[Qemu-devel] [PATCH v7 16/25] q35: add "intremap" parameter to enable IR

[Peter Xu <peterx@redhat.com>]

One flag is added to specify whether to enable IR for emulated IOMMU. By
default, interrupt remapping is not supportted. To enable it, we should
specify something like:

$ qemu-system-x86_64 -M q35,iommu=on,intremap=on

To be more clear, the following command:

$ qemu-system-x86_64 -M q35,iommu=on

Will enable IOMMU only, without interrupt remapping support.

Currently, Intel IOMMU IR only support kernel-irqchip={off|split}. We
need to specify either of it in -M as well.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 hw/core/machine.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 276ad61..5994b9f 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -300,6 +300,20 @@ static void machine_set_iommu(Object *obj, bool value, Error **errp)
     ms->iommu = value;
 }
 
+static bool machine_get_intremap(Object *obj, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+
+    return ms->iommu_intr;
+}
+
+static void machine_set_intremap(Object *obj, bool value, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+
+    ms->iommu_intr = value;
+}
+
 static void machine_set_suppress_vmdesc(Object *obj, bool value, Error **errp)
 {
     MachineState *ms = MACHINE(obj);
@@ -480,6 +494,12 @@ static void machine_initfn(Object *obj)
     object_property_set_description(obj, "iommu",
                                     "Set on/off to enable/disable Intel IOMMU (VT-d)",
                                     NULL);
+    object_property_add_bool(obj, "intremap", machine_get_intremap,
+                             machine_set_intremap, NULL);
+    object_property_set_description(obj, "intremap",
+                                    "Set on/off to enable/disable IOMMU"
+                                    " interrupt remapping",
+                                    NULL);
     object_property_add_bool(obj, "suppress-vmdesc",
                              machine_get_suppress_vmdesc,
                              machine_set_suppress_vmdesc, NULL);
-- 
2.4.11