hw/intc: arm_gicv3_hvf: save/restore Apple GIC state

On HVF, some of the GIC state is in an opaque Apple-provided structure.

Save/restore that state to be able to save/restore VMs that use the hardware GIC.

Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Message-id: 20260429190532.26538-3-mohamed@unpredictable.fr
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/intc/arm_gicv3_common.c

@@ -305,6 +305,7 @@ static const VMStateDescription vmstate_gicv3 = {
     .subsections = (const VMStateDescription * const []) {
         &vmstate_gicv3_gicd_no_migration_shift_bug,
         &vmstate_gicv3_gicd_nmi,
+        &vmstate_gicv3_hvf,
         NULL
     }
 };

hw/intc/arm_gicv3_hvf.c

@@ -13,6 +13,7 @@
 #include "qemu/error-report.h"
 #include "qemu/module.h"
 #include "system/runstate.h"
+#include "migration/vmstate.h"
 #include "system/hvf.h"
 #include "system/hvf_int.h"
 #include "hvf_arm.h"
@@ -37,8 +38,13 @@ struct HVFARMGICv3Class {
 
 typedef struct HVFARMGICv3Class HVFARMGICv3Class;
 
-/* This is reusing the GICv3State typedef from ARM_GICV3_ITS_COMMON */
-DECLARE_OBJ_CHECKERS(GICv3State, HVFARMGICv3Class,
+typedef struct HVFGICv3State {
+    GICv3State parent_obj;
+    uint32_t size;
+    void *state;
+} HVFGICv3State;
+
+DECLARE_OBJ_CHECKERS(HVFGICv3State, HVFARMGICv3Class,
                      HVF_GICV3, TYPE_HVF_GICV3);
 
 /*
@@ -668,7 +674,7 @@ static const ARMCPRegInfo gicv3_cpuif_reginfo[] = {
 static void hvf_gicv3_realize(DeviceState *dev, Error **errp)
 {
     ERRP_GUARD();
-    GICv3State *s = HVF_GICV3(dev);
+    GICv3State *s = (GICv3State *)HVF_GICV3(dev);
     HVFARMGICv3Class *kgc = HVF_GICV3_GET_CLASS(s);
     int i;
 
@@ -715,6 +721,86 @@ static void hvf_gicv3_realize(DeviceState *dev, Error **errp)
     }
 }
 
+/*
+ * HVF doesn't have a way to save the RDIST pending tables
+ * to guest memory, only to an opaque data structure.
+ */
+static bool gicv3_is_hvf(void *opaque)
+{
+    return hvf_enabled() && hvf_irqchip_in_kernel();
+}
+
+static int hvf_gic_opaque_state_save(void *opaque)
+{
+    HVFGICv3State *gic = opaque;
+    hv_gic_state_t gic_state;
+    hv_return_t err;
+    size_t size;
+
+    gic_state = hv_gic_state_create();
+    if (gic_state == NULL) {
+        error_report("hvf: vgic: failed to create hv_gic_state_create.");
+        return 1;
+    }
+    err = hv_gic_state_get_size(gic_state, &size);
+    gic->size = size;
+    if (err != HV_SUCCESS) {
+        error_report("hvf: vgic: failed to get GIC state size.");
+        os_release(gic_state);
+        return 1;
+    }
+    gic->state = g_malloc0(gic->size);
+    err = hv_gic_state_get_data(gic_state, gic->state);
+    if (err != HV_SUCCESS) {
+        error_report("hvf: vgic: failed to get GIC state.");
+        os_release(gic_state);
+        return 1;
+    }
+
+    os_release(gic_state);
+    return 0;
+}
+
+static void hvf_gic_opaque_state_free(void *opaque)
+{
+    HVFGICv3State *gic = opaque;
+    free(gic->state);
+}
+
+static int hvf_gic_opaque_state_restore(void *opaque, int version_id)
+{
+    HVFGICv3State *gic = opaque;
+    hv_return_t err;
+    if (!gic->size) {
+        return 0;
+    }
+    err = hv_gic_set_state(gic->state, gic->size);
+    if (err != HV_SUCCESS) {
+        error_report("hvf: vgic: failed to restore GIC state.");
+        return 1;
+    }
+    return 0;
+}
+
+const VMStateDescription vmstate_gicv3_hvf = {
+    .name = "arm_gicv3/hvf_gic_state",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = gicv3_is_hvf,
+    .pre_save = hvf_gic_opaque_state_save,
+    .post_save = hvf_gic_opaque_state_free,
+    .post_load = hvf_gic_opaque_state_restore,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (const VMStateField[]) {
+        VMSTATE_UINT32(size, HVFGICv3State),
+        VMSTATE_VBUFFER_ALLOC_UINT32(state,
+                                     HVFGICv3State, 0, 0,
+                                     size),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
 static void hvf_gicv3_class_init(ObjectClass *klass, const void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -734,7 +820,7 @@ static void hvf_gicv3_class_init(ObjectClass *klass, const void *data)
 static const TypeInfo hvf_arm_gicv3_info = {
     .name = TYPE_HVF_GICV3,
     .parent = TYPE_ARM_GICV3_COMMON,
-    .instance_size = sizeof(GICv3State),
+    .instance_size = sizeof(HVFGICv3State),
     .class_init = hvf_gicv3_class_init,
     .class_size = sizeof(HVFARMGICv3Class),
 };

hw/intc/arm_gicv3_hvf_stub.c

@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * ARM Generic Interrupt Controller using HVF platform support stub
+ *
+ * Copyright (c) 2026 Mohamed Mediouni
+ *
+ */
+#include "qemu/osdep.h"
+#include "hw/intc/arm_gicv3_common.h"
+#include "migration/vmstate.h"
+#include "qemu/typedefs.h"
+
+static bool needed_never(void *opaque)
+{
+    return false;
+}
+
+const VMStateDescription vmstate_gicv3_hvf = {
+    .name = "arm_gicv3/hvf_gic_state",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = needed_never,
+    .version_id = 1,
+    .minimum_version_id = 1,
+};

hw/intc/meson.build

@@ -43,6 +43,7 @@ arm_common_ss.add(when: 'CONFIG_ARM_GICV3', if_true: files('arm_gicv3_cpuif.c'))
 specific_ss.add(when: 'CONFIG_ARM_GIC_KVM', if_true: files('arm_gic_kvm.c'))
 specific_ss.add(when: ['CONFIG_WHPX', 'TARGET_AARCH64'], if_true: files('arm_gicv3_whpx.c'))
 specific_ss.add(when: ['CONFIG_HVF', 'CONFIG_ARM_GICV3'], if_true: files('arm_gicv3_hvf.c'))
+specific_ss.add(when: ['CONFIG_HVF', 'CONFIG_ARM_GICV3'], if_false: files('arm_gicv3_hvf_stub.c'))
 specific_ss.add(when: ['CONFIG_ARM_GIC_KVM', 'TARGET_AARCH64'], if_true: files('arm_gicv3_kvm.c', 'arm_gicv3_its_kvm.c'))
 arm_common_ss.add(when: 'CONFIG_ARM_V7M', if_true: files('armv7m_nvic.c'))
 specific_ss.add(when: 'CONFIG_GRLIB', if_true: files('grlib_irqmp.c'))

include/hw/intc/arm_gicv3_common.h

@@ -339,4 +339,7 @@ void gicv3_init_irqs_and_mmio(GICv3State *s, qemu_irq_handler handler,
  */
 const char *gicv3_class_name(void);
 
+/* HVF vGIC-specific state: stubbed out on a build with HVF disabled */
+extern const VMStateDescription vmstate_gicv3_hvf;
+
 #endif