WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] [PATCH v4 08/10] xen: use host E820 map for dom0

From: Ian Campbell <ian.campbell@xxxxxxxxxx>

When running as initial domain, get the real physical memory map from
xen using the XENMEM_machine_memory_map hypercall and use it to setup
the e820 regions.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
 arch/x86/xen/setup.c           |   48 +++++++++++++++++++++++++++++++++++++--
 include/xen/interface/memory.h |   28 +++++++++++++++++++++++
 2 files changed, 73 insertions(+), 3 deletions(-)

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 62ceb78..516cba8 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -107,14 +107,56 @@ static unsigned long __init 
xen_return_unused_memory(unsigned long max_pfn,
 
 char * __init xen_memory_setup(void)
 {
+       static __initdata struct e820entry map[E820MAX];
+
        unsigned long max_pfn = xen_start_info->nr_pages;
+       struct xen_memory_map memmap;
+       unsigned long long mem_end;
+       int op;
+       int rc;
+       int i;
 
        max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
+       mem_end = PFN_PHYS((u64)max_pfn);
+
+       memmap.nr_entries = E820MAX;
+       set_xen_guest_handle(memmap.buffer, map);
+
+       op = xen_initial_domain() ?
+               XENMEM_machine_memory_map :
+               XENMEM_memory_map;
+       rc = HYPERVISOR_memory_op(op, &memmap);
+       if (rc == -ENOSYS) {
+               memmap.nr_entries = 1;
+               map[0].addr = 0ULL;
+               map[0].size = mem_end;
+               /* 8MB slack (to balance backend allocations). */
+               map[0].size += 8ULL << 20;
+               map[0].type = E820_RAM;
+               rc = 0;
+       }
+       BUG_ON(rc);
 
        e820.nr_map = 0;
-
-       e820_add_region(0, PFN_PHYS((u64)max_pfn), E820_RAM);
-
+       for (i = 0; i < memmap.nr_entries; i++) {
+               unsigned long long end = map[i].addr + map[i].size;
+               if (map[i].type == E820_RAM) {
+                       if (map[i].addr > mem_end) {
+                               printk(KERN_WARNING "You need to increase the "
+                                               "CONFIG_XEN_MAX_DOMAIN_MEMORY 
value to take "
+                                               "advantage of the extra %llu 
gobs of memory!\n",
+                                               map[i].size);
+                               continue;
+                       }
+                       if (end > mem_end) {
+                               /* Truncate region to max_mem. */
+                               map[i].size -= end - mem_end;
+                       }
+               }
+               if (map[i].size > 0)
+                       e820_add_region(map[i].addr, map[i].size, map[i].type);
+       }
+       
        /*
         * Even though this is normal, usable memory under Xen, reserve
         * ISA memory anyway because too many things think they can poke
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index d3938d3..4c4b817 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -186,6 +186,34 @@ struct xen_translate_gpfn_list {
 };
 DEFINE_GUEST_HANDLE_STRUCT(xen_translate_gpfn_list);
 
+/*
+ * Returns the pseudo-physical memory map as it was when the domain
+ * was started (specified by XENMEM_set_memory_map).
+ * arg == addr of struct xen_memory_map.
+ */
+#define XENMEM_memory_map           9
+struct xen_memory_map {
+    /*
+     * On call the number of entries which can be stored in buffer. On
+     * return the number of entries which have been stored in
+     * buffer.
+     */
+    unsigned int nr_entries;
+
+    /*
+     * Entries in the buffer are in the same format as returned by the
+     * BIOS INT 0x15 EAX=0xE820 call.
+     */
+    GUEST_HANDLE(void) buffer;
+};
+DEFINE_GUEST_HANDLE_STRUCT(xen_memory_map);
+
+/*
+ * Returns the real physical memory map. Passes the same structure as
+ * XENMEM_memory_map.
+ * arg == addr of struct xen_memory_map.
+ */
+#define XENMEM_machine_memory_map   10
 
 /*
  * Prevent the balloon driver from changing the memory reservation
-- 
1.5.6.5


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>