From 47c8c915b1628360d4d7d483e421e49b6bcfc371 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Wed, 23 Oct 2019 21:17:40 +0200 Subject: [PATCH] spapr: Don't request to unplug the same core twice We must not call spapr_drc_detach() on a detached DRC otherwise bad things can happen, ie. QEMU hangs or crashes. This is easily demonstrated with a CPU hotplug/unplug loop using QMP. Signed-off-by: Greg Kurz Message-Id: <157185826035.3073024.1664101000438499392.stgit@bahia.lan> Signed-off-by: David Gibson --- hw/ppc/spapr.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index f9410d390a..94f9d27096 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -3741,9 +3741,10 @@ void spapr_core_unplug_request(HotplugHandler *hotplug_dev, DeviceState *dev, spapr_vcpu_id(spapr, cc->core_id)); g_assert(drc); - spapr_drc_detach(drc); - - spapr_hotplug_req_remove_by_index(drc); + if (!spapr_drc_unplug_requested(drc)) { + spapr_drc_detach(drc); + spapr_hotplug_req_remove_by_index(drc); + } } int spapr_core_dt_populate(SpaprDrc *drc, SpaprMachineState *spapr, -- 2.39.2