[libvirt] [PATCHv2 2/2] Add USB option capability

[Li Zhang]

From: Li Zhang <zhlcindy at linux.vnet.ibm.com>

To avoid the collision for creating USB controllers in machine->init()
and -device xx command line, it needs to set usb=off to avoid one USB
controller created in machine->init(). So that libvirt can use -device
or -usb to create USB controller sucessfully.
So QEMU_CAPS_MACHINE_USB_OPT capability is added, and it is for QEMU
v1.3.0 onwards which supports USB option.

Signed-off-by: Li Zhang <zhlcindy at linux.vnet.ibm.com>
---
 v2 -> v1:
  * Rename QEMU_CAPS_USB_OPT to QEMU_CAPS_MACHINE_USB_OPT suggested by Daniel
  * Corret QEMU version with v1.3.0 suggested by Daniel

 src/qemu/qemu_capabilities.c |    7 ++++++-
 src/qemu/qemu_capabilities.h |    1 +
 src/qemu/qemu_command.c      |    6 ++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 778e825..6ea09cc 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -211,7 +211,8 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
               "rng-random", /* 130 */
               "rng-egd",
               "virtio-ccw",
-              "machine-opt"
+              "machine-opt",
+              "machine-usb-opt"
     );
 
 struct _virQEMUCaps {
@@ -2446,6 +2447,10 @@ virQEMUCapsInitQMP(virQEMUCapsPtr qemuCaps,
     /* machine option is supported for newer version */
     virQEMUCapsSet(qemuCaps, QEMU_CAPS_MACHINE_OPT);
 
+    /* USB option is supported v1.3.0 onwards */
+    if (qemuCaps->version >= 1003000)
+        virQEMUCapsSet(qemuCaps, QEMU_CAPS_MACHINE_USB_OPT);
+
     if (!(archstr = qemuMonitorGetTargetArch(mon)))
         goto cleanup;
 
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 66df556..a23df1f 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -173,6 +173,7 @@ enum virQEMUCapsFlags {
     QEMU_CAPS_OBJECT_RNG_EGD     = 131, /* EGD protocol daemon for rng */
     QEMU_CAPS_VIRTIO_CCW         = 132, /* -device virtio-*-ccw */
     QEMU_CAPS_MACHINE_OPT        = 133, /* -machine xxxx*/
+    QEMU_CAPS_MACHINE_USB_OPT    = 134, /* -machine xxxx*/
 
     QEMU_CAPS_LAST,                   /* this must always be the last item */
 };
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index c39faf0..5472c8b 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4964,6 +4964,12 @@ qemuBuildMachineArgStr(virCommandPtr cmd,
         virCommandAddArg(cmd, "-machine");
         virBufferAsprintf(&buf, "%s", def->os.machine);
 
+        /* To avoid the collision of creating USB controllers when calling
+         * machine->init in QEMU, it needs to set usb=off
+         */
+        if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_MACHINE_USB_OPT))
+            virBufferAsprintf(&buf, ",usb=off");
+
         if (def->mem.dump_core) {
             if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DUMP_GUEST_CORE)) {
                 virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
-- 
1.7.10.1