On 2/3/2025 11:58 AM, Peter Xu wrote:
On Wed, Jan 29, 2025 at 06:42:58AM -0800, Steve Sistare wrote:
Define a vmstate priority that is lower than the default, so its handlers
run after all default priority handlers. Since 0 is no longer the default
priority, translate an uninitialized priority of 0 to MIG_PRI_DEFAULT.
CPR for vfio will use this to install handlers for containers that run
after handlers for the devices that they contain.
Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
---
include/migration/vmstate.h | 3 ++-
migration/savevm.c | 4 ++--
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index a1dfab4..3055a46 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -155,7 +155,8 @@ enum VMStateFlags {
};
typedef enum {
- MIG_PRI_DEFAULT = 0,
Shall we still keep a defintion for 0? Or at least add a comment link to
save_state_priority() - it might be helpful for whoever jumps to this enum
defintion when reading.. and get confused how a default value is non-zero.
Or define it as something like:
MIG_PRI_UNINITIALIZED = 0, /* Most devices don't set a priority, it
will
* be routed to MIG_PRI_DEFAULT */
Sure, I'll add MIG_PRI_UNINITIALIZED.
- Steve
+ MIG_PRI_LOW = 1, /* Must happen after default */
+ MIG_PRI_DEFAULT,
MIG_PRI_IOMMU, /* Must happen before PCI devices */
MIG_PRI_PCI_BUS, /* Must happen before IOMMU */
MIG_PRI_VIRTIO_MEM, /* Must happen before IOMMU */
diff --git a/migration/savevm.c b/migration/savevm.c
index 264bc06..5dd2dc4 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -232,7 +232,7 @@ typedef struct SaveState {
static SaveState savevm_state = {
.handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers),
- .handler_pri_head = { [MIG_PRI_DEFAULT ... MIG_PRI_MAX] = NULL },
+ .handler_pri_head = { [0 ... MIG_PRI_MAX] = NULL },
.global_section_id = 0,
};
@@ -704,7 +704,7 @@ static int calculate_compat_instance_id(const char *idstr)
static inline MigrationPriority save_state_priority(SaveStateEntry *se)
{
- if (se->vmsd) {
+ if (se->vmsd && se->vmsd->priority) {
return se->vmsd->priority;
}
return MIG_PRI_DEFAULT;
--
1.8.3.1
