If 'size' option is not given, 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 | 33 ++++++++++++++++++++-------------
2 files changed, 40 insertions(+), 21 deletions(-)
diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
index 42efb2f..6ee4352 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);
+ }
}
#endif
+
+ if (!backend->size) {
+ error_setg(&local_err, "can't create backend with size 0");
+ }
+
+ out:
+ error_propagate(errp, local_err);
}
static char *get_mem_path(Object *o, Error **errp)
diff --git a/exec.c b/exec.c
index 264a25f..89065bd 100644
--- a/exec.c
+++ b/exec.c
@@ -1234,7 +1234,7 @@ static int64_t get_file_size(int fd)
}
static void *file_ram_alloc(RAMBlock *block,
- ram_addr_t memory,
+ ram_addr_t *memory,
const char *path,
Error **errp)
{
@@ -1245,6 +1245,7 @@ static void *file_ram_alloc(RAMBlock *block,
void *area = MAP_FAILED;
int fd = -1;
int64_t file_size;
+ ram_addr_t mem_size = *memory;
if (kvm_enabled() && !kvm_has_sync_mmu()) {
error_setg(errp,
@@ -1309,21 +1310,27 @@ static void *file_ram_alloc(RAMBlock *block,
file_size = get_file_size(fd);
- if (memory < block->page_size) {
+ if (!mem_size && file_size > 0) {
+ mem_size = file_size;
+ memory_region_set_size(block->mr, mem_size);
+ }
+
+ if (mem_size < block->page_size) {
error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to "
"or larger than page size 0x%zx",
- memory, block->page_size);
+ mem_size, block->page_size);
goto error;
}
- if (file_size > 0 && file_size < memory) {
+ if (file_size > 0 && file_size < mem_size) {
error_setg(errp, "backing store %s size %"PRId64
" does not match 'size' option %"PRIu64,
- path, file_size, memory);
+ path, file_size, mem_size);
goto error;
}
- memory = ROUND_UP(memory, block->page_size);
+ mem_size = ROUND_UP(mem_size, block->page_size);
+ *memory = mem_size;
/*
* ftruncate is not supported by hugetlbfs in older
@@ -1339,11 +1346,11 @@ static void *file_ram_alloc(RAMBlock *block,
* those labels. Therefore, extending the non-empty backend file
* is disabled as well.
*/
- if (!file_size && ftruncate(fd, memory)) {
+ if (!file_size && ftruncate(fd, mem_size)) {
perror("ftruncate");
}
- area = qemu_ram_mmap(fd, memory, block->mr->align,
+ area = qemu_ram_mmap(fd, mem_size, block->mr->align,
block->flags & RAM_SHARED);
if (area == MAP_FAILED) {
error_setg_errno(errp, errno,
@@ -1352,7 +1359,7 @@ static void *file_ram_alloc(RAMBlock *block,
}
if (mem_prealloc) {
- os_mem_prealloc(fd, area, memory, errp);
+ os_mem_prealloc(fd, area, mem_size, errp);
if (errp && *errp) {
goto error;
}
@@ -1363,7 +1370,7 @@ static void *file_ram_alloc(RAMBlock *block,
error:
if (area != MAP_FAILED) {
- qemu_ram_munmap(area, memory);
+ qemu_ram_munmap(area, mem_size);
}
if (unlink_on_error) {
unlink(path);
@@ -1690,15 +1697,15 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
size = HOST_PAGE_ALIGN(size);
new_block = g_malloc0(sizeof(*new_block));
new_block->mr = mr;
- new_block->used_length = size;
- new_block->max_length = size;
new_block->flags = share ? RAM_SHARED : 0;
- new_block->host = file_ram_alloc(new_block, size,
+ new_block->host = file_ram_alloc(new_block, &size,
mem_path, errp);
if (!new_block->host) {
g_free(new_block);
return NULL;
}
+ new_block->used_length = size;
+ new_block->max_length = size;
ram_block_add(new_block, &local_err);
if (local_err) {
--
2.10.1
