[PATCH v1 04/23] q35/xen: Add Xen platform device support for Q35

[Joel Upham]

Current Xen/QEMU method to control Xen Platform device on i440 is a bit
odd -- enabling/disabling Xen platform device actually modifies the QEMU
emulated machine type, namely xenfv <--> pc.

In order to avoid multiplying machine types, use a new way to control Xen
Platform device for QEMU -- "xen-platform-dev" machine property (bool).
To maintain backward compatibility with existing Xen/QEMU setups, this
is only applicable to q35 machine currently. i440 emulation still uses the
old method (i.e. xenfv/pc machine selection) to control Xen Platform
device, this may be changed later to xen-platform-dev property as well.

This way we can use a single machine type (q35) and change just
xen-platform-dev value to on/off to control Xen platform device.

Signed-off-by: Alexey Gerasimenko <x1917x@xxxxxxxxx>
Signed-off-by: Joel Upham <jupham125@gmail.com>
---
 hw/core/machine.c   | 19 +++++++++++++++++++
 hw/i386/pc_q35.c    | 20 +++++++++++++++++++-
 include/hw/boards.h |  1 +
 qemu-options.hx     |  1 +
 4 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 1000406211..703138d2ec 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -455,6 +455,20 @@ static void machine_set_graphics(Object *obj, bool value, 
Error **errp)
     ms->enable_graphics = value;
 }
 
+static bool machine_get_xen_platform_dev(Object *obj, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+
+    return ms->xen_platform_dev;
+}
+
+static void machine_set_xen_platform_dev(Object *obj, bool value, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+
+    ms->xen_platform_dev = value;
+}
+
 static char *machine_get_firmware(Object *obj, Error **errp)
 {
     MachineState *ms = MACHINE(obj);
@@ -1004,6 +1018,11 @@ static void machine_class_init(ObjectClass *oc, void 
*data)
     object_class_property_set_description(oc, "graphics",
         "Set on/off to enable/disable graphics emulation");
 
+    object_class_property_add_bool(oc, "xen-platform-dev",
+        machine_get_xen_platform_dev, machine_set_xen_platform_dev);
+    object_class_property_set_description(oc, "xen-platform-dev",
+        "Set on/off to enable/disable Xen Platform device");
+
     object_class_property_add_str(oc, "firmware",
         machine_get_firmware, machine_set_firmware);
     object_class_property_set_description(oc, "firmware",
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 6155427e48..789a23ce6b 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -57,10 +57,24 @@
 #include "hw/hyperv/vmbus-bridge.h"
 #include "hw/mem/nvdimm.h"
 #include "hw/i386/acpi-build.h"
+#include "hw/xen/xen-x86.h"
+#include "sysemu/xen.h"
 
 /* ICH9 AHCI has 6 ports */
 #define MAX_SATA_PORTS     6
 
+static void q35_xen_hvm_init(MachineState *machine)
+{
+    PCMachineState *pcms = PC_MACHINE(machine);
+
+    if (xen_enabled()) {
+        /* check if Xen Platform device is enabled */
+        if (machine->xen_platform_dev) {
+            pci_create_simple(pcms->bus, -1, "xen-platform");
+        }
+    }
+}
+
 struct ehci_companions {
     const char *name;
     int func;
@@ -273,8 +287,12 @@ static void pc_q35_init(MachineState *machine)
     for (i = 0; i < IOAPIC_NUM_PINS; i++) {
         qdev_connect_gpio_out_named(lpc_dev, ICH9_GPIO_GSI, i, x86ms->gsi[i]);
     }
-    isa_bus = ISA_BUS(qdev_get_child_bus(lpc_dev, "isa.0"));
 
+    if (xen_enabled()) {
+        q35_xen_hvm_init(machine);
+    }
+
+    isa_bus = ISA_BUS(qdev_get_child_bus(lpc_dev, "isa.0"));
     if (x86ms->pic == ON_OFF_AUTO_ON || x86ms->pic == ON_OFF_AUTO_AUTO) {
         pc_i8259_create(isa_bus, gsi_state->i8259_irq);
     }
diff --git a/include/hw/boards.h b/include/hw/boards.h
index a385010909..0b021f0764 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -339,6 +339,7 @@ struct MachineState {
     bool mem_merge;
     bool usb;
     bool usb_disabled;
+    bool xen_platform_dev;
     char *firmware;
     bool iommu;
     bool suppress_vmdesc;
diff --git a/qemu-options.hx b/qemu-options.hx
index b37eb9662b..ea018257da 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -30,6 +30,7 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
     "                vmport=on|off|auto controls emulation of vmport (default: 
auto)\n"
     "                dump-guest-core=on|off include guest memory in a core 
dump (default=on)\n"
     "                mem-merge=on|off controls memory merge support (default: 
on)\n"
+    "                xen-platform-dev=on|off controls Xen Platform device 
(default=off)\n"
     "                aes-key-wrap=on|off controls support for AES key wrapping 
(default=on)\n"
     "                dea-key-wrap=on|off controls support for DEA key wrapping 
(default=on)\n"
     "                suppress-vmdesc=on|off disables self-describing migration 
(default=off)\n"
-- 
2.34.1