static FWCfgState *bochs_bios_init(void) { FWCfgState *fw_cfg; uint8_t *smbios_tables, *smbios_anchor; size_t smbios_tables_len, smbios_anchor_len; uint64_t *numa_fw_cfg; int i, j; unsigned int apic_id_limit = pc_apic_id_limit(max_cpus); fw_cfg = fw_cfg_init_io(BIOS_CFG_IOPORT); /* FW_CFG_MAX_CPUS is a bit confusing/problematic on x86: * * SeaBIOS needs FW_CFG_MAX_CPUS for CPU hotplug, but the CPU hotplug * QEMU<->SeaBIOS interface is not based on the "CPU index", but on the APIC * ID of hotplugged CPUs[1]. This means that FW_CFG_MAX_CPUS is not the * "maximum number of CPUs", but the "limit to the APIC ID values SeaBIOS * may see". * * So, this means we must not use max_cpus, here, but the maximum possible * APIC ID value, plus one. * * [1] The only kind of "CPU identifier" used between SeaBIOS and QEMU is * the APIC ID, not the "CPU index" */ fw_cfg_add_i16(fw_cfg, FW_CFG_MAX_CPUS, (uint16_t)apic_id_limit); fw_cfg_add_i32(fw_cfg, FW_CFG_ID, 1); fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size); fw_cfg_add_bytes(fw_cfg, FW_CFG_ACPI_TABLES, acpi_tables, acpi_tables_len); fw_cfg_add_i32(fw_cfg, FW_CFG_IRQ0_OVERRIDE, kvm_allows_irq0_override()); smbios_tables = smbios_get_table_legacy(&smbios_tables_len); if (smbios_tables) { fw_cfg_add_bytes(fw_cfg, FW_CFG_SMBIOS_ENTRIES, smbios_tables, smbios_tables_len); } smbios_get_tables(&smbios_tables, &smbios_tables_len, &smbios_anchor, &smbios_anchor_len); if (smbios_anchor) { fw_cfg_add_file(fw_cfg, "etc/smbios/smbios-tables", smbios_tables, smbios_tables_len); fw_cfg_add_file(fw_cfg, "etc/smbios/smbios-anchor", smbios_anchor, smbios_anchor_len); } fw_cfg_add_bytes(fw_cfg, FW_CFG_E820_TABLE, &e820_reserve, sizeof(e820_reserve)); fw_cfg_add_file(fw_cfg, "etc/e820", e820_table, sizeof(struct e820_entry) * e820_entries); fw_cfg_add_bytes(fw_cfg, FW_CFG_HPET, &hpet_cfg, sizeof(hpet_cfg)); /* allocate memory for the NUMA channel: one (64bit) word for the number * of nodes, one word for each VCPU->node and one word for each node to * hold the amount of memory. */ numa_fw_cfg = g_new0(uint64_t, 1 + apic_id_limit + nb_numa_nodes); numa_fw_cfg[0] = cpu_to_le64(nb_numa_nodes); for (i = 0; i < max_cpus; i++) { unsigned int apic_id = x86_cpu_apic_id_from_index(i); assert(apic_id < apic_id_limit); for (j = 0; j < nb_numa_nodes; j++) { if (test_bit(i, numa_info[j].node_cpu)) { numa_fw_cfg[apic_id + 1] = cpu_to_le64(j); break; } } } for (i = 0; i < nb_numa_nodes; i++) { numa_fw_cfg[apic_id_limit + 1 + i] = cpu_to_le64(numa_info[i].node_mem); } fw_cfg_add_bytes(fw_cfg, FW_CFG_NUMA, numa_fw_cfg, (1 + apic_id_limit + nb_numa_nodes) * sizeof(*numa_fw_cfg)); return fw_cfg; }