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Re: [PATCH for-6.0] hw/ppc: Do not re-read the clock on pre_save if doin
From: |
David Gibson |
Subject: |
Re: [PATCH for-6.0] hw/ppc: Do not re-read the clock on pre_save if doing savevm |
Date: |
Thu, 3 Dec 2020 13:31:27 +1100 |
On Wed, Dec 02, 2020 at 06:28:26PM +0100, Greg Kurz wrote:
> A guest with enough RAM, eg. 128G, is likely to detect savevm downtime
> and to complain about stalled CPUs. This happens because we re-read
> the timebase just before migrating it and we thus don't account for
> all the time between VM stop and pre-save.
>
> A very similar situation was already addressed for live migration of
> paused guests (commit d14f33976282). Extend the logic to do the same
> with savevm.
>
> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1893787
> Signed-off-by: Greg Kurz <groug@kaod.org>
Applied to ppc-for-6.0, thanks.
> ---
> hw/ppc/ppc.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
> index 1b9827207676..5cbbff1f8d0c 100644
> --- a/hw/ppc/ppc.c
> +++ b/hw/ppc/ppc.c
> @@ -1027,7 +1027,8 @@ static void timebase_save(PPCTimebase *tb)
> */
> tb->guest_timebase = ticks + first_ppc_cpu->env.tb_env->tb_offset;
>
> - tb->runstate_paused = runstate_check(RUN_STATE_PAUSED);
> + tb->runstate_paused =
> + runstate_check(RUN_STATE_PAUSED) ||
> runstate_check(RUN_STATE_SAVE_VM);
> }
>
> static void timebase_load(PPCTimebase *tb)
> @@ -1088,7 +1089,7 @@ static int timebase_pre_save(void *opaque)
> {
> PPCTimebase *tb = opaque;
>
> - /* guest_timebase won't be overridden in case of paused guest */
> + /* guest_timebase won't be overridden in case of paused guest or savevm
> */
> if (!tb->runstate_paused) {
> timebase_save(tb);
> }
>
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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