[Qemu-devel] [RFC v1 2/3] ramlist: apply fine grain lock for ram_list

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

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

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 cpu-all.h |    1 +
 exec.c    |   46 +++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/cpu-all.h b/cpu-all.h
index 6aa7e58..d3ead99 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -498,6 +498,7 @@ typedef struct RAMBlock {
 } RAMBlock;
 
 typedef struct RAMList {
+    QemuMutex lock;
     uint8_t *phys_dirty;
     QLIST_HEAD(, RAMBlock) blocks;
 } RAMList;
diff --git a/exec.c b/exec.c
index fe84718..e5f1c0f 100644
--- a/exec.c
+++ b/exec.c
@@ -2444,6 +2444,7 @@ static ram_addr_t find_ram_offset(ram_addr_t size)
     if (QLIST_EMPTY(&ram_list.blocks))
         return 0;
 
+    qemu_mutex_lock(&ram_list.lock);
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         ram_addr_t end, next = RAM_ADDR_MAX;
 
@@ -2459,6 +2460,7 @@ static ram_addr_t find_ram_offset(ram_addr_t size)
             mingap = next - end;
         }
     }
+    qemu_mutex_unlock(&ram_list.lock);
 
     if (offset == RAM_ADDR_MAX) {
         fprintf(stderr, "Failed to find gap of requested size: %" PRIu64 "\n",
@@ -2474,8 +2476,10 @@ ram_addr_t last_ram_offset(void)
     RAMBlock *block;
     ram_addr_t last = 0;
 
+    qemu_mutex_lock(&ram_list.lock);
     QLIST_FOREACH(block, &ram_list.blocks, next)
         last = MAX(last, block->offset + block->length);
+    qemu_mutex_unlock(&ram_list.lock);
 
     return last;
 }
@@ -2503,6 +2507,7 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
     RAMBlock *new_block, *block;
 
     new_block = NULL;
+    qemu_mutex_lock(&ram_list.lock);
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         if (block->offset == addr) {
             new_block = block;
@@ -2528,6 +2533,7 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
             abort();
         }
     }
+    qemu_mutex_unlock(&ram_list.lock);
 }
 
 static int memory_try_enable_merging(void *addr, size_t len)
@@ -2582,12 +2588,6 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
     }
     new_block->length = size;
 
-    QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
-
-    ram_list.phys_dirty = g_realloc(ram_list.phys_dirty,
-                                       last_ram_offset() >> TARGET_PAGE_BITS);
-    memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
-           0, size >> TARGET_PAGE_BITS);
     cpu_physical_memory_set_dirty_range(new_block->offset, size, 0xff);
 
     qemu_ram_setup_dump(new_block->host, size);
@@ -2596,6 +2596,15 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
     if (kvm_enabled())
         kvm_setup_guest_memory(new_block->host, size);
 
+    qemu_mutex_lock(&ram_list.lock);
+    QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
+
+    ram_list.phys_dirty = g_realloc(ram_list.phys_dirty,
+                                       last_ram_offset() >> TARGET_PAGE_BITS);
+    memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
+           0, size >> TARGET_PAGE_BITS);
+    qemu_mutex_unlock(&ram_list.lock);
+
     return new_block->offset;
 }
 
@@ -2608,19 +2617,23 @@ void qemu_ram_free_from_ptr(ram_addr_t addr)
 {
     RAMBlock *block;
 
+    qemu_mutex_lock(&ram_list.lock);
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         if (addr == block->offset) {
             QLIST_REMOVE(block, next);
             g_free(block);
+            qemu_mutex_unlock(&ram_list.lock);
             return;
         }
     }
+    qemu_mutex_unlock(&ram_list.lock);
 }
 
 void qemu_ram_free(ram_addr_t addr)
 {
     RAMBlock *block;
 
+    qemu_mutex_lock(&ram_list.lock);
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         if (addr == block->offset) {
             QLIST_REMOVE(block, next);
@@ -2649,10 +2662,11 @@ void qemu_ram_free(ram_addr_t addr)
 #endif
             }
             g_free(block);
+            qemu_mutex_unlock(&ram_list.lock);
             return;
         }
     }
-
+    qemu_mutex_unlock(&ram_list.lock);
 }
 
 #ifndef _WIN32
@@ -2663,6 +2677,7 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
     int flags;
     void *area, *vaddr;
 
+    qemu_mutex_lock(&ram_list.lock);
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         offset = addr - block->offset;
         if (offset < block->length) {
@@ -2711,9 +2726,11 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
                 memory_try_enable_merging(vaddr, length);
                 qemu_ram_setup_dump(vaddr, length);
             }
+            qemu_mutex_unlock(&ram_list.lock);
             return;
         }
     }
+    qemu_mutex_unlock(&ram_list.lock);
 }
 #endif /* !_WIN32 */
 
@@ -2729,6 +2746,7 @@ void *qemu_get_ram_ptr(ram_addr_t addr)
 {
     RAMBlock *block;
 
+    qemu_mutex_lock(&ram_list.lock);
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         if (addr - block->offset < block->length) {
             /* Move this entry to to start of the list.  */
@@ -2742,15 +2760,18 @@ void *qemu_get_ram_ptr(ram_addr_t addr)
                  * In that case just map until the end of the page.
                  */
                 if (block->offset == 0) {
+                    qemu_mutex_unlock(&ram_list.lock);
                     return xen_map_cache(addr, 0, 0);
                 } else if (block->host == NULL) {
                     block->host =
                         xen_map_cache(block->offset, block->length, 1);
                 }
             }
+            qemu_mutex_unlock(&ram_list.lock);
             return block->host + (addr - block->offset);
         }
     }
+    qemu_mutex_unlock(&ram_list.lock);
 
     fprintf(stderr, "Bad ram offset %" PRIx64 "\n", (uint64_t)addr);
     abort();
@@ -2765,6 +2786,7 @@ void *qemu_safe_ram_ptr(ram_addr_t addr)
 {
     RAMBlock *block;
 
+    qemu_mutex_lock(&ram_list.lock);
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         if (addr - block->offset < block->length) {
             if (xen_enabled()) {
@@ -2773,15 +2795,18 @@ void *qemu_safe_ram_ptr(ram_addr_t addr)
                  * In that case just map until the end of the page.
                  */
                 if (block->offset == 0) {
+                    qemu_mutex_unlock(&ram_list.lock);
                     return xen_map_cache(addr, 0, 0);
                 } else if (block->host == NULL) {
                     block->host =
                         xen_map_cache(block->offset, block->length, 1);
                 }
             }
+            qemu_mutex_unlock(&ram_list.lock);
             return block->host + (addr - block->offset);
         }
     }
+    qemu_mutex_unlock(&ram_list.lock);
 
     fprintf(stderr, "Bad ram offset %" PRIx64 "\n", (uint64_t)addr);
     abort();
@@ -2801,13 +2826,16 @@ void *qemu_ram_ptr_length(ram_addr_t addr, ram_addr_t *size)
     } else {
         RAMBlock *block;
 
+        qemu_mutex_lock(&ram_list.lock);
         QLIST_FOREACH(block, &ram_list.blocks, next) {
             if (addr - block->offset < block->length) {
                 if (addr - block->offset + *size > block->length)
                     *size = block->length - addr + block->offset;
+                qemu_mutex_lock(&ram_list.lock);
                 return block->host + (addr - block->offset);
             }
         }
+        qemu_mutex_unlock(&ram_list.lock);
 
         fprintf(stderr, "Bad ram offset %" PRIx64 "\n", (uint64_t)addr);
         abort();
@@ -2829,6 +2857,7 @@ int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
         return 0;
     }
 
+    qemu_mutex_lock(&ram_list.lock);
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         /* This case append when the block is not mapped. */
         if (block->host == NULL) {
@@ -2836,9 +2865,11 @@ int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
         }
         if (host - block->host < block->length) {
             *ram_addr = block->offset + (host - block->host);
+            qemu_mutex_unlock(&ram_list.lock);
             return 0;
         }
     }
+    qemu_mutex_unlock(&ram_list.lock);
 
     return -1;
 }
@@ -3318,6 +3349,7 @@ static void memory_map_init(void)
     address_space_io.name = "I/O";
 
     qemu_mutex_init(&bounce.lock);
+    qemu_mutex_unlock(&ram_list.lock);
 
     memory_listener_register(&core_memory_listener, &address_space_memory);
     memory_listener_register(&io_memory_listener, &address_space_io);
-- 
1.7.4.4