From 26ef65beab852caf2b1ef4976e3473f2d525164d Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Fri, 30 Dec 2016 15:33:11 +0100 Subject: [PATCH] pc: fix crash in rtc_set_memory() if initial cpu is marked as hotplugged 'hotplugged' propperty is meant to be used on migration side when migrating source with hotplugged devices. However though it not exacly correct usage of 'hotplugged' property it's possible to set generic hotplugged property for CPU using -cpu foo,hotplugged=on or -global foo.hotplugged=on in this case qemu crashes with following backtrace: ... because pc_cpu_plug() assumes that hotplugged CPU could appear only after rtc/fw_cfg are initialized. Fix crash by replacing assumption with explicit checks of rtc/fw_cfg and updating them only if they were initialized. Cc: qemu-stable@nongnu.org Reported-by: Eduardo Habkost Reviewed-by: Eduardo Habkost Signed-off-by: Igor Mammedov Message-Id: <1483108391-199542-1-git-send-email-imammedo@redhat.com> Signed-off-by: Paolo Bonzini --- hw/i386/pc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 25e8586b48..f721fde0c2 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1820,8 +1820,10 @@ static void pc_cpu_plug(HotplugHandler *hotplug_dev, /* increment the number of CPUs */ pcms->boot_cpus++; - if (dev->hotplugged) { + if (pcms->rtc) { rtc_set_cpus_count(pcms->rtc, pcms->boot_cpus); + } + if (pcms->fw_cfg) { fw_cfg_modify_i16(pcms->fw_cfg, FW_CFG_NB_CPUS, pcms->boot_cpus); }