From 0ec1c95eea8c68243919ee4f8cd28b9a97dfc2f0 Mon Sep 17 00:00:00 2001
From: Keqian Zhu <zhukeqian1@huawei.com>
Date: Mon, 15 Apr 2024 22:37:53 +0800
Subject: [PATCH] arm/virt: Use separate filed to identify cpu-hotplug enable

The mc->has_hotpluggable_cpus should not be modified after
machine class init.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
---
 accel/kvm/kvm-all.c      |  6 ++++++
 hw/arm/virt-acpi-build.c | 13 +++++--------
 hw/arm/virt.c            | 20 +++++++++++++-------
 include/hw/arm/virt.h    |  1 +
 include/sysemu/kvm.h     |  2 ++
 include/sysemu/kvm_int.h |  1 +
 target/arm/kvm.c         |  7 +++----
 7 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 75a3075c14..b791aad1d6 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -3603,6 +3603,11 @@ bool kvm_kernel_irqchip_split(void)
     return kvm_state->kernel_irqchip_split == ON_OFF_AUTO_ON;
 }
 
+bool kvm_smccc_filter_enabled(void)
+{
+    return kvm_state->kvm_smccc_filter_enabled;
+}
+
 static void kvm_get_dirty_ring_size(Object *obj, Visitor *v,
                                     const char *name, void *opaque,
                                     Error **errp)
@@ -3648,6 +3653,7 @@ static void kvm_accel_instance_init(Object *obj)
     /* KVM dirty ring is by default off */
     s->kvm_dirty_ring_size = 0;
     s->kvm_dirty_ring_with_bitmap = false;
+    s->kvm_smccc_filter_enabled = false;
     s->kvm_eager_split_size = 0;
     s->notify_vmexit = NOTIFY_VMEXIT_OPTION_RUN;
     s->notify_window = 0;
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 46642efac4..99296fc6d8 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -779,12 +779,10 @@ static void build_append_gicr(GArray *table_data, uint64_t base, uint32_t size)
     build_append_int_noprefix(table_data, size, 4); /* Discovery Range Length */
 }
 
-static uint32_t virt_acpi_get_gicc_flags(CPUState *cpu)
+static uint32_t virt_acpi_get_gicc_flags(CPUState *cpu, VirtMachineState *vms)
 {
-    MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
-
     /* can only exist in 'enabled' state */
-    if (!mc->has_hotpluggable_cpus) {
+    if (!vms->cpu_hotplug_enabled) {
         return 1;
     }
 
@@ -842,7 +840,7 @@ build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
         uint64_t physical_base_address = 0, gich = 0, gicv = 0;
         uint32_t vgic_interrupt = vms->virt ? ARCH_GIC_MAINT_IRQ : 0;
         uint32_t pmu_interrupt = vms->pmu ? VIRTUAL_PMU_IRQ : 0;
-        uint32_t flags = virt_acpi_get_gicc_flags(cpu);
+        uint32_t flags = virt_acpi_get_gicc_flags(cpu, vms);
         uint64_t mpidr = qemu_get_cpu_archid(i);
 
         if (vms->gic_version == VIRT_GIC_VERSION_2) {
@@ -1003,7 +1001,6 @@ static void
 build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
 {
     VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
-    MachineClass *mc = MACHINE_GET_CLASS(vms);
     Aml *scope, *dsdt;
     MachineState *ms = MACHINE(vms);
     const MemMapEntry *memmap = vms->memmap;
@@ -1020,8 +1017,8 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
      * the RTC ACPI device at all when using UEFI.
      */
     scope = aml_scope("\\_SB");
-    /* if GED is enabled then cpus AML shall be added as part build_cpus_aml */
-    if (mc->has_hotpluggable_cpus) {
+
+    if (vms->cpu_hotplug_enabled) {
         CPUHotplugFeatures opts = {
              .acpi_1_compatible = false,
              .has_legacy_cphp = false
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 73b29c7f73..44931355d6 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -756,7 +756,7 @@ static void virt_add_gic_cpuhp_notifier(VirtMachineState *vms)
 {
     MachineClass *mc = MACHINE_GET_CLASS(vms);
 
-    if (mc->has_hotpluggable_cpus) {
+    if (mc->has_hotpluggable_cpus && vms->gic_version >= VIRT_GIC_VERSION_3) {
         Notifier *cpuhp_notifier = gicv3_cpuhp_notifier(vms->gic);
         notifier_list_add(&vms->cpuhp_notifiers, cpuhp_notifier);
     }
@@ -2498,11 +2498,16 @@ static void machvirt_init(MachineState *machine)
     has_ged = has_ged && firmware_loaded &&
         virt_is_acpi_enabled(vms) &&
         !!object_class_dynamic_cast(cpu_class, TYPE_AARCH64_CPU);
+
     if (tcg_enabled() || hvf_enabled() || qtest_enabled() ||
+        (kvm_enabled() && !kvm_smccc_filter_enabled()) ||
         (vms->gic_version < VIRT_GIC_VERSION_3) || !has_ged) {
-        mc->has_hotpluggable_cpus = false;
+        vms->cpu_hotplug_enabled = false;
+    } else {
+        vms->cpu_hotplug_enabled = true;
     }
-    if (!mc->has_hotpluggable_cpus) {
+
+    if (!vms->cpu_hotplug_enabled) {
         if (machine->smp.max_cpus > smp_cpus) {
             warn_report("cpu hotplug feature has been disabled");
         }
@@ -3174,7 +3179,6 @@ static void virt_cpu_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
 {
     VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
     MachineState *ms = MACHINE(hotplug_dev);
-    MachineClass *mc = MACHINE_GET_CLASS(ms);
     ARMCPU *cpu = ARM_CPU(dev);
     CPUState *cs = CPU(dev);
     CPUArchId *cpu_slot;
@@ -3218,7 +3222,7 @@ static void virt_cpu_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
         return;
     }
 
-    if (cs->cpu_index >= ms->smp.cpus && !mc->has_hotpluggable_cpus) {
+    if (cs->cpu_index >= ms->smp.cpus && !vms->cpu_hotplug_enabled) {
         error_setg(errp, "CPU [cold|hot]plug not supported on this machine");
         return;
     }
@@ -3304,7 +3308,6 @@ fail:
 static void virt_cpu_unplug_request(HotplugHandler *hotplug_dev,
                                     DeviceState *dev, Error **errp)
 {
-    MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
     VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
     HotplugHandlerClass *hhc;
     ARMCPU *cpu = ARM_CPU(dev);
@@ -3316,7 +3319,7 @@ static void virt_cpu_unplug_request(HotplugHandler *hotplug_dev,
         return;
     }
 
-    if (!mc->has_hotpluggable_cpus) {
+    if (!vms->cpu_hotplug_enabled) {
         error_setg(errp, "CPU hot(un)plug not supported on this machine");
         return;
     }
@@ -3780,6 +3783,9 @@ static void virt_instance_init(Object *obj)
     /* EL2 is also disabled by default, for similar reasons */
     vms->virt = false;
 
+    /* CPU hotplug is enabled by default */
+    vms->cpu_hotplug_enabled = true;
+
     /* High memory is enabled by default */
     vms->highmem = true;
     vms->highmem_compact = !vmc->no_highmem_compact;
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index ae0f5beb26..138531f9c1 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -153,6 +153,7 @@ struct VirtMachineState {
     bool its;
     bool tcg_its;
     bool virt;
+    bool cpu_hotplug_enabled;
     bool ras;
     bool mte;
     bool dtb_randomness;
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index e534411ddc..cfa77cc15b 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -492,6 +492,8 @@ bool kvm_kernel_irqchip_allowed(void);
 bool kvm_kernel_irqchip_required(void);
 bool kvm_kernel_irqchip_split(void);
 
+bool kvm_smccc_filter_enabled(void);
+
 /**
  * kvm_arch_irqchip_create:
  * @KVMState: The KVMState pointer
diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h
index fd846394be..b2d2c59477 100644
--- a/include/sysemu/kvm_int.h
+++ b/include/sysemu/kvm_int.h
@@ -112,6 +112,7 @@ struct KVMState
     uint64_t kvm_dirty_ring_bytes;  /* Size of the per-vcpu dirty ring */
     uint32_t kvm_dirty_ring_size;   /* Number of dirty GFNs per ring */
     bool kvm_dirty_ring_with_bitmap;
+    bool kvm_smccc_filter_enabled;
     uint64_t kvm_eager_split_size;  /* Eager Page Splitting chunk size */
     struct KVMDirtyRingReaper reaper;
     NotifyVmexitOption notify_vmexit;
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 19783d567f..12c1b4b328 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -321,12 +321,11 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
         if (kvm_arm_set_smccc_filter(PSCI_0_2_FN64_CPU_ON,
                                     KVM_SMCCC_FILTER_FWD_TO_USER)) {
             error_report("CPU On PSCI-to-user-space fwd filter install failed");
-            mc->has_hotpluggable_cpus = false;
-        }
-        if (kvm_arm_set_smccc_filter(PSCI_0_2_FN_CPU_OFF,
+        } else if (kvm_arm_set_smccc_filter(PSCI_0_2_FN_CPU_OFF,
                                     KVM_SMCCC_FILTER_FWD_TO_USER)) {
             error_report("CPU Off PSCI-to-user-space fwd filter install failed");
-            mc->has_hotpluggable_cpus = false;
+        } else {
+            s->kvm_smccc_filter_enabled = true;
         }
     }
 
-- 
2.41.0