Re: [PATCH RFC V2 03/37] hw/arm/virt: Move setting of common CPU properties in a function

[Gavin Shan <gshan@redhat.com>]

Hi Salil,

On 9/26/23 20:04, Salil Mehta wrote:
> Factor out CPU properties code common for {hot,cold}-plugged CPUs. This allows
> code reuse.
> 
> Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
> ---
>   hw/arm/virt.c         | 220 ++++++++++++++++++++++++++----------------
>   include/hw/arm/virt.h |   4 +
>   2 files changed, 140 insertions(+), 84 deletions(-)
> 
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 57fe97c242..0eb6bf5a18 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -2018,16 +2018,130 @@ static void virt_cpu_post_init(VirtMachineState *vms, MemoryRegion *sysmem)
>       }
>   }
>   
> +static void virt_cpu_set_properties(Object *cpuobj, const CPUArchId *cpu_slot,
> +                                    Error **errp)
> +{
> +    MachineState *ms = MACHINE(qdev_get_machine());
> +    VirtMachineState *vms = VIRT_MACHINE(ms);
> +    Error *local_err = NULL;
> +    VirtMachineClass *vmc;
> +
> +    vmc = VIRT_MACHINE_GET_CLASS(ms);
> +
> +    /* now, set the cpu object property values */
> +    numa_cpu_pre_plug(cpu_slot, DEVICE(cpuobj), &local_err);
> +    if (local_err) {
> +        goto out;
> +    }
> +
> +    object_property_set_int(cpuobj, "mp-affinity", cpu_slot->arch_id, NULL);
> +
> +    if (!vms->secure) {
> +        object_property_set_bool(cpuobj, "has_el3", false, NULL);
> +    }
> +
> +    if (!vms->virt && object_property_find(cpuobj, "has_el2")) {
> +        object_property_set_bool(cpuobj, "has_el2", false, NULL);
> +    }
> +
> +    if (vmc->kvm_no_adjvtime &&
> +        object_property_find(cpuobj, "kvm-no-adjvtime")) {
> +        object_property_set_bool(cpuobj, "kvm-no-adjvtime", true, NULL);
> +    }
> +
> +    if (vmc->no_kvm_steal_time &&
> +        object_property_find(cpuobj, "kvm-steal-time")) {
> +        object_property_set_bool(cpuobj, "kvm-steal-time", false, NULL);
> +    }
> +
> +    if (vmc->no_pmu && object_property_find(cpuobj, "pmu")) {
> +        object_property_set_bool(cpuobj, "pmu", false, NULL);
> +    }
> +
> +    if (vmc->no_tcg_lpa2 && object_property_find(cpuobj, "lpa2")) {
> +        object_property_set_bool(cpuobj, "lpa2", false, NULL);
> +    }
> +
> +    if (object_property_find(cpuobj, "reset-cbar")) {
> +        object_property_set_int(cpuobj, "reset-cbar",
> +                                vms->memmap[VIRT_CPUPERIPHS].base,
> +                                &local_err);
> +        if (local_err) {
> +            goto out;
> +        }
> +    }
> +
> +    /* link already initialized {secure,tag}-memory regions to this cpu */
> +    object_property_set_link(cpuobj, "memory", OBJECT(vms->sysmem), &local_err);
> +    if (local_err) {
> +        goto out;
> +    }
> +
> +    if (vms->secure) {
> +        object_property_set_link(cpuobj, "secure-memory",
> +                                 OBJECT(vms->secure_sysmem), &local_err);
> +        if (local_err) {
> +            goto out;
> +        }
> +    }
> +
> +    if (vms->mte) {
> +        if (!object_property_find(cpuobj, "tag-memory")) {
> +            error_setg(&local_err, "MTE requested, but not supported "
> +                       "by the guest CPU");
> +            if (local_err) {
> +                goto out;
> +            }
> +        }
> +
> +        object_property_set_link(cpuobj, "tag-memory", OBJECT(vms->tag_sysmem),
> +                                 &local_err);
> +        if (local_err) {
> +            goto out;
> +        }
> +
> +        if (vms->secure) {
> +            object_property_set_link(cpuobj, "secure-tag-memory",
> +                                     OBJECT(vms->secure_tag_sysmem),
> +                                     &local_err);
> +            if (local_err) {
> +                goto out;
> +            }
> +        }
> +    }
> +
> +    /*
> +     * RFC: Question: this must only be called for the hotplugged cpus. For the
> +     * cold booted secondary cpus this is being taken care in arm_load_kernel()
> +     * in boot.c. Perhaps we should remove that code now?
> +     */
> +    if (vms->psci_conduit != QEMU_PSCI_CONDUIT_DISABLED) {
> +        object_property_set_int(cpuobj, "psci-conduit", vms->psci_conduit,
> +                                NULL);
> +
> +        /* Secondary CPUs start in PSCI powered-down state */
> +        if (CPU(cpuobj)->cpu_index > 0) {
> +            object_property_set_bool(cpuobj, "start-powered-off", true, NULL);
> +        }
> +    }
> +
> +out:
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +    }
> +    return;
        ^^^^^^

It's not needed obviously :)

> +}
> +
>   static void machvirt_init(MachineState *machine)
>   {
>       VirtMachineState *vms = VIRT_MACHINE(machine);
>       VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(machine);
>       MachineClass *mc = MACHINE_GET_CLASS(machine);
>       const CPUArchIdList *possible_cpus;
> -    MemoryRegion *sysmem = get_system_memory();
> +    MemoryRegion *secure_tag_sysmem = NULL;
>       MemoryRegion *secure_sysmem = NULL;
>       MemoryRegion *tag_sysmem = NULL;
> -    MemoryRegion *secure_tag_sysmem = NULL;
> +    MemoryRegion *sysmem;
>       int n, virt_max_cpus;
>       bool firmware_loaded;
>       bool aarch64 = true;
> @@ -2071,6 +2185,8 @@ static void machvirt_init(MachineState *machine)
>        */
>       finalize_gic_version(vms);
>   
> +    sysmem = vms->sysmem = get_system_memory();
> +
>       if (vms->secure) {
>           /*
>            * The Secure view of the world is the same as the NonSecure,
> @@ -2078,7 +2194,7 @@ static void machvirt_init(MachineState *machine)
>            * containing the system memory at low priority; any secure-only
>            * devices go in at higher priority and take precedence.
>            */
> -        secure_sysmem = g_new(MemoryRegion, 1);
> +        secure_sysmem = vms->secure_sysmem = g_new(MemoryRegion, 1);
>           memory_region_init(secure_sysmem, OBJECT(machine), "secure-memory",
>                              UINT64_MAX);
>           memory_region_add_subregion_overlap(secure_sysmem, 0, sysmem, -1);
> @@ -2151,6 +2267,23 @@ static void machvirt_init(MachineState *machine)
>           exit(1);
>       }
>   
> +    if (vms->mte) {
> +        /* Create the memory region only once, but link to all cpus later */
> +        tag_sysmem = vms->tag_sysmem = g_new(MemoryRegion, 1);
> +        memory_region_init(tag_sysmem, OBJECT(machine),
> +                           "tag-memory", UINT64_MAX / 32);
> +
> +        if (vms->secure) {
> +            secure_tag_sysmem = vms->secure_tag_sysmem = g_new(MemoryRegion, 1);
> +            memory_region_init(secure_tag_sysmem, OBJECT(machine),
> +                               "secure-tag-memory", UINT64_MAX / 32);
> +
> +            /* As with ram, secure-tag takes precedence over tag.  */
> +            memory_region_add_subregion_overlap(secure_tag_sysmem, 0,
> +                                                tag_sysmem, -1);
> +        }
> +    }
> +
>       create_fdt(vms);
>   
>       assert(possible_cpus->len == max_cpus);
> @@ -2163,15 +2296,10 @@ static void machvirt_init(MachineState *machine)
>           }
>   
>           cpuobj = object_new(possible_cpus->cpus[n].type);
> -        object_property_set_int(cpuobj, "mp-affinity",
> -                                possible_cpus->cpus[n].arch_id, NULL);
>   
>           cs = CPU(cpuobj);
>           cs->cpu_index = n;
>   
> -        numa_cpu_pre_plug(&possible_cpus->cpus[cs->cpu_index], DEVICE(cpuobj),
> -                          &error_fatal);
> -
>           aarch64 &= object_property_get_bool(cpuobj, "aarch64", NULL);
>           object_property_set_int(cpuobj, "socket-id",
>                                   virt_get_socket_id(machine, n), NULL);
> @@ -2182,82 +2310,6 @@ static void machvirt_init(MachineState *machine)
>           object_property_set_int(cpuobj, "thread-id",
>                                   virt_get_thread_id(machine, n), NULL);
>   
> -        if (!vms->secure) {
> -            object_property_set_bool(cpuobj, "has_el3", false, NULL);
> -        }
> -
> -        if (!vms->virt && object_property_find(cpuobj, "has_el2")) {
> -            object_property_set_bool(cpuobj, "has_el2", false, NULL);
> -        }
> -
> -        if (vmc->kvm_no_adjvtime &&
> -            object_property_find(cpuobj, "kvm-no-adjvtime")) {
> -            object_property_set_bool(cpuobj, "kvm-no-adjvtime", true, NULL);
> -        }
> -
> -        if (vmc->no_kvm_steal_time &&
> -            object_property_find(cpuobj, "kvm-steal-time")) {
> -            object_property_set_bool(cpuobj, "kvm-steal-time", false, NULL);
> -        }
> -
> -        if (vmc->no_pmu && object_property_find(cpuobj, "pmu")) {
> -            object_property_set_bool(cpuobj, "pmu", false, NULL);
> -        }
> -
> -        if (vmc->no_tcg_lpa2 && object_property_find(cpuobj, "lpa2")) {
> -            object_property_set_bool(cpuobj, "lpa2", false, NULL);
> -        }
> -
> -        if (object_property_find(cpuobj, "reset-cbar")) {
> -            object_property_set_int(cpuobj, "reset-cbar",
> -                                    vms->memmap[VIRT_CPUPERIPHS].base,
> -                                    &error_abort);
> -        }
> -
> -        object_property_set_link(cpuobj, "memory", OBJECT(sysmem),
> -                                 &error_abort);
> -        if (vms->secure) {
> -            object_property_set_link(cpuobj, "secure-memory",
> -                                     OBJECT(secure_sysmem), &error_abort);
> -        }
> -
> -        if (vms->mte) {
> -            /* Create the memory region only once, but link to all cpus. */
> -            if (!tag_sysmem) {
> -                /*
> -                 * The property exists only if MemTag is supported.
> -                 * If it is, we must allocate the ram to back that up.
> -                 */
> -                if (!object_property_find(cpuobj, "tag-memory")) {
> -                    error_report("MTE requested, but not supported "
> -                                 "by the guest CPU");
> -                    exit(1);
> -                }
> -
> -                tag_sysmem = g_new(MemoryRegion, 1);
> -                memory_region_init(tag_sysmem, OBJECT(machine),
> -                                   "tag-memory", UINT64_MAX / 32);
> -
> -                if (vms->secure) {
> -                    secure_tag_sysmem = g_new(MemoryRegion, 1);
> -                    memory_region_init(secure_tag_sysmem, OBJECT(machine),
> -                                       "secure-tag-memory", UINT64_MAX / 32);
> -
> -                    /* As with ram, secure-tag takes precedence over tag.  */
> -                    memory_region_add_subregion_overlap(secure_tag_sysmem, 0,
> -                                                        tag_sysmem, -1);
> -                }
> -            }
> -
> -            object_property_set_link(cpuobj, "tag-memory", OBJECT(tag_sysmem),
> -                                     &error_abort);
> -            if (vms->secure) {
> -                object_property_set_link(cpuobj, "secure-tag-memory",
> -                                         OBJECT(secure_tag_sysmem),
> -                                         &error_abort);
> -            }
> -        }
> -
>           qdev_realize(DEVICE(cpuobj), NULL, &error_fatal);
>           object_unref(cpuobj);
>       }
> diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
> index e1ddbea96b..13163adb07 100644
> --- a/include/hw/arm/virt.h
> +++ b/include/hw/arm/virt.h
> @@ -148,6 +148,10 @@ struct VirtMachineState {
>       DeviceState *platform_bus_dev;
>       FWCfgState *fw_cfg;
>       PFlashCFI01 *flash[2];
> +    MemoryRegion *sysmem;
> +    MemoryRegion *secure_sysmem;
> +    MemoryRegion *tag_sysmem;
> +    MemoryRegion *secure_tag_sysmem;
>       bool secure;
>       bool highmem;
>       bool highmem_compact;

Thanks,
Gavin