OpenE2K/qemu-e2k
13
4
Fork 0
Code Issues 4 Pull Requests Projects 2 Releases Activity

migration: propagate suspended runstate

Browse Source 
If the outgoing machine was previously suspended, propagate that to the
incoming side via global_state, so a subsequent vm_start restores the
suspended state.  To maintain backward and forward compatibility, reclaim
some space from the runstate member.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/1704312341-66640-6-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>
This commit is contained in:
Steve Sistare 2024-01-03 12:05:34 -08:00 committed by Peter Xu
parent 9ff5e79f2e
commit d3c86c99f3
1 changed files with 27 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
migration/global_state.c
View File

@ -22,7 +22,16 @@
typedef struct {
uint32_t size;
uint8_t runstate[100];
/*
* runstate was 100 bytes, zero padded, but we trimmed it to add a
* few fields and maintain backwards compatibility.
*/
uint8_t runstate[32];
uint8_t has_vm_was_suspended;
uint8_t vm_was_suspended;
uint8_t unused[66];
RunState state;
bool received;
} GlobalState;
@ -35,6 +44,10 @@ static void global_state_do_store(RunState state)
assert(strlen(state_str) < sizeof(global_state.runstate));
strpadcpy((char *)global_state.runstate, sizeof(global_state.runstate),
state_str, '\0');
global_state.has_vm_was_suspended = true;
global_state.vm_was_suspended = vm_get_suspended();
memset(global_state.unused, 0, sizeof(global_state.unused));
}
void global_state_store(void)
@ -59,24 +72,7 @@ RunState global_state_get_runstate(void)
static bool global_state_needed(void *opaque)
{
GlobalState *s = opaque;
char *runstate = (char *)s->runstate;
/* If it is not optional, it is mandatory */
if (migrate_get_current()->store_global_state) {
return true;
}
/* If state is running or paused, it is not needed */
if (strcmp(runstate, "running") == 0 ||
strcmp(runstate, "paused") == 0) {
return false;
}
/* for any other state it is needed */
return true;
return migrate_get_current()->store_global_state;
}
static int global_state_post_load(void *opaque, int version_id)
@ -93,7 +89,7 @@ static int global_state_post_load(void *opaque, int version_id)
sizeof(s->runstate)) == sizeof(s->runstate)) {
/*
* This condition should never happen during migration, because
* all runstate names are shorter than 100 bytes (the size of
* all runstate names are shorter than 32 bytes (the size of
* s->runstate). However, a malicious stream could overflow
* the qapi_enum_parse() call, so we force the last character
* to a NUL byte.
@ -110,6 +106,14 @@ static int global_state_post_load(void *opaque, int version_id)
}
s->state = r;
/*
* global_state is saved on the outgoing side before forcing a stopped
* state, so it may have saved state=suspended and vm_was_suspended=0.
* Now we are in a paused state, and when we later call vm_start, it must
* restore the suspended state, so we must set vm_was_suspended=1 here.
*/
vm_set_suspended(s->vm_was_suspended || r == RUN_STATE_SUSPENDED);
return 0;
}
@ -134,6 +138,9 @@ static const VMStateDescription vmstate_globalstate = {
.fields = (VMStateField[]) {
VMSTATE_UINT32(size, GlobalState),
VMSTATE_BUFFER(runstate, GlobalState),
VMSTATE_UINT8(has_vm_was_suspended, GlobalState),
VMSTATE_UINT8(vm_was_suspended, GlobalState),
VMSTATE_BUFFER(unused, GlobalState),
VMSTATE_END_OF_LIST()
},
};