[Qemu-devel] [PATCH 08/15] memory: introduce PhysMap to present snapshot of toploygy

[Liu Ping Fan <qemulist@gmail.com>]

From: Liu Ping Fan <pingfank@linux.vnet.ibm.com>

PhysMap contain the flatview and radix-tree view, they are snapshot
of system topology and should be consistent. With PhysMap, we can
swap the pointer when updating and achieve the atomic.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 exec.c   |    8 --------
 memory.c |   33 ---------------------------------
 memory.h |   62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 60 insertions(+), 43 deletions(-)

diff --git a/exec.c b/exec.c
index 0e29ef9..01b91b0 100644
--- a/exec.c
+++ b/exec.c
@@ -156,8 +156,6 @@ typedef struct PageDesc {
 #endif
 
 /* Size of the L2 (and L3, etc) page tables.  */
-#define L2_BITS 10
-#define L2_SIZE (1 << L2_BITS)
 
 #define P_L2_LEVELS \
     (((TARGET_PHYS_ADDR_SPACE_BITS - TARGET_PAGE_BITS - 1) / L2_BITS) + 1)
@@ -185,7 +183,6 @@ uintptr_t qemu_host_page_mask;
 static void *l1_map[V_L1_SIZE];
 
 #if !defined(CONFIG_USER_ONLY)
-typedef struct PhysPageEntry PhysPageEntry;
 
 static MemoryRegionSection *phys_sections;
 static unsigned phys_sections_nb, phys_sections_nb_alloc;
@@ -194,11 +191,6 @@ static uint16_t phys_section_notdirty;
 static uint16_t phys_section_rom;
 static uint16_t phys_section_watch;
 
-struct PhysPageEntry {
-    uint16_t is_leaf : 1;
-     /* index into phys_sections (is_leaf) or phys_map_nodes (!is_leaf) */
-    uint16_t ptr : 15;
-};
 
 /* Simple allocator for PhysPageEntry nodes */
 static PhysPageEntry (*phys_map_nodes)[L2_SIZE];
diff --git a/memory.c b/memory.c
index 2eaa2fc..c7f2cfd 100644
--- a/memory.c
+++ b/memory.c
@@ -31,17 +31,6 @@ static bool global_dirty_log = false;
 static QTAILQ_HEAD(memory_listeners, MemoryListener) memory_listeners
     = QTAILQ_HEAD_INITIALIZER(memory_listeners);
 
-typedef struct AddrRange AddrRange;
-
-/*
- * Note using signed integers limits us to physical addresses at most
- * 63 bits wide.  They are needed for negative offsetting in aliases
- * (large MemoryRegion::alias_offset).
- */
-struct AddrRange {
-    Int128 start;
-    Int128 size;
-};
 
 static AddrRange addrrange_make(Int128 start, Int128 size)
 {
@@ -197,28 +186,6 @@ static bool memory_region_ioeventfd_equal(MemoryRegionIoeventfd a,
         && !memory_region_ioeventfd_before(b, a);
 }
 
-typedef struct FlatRange FlatRange;
-typedef struct FlatView FlatView;
-
-/* Range of memory in the global map.  Addresses are absolute. */
-struct FlatRange {
-    MemoryRegion *mr;
-    target_phys_addr_t offset_in_region;
-    AddrRange addr;
-    uint8_t dirty_log_mask;
-    bool readable;
-    bool readonly;
-};
-
-/* Flattened global view of current active memory hierarchy.  Kept in sorted
- * order.
- */
-struct FlatView {
-    FlatRange *ranges;
-    unsigned nr;
-    unsigned nr_allocated;
-};
-
 typedef struct AddressSpace AddressSpace;
 typedef struct AddressSpaceOps AddressSpaceOps;
 
diff --git a/memory.h b/memory.h
index 740f018..357edd8 100644
--- a/memory.h
+++ b/memory.h
@@ -29,12 +29,72 @@
 #include "qemu-thread.h"
 #include "qemu/reclaimer.h"
 
+typedef struct AddrRange AddrRange;
+typedef struct FlatRange FlatRange;
+typedef struct FlatView FlatView;
+typedef struct PhysPageEntry PhysPageEntry;
+typedef struct PhysMap PhysMap;
+typedef struct MemoryRegionSection MemoryRegionSection;
 typedef struct MemoryRegionOps MemoryRegionOps;
 typedef struct MemoryRegionLifeOps MemoryRegionLifeOps;
 typedef struct MemoryRegion MemoryRegion;
 typedef struct MemoryRegionPortio MemoryRegionPortio;
 typedef struct MemoryRegionMmio MemoryRegionMmio;
 
+/*
+ * Note using signed integers limits us to physical addresses at most
+ * 63 bits wide.  They are needed for negative offsetting in aliases
+ * (large MemoryRegion::alias_offset).
+ */
+struct AddrRange {
+    Int128 start;
+    Int128 size;
+};
+
+/* Range of memory in the global map.  Addresses are absolute. */
+struct FlatRange {
+    MemoryRegion *mr;
+    target_phys_addr_t offset_in_region;
+    AddrRange addr;
+    uint8_t dirty_log_mask;
+    bool readable;
+    bool readonly;
+};
+
+/* Flattened global view of current active memory hierarchy.  Kept in sorted
+ * order.
+ */
+struct FlatView {
+    FlatRange *ranges;
+    unsigned nr;
+    unsigned nr_allocated;
+};
+
+struct PhysPageEntry {
+    uint16_t is_leaf:1;
+     /* index into phys_sections (is_leaf) or phys_map_nodes (!is_leaf) */
+    uint16_t ptr:15;
+};
+
+#define L2_BITS 10
+#define L2_SIZE (1 << L2_BITS)
+/* This is a multi-level map on the physical address space.
+   The bottom level has pointers to MemoryRegionSections.  */
+struct PhysMap {
+    Atomic ref;
+    PhysPageEntry root;
+    PhysPageEntry (*phys_map_nodes)[L2_SIZE];
+    unsigned phys_map_nodes_nb;
+    unsigned phys_map_nodes_nb_alloc;
+
+    MemoryRegionSection *phys_sections;
+    unsigned phys_sections_nb;
+    unsigned phys_sections_nb_alloc;
+
+    /* FlatView */
+    FlatView views[2];
+};
+
 /* Must match *_DIRTY_FLAGS in cpu-all.h.  To be replaced with dynamic
  * registration.
  */
@@ -167,8 +227,6 @@ struct MemoryRegionPortio {
 
 #define PORTIO_END_OF_LIST() { }
 
-typedef struct MemoryRegionSection MemoryRegionSection;
-
 /**
  * MemoryRegionSection: describes a fragment of a #MemoryRegion
  *
-- 
1.7.4.4