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 10/19] xen/dom0: Use host E820 map

To: Ingo Molnar <mingo@xxxxxxx>
Subject: [Xen-devel] [PATCH 10/19] xen/dom0: Use host E820 map
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Mon, 16 Feb 2009 15:46:04 -0800
Cc: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Ian Campbell <Ian.Campbell@xxxxxxxxxx>, the arch/x86 maintainers <x86@xxxxxxxxxx>, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>, Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>, Yinghai Lu <yinghai@xxxxxxxxxx>, Ian Campbell <ian.campbell@xxxxxxxxxx>
Delivery-date: Mon, 16 Feb 2009 16:02:06 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <f156acbfffc23cccd71b71d36e6668c6c246f3b4.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx>
In-reply-to: <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <edde7fdd064390d321bdafcfb993b28b4d2588b1.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <9fbd402b72d6c494f453ff86e071ac1b2658ece9.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <f47f399029ba9035a14ae381b6ae504a5c5bd445.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <f1402ed2345e1d654faa823afefa53fc4745e368.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <f0d2b3f946de1b3398c278c7a33069f670b78268.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <83b1377d81029933b769798dbe1ca134f6d365ae.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <630b678d3259163fc237f673b6f2a4a5fa76ac25.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <8349825a016bec5b8712940ad6f8c3f18f8003fb.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <f156acbfffc23cccd71b71d36e6668c6c246f3b4.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <f156acbfffc23cccd71b71d36e6668c6c246f3b4.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx>
References: <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
From: Ian Campbell <ian.campbell@xxxxxxxxxx>

Unlike the non-paravirt Xen port we do not have distinct psuedo-physical
and I/O memory resource-spaces and therefore resources in the two
can clash. Fix this by registering a memory map which matches the
underlying I/O map. Currently this wastes the memory in the reserved
regions. Eventually we should remap this memory to the end of the
address space.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 arch/x86/xen/setup.c           |   45 +++++++++++++++++++++++++++++++++++++--
 include/xen/interface/memory.h |   29 +++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 3 deletions(-)

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 3e4cf46..175396c 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -19,6 +19,7 @@
 
 #include <xen/page.h>
 #include <xen/interface/callback.h>
+#include <xen/interface/memory.h>
 #include <xen/interface/physdev.h>
 #include <xen/features.h>
 
@@ -36,16 +37,54 @@ extern void xen_syscall32_target(void);
 /**
  * machine_specific_memory_setup - Hook for machine specific memory setup.
  **/
-
 char * __init xen_memory_setup(void)
 {
        unsigned long max_pfn = xen_start_info->nr_pages;
+       unsigned long long mem_end;
+       int rc;
+       struct xen_memory_map memmap;
+       /*
+        * This is rather large for a stack variable but this early in
+        * the boot process we know we have plenty slack space.
+        */
+       struct e820entry map[E820MAX];
+       int op = xen_initial_domain() ?
+               XENMEM_machine_memory_map :
+               XENMEM_memory_map;
+       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);
+
+       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)
+                               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
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index af36ead..e6c6bcb 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -142,4 +142,33 @@ 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
+
 #endif /* __XEN_PUBLIC_MEMORY_H__ */
-- 
1.6.0.6


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

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