Am 21.01.2013 12:31, schrieb Eduardo Habkost: > On Mon, Jan 21, 2013 at 12:18:55PM +0100, Andreas Färber wrote: >> Am 17.01.2013 21:59, schrieb Eduardo Habkost: >>> This function will be used by both the CPU initialization code and the >>> fw_cfg table initialization code. >>> >>> Later this function will be updated to generate APIC IDs according to >>> the CPU topology. >>> >>> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> >>> --- >>> target-i386/cpu.c | 17 ++++++++++++++++- >>> target-i386/cpu.h | 2 ++ >>> 2 files changed, 18 insertions(+), 1 deletion(-) >>> >>> diff --git a/target-i386/cpu.c b/target-i386/cpu.c >>> index d1a14d5..d90789d 100644 >>> --- a/target-i386/cpu.c >>> +++ b/target-i386/cpu.c >>> @@ -2194,6 +2194,21 @@ void x86_cpu_realize(Object *obj, Error **errp) >>> cpu_reset(CPU(cpu)); >>> } >>> >>> +/* Calculates initial APIC ID for a specific CPU index >>> + * >>> + * Currently we need to be able to calculate the APIC ID from the CPU index >>> + * alone (without requiring a CPU object), as the QEMU<->Seabios >>> interfaces have >>> + * no concept of "CPU index", and the NUMA tables on fw_cfg need the APIC >>> ID of >>> + * all CPUs up to max_cpus. >>> + */ >>> +uint32_t apic_id_for_cpu(unsigned int cpu_index) >> >> Can we rather make this x86_cpu_apic_id(X86CPU *cpu) to account for >> future changes to topology modelling? > > We can't make it get a X86CPU as parameter, because the ACPI tables have > to be built up to max_cpus, before the CPUs get actually created. But it > can be renamed, yes.
I see. Is this a limitation of the current code? IIUC the cpu_index is set once during qemu_init_vcpu() by counting the CPUArchStates in the first_cpu list. So if we hot-unplug a non-last CPU this is gonna result in chaos. Therefore I was hoping we could do something more clever than hardcoding cpu_index in our internal API ... but we can refactor that as follow-up when the need comes up. Andreas -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
