Re: [Qemu-arm] [PATCH] ARM: ACPI: Fix MPIDR value in ACPI table

[Peter Maydell]

On 31 October 2015 at 18:53, Peter Crosthwaite
<address@hidden> wrote:
> On Sat, Oct 31, 2015 at 2:50 AM, Shannon Zhao <address@hidden> wrote:
>> From: Shannon Zhao <address@hidden>
>>
>> Use mp_affinity of ARMCPU as the CPU MPIDR instead of the CPU index.
>>
>> Signed-off-by: Shannon Zhao <address@hidden>
>> ---
>> This patch is based on below patch.
>> http://lists.nongnu.org/archive/html/qemu-devel/2015-10/msg06919.html
>>
>>  hw/arm/virt-acpi-build.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
>> index 29a1980..1c621cb 100644
>> --- a/hw/arm/virt-acpi-build.c
>> +++ b/hw/arm/virt-acpi-build.c
>> @@ -451,13 +451,15 @@ build_madt(GArray *table_data, GArray *linker, 
>> VirtGuestInfo *guest_info,
>>      for (i = 0; i < guest_info->smp_cpus; i++) {
>>          AcpiMadtGenericInterrupt *gicc = acpi_data_push(table_data,
>>                                                       sizeof *gicc);
>> +        ARMCPU *armcpu = ARM_CPU(qemu_get_cpu(i));
>> +
>>          gicc->type = ACPI_APIC_GENERIC_INTERRUPT;
>>          gicc->length = sizeof(*gicc);
>>          if (guest_info->gic_version == 2) {
>>              gicc->base_address = memmap[VIRT_GIC_CPU].base;
>>          }
>>          gicc->cpu_interface_number = i;
>> -        gicc->arm_mpidr = i;
>> +        gicc->arm_mpidr = armcpu->mp_affinity;
>
> As a general rule, hw/ should not be reaching into the CPU state
> struct like this. What is the real HW equivalent of this query?

This is just doing the same thing the hw/arm/virt.c code does
to populate the dt... (In real firmware it would presumably
either (a) have a fixed ACPI table or (b) maybe read the MPIDR,
but neither of those really fits here I think.)

thanks
-- PMM