hostmem: allow preallocation of any memory region

And allow preallocation of file-based memory even without -mem-prealloc.
Some care is necessary because -mem-prealloc does not allow disabling
preallocation for hostmem-file.

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>
This commit is contained in:
Paolo Bonzini 2014-06-10 19:15:23 +08:00 committed by Michael S. Tsirkin
parent 605d0a945d
commit a35ba7be4b
7 changed files with 75 additions and 0 deletions

View file

@ -105,6 +105,41 @@ static void host_memory_backend_set_dump(Object *obj, bool value, Error **errp)
}
}
static bool host_memory_backend_get_prealloc(Object *obj, Error **errp)
{
HostMemoryBackend *backend = MEMORY_BACKEND(obj);
return backend->prealloc || backend->force_prealloc;
}
static void host_memory_backend_set_prealloc(Object *obj, bool value,
Error **errp)
{
HostMemoryBackend *backend = MEMORY_BACKEND(obj);
if (backend->force_prealloc) {
if (value) {
error_setg(errp,
"remove -mem-prealloc to use the prealloc property");
return;
}
}
if (!memory_region_size(&backend->mr)) {
backend->prealloc = value;
return;
}
if (value && !backend->prealloc) {
int fd = memory_region_get_fd(&backend->mr);
void *ptr = memory_region_get_ram_ptr(&backend->mr);
uint64_t sz = memory_region_size(&backend->mr);
os_mem_prealloc(fd, ptr, sz);
backend->prealloc = true;
}
}
static void host_memory_backend_init(Object *obj)
{
HostMemoryBackend *backend = MEMORY_BACKEND(obj);
@ -113,6 +148,7 @@ static void host_memory_backend_init(Object *obj)
"mem-merge", true);
backend->dump = qemu_opt_get_bool(qemu_get_machine_opts(),
"dump-guest-core", true);
backend->prealloc = mem_prealloc;
object_property_add_bool(obj, "merge",
host_memory_backend_get_merge,
@ -120,6 +156,9 @@ static void host_memory_backend_init(Object *obj)
object_property_add_bool(obj, "dump",
host_memory_backend_get_dump,
host_memory_backend_set_dump, NULL);
object_property_add_bool(obj, "prealloc",
host_memory_backend_get_prealloc,
host_memory_backend_set_prealloc, NULL);
object_property_add(obj, "size", "int",
host_memory_backend_get_size,
host_memory_backend_set_size, NULL, NULL, NULL);
@ -165,6 +204,9 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
if (!backend->dump) {
qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
}
if (backend->prealloc) {
os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz);
}
}
}