Re: [PATCH v5 02/13] accel, hw/arm, include/system/hvf: infrastructure changes for HVF vGIC

[Philippe Mathieu-Daudé]

On 28/7/25 15:41, Mohamed Mediouni wrote:

Misc changes needed for HVF vGIC enablement.

Signed-off-by: Mohamed Mediouni <moha...@unpredictable.fr>
---
  accel/hvf/hvf-all.c        | 44 ++++++++++++++++++++++++++++++++++++++
  accel/stubs/hvf-stub.c     |  1 +
  hw/arm/virt.c              | 16 +++++++++-----
  hw/intc/arm_gicv3_common.c |  3 +++
  include/system/hvf.h       |  3 +++
  system/vl.c                |  2 ++
  6 files changed, 64 insertions(+), 5 deletions(-)

diff --git a/accel/hvf/hvf-all.c b/accel/hvf/hvf-all.c
index 0a4b498e83..5af76ba7a6 100644
--- a/accel/hvf/hvf-all.c
+++ b/accel/hvf/hvf-all.c
@@ -10,6 +10,8 @@

#include "qemu/osdep.h"

  #include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "qapi/qapi-visit-common.h"
  #include "accel/accel-ops.h"
  #include "system/address-spaces.h"
  #include "system/memory.h"
@@ -20,6 +22,7 @@
  #include "trace.h"

bool hvf_allowed;

+bool hvf_kernel_irqchip;

OK.

struct mac_slot {

      int present;
@@ -290,6 +293,41 @@ static int hvf_gdbstub_sstep_flags(AccelState *as)
      return SSTEP_ENABLE | SSTEP_NOIRQ;
  }

+static void hvf_set_kernel_irqchip(Object *obj, Visitor *v,

+                                   const char *name, void *opaque,
+                                   Error **errp)
+{
+#ifdef __aarch64__

We try to avoid such #ifdef'ry...

+    OnOffSplit mode;
+    if (!visit_type_OnOffSplit(v, name, &mode, errp)) {
+        return;
+    }
+
+    switch (mode) {
+    case ON_OFF_SPLIT_ON:
+        hvf_kernel_irqchip = true;
+        break;
+
+    case ON_OFF_SPLIT_OFF:
+        hvf_kernel_irqchip = false;
+        break;
+
+    case ON_OFF_SPLIT_SPLIT:
+        error_setg(errp, "HVF: split irqchip is not supported on Arm.");
+        break;
+
+    default:
+        /*
+         * The value was checked in visit_type_OnOffSplit() above. If
+         * we get here, then something is wrong in QEMU.
+         */
+        abort();
+    }
+#else
+    error_setg(errp, "HVF: setting irqchip configuration not supported on 
x86_64.");
+#endif
+}
+
  static void hvf_accel_class_init(ObjectClass *oc, const void *data)
  {
      AccelClass *ac = ACCEL_CLASS(oc);
@@ -297,6 +335,12 @@ static void hvf_accel_class_init(ObjectClass *oc, const 
void *data)
      ac->init_machine = hvf_accel_init;
      ac->allowed = &hvf_allowed;
      ac->gdbstub_supported_sstep_flags = hvf_gdbstub_sstep_flags;

... better add hvf_arch_register_class_properties(), empty stub
on x86 and filled in aarch64.

+    hvf_kernel_irqchip = true;
+    object_class_property_add(oc, "kernel-irqchip", "on|off|split",
+        NULL, hvf_set_kernel_irqchip,
+        NULL, NULL);
+    object_class_property_set_description(oc, "kernel-irqchip",
+        "Configure HVF irqchip");
  }

diff --git a/system/vl.c b/system/vl.c
index 3b7057e6c6..1c072d15a4 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -1773,6 +1773,8 @@ static void qemu_apply_legacy_machine_options(QDict 
*qdict)
                                     false);
          object_register_sugar_prop(ACCEL_CLASS_NAME("whpx"), 
"kernel-irqchip", value,
                                     false);
+        object_register_sugar_prop(ACCEL_CLASS_NAME("hvf"), "kernel-irqchip", 
value,
+                                   false);

Discussing about this object_register_sugar_prop() call on IRC, Paolo
said:

 > It's okay the property already exists for KVM so it's okay to add
 > the synonym for HVF as well
 > Maybe make sure it's not registered for x86?

          qdict_del(qdict, "kernel-irqchip");
      }