In this way, we can avoid to invoke qemu_get_ram_block()
at most time, which can save cpu cycle.
Signed-off-by: Gonglei <arei.gong...@huawei.com>
---
exec.c | 48 ++++++++++++++++++++++++++++++------------------
hw/misc/ivshmem.c | 6 ++++--
hw/virtio/vhost-user.c | 11 ++++++-----
include/exec/ram_addr.h | 6 +++---
memory.c | 3 ++-
5 files changed, 45 insertions(+), 29 deletions(-)
diff --git a/exec.c b/exec.c
index b0ecbcd..f3348aa 100644
--- a/exec.c
+++ b/exec.c
@@ -1813,37 +1813,49 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
}
#endif /* !_WIN32 */
-int qemu_get_ram_fd(ram_addr_t addr)
+int qemu_get_ram_fd(RAMBlock *ram_block, ram_addr_t addr)
{
- RAMBlock *block;
+ RAMBlock *block = ram_block;
int fd;
- rcu_read_lock();
- block = qemu_get_ram_block(addr);
- fd = block->fd;
- rcu_read_unlock();
+ if (block == NULL) {
+ rcu_read_lock();
+ block = qemu_get_ram_block(addr);
+ fd = block->fd;
+ rcu_read_unlock();
+ } else {
+ fd = block->fd;
+ }
return fd;
}
-void qemu_set_ram_fd(ram_addr_t addr, int fd)
+void qemu_set_ram_fd(RAMBlock *ram_block, ram_addr_t addr, int fd)
{
- RAMBlock *block;
+ RAMBlock *block = ram_block;
- rcu_read_lock();
- block = qemu_get_ram_block(addr);
- block->fd = fd;
- rcu_read_unlock();
+ if (block == NULL) {
+ rcu_read_lock();
+ block = qemu_get_ram_block(addr);
+ block->fd = fd;
+ rcu_read_unlock();
+ } else {
+ block->fd = fd;
+ }
}
-void *qemu_get_ram_block_host_ptr(ram_addr_t addr)
+void *qemu_get_ram_block_host_ptr(RAMBlock *ram_block, ram_addr_t addr)
{
- RAMBlock *block;
+ RAMBlock *block = ram_block;
void *ptr;
- rcu_read_lock();
- block = qemu_get_ram_block(addr);
- ptr = ramblock_ptr(block, 0);
- rcu_read_unlock();
+ if (block == NULL) {
+ rcu_read_lock();
+ block = qemu_get_ram_block(addr);
+ ptr = ramblock_ptr(block, 0);
+ rcu_read_unlock();
+ } else {
+ ptr = ramblock_ptr(block, 0);
+ }
return ptr;
}
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index e40f23b..5ba0af7 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -533,7 +533,8 @@ 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);
+ qemu_set_ram_fd(s->server_bar2.ram_block,
+ memory_region_get_ram_addr(&s->server_bar2), fd);
s->ivshmem_bar2 = &s->server_bar2;
}
@@ -940,7 +941,8 @@ static void ivshmem_exit(PCIDevice *dev)
strerror(errno));
}
- fd = qemu_get_ram_fd(memory_region_get_ram_addr(s->ivshmem_bar2));
+ fd = qemu_get_ram_fd(s->ivshmem_bar2->ram_block,
+ memory_region_get_ram_addr(s->ivshmem_bar2));
close(fd);
}
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 5914e85..4b93533 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,
+ mr = qemu_ram_addr_from_host((void *)(uintptr_t)reg->userspace_addr,
&ram_addr);
- fd = qemu_get_ram_fd(ram_addr);
+ fd = qemu_get_ram_fd(mr->ram_block, ram_addr);
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) qemu_get_ram_block_host_ptr(mr->ram_block,
ram_addr);
assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
fds[fd_num++] = fd;
}
@@ -622,11 +623,11 @@ static bool vhost_user_can_merge(struct vhost_dev *dev,
mr = qemu_ram_addr_from_host((void *)(uintptr_t)start1, &ram_addr);
assert(mr);
- mfd = qemu_get_ram_fd(ram_addr);
+ mfd = qemu_get_ram_fd(mr->ram_block, ram_addr);
mr = qemu_ram_addr_from_host((void *)(uintptr_t)start2, &ram_addr);
assert(mr);
- rfd = qemu_get_ram_fd(ram_addr);
+ rfd = qemu_get_ram_fd(mr->ram_block, ram_addr);
return mfd == rfd;
}
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 5b6e1b8..4e1e5c3 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -105,9 +105,9 @@ 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);
+int qemu_get_ram_fd(RAMBlock *ram_block, ram_addr_t addr);
+void qemu_set_ram_fd(RAMBlock *ram_block, ram_addr_t addr, int fd);
+void *qemu_get_ram_block_host_ptr(RAMBlock *ram_block, 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 239e6da..fa2b6e2 100644
--- a/memory.c
+++ b/memory.c
@@ -1641,7 +1641,8 @@ int memory_region_get_fd(MemoryRegion *mr)
assert(mr->ram_block);
- return qemu_get_ram_fd(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK);
+ return qemu_get_ram_fd(mr->ram_block,
+ memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK);
}
void *memory_region_get_ram_ptr(MemoryRegion *mr)
--
1.7.12.4
