From: Paolo Bonzini <pbonzini@redhat.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: qemu-devel@nongnu.org, qemu-stable@nongnu.org
Subject: Re: [PULL 30/33] migration: do not restart VM after successful snapshot-load
Date: Wed, 12 May 2021 10:05:23 +0200 [thread overview]
Message-ID: <9c737fec-4830-2c7b-504f-2bf7a08a18ec@redhat.com> (raw)
In-Reply-To: <YJpGxIcrLeZ21EUT@work-vm>
On 11/05/21 10:56, Dr. David Alan Gilbert wrote:
> * Paolo Bonzini (pbonzini@redhat.com) wrote:
>> The HMP loadvm code is calling load_snapshot rather than
>> qmp_snapshot_load, in order to bypass the job infrastructure. The code
>> around it is almost the same, with one difference: hmp_loadvm is
>> restarting the VM if load_snapshot fails, qmp_snapshot_load is doing so
>> if load_snapshot succeeds.
>>
>> Fix the bug in QMP by moving the common code to load_snapshot.
>
> See my comment:
> https://lists.gnu.org/archive/html/qemu-devel/2021-05/msg01103.html
>
> but you've also lost Eric's Rb.
Sorry, I missed both replies. As Daniel pointed out, the bug is in the
QMP version. Kevin has the correct fix, I'll send the cleanup of
vm_stop/vm_start separately on top of his patch.
Paolo
> Dave
>
>> Cc: qemu-stable@nongnu.org
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> ---
>> migration/savevm.c | 16 ++++++++--------
>> monitor/hmp-cmds.c | 7 +------
>> 2 files changed, 9 insertions(+), 14 deletions(-)
>>
>> diff --git a/migration/savevm.c b/migration/savevm.c
>> index 52e2d72e4b..a899191cbf 100644
>> --- a/migration/savevm.c
>> +++ b/migration/savevm.c
>> @@ -2992,6 +2992,7 @@ bool load_snapshot(const char *name, const char *vmstate,
>> int ret;
>> AioContext *aio_context;
>> MigrationIncomingState *mis = migration_incoming_get_current();
>> + int saved_vm_running = runstate_is_running();
>>
>> if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
>> return false;
>> @@ -3024,6 +3025,8 @@ bool load_snapshot(const char *name, const char *vmstate,
>> return false;
>> }
>>
>> + vm_stop(RUN_STATE_RESTORE_VM);
>> +
>> /*
>> * Flush the record/replay queue. Now the VM state is going
>> * to change. Therefore we don't need to preserve its consistency
>> @@ -3061,13 +3064,17 @@ bool load_snapshot(const char *name, const char *vmstate,
>>
>> if (ret < 0) {
>> error_setg(errp, "Error %d while loading VM state", ret);
>> - return false;
>> + goto err_restart;
>> }
>>
>> return true;
>>
>> err_drain:
>> bdrv_drain_all_end();
>> +err_restart:
>> + if (saved_vm_running) {
>> + vm_start();
>> + }
>> return false;
>> }
>>
>> @@ -3135,17 +3142,10 @@ static void snapshot_load_job_bh(void *opaque)
>> {
>> Job *job = opaque;
>> SnapshotJob *s = container_of(job, SnapshotJob, common);
>> - int orig_vm_running;
>>
>> job_progress_set_remaining(&s->common, 1);
>>
>> - orig_vm_running = runstate_is_running();
>> - vm_stop(RUN_STATE_RESTORE_VM);
>> -
>> s->ret = load_snapshot(s->tag, s->vmstate, true, s->devices, s->errp);
>> - if (s->ret && orig_vm_running) {
>> - vm_start();
>> - }
>>
>> job_progress_update(&s->common, 1);
>>
>> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
>> index 0ad5b77477..a39436c8cb 100644
>> --- a/monitor/hmp-cmds.c
>> +++ b/monitor/hmp-cmds.c
>> @@ -1127,15 +1127,10 @@ void hmp_balloon(Monitor *mon, const QDict *qdict)
>>
>> void hmp_loadvm(Monitor *mon, const QDict *qdict)
>> {
>> - int saved_vm_running = runstate_is_running();
>> const char *name = qdict_get_str(qdict, "name");
>> Error *err = NULL;
>>
>> - vm_stop(RUN_STATE_RESTORE_VM);
>> -
>> - if (!load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
>> - vm_start();
>> - }
>> + load_snapshot(name, NULL, false, NULL, &err);
>> hmp_handle_error(mon, err);
>> }
>>
>> --
>> 2.26.2
>>
>>
>>
next prev parent reply other threads:[~2021-05-12 8:06 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 8:13 [PULL 00/33] Misc (mostly i386) patches for 2021-05-11 Paolo Bonzini
2021-05-11 8:13 ` [PULL 01/33] target/i386: Rename helper_fldt, helper_fstt Paolo Bonzini
2021-05-11 8:13 ` [PULL 02/33] target/i386: Split out do_fsave, do_frstor, do_fxsave, do_fxrstor Paolo Bonzini
2021-05-11 8:13 ` [PULL 03/33] i386: split cpu accelerators from cpu.c, using AccelCPUClass Paolo Bonzini
2021-08-20 16:55 ` Peter Maydell
2021-08-20 17:02 ` Philippe Mathieu-Daudé
2021-08-20 17:10 ` Peter Maydell
2021-05-11 8:13 ` [PULL 04/33] cpu: call AccelCPUClass::cpu_realizefn in cpu_exec_realizefn Paolo Bonzini
2021-05-11 8:13 ` [PULL 05/33] accel: introduce new accessor functions Paolo Bonzini
2021-05-11 8:13 ` [PULL 06/33] target/i386: fix host_cpu_adjust_phys_bits error handling Paolo Bonzini
2021-05-11 8:13 ` [PULL 07/33] accel-cpu: make cpu_realizefn return a bool Paolo Bonzini
2021-05-11 8:13 ` [PULL 08/33] i386: split off sysemu-only functionality in tcg-cpu Paolo Bonzini
2021-05-11 8:13 ` [PULL 09/33] i386: split smm helper (sysemu) Paolo Bonzini
2021-05-11 8:13 ` [PULL 10/33] i386: split tcg excp_helper into sysemu and user parts Paolo Bonzini
2021-05-11 8:13 ` [PULL 11/33] i386: move TCG bpt_helper into sysemu/ Paolo Bonzini
2021-05-11 8:13 ` [PULL 12/33] i386: split misc helper user stubs and sysemu part Paolo Bonzini
2021-05-11 8:13 ` [PULL 13/33] i386: separate fpu_helper sysemu-only parts Paolo Bonzini
2021-05-11 8:13 ` [PULL 14/33] i386: split svm_helper into sysemu and stub-only user Paolo Bonzini
2021-05-11 8:13 ` [PULL 15/33] i386: split seg_helper into user-only and sysemu parts Paolo Bonzini
2021-05-11 8:13 ` [PULL 16/33] i386: split off sysemu part of cpu.c Paolo Bonzini
2021-05-11 8:13 ` [PULL 17/33] target/i386: gdbstub: introduce aux functions to read/write CS64 regs Paolo Bonzini
2021-05-11 8:13 ` [PULL 18/33] target/i386: gdbstub: only write CR0/CR2/CR3/EFER for sysemu Paolo Bonzini
2021-05-11 8:13 ` [PULL 19/33] i386: make cpu_load_efer sysemu-only Paolo Bonzini
2021-05-11 8:13 ` [PULL 20/33] accel: move call to accel_init_interfaces Paolo Bonzini
2021-05-11 8:13 ` [PULL 21/33] accel: add init_accel_cpu for adapting accel behavior to CPU type Paolo Bonzini
2021-05-11 8:13 ` [PULL 22/33] target/i386: merge SVM_NPTEXIT_* with PF_ERROR_* constants Paolo Bonzini
2021-05-11 8:13 ` [PULL 23/33] target/i386: move paging mode constants from SVM to cpu.h Paolo Bonzini
2021-05-11 8:13 ` [PULL 24/33] target/i386: extract mmu_translate Paolo Bonzini
2021-05-11 8:13 ` [PULL 25/33] target/i386: pass cr3 to mmu_translate Paolo Bonzini
2021-05-11 8:13 ` [PULL 26/33] target/i386: extend pg_mode to more CR0 and CR4 bits Paolo Bonzini
2021-05-11 8:13 ` [PULL 27/33] target/i386: allow customizing the next phase of the translation Paolo Bonzini
2021-05-11 8:13 ` [PULL 28/33] target/i386: use mmu_translate for NPT walk Paolo Bonzini
2021-05-11 8:13 ` [PULL 29/33] main-loop: remove dead code Paolo Bonzini
2021-05-11 8:13 ` [PULL 30/33] migration: do not restart VM after successful snapshot-load Paolo Bonzini
2021-05-11 8:56 ` Dr. David Alan Gilbert
2021-05-12 8:05 ` Paolo Bonzini [this message]
2021-05-11 9:09 ` Daniel P. Berrangé
2021-05-11 17:06 ` Daniel P. Berrangé
2021-05-12 7:45 ` Kevin Wolf
2021-05-12 18:11 ` Paolo Bonzini
2021-05-11 8:13 ` [PULL 31/33] qemu-option: support accept-any QemuOptsList in qemu_opts_absorb_qdict Paolo Bonzini
2021-05-11 8:13 ` [PULL 32/33] configure: fix detection of gdbus-codegen Paolo Bonzini
2021-05-11 8:13 ` [PULL 33/33] coverity-scan: list components, move model to scripts/coverity-scan Paolo Bonzini
2021-05-11 8:48 ` [PULL 00/33] Misc (mostly i386) patches for 2021-05-11 no-reply
2021-05-12 16:29 ` Peter Maydell
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