[PATCH RFC v3 4/8] hw/i386: Add a pc machine option to bypass iommu for primary bus

[Wang Xingang <wangxingang5@huawei.com>]

From: Xingang Wang <wangxingang5@huawei.com>

Add a bypass_iommu pc machine option to bypass iommu translation
for the primary root bus.
The option can be used as manner:
qemu-system-x86_64 -machine q35,bypass_iommu=true

Signed-off-by: Xingang Wang <wangxingang5@huawei.com>
Signed-off-by: Jiahui Cen <cenjiahui@huawei.com>
---
 hw/i386/pc.c         | 18 ++++++++++++++++++
 hw/pci-host/q35.c    |  1 +
 include/hw/i386/pc.h |  1 +
 3 files changed, 20 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 8a84b25a03..2266a0520f 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1529,6 +1529,20 @@ static void pc_machine_set_hpet(Object *obj, bool value, Error **errp)
     pcms->hpet_enabled = value;
 }
 
+static bool pc_machine_get_bypass_iommu(Object *obj, Error **errp)
+{
+    PCMachineState *pcms = PC_MACHINE(obj);
+
+    return pcms->bypass_iommu;
+}
+
+static void pc_machine_set_bypass_iommu(Object *obj, bool value, Error **errp)
+{
+    PCMachineState *pcms = PC_MACHINE(obj);
+
+    pcms->bypass_iommu = value;
+}
+
 static void pc_machine_get_max_ram_below_4g(Object *obj, Visitor *v,
                                             const char *name, void *opaque,
                                             Error **errp)
@@ -1628,6 +1642,7 @@ static void pc_machine_initfn(Object *obj)
 #ifdef CONFIG_HPET
     pcms->hpet_enabled = true;
 #endif
+    pcms->bypass_iommu = false;
 
     pc_system_flash_create(pcms);
     pcms->pcspk = isa_new(TYPE_PC_SPEAKER);
@@ -1752,6 +1767,9 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     object_class_property_add_bool(oc, "hpet",
         pc_machine_get_hpet, pc_machine_set_hpet);
 
+    object_class_property_add_bool(oc, "bypass_iommu",
+        pc_machine_get_bypass_iommu, pc_machine_set_bypass_iommu);
+
     object_class_property_add(oc, PC_MACHINE_MAX_FW_SIZE, "size",
         pc_machine_get_max_fw_size, pc_machine_set_max_fw_size,
         NULL, NULL);
diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index 2eb729dff5..ade05a5539 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -64,6 +64,7 @@ static void q35_host_realize(DeviceState *dev, Error **errp)
                                 s->mch.address_space_io,
                                 0, TYPE_PCIE_BUS);
     PC_MACHINE(qdev_get_machine())->bus = pci->bus;
+    pci->bypass_iommu = PC_MACHINE(qdev_get_machine())->bypass_iommu;
     qdev_realize(DEVICE(&s->mch), BUS(pci->bus), &error_fatal);
 }
 
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index dcf060b791..83ee8f2a01 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -45,6 +45,7 @@ typedef struct PCMachineState {
     bool sata_enabled;
     bool pit_enabled;
     bool hpet_enabled;
+    bool bypass_iommu;
     uint64_t max_fw_size;
 
     /* NUMA information: */
-- 
2.19.1