Re: [PATCH v12 04/28] hw/arm: virt: add GICv2m for the case when ITS is not available

[Pierrick Bouvier]

On 12/28/25 3:53 PM, Mohamed Mediouni wrote:
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>

Reviewed-by: Pierrick Bouvier <pierrick.bouv...@linaro.org>
---
  hw/arm/virt-acpi-build.c |  4 +++-
  hw/arm/virt.c            | 16 +++++++++++++++-
  include/hw/arm/virt.h    |  2 ++
  3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 03b4342574..b6f722657a 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -960,7 +960,9 @@ 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) {

check patch reports:
ERROR: line over 90 characters
#31: FILE: hw/arm/virt-acpi-build.c:965:
+    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 fd0e28f030..0fb8dcb07d 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -959,6 +959,8 @@ 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);
      }
@@ -2444,6 +2446,8 @@ 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);
  
@@ -3488,6 +3492,7 @@ 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;
@@ -3533,10 +3538,19 @@ static void machvirt_machine_init(void)
  }
  type_init(machvirt_machine_init);
  
+static void virt_machine_11_0_options(MachineClass *mc)
+{
+}
+DEFINE_VIRT_MACHINE_AS_LATEST(11, 0)
+
  static void virt_machine_10_2_options(MachineClass *mc)
  {
+    VirtMachineClass *vmc = VIRT_MACHINE_CLASS(OBJECT_CLASS(mc));
+
+    vmc->no_gicv3_with_gicv2m = true;
+    virt_machine_11_0_options(mc);
  }
-DEFINE_VIRT_MACHINE_AS_LATEST(10, 2)
+DEFINE_VIRT_MACHINE(10, 2)
  
  static void virt_machine_10_1_options(MachineClass *mc)
  {
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 8694aaa4e2..c5bc47ee88 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -130,6 +130,7 @@ 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;
  };
  
@@ -178,6 +179,7 @@ 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;
  };