diff options
Diffstat (limited to 'drivers/hv/hv.c')
| -rw-r--r-- | drivers/hv/hv.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index 8dbbed4efa45..714e1ebc834c 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -587,10 +587,41 @@ int hv_synic_cleanup(unsigned int cpu) union hv_synic_simp simp; union hv_synic_siefp siefp; union hv_synic_scontrol sctrl; + struct vmbus_channel *channel, *sc; + bool channel_found = false; + unsigned long flags; if (!hv_context.synic_initialized) return -EFAULT; + /* + * Search for channels which are bound to the CPU we're about to + * cleanup. In case we find one and vmbus is still connected we need to + * fail, this will effectively prevent CPU offlining. There is no way + * we can re-bind channels to different CPUs for now. + */ + mutex_lock(&vmbus_connection.channel_mutex); + list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { + if (channel->target_cpu == cpu) { + channel_found = true; + break; + } + spin_lock_irqsave(&channel->lock, flags); + list_for_each_entry(sc, &channel->sc_list, sc_list) { + if (sc->target_cpu == cpu) { + channel_found = true; + break; + } + } + spin_unlock_irqrestore(&channel->lock, flags); + if (channel_found) + break; + } + mutex_unlock(&vmbus_connection.channel_mutex); + + if (channel_found && vmbus_connection.conn_state == CONNECTED) + return -EBUSY; + /* Turn off clockevent device */ if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE) { clockevents_unbind_device(hv_context.clk_evt[cpu], cpu); |