[Qemu-devel] [PATCH 01/13] q35: add "int-remap" flag to enable intr

[Peter Xu <peterx@redhat.com>]

One flag is added to specify whether to enable INTR 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,int_remap=on

To be more clear, the following command:

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

Will enable Intel IOMMU only, without interrupt remapping support.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 hw/core/machine.c             | 20 ++++++++++++++++++++
 hw/pci-host/q35.c             |  6 ++++--
 include/hw/boards.h           |  1 +
 include/hw/i386/intel_iommu.h |  3 +++
 4 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 6d1a0d8..852cee2 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -298,6 +298,20 @@ static void machine_set_iommu(Object *obj, bool value, Error **errp)
     ms->iommu = value;
 }
 
+static bool machine_get_int_remap(Object *obj, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+
+    return ms->int_remap;
+}
+
+static void machine_set_int_remap(Object *obj, bool value, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+
+    ms->int_remap = value;
+}
+
 static void machine_set_suppress_vmdesc(Object *obj, bool value, Error **errp)
 {
     MachineState *ms = MACHINE(obj);
@@ -461,6 +475,12 @@ 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, "int-remap",
+                             machine_get_int_remap,
+                             machine_set_int_remap, NULL);
+    object_property_set_description(obj, "int-remap",
+                                    "Set on/off to enable/disable Intel IOMMU INTR",
+                                    NULL);
     object_property_add_bool(obj, "suppress-vmdesc",
                              machine_get_suppress_vmdesc,
                              machine_set_suppress_vmdesc, NULL);
diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index 115fb8c..7cd4d87 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -434,13 +434,14 @@ static AddressSpace *q35_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
     return &vtd_as->as;
 }
 
-static void mch_init_dmar(MCHPCIState *mch)
+static void mch_init_dmar(MCHPCIState *mch, bool intr_supported)
 {
     PCIBus *pci_bus = PCI_BUS(qdev_get_parent_bus(DEVICE(mch)));
 
     mch->iommu = INTEL_IOMMU_DEVICE(qdev_create(NULL, TYPE_INTEL_IOMMU_DEVICE));
     object_property_add_child(OBJECT(mch), "intel-iommu",
                               OBJECT(mch->iommu), NULL);
+    mch->iommu->intr_supported = intr_supported;
     qdev_init_nofail(DEVICE(mch->iommu));
     sysbus_mmio_map(SYS_BUS_DEVICE(mch->iommu), 0, Q35_HOST_BRIDGE_IOMMU_ADDR);
 
@@ -507,7 +508,8 @@ static void mch_realize(PCIDevice *d, Error **errp)
     }
     /* Intel IOMMU (VT-d) */
     if (object_property_get_bool(qdev_get_machine(), "iommu", NULL)) {
-        mch_init_dmar(mch);
+        mch_init_dmar(mch, object_property_get_bool(qdev_get_machine(),
+                                                    "int-remap", false));
     }
 }
 
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 0f30959..d488e40 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -127,6 +127,7 @@ struct MachineState {
     bool igd_gfx_passthru;
     char *firmware;
     bool iommu;
+    bool int_remap;
     bool suppress_vmdesc;
 
     ram_addr_t ram_size;
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index b024ffa..6e52c6b 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -123,6 +123,9 @@ struct IntelIOMMUState {
     MemoryRegionIOMMUOps iommu_ops;
     GHashTable *vtd_as_by_busptr;   /* VTDBus objects indexed by PCIBus* reference */
     VTDBus *vtd_as_by_bus_num[VTD_PCI_BUS_MAX]; /* VTDBus objects indexed by bus number */
+
+    /* interrupt remapping */
+    bool intr_supported;            /* Whether IR is supported */
 };
 
 /* Find the VTD Address space associated with the given bus pointer,
-- 
2.4.3