Extend qemu_ram_alloc_from_fd to support resizable ram, and define
qemu_ram_resize_cb to clean up the API.
Add a grow parameter to extend the file if necessary. However, if
grow is false, a zero-sized file is always extended.
Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
---
include/exec/ram_addr.h | 13 +++++++++----
system/memory.c | 4 ++--
system/physmem.c | 35 ++++++++++++++++++++---------------
3 files changed, 31 insertions(+), 21 deletions(-)
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index ff157c1..94bb3cc 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -111,23 +111,30 @@ long qemu_maxrampagesize(void);
*
* Parameters:
* @size: the size in bytes of the ram block
+ * @max_size: the maximum size of the block after resizing
* @mr: the memory region where the ram block is
+ * @resized: callback after calls to qemu_ram_resize
* @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
* RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
* RAM_READONLY_FD, RAM_GUEST_MEMFD
* @mem_path or @fd: specify the backing file or device
* @offset: Offset into target file
+ * @grow: extend file if necessary (but an empty file is always extended).
* @errp: pointer to Error*, to store an error if it happens
*
* Return:
* On success, return a pointer to the ram block.
* On failure, return NULL.
*/
+typedef void (*qemu_ram_resize_cb)(const char *, uint64_t length, void *host);
+
RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
uint32_t ram_flags, const char *mem_path,
off_t offset, Error **errp);
-RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
+RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, ram_addr_t max_size,
+ qemu_ram_resize_cb resized, MemoryRegion *mr,
uint32_t ram_flags, int fd, off_t offset,
+ bool grow,
Error **errp);
RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
@@ -135,9 +142,7 @@ RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void
*host,
RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr,
Error **errp);
RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
- void (*resized)(const char*,
- uint64_t length,
- void *host),
+ qemu_ram_resize_cb resized,
MemoryRegion *mr, Error **errp);
void qemu_ram_free(RAMBlock *block);
diff --git a/system/memory.c b/system/memory.c
index b17b553..4c82979 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -1680,8 +1680,8 @@ bool memory_region_init_ram_from_fd(MemoryRegion *mr,
mr->readonly = !!(ram_flags & RAM_READONLY);
mr->terminates = true;
mr->destructor = memory_region_destructor_ram;
- mr->ram_block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, offset,
- &err);
+ mr->ram_block = qemu_ram_alloc_from_fd(size, size, NULL, mr, ram_flags, fd,
+ offset, false, &err);
if (err) {
mr->size = int128_zero();
object_unparent(OBJECT(mr));
diff --git a/system/physmem.c b/system/physmem.c
index 792844d..4d13761 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1942,8 +1942,10 @@ out_free:
}
#ifdef CONFIG_POSIX
-RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
+RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, ram_addr_t max_size,
+ qemu_ram_resize_cb resized, MemoryRegion *mr,
uint32_t ram_flags, int fd, off_t offset,
+ bool grow,
Error **errp)
{
RAMBlock *new_block;
@@ -1953,7 +1955,9 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size,
MemoryRegion *mr,
/* Just support these ram flags by now. */
assert((ram_flags & ~(RAM_SHARED | RAM_PMEM | RAM_NORESERVE |
RAM_PROTECTED | RAM_NAMED_FILE | RAM_READONLY |
- RAM_READONLY_FD | RAM_GUEST_MEMFD)) == 0);
+ RAM_READONLY_FD | RAM_GUEST_MEMFD |
+ RAM_RESIZEABLE)) == 0);
+ assert(max_size >= size);
if (xen_enabled()) {
error_setg(errp, "-mem-path not supported with Xen");
@@ -1968,13 +1972,15 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size,
MemoryRegion *mr,
size = TARGET_PAGE_ALIGN(size);
size = REAL_HOST_PAGE_ALIGN(size);
+ max_size = TARGET_PAGE_ALIGN(max_size);
+ max_size = REAL_HOST_PAGE_ALIGN(max_size);
file_size = get_file_size(fd);
- if (file_size && file_size < offset + size) {
+ if (file_size && file_size < offset + max_size && !grow) {
error_setg(errp, "%s backing store size 0x%" PRIx64
" is too small for 'size' option 0x" RAM_ADDR_FMT
" plus 'offset' option 0x%" PRIx64,
- memory_region_name(mr), file_size, size,
+ memory_region_name(mr), file_size, max_size,
(uint64_t)offset);
return NULL;
}
@@ -1990,11 +1996,13 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size,
MemoryRegion *mr,
new_block = g_malloc0(sizeof(*new_block));
new_block->mr = mr;
new_block->used_length = size;
- new_block->max_length = size;
+ new_block->max_length = max_size;
+ new_block->resized = resized;
new_block->flags = ram_flags;
new_block->guest_memfd = -1;
- new_block->host = file_ram_alloc(new_block, size, fd, !file_size, offset,
- errp);
+ new_block->host = file_ram_alloc(new_block, max_size, fd,
+ file_size < offset + max_size,
+ offset, errp);
if (!new_block->host) {
g_free(new_block);
return NULL;
@@ -2046,7 +2054,8 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
return NULL;
}
- block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, offset, errp);
+ block = qemu_ram_alloc_from_fd(size, size, NULL, mr, ram_flags, fd, offset,
+ false, errp);
if (!block) {
if (created) {
unlink(mem_path);
@@ -2061,9 +2070,7 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
static
RAMBlock *qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size,
- void (*resized)(const char*,
- uint64_t length,
- void *host),
+ qemu_ram_resize_cb resized,
void *host, uint32_t ram_flags,
MemoryRegion *mr, Error **errp)
{
@@ -2115,10 +2122,8 @@ RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t
ram_flags,
}
RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t maxsz,
- void (*resized)(const char*,
- uint64_t length,
- void *host),
- MemoryRegion *mr, Error **errp)
+ qemu_ram_resize_cb resized,
+ MemoryRegion *mr, Error **errp)
{
return qemu_ram_alloc_internal(size, maxsz, resized, NULL,
RAM_RESIZEABLE, mr, errp);
--
1.8.3.1
