Re: [Qemu-devel] [PATCH v8 18/26] i386: define pc guest info

[Igor Mammedov]

On Thu, 3 Oct 2013 18:05:35 +0300
"Michael S. Tsirkin" <address@hidden> wrote:

> This defines a structure that will be used to fill in acpi tables
> where relevant properties are not yet available using QOM.
> 
> Reviewed-by: Laszlo Ersek <address@hidden>
> Reviewed-by: Gerd Hoffmann <address@hidden>
> Tested-by: Gerd Hoffmann <address@hidden>
> Signed-off-by: Michael S. Tsirkin <address@hidden>
> ---
>  include/hw/i386/pc.h |  9 +++++++++
>  hw/i386/pc.c         | 31 +++++++++++++++++++++++++++++++
>  2 files changed, 40 insertions(+)
> 
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 9b2ddc4..085a621 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -9,6 +9,9 @@
>  #include "hw/i386/ioapic.h"
>  
>  #include "qemu/range.h"
> +#include "qemu/bitmap.h"
> +#include "sysemu/sysemu.h"
> +#include "hw/pci/pci.h"
>  
>  /* PC-style peripherals (also used by other machines).  */
>  
> @@ -20,6 +23,12 @@ typedef struct PcPciInfo {
>  struct PcGuestInfo {
>      bool has_pci_info;
>      bool isapc_ram_fw;
> +    hwaddr ram_size;
> +    unsigned apic_id_limit;
> +    bool apic_xrupt_override;
> +    uint64_t numa_nodes;
> +    uint64_t *node_mem;
> +    uint64_t *node_cpu;
>      FWCfgState *fw_cfg;
>  };
>  
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 0c313fe..dbae9da 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1028,6 +1028,23 @@ static void pc_fw_cfg_guest_info(PcGuestInfo 
> *guest_info)
>      fw_cfg_add_file(guest_info->fw_cfg, "etc/pci-info", info, sizeof *info);
>  }
>  
> +static void pc_set_cpu_guest_info(CPUState *cpu, PcGuestInfo *guest_info)
> +{
> +    CPUClass *klass = CPU_GET_CLASS(cpu);
> +    uint64_t apic_id = klass->get_arch_id(cpu);
> +    int j;
> +
> +    assert(apic_id < guest_info->apic_id_limit);
> +
> +    for (j = 0; j < guest_info->numa_nodes; j++) {
> +        assert(cpu->cpu_index < max_cpus);
> +        if (test_bit(cpu->cpu_index, node_cpumask[j])) {
> +            guest_info->node_cpu[apic_id] = cpu_to_le64(j);
> +            break;
> +        }
> +    }
> +}
> +
>  typedef struct PcGuestInfoState {
>      PcGuestInfo info;
>      Notifier machine_done;
> @@ -1047,6 +1064,20 @@ PcGuestInfo *pc_guest_info_init(ram_addr_t 
> below_4g_mem_size,
>  {
>      PcGuestInfoState *guest_info_state = g_malloc0(sizeof *guest_info_state);
>      PcGuestInfo *guest_info = &guest_info_state->info;
> +    CPUState *cpu;
> +
> +    guest_info->ram_size = below_4g_mem_size + above_4g_mem_size;
> +    guest_info->apic_id_limit = pc_apic_id_limit(max_cpus);
> +    guest_info->apic_xrupt_override = kvm_allows_irq0_override();
> +    guest_info->numa_nodes = nb_numa_nodes;
> +    guest_info->node_mem = g_memdup(node_mem, guest_info->numa_nodes *
> +                                    sizeof *guest_info->node_mem);
> +    guest_info->node_cpu = g_malloc0(guest_info->apic_id_limit *
> +                                     sizeof *guest_info->node_cpu);
> +
> +    CPU_FOREACH(cpu) {
> +        pc_set_cpu_guest_info(cpu, guest_info);
> +    }

pc_guest_info_init() is called only once, now lets suppose we hotplug CPUs
and then reboot guest. Hotadded CPUs won't be accounted in guest_info.node_cpu
since it's initialized only once and is never updated. As result guest will
get stale SRAT table.

Using a callback in acpi_setup/update could allow to get an updated guest_info.

>  
>      guest_info_state->machine_done.notify = pc_guest_info_machine_done;
>      qemu_add_machine_init_done_notifier(&guest_info_state->machine_done);