From 4ec60c76d5ab513e375f17b043d2b9cb849adf6c Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Wed, 6 Jul 2016 08:20:40 +0200 Subject: pc: cpu: Consolidate apic-id validity checks in pc_cpu_pre_plug() Machine code knows about all possible APIC IDs so use that instead of hack which does O(n^2) complexity duplicate checks, interating over global CPUs list. As result duplicate check is done only once with O(log n) complexity. Signed-off-by: Igor Mammedov Reviewed-by: Eduardo Habkost Signed-off-by: Eduardo Habkost --- hw/i386/pc.c | 43 +++++++++++++++++++++++++++++++------------ 1 file changed, 31 insertions(+), 12 deletions(-) (limited to 'hw/i386') diff --git a/hw/i386/pc.c b/hw/i386/pc.c index c9999a8da2..81206f4855 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1122,18 +1122,6 @@ void pc_hot_add_cpu(const int64_t id, Error **errp) return; } - if (cpu_exists(apic_id)) { - error_setg(errp, "Unable to add CPU: %" PRIi64 - ", it already exists", id); - return; - } - - if (id >= max_cpus) { - error_setg(errp, "Unable to add CPU: %" PRIi64 - ", max allowed: %d", id, max_cpus - 1); - return; - } - if (apic_id >= ACPI_CPU_HOTPLUG_ID_LIMIT) { error_setg(errp, "Unable to add CPU: %" PRIi64 ", resulting APIC ID (%" PRIi64 ") is too large", @@ -1852,6 +1840,36 @@ static void pc_cpu_unplug_cb(HotplugHandler *hotplug_dev, error_propagate(errp, local_err); } +static void pc_cpu_pre_plug(HotplugHandler *hotplug_dev, + DeviceState *dev, Error **errp) +{ + int idx; + X86CPU *cpu = X86_CPU(dev); + PCMachineState *pcms = PC_MACHINE(hotplug_dev); + CPUArchId *cpu_slot = pc_find_cpu_slot(pcms, CPU(dev), &idx); + + if (!cpu_slot) { + error_setg(errp, "Invalid CPU index with APIC ID (%" PRIu32 + "), valid range 0:%d", cpu->apic_id, + pcms->possible_cpus->len - 1); + return; + } + + if (cpu_slot->cpu) { + error_setg(errp, "CPU[%d] with APIC ID %" PRIu32 " exists", + idx, cpu->apic_id); + return; + } +} + +static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev, + DeviceState *dev, Error **errp) +{ + if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) { + pc_cpu_pre_plug(hotplug_dev, dev, errp); + } +} + static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, Error **errp) { @@ -2149,6 +2167,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data) mc->hot_add_cpu = pc_hot_add_cpu; mc->max_cpus = 255; mc->reset = pc_machine_reset; + hc->pre_plug = pc_machine_device_pre_plug_cb; hc->plug = pc_machine_device_plug_cb; hc->unplug_request = pc_machine_device_unplug_request_cb; hc->unplug = pc_machine_device_unplug_cb; -- cgit v1.2.3