[PATCH v7 04/24] hw/arm: virt: add GICv2m for the case when ITS is not available

Mohamed Mediouni
2025-10-16T16:57:01Z

On Hypervisor.framework for macOS and WHPX for Windows, the provided environment is a GICv3 without ITS.

As such, support a GICv3 w/ GICv2m for that scenario.

Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
---
hw/arm/virt-acpi-build.c | 4 +++-
hw/arm/virt.c | 8 ++++++++
include/hw/arm/virt.h | 2 ++
3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 8bb6b60515..0a6ec74aa0 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -959,7 +959,9 @@ build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
build_append_int_noprefix(table_data, memmap[VIRT_GIC_ITS].base, 8);
build_append_int_noprefix(table_data, 0, 4); /* Reserved */
}
- } else {
+ }
+
+ if (!(vms->gic_version != VIRT_GIC_VERSION_2 && vms->its) && !vms->no_gicv3_with_gicv2m) {
const uint16_t spi_base = vms->irqmap[VIRT_GIC_V2M] + ARM_SPI_BASE;

/* 5.2.12.16 GIC MSI Frame Structure */
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 175023897a..61d7bab803 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -956,6 +956,8 @@ static void create_gic(VirtMachineState *vms, MemoryRegion *mem)

if (vms->gic_version != VIRT_GIC_VERSION_2 && vms->its) {
create_its(vms);
+ } else if (vms->gic_version != VIRT_GIC_VERSION_2 && !vms->no_gicv3_with_gicv2m) {
+ create_v2m(vms);
} else if (vms->gic_version == VIRT_GIC_VERSION_2) {
create_v2m(vms);
}
@@ -2447,6 +2449,8 @@ static void machvirt_init(MachineState *machine)
vms->ns_el2_virt_timer_irq = ns_el2_virt_timer_present() &&
!vmc->no_ns_el2_virt_timer_irq;

+ vms->no_gicv3_with_gicv2m = vmc->no_gicv3_with_gicv2m;
+
fdt_add_timer_nodes(vms);
fdt_add_cpu_nodes(vms);

@@ -3484,6 +3488,7 @@ static void virt_instance_init(Object *obj)
vms->its = true;
/* Allow ITS emulation if the machine version supports it */
vms->tcg_its = !vmc->no_tcg_its;
+ vms->no_gicv3_with_gicv2m = false;

/* Default disallows iommu instantiation */
vms->iommu = VIRT_IOMMU_NONE;
@@ -3536,9 +3541,12 @@ DEFINE_VIRT_MACHINE_AS_LATEST(10, 2)

static void virt_machine_10_1_options(MachineClass *mc)
{
+ VirtMachineClass *vmc = VIRT_MACHINE_CLASS(OBJECT_CLASS(mc));
+
virt_machine_10_2_options(mc);
mc->smbios_memory_device_size = 2047 * TiB;
compat_props_add(mc->compat_props, hw_compat_10_1, hw_compat_10_1_len);
+ vmc->no_gicv3_with_gicv2m = true;
}
DEFINE_VIRT_MACHINE(10, 1)

diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 04a09af354..d31348dd61 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -132,6 +132,7 @@ struct VirtMachineClass {
bool no_cpu_topology;
bool no_tcg_lpa2;
bool no_ns_el2_virt_timer_irq;
+ bool no_gicv3_with_gicv2m;
bool no_nested_smmu;
};

@@ -180,6 +181,7 @@ struct VirtMachineState {
char *oem_id;
char *oem_table_id;
bool ns_el2_virt_timer_irq;
+ bool no_gicv3_with_gicv2m;
CXLState cxl_devices_state;
bool legacy_smmuv3_present;
};
--
2.50.1 (Apple Git-155)