On Fri, Aug 05, 2016 at 11:46:15AM +0200, Igor Mammedov wrote: > Currently firmware uses 1 byte at 0x5F offset in RTC CMOS > to get number of CPUs present at boot. However 1 byte is > not enough to handle more than 255 CPUs. So add a new > fw_cfg file that would allow QEMU to tell it. > For compat reasons add file only for machine types that > support more than 255 CPUs. > > Signed-off-by: Igor Mammedov <imamm...@redhat.com>
Do we really need this? Why differentiate between boot cpus and others? How about reusing the hotplug register, such that it looks just as if all CPUs were just added by hotplug? > --- > hw/i386/pc.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > index c2cd5bd..2b5581a 100644 > --- a/hw/i386/pc.c > +++ b/hw/i386/pc.c > @@ -1235,9 +1235,11 @@ void pc_machine_done(Notifier *notifier, void *data) > PCMachineState *pcms = container_of(notifier, > PCMachineState, machine_done); > PCIBus *bus = pcms->bus; > + static uint16_t boot_cpus; > > /* set the number of CPUs */ > - rtc_set_memory(pcms->rtc, 0x5f, pc_present_cpus_count(pcms) - 1); > + boot_cpus = pc_present_cpus_count(pcms); > + rtc_set_memory(pcms->rtc, 0x5f, boot_cpus - 1); > > if (bus) { > int extra_hosts = 0; > @@ -1258,8 +1260,16 @@ void pc_machine_done(Notifier *notifier, void *data) > > acpi_setup(); > if (pcms->fw_cfg) { > + MachineClass *mc = MACHINE_GET_CLASS(pcms); > + > pc_build_smbios(pcms->fw_cfg); > pc_build_feature_control_file(pcms); > + > + if (mc->max_cpus > 255) { > + boot_cpus = cpu_to_le16(boot_cpus); > + fw_cfg_add_file(pcms->fw_cfg, "etc/boot-cpus", &boot_cpus, > + sizeof(boot_cpus)); > + } > } > } > > -- > 2.7.4