diff mbox series

[PULL,08/26] system/physmem: Per-AddressSpace bounce buffering

Message ID 20240508174510.60470-9-philmd@linaro.org
State Accepted
Commit 69e78f1b3484e429274352a464a94fa1d78be339
Headers show
Series [PULL,01/26] block/qcow2-bitmap: Replace g_memdup() by g_memdup2() | expand

Commit Message

Philippe Mathieu-Daudé May 8, 2024, 5:44 p.m. UTC 
From: Mattias Nissler <mnissler@rivosinc.com>

Instead of using a single global bounce buffer, give each AddressSpace
its own bounce buffer. The MapClient callback mechanism moves to
AddressSpace accordingly.

This is in preparation for generalizing bounce buffer handling further
to allow multiple bounce buffers, with a total allocation limit
configured per AddressSpace.

Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mattias Nissler <mnissler@rivosinc.com>
Message-ID: <20240507094210.300566-2-mnissler@rivosinc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
[PMD: Split patch, part 2/2]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/exec/memory.h | 19 +++++++++++
 system/memory.c       |  7 +++++
 system/physmem.c      | 73 ++++++++++++++++---------------------------
 3 files changed, 53 insertions(+), 46 deletions(-)
diff mbox series

Patch

diff --git a/include/exec/memory.h b/include/exec/memory.h
index e1e0c5a3de..d417d7f363 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -1112,6 +1112,19 @@  struct MemoryListener {
     QTAILQ_ENTRY(MemoryListener) link_as;
 };
 
+typedef struct AddressSpaceMapClient {
+    QEMUBH *bh;
+    QLIST_ENTRY(AddressSpaceMapClient) link;
+} AddressSpaceMapClient;
+
+typedef struct {
+    MemoryRegion *mr;
+    void *buffer;
+    hwaddr addr;
+    hwaddr len;
+    bool in_use;
+} BounceBuffer;
+
 /**
  * struct AddressSpace: describes a mapping of addresses to #MemoryRegion objects
  */
@@ -1129,6 +1142,12 @@  struct AddressSpace {
     struct MemoryRegionIoeventfd *ioeventfds;
     QTAILQ_HEAD(, MemoryListener) listeners;
     QTAILQ_ENTRY(AddressSpace) address_spaces_link;
+
+    /* Bounce buffer to use for this address space. */
+    BounceBuffer bounce;
+    /* List of callbacks to invoke when buffers free up */
+    QemuMutex map_client_list_lock;
+    QLIST_HEAD(, AddressSpaceMapClient) map_client_list;
 };
 
 typedef struct AddressSpaceDispatch AddressSpaceDispatch;
diff --git a/system/memory.c b/system/memory.c
index 49f1cb2c38..642a449f8c 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -3174,6 +3174,9 @@  void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)
     as->ioeventfds = NULL;
     QTAILQ_INIT(&as->listeners);
     QTAILQ_INSERT_TAIL(&address_spaces, as, address_spaces_link);
+    as->bounce.in_use = false;
+    qemu_mutex_init(&as->map_client_list_lock);
+    QLIST_INIT(&as->map_client_list);
     as->name = g_strdup(name ? name : "anonymous");
     address_space_update_topology(as);
     address_space_update_ioeventfds(as);
@@ -3181,6 +3184,10 @@  void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)
 
 static void do_address_space_destroy(AddressSpace *as)
 {
+    assert(!qatomic_read(&as->bounce.in_use));
+    assert(QLIST_EMPTY(&as->map_client_list));
+    qemu_mutex_destroy(&as->map_client_list_lock);
+
     assert(QTAILQ_EMPTY(&as->listeners));
 
     flatview_unref(as->current_map);
diff --git a/system/physmem.c b/system/physmem.c
index b76b3d2184..342b7a8fd4 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3047,26 +3047,8 @@  void cpu_flush_icache_range(hwaddr start, hwaddr len)
                                      NULL, len, FLUSH_CACHE);
 }
 
-typedef struct {
-    MemoryRegion *mr;
-    void *buffer;
-    hwaddr addr;
-    hwaddr len;
-    bool in_use;
-} BounceBuffer;
-
-static BounceBuffer bounce;
-
-typedef struct MapClient {
-    QEMUBH *bh;
-    QLIST_ENTRY(MapClient) link;
-} MapClient;
-
-QemuMutex map_client_list_lock;
-static QLIST_HEAD(, MapClient) map_client_list
-    = QLIST_HEAD_INITIALIZER(map_client_list);
-
-static void address_space_unregister_map_client_do(MapClient *client)
+static void
+address_space_unregister_map_client_do(AddressSpaceMapClient *client)
 {
     QLIST_REMOVE(client, link);
     g_free(client);
@@ -3074,10 +3056,10 @@  static void address_space_unregister_map_client_do(MapClient *client)
 
 static void address_space_notify_map_clients_locked(AddressSpace *as)
 {
-    MapClient *client;
+    AddressSpaceMapClient *client;
 
-    while (!QLIST_EMPTY(&map_client_list)) {
-        client = QLIST_FIRST(&map_client_list);
+    while (!QLIST_EMPTY(&as->map_client_list)) {
+        client = QLIST_FIRST(&as->map_client_list);
         qemu_bh_schedule(client->bh);
         address_space_unregister_map_client_do(client);
     }
@@ -3085,14 +3067,14 @@  static void address_space_notify_map_clients_locked(AddressSpace *as)
 
 void address_space_register_map_client(AddressSpace *as, QEMUBH *bh)
 {
-    MapClient *client = g_malloc(sizeof(*client));
+    AddressSpaceMapClient *client = g_malloc(sizeof(*client));
 
-    QEMU_LOCK_GUARD(&map_client_list_lock);
+    QEMU_LOCK_GUARD(&as->map_client_list_lock);
     client->bh = bh;
-    QLIST_INSERT_HEAD(&map_client_list, client, link);
+    QLIST_INSERT_HEAD(&as->map_client_list, client, link);
     /* Write map_client_list before reading in_use.  */
     smp_mb();
-    if (!qatomic_read(&bounce.in_use)) {
+    if (!qatomic_read(&as->bounce.in_use)) {
         address_space_notify_map_clients_locked(as);
     }
 }
@@ -3110,15 +3092,14 @@  void cpu_exec_init_all(void)
     finalize_target_page_bits();
     io_mem_init();
     memory_map_init();
-    qemu_mutex_init(&map_client_list_lock);
 }
 
 void address_space_unregister_map_client(AddressSpace *as, QEMUBH *bh)
 {
-    MapClient *client;
+    AddressSpaceMapClient *client;
 
-    QEMU_LOCK_GUARD(&map_client_list_lock);
-    QLIST_FOREACH(client, &map_client_list, link) {
+    QEMU_LOCK_GUARD(&as->map_client_list_lock);
+    QLIST_FOREACH(client, &as->map_client_list, link) {
         if (client->bh == bh) {
             address_space_unregister_map_client_do(client);
             break;
@@ -3128,7 +3109,7 @@  void address_space_unregister_map_client(AddressSpace *as, QEMUBH *bh)
 
 static void address_space_notify_map_clients(AddressSpace *as)
 {
-    QEMU_LOCK_GUARD(&map_client_list_lock);
+    QEMU_LOCK_GUARD(&as->map_client_list_lock);
     address_space_notify_map_clients_locked(as);
 }
 
@@ -3220,25 +3201,25 @@  void *address_space_map(AddressSpace *as,
     mr = flatview_translate(fv, addr, &xlat, &l, is_write, attrs);
 
     if (!memory_access_is_direct(mr, is_write)) {
-        if (qatomic_xchg(&bounce.in_use, true)) {
+        if (qatomic_xchg(&as->bounce.in_use, true)) {
             *plen = 0;
             return NULL;
         }
         /* Avoid unbounded allocations */
         l = MIN(l, TARGET_PAGE_SIZE);
-        bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, l);
-        bounce.addr = addr;
-        bounce.len = l;
+        as->bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, l);
+        as->bounce.addr = addr;
+        as->bounce.len = l;
 
         memory_region_ref(mr);
-        bounce.mr = mr;
+        as->bounce.mr = mr;
         if (!is_write) {
             flatview_read(fv, addr, MEMTXATTRS_UNSPECIFIED,
-                               bounce.buffer, l);
+                          as->bounce.buffer, l);
         }
 
         *plen = l;
-        return bounce.buffer;
+        return as->bounce.buffer;
     }
 
 
@@ -3256,7 +3237,7 @@  void *address_space_map(AddressSpace *as,
 void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
                          bool is_write, hwaddr access_len)
 {
-    if (buffer != bounce.buffer) {
+    if (buffer != as->bounce.buffer) {
         MemoryRegion *mr;
         ram_addr_t addr1;
 
@@ -3272,14 +3253,14 @@  void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
         return;
     }
     if (is_write) {
-        address_space_write(as, bounce.addr, MEMTXATTRS_UNSPECIFIED,
-                            bounce.buffer, access_len);
+        address_space_write(as, as->bounce.addr, MEMTXATTRS_UNSPECIFIED,
+                            as->bounce.buffer, access_len);
     }
-    qemu_vfree(bounce.buffer);
-    bounce.buffer = NULL;
-    memory_region_unref(bounce.mr);
+    qemu_vfree(as->bounce.buffer);
+    as->bounce.buffer = NULL;
+    memory_region_unref(as->bounce.mr);
     /* Clear in_use before reading map_client_list.  */
-    qatomic_set_mb(&bounce.in_use, false);
+    qatomic_set_mb(&as->bounce.in_use, false);
     address_space_notify_map_clients(as);
 }