On Mon, 17 Oct 2016 19:44:52 -0200 Eduardo Habkost <ehabk...@redhat.com> wrote:
> On Thu, Oct 13, 2016 at 11:52:39AM +0200, Igor Mammedov wrote: > [...] > > @@ -236,7 +237,11 @@ void build_legacy_cpu_hotplug_aml(Aml *ctx, > > MachineState *machine, > > /* The current AML generator can cover the APIC ID range [0..255], > > * inclusive, for VCPU hotplug. */ > > QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256); > > - g_assert(pcms->apic_id_limit <= ACPI_CPU_HOTPLUG_ID_LIMIT); > > + if (pcms->apic_id_limit > ACPI_CPU_HOTPLUG_ID_LIMIT) { > > + error_report("max_cpus is too large. APIC ID of last CPU is %u", > > + pcms->apic_id_limit - 1); > > + exit(1); > > + } > > Moving the check here seems to make sense, but: > > > > > /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */ > > dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE)); > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > > index 93ff49c..f1c1013 100644 > > --- a/hw/i386/pc.c > > +++ b/hw/i386/pc.c > > @@ -778,7 +778,6 @@ static FWCfgState *bochs_bios_init(AddressSpace *as, > > PCMachineState *pcms) > > [Added more context below to show the code around the change] > > > numa_fw_cfg = g_new0(uint64_t, 1 + pcms->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 < pcms->apic_id_limit); > > If you really needed to remove this assert, that means you can > write beyond the end of numa_fw_fg[] below. Are you sure you need > to remove it? > > > j = numa_get_node_for_cpu(i); > > if (j < nb_numa_nodes) { > > numa_fw_cfg[apic_id + 1] = cpu_to_le64(j); > > ^^^^^^^^^^^ here > > > } Another more radical way to deal with legacy FW_CFG_NUMA could be to remove it altogether if machine has x2APIC cpus. It'd be possible to do due to BIOS using QEMU provided BIOS tables and not using/calling code for built in/legacy ACPI tables. Could do it as patch on top if that's sounds ok. > > } > > > > @@ -1190,12 +1189,6 @@ void pc_cpus_init(PCMachineState *pcms) > > * This is used for FW_CFG_MAX_CPUS. See comments on bochs_bios_init(). > > */ > > pcms->apic_id_limit = x86_cpu_apic_id_from_index(max_cpus - 1) + 1; > > - if (pcms->apic_id_limit > ACPI_CPU_HOTPLUG_ID_LIMIT) { > > - error_report("max_cpus is too large. APIC ID of last CPU is %u", > > - pcms->apic_id_limit - 1); > > - exit(1); > > - } > > - > > pcms->possible_cpus = g_malloc0(sizeof(CPUArchIdList) + > > sizeof(CPUArchId) * max_cpus); > > for (i = 0; i < max_cpus; i++) { > > -- > > 2.7.4 > > >