[PATCH 1/1] hw/arm: virt: add GICv2m for the case when ITS is not available

[Mohamed Mediouni]

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 <moha...@unpredictable.fr>
---
 hw/arm/virt-acpi-build.c | 4 +++-
 hw/arm/virt.c            | 8 +++++++-
 include/hw/arm/virt.h    | 2 ++
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index b01fc4f8ef..7fc8f8e6b8 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -848,7 +848,9 @@ 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->its && !vms->no_gicv2m_when_no_its_available) {
         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 ef6be3660f..8af0ce95ba 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -854,7 +854,7 @@ static void create_gic(VirtMachineState *vms, MemoryRegion 
*mem)
                             redist_region_count);
 
         if (!kvm_irqchip_in_kernel()) {
-            if (vms->tcg_its) {
+            if (vms->its && vms->tcg_its) {
                 object_property_set_link(OBJECT(vms->gic), "sysmem",
                                          OBJECT(mem), &error_fatal);
                 qdev_prop_set_bit(vms->gic, "has-lpi", true);
@@ -2402,6 +2402,8 @@ 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_gicv2m_when_no_its_available = 
vmc->no_gicv2m_when_no_its_available;
+
     fdt_add_timer_nodes(vms);
     fdt_add_cpu_nodes(vms);
 
@@ -3410,6 +3412,7 @@ 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_gicv2m_when_no_its_available = false;
 
     /* Default disallows iommu instantiation */
     vms->iommu = VIRT_IOMMU_NONE;
@@ -3462,8 +3465,11 @@ DEFINE_VIRT_MACHINE_AS_LATEST(10, 1)
 
 static void virt_machine_10_0_options(MachineClass *mc)
 {
+    VirtMachineClass *vmc = VIRT_MACHINE_CLASS(OBJECT_CLASS(mc));
+
     virt_machine_10_1_options(mc);
     compat_props_add(mc->compat_props, hw_compat_10_0, hw_compat_10_0_len);
+    vmc->no_gicv2m_when_no_its_available = true;
 }
 DEFINE_VIRT_MACHINE(10, 0)
 
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 365a28b082..15b8357394 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -131,6 +131,7 @@ struct VirtMachineClass {
     bool no_cpu_topology;
     bool no_tcg_lpa2;
     bool no_ns_el2_virt_timer_irq;
+    bool no_gicv2m_when_no_its_available;
     bool no_nested_smmu;
 };
 
@@ -178,6 +179,7 @@ struct VirtMachineState {
     char *oem_id;
     char *oem_table_id;
     bool ns_el2_virt_timer_irq;
+    bool no_gicv2m_when_no_its_available;
     CXLState cxl_devices_state;
 };
 
-- 
2.39.5 (Apple Git-154)