[Qemu-devel] [PATCH 1/4] memory: remove qemu_get_ram_fd, qemu_set_ram_fd, qemu_ram_block_host_ptr

[Paolo Bonzini <pbonzini@redhat.com>]

Remove direct uses of ram_addr_t and optimize memory_region_{get,set}_fd
now that a MemoryRegion knows its RAMBlock directly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 exec.c                  | 34 ----------------------------------
 hw/misc/ivshmem.c       |  5 ++---
 hw/virtio/vhost-user.c  | 15 +++++++--------
 include/exec/memory.h   | 11 +++++++++++
 include/exec/ram_addr.h |  3 ---
 memory.c                | 21 +++++++++++++++++----
 6 files changed, 37 insertions(+), 52 deletions(-)

diff --git a/exec.c b/exec.c
index a3a93ae..3330e7d 100644
--- a/exec.c
+++ b/exec.c
@@ -1815,40 +1815,6 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
 }
 #endif /* !_WIN32 */
 
-int qemu_get_ram_fd(ram_addr_t addr)
-{
-    RAMBlock *block;
-    int fd;
-
-    rcu_read_lock();
-    block = qemu_get_ram_block(addr);
-    fd = block->fd;
-    rcu_read_unlock();
-    return fd;
-}
-
-void qemu_set_ram_fd(ram_addr_t addr, int fd)
-{
-    RAMBlock *block;
-
-    rcu_read_lock();
-    block = qemu_get_ram_block(addr);
-    block->fd = fd;
-    rcu_read_unlock();
-}
-
-void *qemu_get_ram_block_host_ptr(ram_addr_t addr)
-{
-    RAMBlock *block;
-    void *ptr;
-
-    rcu_read_lock();
-    block = qemu_get_ram_block(addr);
-    ptr = ramblock_ptr(block, 0);
-    rcu_read_unlock();
-    return ptr;
-}
-
 /* Return a host pointer to ram allocated with qemu_ram_alloc.
  * This should not be used for general purpose DMA.  Use address_space_map
  * or address_space_rw instead. For local memory (e.g. video ram) that the
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index e40f23b..90be9f7 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -33,7 +33,6 @@
 #include "sysemu/hostmem.h"
 #include "sysemu/qtest.h"
 #include "qapi/visitor.h"
-#include "exec/ram_addr.h"
 
 #include "hw/misc/ivshmem.h"
 
@@ -533,7 +532,7 @@ static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
     }
     memory_region_init_ram_ptr(&s->server_bar2, OBJECT(s),
                                "ivshmem.bar2", size, ptr);
-    qemu_set_ram_fd(memory_region_get_ram_addr(&s->server_bar2), fd);
+    memory_region_set_fd(&s->server_bar2, fd);
     s->ivshmem_bar2 = &s->server_bar2;
 }
 
@@ -940,7 +939,7 @@ static void ivshmem_exit(PCIDevice *dev)
                              strerror(errno));
             }
 
-            fd = qemu_get_ram_fd(memory_region_get_ram_addr(s->ivshmem_bar2));
+            fd = memory_region_get_fd(s->ivshmem_bar2);
             close(fd);
         }
 
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 5914e85..41908c0 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -248,17 +248,18 @@ static int vhost_user_set_mem_table(struct vhost_dev *dev,
     for (i = 0; i < dev->mem->nregions; ++i) {
         struct vhost_memory_region *reg = dev->mem->regions + i;
         ram_addr_t ram_addr;
+        MemoryRegion *mr;
 
         assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
-        qemu_ram_addr_from_host((void *)(uintptr_t)reg->userspace_addr,
-                                &ram_addr);
-        fd = qemu_get_ram_fd(ram_addr);
+        mr = qemu_ram_addr_from_host((void *)(uintptr_t)reg->userspace_addr,
+                                     &ram_addr);
+        fd = memory_region_get_fd(mr);
         if (fd > 0) {
             msg.payload.memory.regions[fd_num].userspace_addr = reg->userspace_addr;
             msg.payload.memory.regions[fd_num].memory_size  = reg->memory_size;
             msg.payload.memory.regions[fd_num].guest_phys_addr = reg->guest_phys_addr;
             msg.payload.memory.regions[fd_num].mmap_offset = reg->userspace_addr -
-                (uintptr_t) qemu_get_ram_block_host_ptr(ram_addr);
+                (uintptr_t) memory_region_get_ram_ptr(mr);
             assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
             fds[fd_num++] = fd;
         }
@@ -621,12 +622,10 @@ static bool vhost_user_can_merge(struct vhost_dev *dev,
     MemoryRegion *mr;
 
     mr = qemu_ram_addr_from_host((void *)(uintptr_t)start1, &ram_addr);
-    assert(mr);
-    mfd = qemu_get_ram_fd(ram_addr);
+    mfd = memory_region_get_fd(mr);
 
     mr = qemu_ram_addr_from_host((void *)(uintptr_t)start2, &ram_addr);
-    assert(mr);
-    rfd = qemu_get_ram_fd(ram_addr);
+    rfd = memory_region_get_fd(mr);
 
     return mfd == rfd;
 }
diff --git a/include/exec/memory.h b/include/exec/memory.h
index f649697..1678494 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -667,6 +667,17 @@ static inline bool memory_region_is_rom(MemoryRegion *mr)
 int memory_region_get_fd(MemoryRegion *mr);
 
 /**
+ * memory_region_set_fd: Mark a RAM memory region as backed by a
+ * file descriptor.
+ *
+ * This function is typically used after memory_region_init_ram_ptr().
+ *
+ * @mr: the memory region being queried.
+ * @fd: the file descriptor that backs @mr.
+ */
+void memory_region_set_fd(MemoryRegion *mr, int fd);
+
+/**
  * memory_region_get_ram_ptr: Get a pointer into a RAM memory region.
  *
  * Returns a host pointer to a RAM memory region (created with
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 5b6e1b8..2a9465d 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -105,9 +105,6 @@ RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
                                                     uint64_t length,
                                                     void *host),
                                     MemoryRegion *mr, Error **errp);
-int qemu_get_ram_fd(ram_addr_t addr);
-void qemu_set_ram_fd(ram_addr_t addr, int fd);
-void *qemu_get_ram_block_host_ptr(ram_addr_t addr);
 void qemu_ram_free(RAMBlock *block);
 
 int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
diff --git a/memory.c b/memory.c
index 0f52522..d6a4a68 100644
--- a/memory.c
+++ b/memory.c
@@ -1626,13 +1626,26 @@ void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,
 
 int memory_region_get_fd(MemoryRegion *mr)
 {
-    if (mr->alias) {
-        return memory_region_get_fd(mr->alias);
+    int fd;
+
+    rcu_read_lock();
+    while (mr->alias) {
+        mr = mr->alias;
     }
+    fd = mr->ram_block->fd;
+    rcu_read_unlock();
 
-    assert(mr->ram_block);
+    return fd;
+}
 
-    return qemu_get_ram_fd(memory_region_get_ram_addr(mr));
+void memory_region_set_fd(MemoryRegion *mr, int fd)
+{
+    rcu_read_lock();
+    while (mr->alias) {
+        mr = mr->alias;
+    }
+    mr->ram_block->fd = fd;
+    rcu_read_unlock();
 }
 
 void *memory_region_get_ram_ptr(MemoryRegion *mr)
-- 
2.5.5