Re: [RFC PATCH v2 07/13] hw/arm/virt-acpi-build: distinguish possible and present cpus Message

[Ying Fang]

On 10/30/2020 1:20 AM, Andrew Jones wrote:
> You need to remove 'Message' from the summary.
>
> On Tue, Oct 20, 2020 at 09:14:34PM +0800, Ying Fang wrote:
> > When building ACPI tables regarding CPUs we should always build
> > them for the number of possible CPUs, not the number of present
> > CPUs. We then ensure only the present CPUs are enabled.
> >
> > Signed-off-by: Andrew Jones <drjones@redhat.com>
>
> I guess my s-o-b is here because this is a rework of
>
> https://github.com/rhdrjones/qemu/commit/b18d7a889f424b8a8679c43d7f4804fdeeeaf3fd
>
> I think it changed enough you could just drop my authorship. A
> based-on comment in the commit message would be more than enough.
>
> Comment on the patch below.
>
> > Signed-off-by: Ying Fang <fangying1@huawei.com>
> > ---
> >   hw/arm/virt-acpi-build.c | 17 ++++++++++++-----
> >   1 file changed, 12 insertions(+), 5 deletions(-)
> >
> > diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> > index a222981737..fae5a26741 100644
> > --- a/hw/arm/virt-acpi-build.c
> > +++ b/hw/arm/virt-acpi-build.c
> > @@ -57,14 +57,18 @@
> >   
> >   #define ARM_SPI_BASE 32
> >   
> > -static void acpi_dsdt_add_cpus(Aml *scope, int cpus)
> > +static void acpi_dsdt_add_cpus(Aml *scope, VirtMachineState *vms)
> >   {
> >       uint16_t i;
> > +    CPUArchIdList *possible_cpus = MACHINE(vms)->possible_cpus;
> >   
> > -    for (i = 0; i < cpus; i++) {
> > +    for (i = 0; i < possible_cpus->len; i++) {
> >           Aml *dev = aml_device("C%.03X", i);
> >           aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0007")));
> >           aml_append(dev, aml_name_decl("_UID", aml_int(i)));
> > +        if (possible_cpus->cpus[i].cpu == NULL) {
> > +            aml_append(dev, aml_name_decl("_STA", aml_int(0)));
> > +        }
> >           aml_append(scope, dev);
> >       }
> >   }
> > @@ -470,6 +474,7 @@ build_madt(GArray *table_data, BIOSLinker *linker, 
> > VirtMachineState *vms)
> >       const int *irqmap = vms->irqmap;
> >       AcpiMadtGenericDistributor *gicd;
> >       AcpiMadtGenericMsiFrame *gic_msi;
> > +    int possible_cpus = MACHINE(vms)->possible_cpus->len;
> >       int i;
> >   
> >       acpi_data_push(table_data, sizeof(AcpiMultipleApicTable));
> > @@ -480,7 +485,7 @@ build_madt(GArray *table_data, BIOSLinker *linker, 
> > VirtMachineState *vms)
> >       gicd->base_address = cpu_to_le64(memmap[VIRT_GIC_DIST].base);
> >       gicd->version = vms->gic_version;
> >   
> > -    for (i = 0; i < MACHINE(vms)->smp.cpus; i++) {
> > +    for (i = 0; i < possible_cpus; i++) {
> >           AcpiMadtGenericCpuInterface *gicc = acpi_data_push(table_data,
> >                                                              sizeof(*gicc));
> >           ARMCPU *armcpu = ARM_CPU(qemu_get_cpu(i));
> > @@ -495,7 +500,9 @@ build_madt(GArray *table_data, BIOSLinker *linker, 
> > VirtMachineState *vms)
> >           gicc->cpu_interface_number = cpu_to_le32(i);
> >           gicc->arm_mpidr = cpu_to_le64(armcpu->mp_affinity);
> >           gicc->uid = cpu_to_le32(i);
> > -        gicc->flags = cpu_to_le32(ACPI_MADT_GICC_ENABLED);
> > +        if (i < MACHINE(vms)->smp.cpus) {
>
> Shouldn't this be
>
>          if (possible_cpus->cpus[i].cpu != NULL) {
>
> > +            gicc->flags = cpu_to_le32(ACPI_MADT_GICC_ENABLED);
> > +        }

I now realized that I switched to use current cpu number as the limit to
make GIC flags enabled here.
However to judge NULL is much more suitable here.

Thanks,
Ying.

> >   
> >           if (arm_feature(&armcpu->env, ARM_FEATURE_PMU)) {
> >               gicc->performance_interrupt = cpu_to_le32(PPI(VIRTUAL_PMU_IRQ));
> > @@ -599,7 +606,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, 
> > VirtMachineState *vms)
> >        * the RTC ACPI device at all when using UEFI.
> >        */
> >       scope = aml_scope("\\_SB");
> > -    acpi_dsdt_add_cpus(scope, ms->smp.cpus);
> > +    acpi_dsdt_add_cpus(scope, vms);
> >       acpi_dsdt_add_uart(scope, &memmap[VIRT_UART],
> >                          (irqmap[VIRT_UART] + ARM_SPI_BASE));
> >       if (vmc->acpi_expose_flash) {
> > --
> > 2.23.0
>
> Thanks,
> drew
>
> .