/*
* Temporarily drop the record/replay mutex to let rr_cpu_thread_fn()
@@ -479,6 +480,7 @@ static void s390_machine_reset(MachineState *machine,
ResetType type)
switch (reset_type) {
case S390_RESET_EXTERNAL:
case S390_RESET_REIPL:
+ case S390_RESET_REIPL_CLEAR:
/*
* Reset the subsystem which includes a AP reset. If a PV
* guest had APQNs attached the AP reset is a prerequisite to
@@ -489,6 +491,10 @@ static void s390_machine_reset(MachineState *machine,
ResetType type)
s390_machine_unprotect(ms);
}
+ if (reset_type == S390_RESET_REIPL_CLEAR) {
+ ram_block_discard_range(rb, 0 , qemu_ram_get_used_length(rb));
+ }
+
...
Do I see that right that this patch never made it into qemu master? IIRC
Matt has clarified all concerns?
I was hoping to see a reply from David that he's fine with the patch now...
David?
Staring at this again, one more point regarding userfaultfd: doing the
discard on the destination while postcopy is active might be problematic.
I don't remember all details, but I think that if we have the following:
1) Migrate page X to dst
2) Discard page X on dst
3) Access page X on dst
that postcopy_request_page()->migrate_send_rp_req_pages() would assume
that the page was already transferred (marked received in the receive
bitmap during 1) ) and essentially never place a fresh zeropage during
3) to be stuck forever.
--
Cheers
David
