If 'size' option is not specified, QEMU will use the file size of
'mem-path' instead. If an empty file, a non-existing file or a directory
is specified by option 'mem-path', a non-zero option 'size' is still
needed.
Signed-off-by: Haozhong Zhang <haozhong.zh...@intel.com>
---
backends/hostmem-file.c | 28 ++++++++++++++++++++--------
exec.c | 27 +++++++++++++++++++++++++++
2 files changed, 47 insertions(+), 8 deletions(-)
diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
index 42efb2f..56cc96b 100644
--- a/backends/hostmem-file.c
+++ b/backends/hostmem-file.c
@@ -39,17 +39,14 @@ static void
file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
{
HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
+ Error *local_err = NULL;
- if (!backend->size) {
- error_setg(errp, "can't create backend with size 0");
- return;
- }
if (!fb->mem_path) {
- error_setg(errp, "mem-path property not set");
- return;
+ error_setg(&local_err, "mem-path property not set");
+ goto out;
}
#ifndef CONFIG_LINUX
- error_setg(errp, "-mem-path not supported on this host");
+ error_setg(&local_err, "-mem-path not supported on this host");
#else
if (!memory_region_size(&backend->mr)) {
gchar *path;
@@ -58,10 +55,25 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error
**errp)
memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
path,
backend->size, fb->share,
- fb->mem_path, errp);
+ fb->mem_path, &local_err);
g_free(path);
+
+ if (local_err) {
+ goto out;
+ }
+
+ if (!backend->size) {
+ backend->size = memory_region_size(&backend->mr);
+ }
+ }
+
+ if (!backend->size) {
+ error_setg(&local_err, "can't create backend with size 0");
}
#endif
+
+ out:
+ error_propagate(errp, local_err);
}
static char *get_mem_path(Object *o, Error **errp)
diff --git a/exec.c b/exec.c
index 42045aa..b81c9a8 100644
--- a/exec.c
+++ b/exec.c
@@ -1676,6 +1676,7 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
int fd = -1;
bool unlink_on_error = false;
int64_t file_size;
+ uint64_t mr_size;
Error *local_err = NULL;
if (xen_enabled()) {
@@ -1704,6 +1705,32 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
*/
file_size = get_file_size(fd);
+ if (!size && file_size >= 0) {
+ if (!file_size) {
+ error_setg(&local_err,
+ "%s is empty or a directory, 'size' option must be
specified",
+ mem_path);
+ goto out;
+ }
+
+ mr_size = memory_region_size(mr);
+ if (mr_size && mr_size != size) {
+ error_setg(&local_err, "cannot resize non-empty memory region");
+ goto out;
+ }
+ if (!mr_size) {
+ memory_region_set_size(mr, file_size);
+ }
+ size = file_size;
+ }
+
+ if (!size) {
+ error_setg(&local_err,
+ "cannot get size of %s, 'size' option must be specified",
+ mem_path);
+ goto out;
+ }
+
size = HOST_PAGE_ALIGN(size);
if (file_size > 0 && file_size < size) {
error_setg(&local_err, "backing store %s size 0x%"PRIx64
--
2.10.1
