[Qemu-devel] [RFC][PATCH 01/16 v8] Add API to create memory mapping list

[Wen Congyang <wency@cn.fujitsu.com>]

The memory mapping list stores virtual address and physical address mapping.
The virtual address and physical address are contiguous in the mapping.
The folloing patch will use this information to create PT_LOAD in the vmcore.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
 Makefile.target  |    1 +
 memory_mapping.c |  166 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 memory_mapping.h |   47 +++++++++++++++
 3 files changed, 214 insertions(+), 0 deletions(-)
 create mode 100644 memory_mapping.c
 create mode 100644 memory_mapping.h

diff --git a/Makefile.target b/Makefile.target
index 68a5641..9227e4e 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -208,6 +208,7 @@ obj-$(CONFIG_KVM) += kvm.o kvm-all.o
 obj-$(CONFIG_NO_KVM) += kvm-stub.o
 obj-$(CONFIG_VGA) += vga.o
 obj-y += memory.o savevm.o
+obj-y += memory_mapping.o
 LIBS+=-lz
 
 obj-i386-$(CONFIG_KVM) += hyperv.o
diff --git a/memory_mapping.c b/memory_mapping.c
new file mode 100644
index 0000000..718f271
--- /dev/null
+++ b/memory_mapping.c
@@ -0,0 +1,166 @@
+/*
+ * QEMU memory mapping
+ *
+ * Copyright Fujitsu, Corp. 2011, 2012
+ *
+ * Authors:
+ *     Wen Congyang <wency@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "cpu.h"
+#include "cpu-all.h"
+#include "memory_mapping.h"
+
+static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list,
+                                                   MemoryMapping *mapping)
+{
+    MemoryMapping *p;
+
+    QTAILQ_FOREACH(p, &list->head, next) {
+        if (p->phys_addr >= mapping->phys_addr) {
+            QTAILQ_INSERT_BEFORE(p, mapping, next);
+            return;
+        }
+    }
+    QTAILQ_INSERT_TAIL(&list->head, mapping, next);
+}
+
+static void create_new_memory_mapping(MemoryMappingList *list,
+                                      target_phys_addr_t phys_addr,
+                                      target_phys_addr_t virt_addr,
+                                      ram_addr_t length)
+{
+    MemoryMapping *memory_mapping;
+
+    memory_mapping = g_malloc(sizeof(MemoryMapping));
+    memory_mapping->phys_addr = phys_addr;
+    memory_mapping->virt_addr = virt_addr;
+    memory_mapping->length = length;
+    list->last_mapping = memory_mapping;
+    list->num++;
+    memory_mapping_list_add_mapping_sorted(list, memory_mapping);
+}
+
+static inline bool mapping_contiguous(MemoryMapping *map,
+                                      target_phys_addr_t phys_addr,
+                                      target_phys_addr_t virt_addr)
+{
+    return phys_addr == map->phys_addr + map->length &&
+           virt_addr == map->virt_addr + map->length;
+}
+
+/*
+ * [map->phys_addr, map->phys_addr + map->length) and
+ * [phys_addr, phys_addr + length) have intersection?
+ */
+static inline bool mapping_have_same_region(MemoryMapping *map,
+                                            target_phys_addr_t phys_addr,
+                                            ram_addr_t length)
+{
+    return !(phys_addr + length < map->phys_addr ||
+             phys_addr >= map->phys_addr + map->length);
+}
+
+/*
+ * [map->phys_addr, map->phys_addr + map->length) and
+ * [phys_addr, phys_addr + length) have intersection. The virtual address in the
+ * intersection are the same?
+ */
+static inline bool mapping_conflict(MemoryMapping *map,
+                                    target_phys_addr_t phys_addr,
+                                    target_phys_addr_t virt_addr)
+{
+    return virt_addr - map->virt_addr != phys_addr - map->phys_addr;
+}
+
+/*
+ * [map->virt_addr, map->virt_addr + map->length) and
+ * [virt_addr, virt_addr + length) have intersection. And the physical address
+ * in the intersection are the same.
+ */
+static inline void mapping_merge(MemoryMapping *map,
+                                 target_phys_addr_t virt_addr,
+                                 ram_addr_t length)
+{
+    if (virt_addr < map->virt_addr) {
+        map->length += map->virt_addr - virt_addr;
+        map->virt_addr = virt_addr;
+    }
+
+    if ((virt_addr + length) >
+        (map->virt_addr + map->length)) {
+        map->length = virt_addr + length - map->virt_addr;
+    }
+}
+
+void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,
+                                          target_phys_addr_t phys_addr,
+                                          target_phys_addr_t virt_addr,
+                                          ram_addr_t length)
+{
+    MemoryMapping *memory_mapping, *last_mapping;
+
+    if (QTAILQ_EMPTY(&list->head)) {
+        create_new_memory_mapping(list, phys_addr, virt_addr, length);
+        return;
+    }
+
+    last_mapping = list->last_mapping;
+    if (last_mapping) {
+        if (mapping_contiguous(last_mapping, phys_addr, virt_addr)) {
+            last_mapping->length += length;
+            return;
+        }
+    }
+
+    QTAILQ_FOREACH(memory_mapping, &list->head, next) {
+        if (mapping_contiguous(memory_mapping, phys_addr, virt_addr)) {
+            memory_mapping->length += length;
+            list->last_mapping = memory_mapping;
+            return;
+        }
+
+        if (phys_addr + length < memory_mapping->phys_addr) {
+            /* create a new region before memory_mapping */
+            break;
+        }
+
+        if (mapping_have_same_region(memory_mapping, phys_addr, length)) {
+            if (mapping_conflict(memory_mapping, phys_addr, virt_addr)) {
+                continue;
+            }
+
+            /* merge this region into memory_mapping */
+            mapping_merge(memory_mapping, virt_addr, length);
+            list->last_mapping = memory_mapping;
+            return;
+        }
+    }
+
+    /* this region can not be merged into any existed memory mapping. */
+    create_new_memory_mapping(list, phys_addr, virt_addr, length);
+}
+
+void memory_mapping_list_free(MemoryMappingList *list)
+{
+    MemoryMapping *p, *q;
+
+    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
+        QTAILQ_REMOVE(&list->head, p, next);
+        g_free(p);
+    }
+
+    list->num = 0;
+    list->last_mapping = NULL;
+}
+
+void memory_mapping_list_init(MemoryMappingList *list)
+{
+    list->num = 0;
+    list->last_mapping = NULL;
+    QTAILQ_INIT(&list->head);
+}
diff --git a/memory_mapping.h b/memory_mapping.h
new file mode 100644
index 0000000..836b047
--- /dev/null
+++ b/memory_mapping.h
@@ -0,0 +1,47 @@
+/*
+ * QEMU memory mapping
+ *
+ * Copyright Fujitsu, Corp. 2011, 2012
+ *
+ * Authors:
+ *     Wen Congyang <wency@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef MEMORY_MAPPING_H
+#define MEMORY_MAPPING_H
+
+#include "qemu-queue.h"
+
+/* The physical and virtual address in the memory mapping are contiguous. */
+typedef struct MemoryMapping {
+    target_phys_addr_t phys_addr;
+    target_ulong virt_addr;
+    ram_addr_t length;
+    QTAILQ_ENTRY(MemoryMapping) next;
+} MemoryMapping;
+
+typedef struct MemoryMappingList {
+    unsigned int num;
+    MemoryMapping *last_mapping;
+    QTAILQ_HEAD(, MemoryMapping) head;
+} MemoryMappingList;
+
+/*
+ * add or merge the memory region [phys_addr, phys_addr + length) into the
+ * memory mapping's list. The region's virtual address starts with virt_addr,
+ * and is contiguous. The list is sorted by phys_addr.
+ */
+void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,
+                                          target_phys_addr_t phys_addr,
+                                          target_phys_addr_t virt_addr,
+                                          ram_addr_t length);
+
+void memory_mapping_list_free(MemoryMappingList *list);
+
+void memory_mapping_list_init(MemoryMappingList *list);
+
+#endif
-- 
1.7.1