out.address_bits != 0) &&
-         (exch.out.address_bits <
-          (get_order_from_pages(max_page) + PAGE_SHIFT)) )
-    {
-        if ( exch.out.address_bits <= PAGE_SHIFT )
-        {
-            rc = -ENOMEM;
-            goto fail_early;
-        }
-        memflags = MEMF_bits(exch.out.address_bits);
-    }
-
     if ( exch.in.extent_order <= exch.out.extent_order )
     {
         in_chunk_order  = exch.out.extent_order - exch.in.extent_order;
@@ -343,6 +331,9 @@ static long memory_exchange(XEN_GUEST_HANDLE(xen_memory_exchange_t) arg)
     }
     d = current->domain;
 
+    memflags |= MEMF_bits(domain_clamp_alloc_bitsize(
+        d, exch.out.address_bits ? : (BITS_PER_LONG+PAGE_SHIFT)));
+
     cpu = select_local_cpu(d);
 
     for ( i = (exch.nr_exchanged >> in_chunk_order);
diff --git a/common/page_alloc.c b/common/page_alloc.c
index 6c84335..4cbece4 100644
--- a/common/page_alloc.c
+++ b/common/page_alloc.c
@@ -817,15 +817,13 @@ struct page_info *__alloc_domheap_pages(
 
     ASSERT(!in_irq());
 
-    if ( bits )
-    {
-        bits = domain_clamp_alloc_bitsize(d, bits);
-        if ( bits <= (PAGE_SHIFT + 1) )
-            return NULL;
-        bits -= PAGE_SHIFT + 1;
-        if ( bits < zone_hi )
-            zone_hi = bits;
-    }
+    bits = domain_clamp_alloc_bitsize(d, bits ? : (BITS_PER_LONG+PAGE_SHIFT));
+    if ( bits <= (PAGE_SHIFT + 1) )
+        return NULL;
+
+    bits -= PAGE_SHIFT + 1;
+    if ( bits < zone_hi )
+        zone_hi = bits;
 
     if ( (zone_hi + PAGE_SHIFT) >= dma_bitsize )
     {
diff --git a/include/public/grant_table.h b/include/public/grant_table.h
index 222ac37..d0ba9e9 100644
--- a/include/public/grant_table.h
+++ b/include/public/grant_table.h
@@ -370,7 +370,8 @@ DEFINE_XEN_GUEST_HANDLE(gnttab_query_size_t);
 #define GNTST_no_device_space  (-7) /* Out of space in I/O MMU.              */
 #define GNTST_permission_denied (-8) /* Not enough privilege for operation.  */
 #define GNTST_bad_page         (-9) /* Specified page was invalid for op.    */
-#define GNTST_bad_copy_arg    (-10) /* copy arguments cross page boundary */
+#define GNTST_bad_copy_arg    (-10) /* copy arguments cross page boundary.   */
+#define GNTST_address_too_big (-11) /* transfer page address too large.      */
 
 #define GNTTABOP_error_msgs {                   \
     "okay",                                     \
@@ -383,7 +384,8 @@ DEFINE_XEN_GUEST_HANDLE(gnttab_query_size_t);
     "no spare translation slot in the I/O MMU", \
     "permission denied",                        \
     "bad page",                                 \
-    "copy arguments cross page boundary"        \
+    "copy arguments cross page boundary",       \
+    "page address size too large"               \
 }
 
 #endif /* __XEN_PUBLIC_GRANT_TABLE_H__ */