diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2014-06-10 19:15:24 +0800 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2014-06-19 18:44:20 +0300 |
| commit | dbcb8981183592be129b2e624b7bcd4245e75fbc (patch) | |
| tree | 639391848fc2cb66c281fb7e8a9fae377bee87f1 /exec.c | |
| parent | a35ba7be4b696d4c7b47318fd2022e6c3eca0a63 (diff) | |
hostmem: add property to map memory with MAP_SHARED
A new "share" property can be used with the "memory-file" backend to
map memory with MAP_SHARED instead of MAP_PRIVATE.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'exec.c')
| -rw-r--r-- | exec.c | 18 |
1 files changed, 10 insertions, 8 deletions
@@ -73,6 +73,9 @@ static MemoryRegion io_mem_unassigned; /* RAM is pre-allocated and passed into qemu_ram_alloc_from_ptr */ #define RAM_PREALLOC (1 << 0) +/* RAM is mmap-ed with MAP_SHARED */ +#define RAM_SHARED (1 << 1) + #endif struct CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus); @@ -1074,7 +1077,9 @@ static void *file_ram_alloc(RAMBlock *block, perror("ftruncate"); } - area = mmap(0, memory, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + area = mmap(0, memory, PROT_READ | PROT_WRITE, + (block->flags & RAM_SHARED ? MAP_SHARED : MAP_PRIVATE), + fd, 0); if (area == MAP_FAILED) { error_setg_errno(errp, errno, "unable to map backing store for hugepages"); @@ -1286,7 +1291,7 @@ static ram_addr_t ram_block_add(RAMBlock *new_block) #ifdef __linux__ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, - const char *mem_path, + bool share, const char *mem_path, Error **errp) { RAMBlock *new_block; @@ -1311,6 +1316,7 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, new_block = g_malloc0(sizeof(*new_block)); new_block->mr = mr; new_block->length = size; + new_block->flags = share ? RAM_SHARED : 0; new_block->host = file_ram_alloc(new_block, size, mem_path, errp); if (!new_block->host) { @@ -1413,12 +1419,8 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length) flags = MAP_FIXED; munmap(vaddr, length); if (block->fd >= 0) { -#ifdef MAP_POPULATE - flags |= mem_prealloc ? MAP_POPULATE | MAP_SHARED : - MAP_PRIVATE; -#else - flags |= MAP_PRIVATE; -#endif + flags |= (block->flags & RAM_SHARED ? + MAP_SHARED : MAP_PRIVATE); area = mmap(vaddr, length, PROT_READ | PROT_WRITE, flags, block->fd, offset); } else { |