Save the memfd for anonymous ramblocks in CPR state, along with a name
that uniquely identifies it. The block's idstr is not yet set, so it
cannot be used for this purpose. Find the saved memfd in new QEMU when
creating a block. QEMU hard-codes the length of some internally-created
blocks, so to guard against that length changing, use lseek to get the
actual length of an incoming memfd.
Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
---
system/physmem.c | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/system/physmem.c b/system/physmem.c
index efe95ff..e37352e 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -73,6 +73,7 @@
#include "qapi/qapi-types-migration.h"
#include "migration/options.h"
+#include "migration/cpr.h"
#include "migration/vmstate.h"
#include "qemu/range.h"
@@ -1641,6 +1642,19 @@ void qemu_ram_unset_idstr(RAMBlock *block)
}
}
+static char *cpr_name(RAMBlock *block)
+{
+ MemoryRegion *mr = block->mr;
+ const char *mr_name = memory_region_name(mr);
+ g_autofree char *id = mr->dev ? qdev_get_dev_path(mr->dev) : NULL;
+
+ if (id) {
+ return g_strdup_printf("%s/%s", id, mr_name);
+ } else {
+ return g_strdup(mr_name);
+ }
+}
+
size_t qemu_ram_pagesize(RAMBlock *rb)
{
return rb->page_size;
@@ -1836,13 +1850,17 @@ static void ram_block_add(RAMBlock *new_block, Error
**errp)
} else if (new_block->flags & RAM_SHARED) {
size_t max_length = new_block->max_length;
MemoryRegion *mr = new_block->mr;
- const char *name = memory_region_name(mr);
+ g_autofree char *name = cpr_name(new_block);
new_block->mr->align = QEMU_VMALLOC_ALIGN;
+ new_block->fd = cpr_find_fd(name, 0);
if (new_block->fd == -1) {
new_block->fd = qemu_memfd_create(name, max_length + mr->align,
0, 0, 0, errp);
+ cpr_save_fd(name, 0, new_block->fd);
+ } else {
+ new_block->max_length = lseek(new_block->fd, 0, SEEK_END);
}
if (new_block->fd >= 0) {
@@ -1852,6 +1870,7 @@ static void ram_block_add(RAMBlock *new_block, Error
**errp)
false, 0, errp);
}
if (!new_block->host) {
+ cpr_delete_fd(name, 0);
qemu_mutex_unlock_ramlist();
return;
}
@@ -2162,6 +2181,8 @@ static void reclaim_ramblock(RAMBlock *block)
void qemu_ram_free(RAMBlock *block)
{
+ g_autofree char *name = NULL;
+
if (!block) {
return;
}
@@ -2172,6 +2193,8 @@ void qemu_ram_free(RAMBlock *block)
}
qemu_mutex_lock_ramlist();
+ name = cpr_name(block);
+ cpr_delete_fd(name, 0);
QLIST_REMOVE_RCU(block, next);
ram_list.mru_block = NULL;
/* Write list before version */
--
1.8.3.1
