From e3cadac073a99489df1627be56c3f487f5cb9e31 Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Wed, 16 Nov 2016 14:04:41 +0100 Subject: pc: fix FW_CFG_NB_CPUS to account for -device added CPUs Signed-off-by: Igor Mammedov Message-Id: <1479301481-197333-1-git-send-email-imammedo@redhat.com> Reviewed-by: Eduardo Habkost Signed-off-by: Eduardo Habkost --- hw/i386/pc.c | 44 +++++++++++++++++++++++++++----------------- include/hw/i386/pc.h | 2 ++ 2 files changed, 29 insertions(+), 17 deletions(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index e8757b4c62..a9e64a88e5 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -744,7 +744,7 @@ static FWCfgState *bochs_bios_init(AddressSpace *as, PCMachineState *pcms) int i, j; fw_cfg = fw_cfg_init_io_dma(FW_CFG_IO_BASE, FW_CFG_IO_BASE + 4, as); - fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus); + fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, pcms->boot_cpus); /* FW_CFG_MAX_CPUS is a bit confusing/problematic on x86: * @@ -1087,17 +1087,6 @@ void pc_acpi_smi_interrupt(void *opaque, int irq, int level) } } -static int pc_present_cpus_count(PCMachineState *pcms) -{ - int i, boot_cpus = 0; - for (i = 0; i < pcms->possible_cpus->len; i++) { - if (pcms->possible_cpus->cpus[i].cpu) { - boot_cpus++; - } - } - return boot_cpus; -} - static X86CPU *pc_new_cpu(const char *typename, int64_t apic_id, Error **errp) { @@ -1234,6 +1223,19 @@ static void pc_build_feature_control_file(PCMachineState *pcms) fw_cfg_add_file(pcms->fw_cfg, "etc/msr_feature_control", val, sizeof(*val)); } +static void rtc_set_cpus_count(ISADevice *rtc, uint16_t cpus_count) +{ + if (cpus_count > 0xff) { + /* If the number of CPUs can't be represented in 8 bits, the + * BIOS must use "FW_CFG_NB_CPUS". Set RTC field to 0 just + * to make old BIOSes fail more predictably. + */ + rtc_set_memory(rtc, 0x5f, 0); + } else { + rtc_set_memory(rtc, 0x5f, cpus_count - 1); + } +} + static void pc_machine_done(Notifier *notifier, void *data) { @@ -1242,7 +1244,7 @@ void pc_machine_done(Notifier *notifier, void *data) PCIBus *bus = pcms->bus; /* set the number of CPUs */ - rtc_set_memory(pcms->rtc, 0x5f, pc_present_cpus_count(pcms) - 1); + rtc_set_cpus_count(pcms->rtc, pcms->boot_cpus); if (bus) { int extra_hosts = 0; @@ -1265,6 +1267,8 @@ void pc_machine_done(Notifier *notifier, void *data) if (pcms->fw_cfg) { pc_build_smbios(pcms->fw_cfg); pc_build_feature_control_file(pcms); + /* update FW_CFG_NB_CPUS to account for -device added CPUs */ + fw_cfg_modify_i16(pcms->fw_cfg, FW_CFG_NB_CPUS, pcms->boot_cpus); } if (pcms->apic_id_limit > 255) { @@ -1342,7 +1346,7 @@ void xen_load_linux(PCMachineState *pcms) assert(MACHINE(pcms)->kernel_filename != NULL); fw_cfg = fw_cfg_init_io(FW_CFG_IO_BASE); - fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus); + fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, pcms->boot_cpus); rom_set_fw(fw_cfg); load_linux(pcms, fw_cfg); @@ -1812,9 +1816,11 @@ static void pc_cpu_plug(HotplugHandler *hotplug_dev, } } + /* increment the number of CPUs */ + pcms->boot_cpus++; if (dev->hotplugged) { - /* increment the number of CPUs */ - rtc_set_memory(pcms->rtc, 0x5f, rtc_get_memory(pcms->rtc, 0x5f) + 1); + rtc_set_cpus_count(pcms->rtc, pcms->boot_cpus); + fw_cfg_modify_i16(pcms->fw_cfg, FW_CFG_NB_CPUS, pcms->boot_cpus); } found_cpu = pc_find_cpu_slot(pcms, CPU(dev), NULL); @@ -1868,7 +1874,11 @@ static void pc_cpu_unplug_cb(HotplugHandler *hotplug_dev, found_cpu->cpu = NULL; object_unparent(OBJECT(dev)); - rtc_set_memory(pcms->rtc, 0x5f, rtc_get_memory(pcms->rtc, 0x5f) - 1); + /* decrement the number of CPUs */ + pcms->boot_cpus--; + /* Update the number of CPUs in CMOS */ + rtc_set_cpus_count(pcms->rtc, pcms->boot_cpus); + fw_cfg_modify_i16(pcms->fw_cfg, FW_CFG_NB_CPUS, pcms->boot_cpus); out: error_propagate(errp, local_err); } diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index e32e9574ca..67a1a9e786 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -36,6 +36,7 @@ /** * PCMachineState: * @acpi_dev: link to ACPI PM device that performs ACPI hotplug handling + * @boot_cpus: number of present VCPUs */ struct PCMachineState { /*< private >*/ @@ -70,6 +71,7 @@ struct PCMachineState { bool apic_xrupt_override; unsigned apic_id_limit; CPUArchIdList *possible_cpus; + uint16_t boot_cpus; /* NUMA information: */ uint64_t numa_nodes; -- cgit v1.2.1