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Re: [PATCH 4/6] spapr: Use spapr_drc_reset_all() at machine reset
From: |
David Gibson |
Subject: |
Re: [PATCH 4/6] spapr: Use spapr_drc_reset_all() at machine reset |
Date: |
Mon, 28 Dec 2020 18:29:08 +1100 |
On Fri, Dec 18, 2020 at 11:33:58AM +0100, Greg Kurz wrote:
> Documentation of object_child_foreach_recursive() clearly stipulates
> that "it is forbidden to add or remove children from @obj from the @fn
> callback". But this is exactly what we do during machine reset. The call
> to spapr_drc_reset() can finalize the hot-unplug sequence of a PHB or a
> PCI bridge, both of which will then in turn destroy their PCI DRCs. This
> could potentially invalidate the iterator used by do_object_child_foreach().
> It is pure luck that this haven't caused any issues so far.
>
> Use spapr_drc_reset_all() since it can cope with DRC removal.
>
> Signed-off-by: Greg Kurz <groug@kaod.org>
Applied, thanks.
> ---
> hw/ppc/spapr.c | 15 +--------------
> 1 file changed, 1 insertion(+), 14 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 43dded87f498..8528bc90fec4 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1566,19 +1566,6 @@ void spapr_setup_hpt(SpaprMachineState *spapr)
> }
> }
>
> -static int spapr_reset_drcs(Object *child, void *opaque)
> -{
> - SpaprDrc *drc =
> - (SpaprDrc *) object_dynamic_cast(child,
> - TYPE_SPAPR_DR_CONNECTOR);
> -
> - if (drc) {
> - spapr_drc_reset(drc);
> - }
> -
> - return 0;
> -}
> -
> static void spapr_machine_reset(MachineState *machine)
> {
> SpaprMachineState *spapr = SPAPR_MACHINE(machine);
> @@ -1633,7 +1620,7 @@ static void spapr_machine_reset(MachineState *machine)
> * will crash QEMU if the DIMM holding the vring goes away). To avoid
> such
> * situations, we reset DRCs after all devices have been reset.
> */
> - object_child_foreach_recursive(object_get_root(), spapr_reset_drcs,
> NULL);
> + spapr_drc_reset_all(spapr);
>
> spapr_clear_pending_events(spapr);
>
--
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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- Re: [PATCH 1/6] spapr: Call spapr_drc_reset() for all DRCs at CAS, (continued)
- [PATCH 2/6] spapr: Fix reset of transient DR connectors, Greg Kurz, 2020/12/18
- [PATCH 3/6] spapr: Introduce spapr_drc_reset_all(), Greg Kurz, 2020/12/18
- [PATCH 4/6] spapr: Use spapr_drc_reset_all() at machine reset, Greg Kurz, 2020/12/18
- [PATCH 6/6] spapr: Model DR connectors as simple objects, Greg Kurz, 2020/12/18
- [PATCH 5/6] spapr: Add drc_ prefix to the DRC realize and unrealize functions, Greg Kurz, 2020/12/18
- Re: [PATCH 0/6] spapr: Fix visibility and traversal of DR connectors, Daniel Henrique Barboza, 2020/12/22