Re: [Qemu-devel] [PATCH v8 4/7] s390x/cpu: Tolerate max_cpus

[David Hildenbrand]

> Once hotplug is enabled, interrupts may come in for CPUs
> with an address > smp_cpus.  Allocate for this and allow
> search routines to look beyond smp_cpus.
> 
> Signed-off-by: Matthew Rosato <address@hidden>
> ---
>  hw/s390x/s390-virtio.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
> index c501a48..90bc58a 100644
> --- a/hw/s390x/s390-virtio.c
> +++ b/hw/s390x/s390-virtio.c
> @@ -58,15 +58,16 @@
>  #define S390_TOD_CLOCK_VALUE_MISSING    0x00
>  #define S390_TOD_CLOCK_VALUE_PRESENT    0x01
> 
> -static S390CPU **ipi_states;
> +static S390CPU **cpu_states;
> 
>  S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>  {
> -    if (cpu_addr >= smp_cpus) {
> +    if (cpu_addr >= max_cpus) {
>          return NULL;
>      }
> 
> -    return ipi_states[cpu_addr];
> +    /* Fast lookup via CPU ID */
> +    return cpu_states[cpu_addr];
>  }
> 
>  void s390_init_ipl_dev(const char *kernel_filename,
> @@ -101,14 +102,14 @@ void s390_init_cpus(MachineState *machine)
>          machine->cpu_model = "host";
>      }
> 
> -    ipi_states = g_malloc(sizeof(S390CPU *) * smp_cpus);
> +    cpu_states = g_malloc0(sizeof(S390CPU *) * max_cpus);
> 
> -    for (i = 0; i < smp_cpus; i++) {
> +    for (i = 0; i < max_cpus; i++) {
>          S390CPU *cpu;
> 
>          cpu = cpu_s390x_init(machine->cpu_model);
> 
> -        ipi_states[i] = cpu;
> +        cpu_states[i] = cpu;

This looks wrong (creating all cpus). But the net patch fixes it again.

Can you make this patch a simple rename patch and move the max_cpu stuff into
the next patch if this makes sense?

Or simply set the cpu_state for everything above smp_cpus to zero in this patch.

Whatever you think makes sense.

>      }
>  }
> 


David