From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42591) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZNDiN-0001kV-68 for qemu-devel@nongnu.org; Thu, 06 Aug 2015 01:27:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZNDiG-0007sz-0x for qemu-devel@nongnu.org; Thu, 06 Aug 2015 01:27:39 -0400 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:34038) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZNDiF-0007r0-Az for qemu-devel@nongnu.org; Thu, 06 Aug 2015 01:27:31 -0400 Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 6 Aug 2015 10:57:29 +0530 From: Bharata B Rao Date: Thu, 6 Aug 2015 10:57:16 +0530 Message-Id: <1438838837-28504-11-git-send-email-bharata@linux.vnet.ibm.com> In-Reply-To: <1438838837-28504-1-git-send-email-bharata@linux.vnet.ibm.com> References: <1438838837-28504-1-git-send-email-bharata@linux.vnet.ibm.com> Subject: [Qemu-devel] [RFC PATCH v4 10/11] spapr: CPU hot unplug support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: aik@ozlabs.ru, Bharata B Rao , mdroth@linux.vnet.ibm.com, agraf@suse.de, qemu-ppc@nongnu.org, tyreld@linux.vnet.ibm.com, nfont@linux.vnet.ibm.com, imammedo@redhat.com, afaerber@suse.de, david@gibson.dropbear.id.au Support hot removal of CPU for sPAPR guests by sending the hot unplug notification to the guest via EPOW interrupt. Release the vCPU object after CPU hot unplug so that vCPU fd can be parked and reused. Signed-off-by: Bharata B Rao --- hw/ppc/spapr.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 004a8e1..c05d85b 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -2374,11 +2374,83 @@ static void spapr_machine_device_plug(HotplugHandler *hotplug_dev, } } +static void spapr_cpu_destroy(PowerPCCPU *cpu) +{ + sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine()); + + xics_cpu_destroy(spapr->icp, cpu); + qemu_unregister_reset(spapr_cpu_reset, cpu); +} + +static void spapr_cpu_release(DeviceState *dev, void *opaque) +{ + CPUState *cs; + int i; + int id = ppc_get_vcpu_dt_id(POWERPC_CPU(CPU(dev))); + + for (i = id; i < id + smp_threads; i++) { + CPU_FOREACH(cs) { + PowerPCCPU *cpu = POWERPC_CPU(cs); + + if (i == ppc_get_vcpu_dt_id(cpu)) { + spapr_cpu_destroy(cpu); + cpu_remove(cs); + } + } + } +} + +static int spapr_cpu_unplug(HotplugHandler *hotplug_dev, DeviceState *dev, + Error **errp) +{ + CPUState *cs = CPU(dev); + PowerPCCPU *cpu = POWERPC_CPU(cs); + int id = ppc_get_vcpu_dt_id(cpu); + int smt = kvmppc_smt_threads(); + sPAPRDRConnector *drc = + spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, id); + sPAPRDRConnectorClass *drck; + Error *local_err = NULL; + + /* + * SMT threads return from here, only main thread (core) will + * continue and signal hot unplug event to the guest. + */ + if ((id % smt) != 0) { + return 0; + } + g_assert(drc); + + drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc); + drck->detach(drc, dev, spapr_cpu_release, NULL, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return -1; + } + + /* + * In addition to hotplugged CPUs, send the hot-unplug notification + * interrupt to the guest for coldplugged CPUs started via -device + * option too. + */ + spapr_hotplug_req_remove_event(drc); + + return 0; +} + static void spapr_machine_device_unplug(HotplugHandler *hotplug_dev, DeviceState *dev, Error **errp) { + sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(qdev_get_machine()); + if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) { error_setg(errp, "Memory hot unplug not supported by sPAPR"); + } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) { + if (!smc->dr_cpu_enabled) { + error_setg(errp, "CPU hot unplug not supported on this machine"); + return; + } + spapr_cpu_unplug(hotplug_dev, dev, errp); } } -- 2.1.0