[libvirt] [PATCHv2 1/1] Optimize machine option to set more options with it.

[Li Zhang]

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

Currently, -machine option is used only when dump-guest-core is used.

To use options defined in machine option for new version of QEMU,
it needs to use -machine xxx, and to be compatible with older version
 -M, this patch addes QEMU_CAPS_MACH_OPT capability, and assumes
 -machine is used for QEMU v1.0 onwards.

To avoid the collision for creating USB controllers when using USB
option and -device xxxx, it needs to set usb=off in machine option.
QEMU_CAPS_USB_OPT capability is added, and it will be for QEMU
v1.3.0-rc0 onwards which supports USB option.

Signed-off-by: Li Zhang <zhlcindy at linux.vnet.ibm.com>
---
 src/qemu/qemu_capabilities.c |   10 ++++++++++
 src/qemu/qemu_capabilities.h |    2 ++
 src/qemu/qemu_command.c      |   36 +++++++++++++++++++++++++-----------
 tests/qemuxml2argvtest.c     |    4 ++--
 4 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 51fc9dc..79eb83f 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -205,6 +205,8 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
               "usb-serial", /* 125 */
               "usb-net",
               "add-fd",
+              "mach-opt",
+              "usb-opt",
 
     );
 
@@ -2416,6 +2418,14 @@ virQEMUCapsInitQMP(virQEMUCapsPtr qemuCaps,
 
     virQEMUCapsInitQMPBasic(qemuCaps);
 
+    /* Assuming to use machine option v1.0 onwards*/
+    if (qemuCaps->version >= 1000000)
+        virQEMUCapsSet(qemuCaps, QEMU_CAPS_MACH_OPT);
+
+    /* USB option is supported v1.3.0-rc0 onwards */
+    if (qemuCaps->version >= 1002090)
+        virQEMUCapsSet(qemuCaps, QEMU_CAPS_USB_OPT);
+
     if (!(archstr = qemuMonitorGetTargetArch(mon)))
         goto cleanup;
 
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index e69d558..06aaa68 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -166,6 +166,8 @@ enum virQEMUCapsFlags {
     QEMU_CAPS_DEVICE_USB_SERIAL  = 125, /* -device usb-serial */
     QEMU_CAPS_DEVICE_USB_NET     = 126, /* -device usb-net */
     QEMU_CAPS_ADD_FD             = 127, /* -add-fd */
+    QEMU_CAPS_MACH_OPT           = 128, /* -machine xxxx*/
+    QEMU_CAPS_USB_OPT            = 129, /* -machine xxxx,usb=off*/
 
     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 6c28123..e7dde21 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4614,6 +4614,8 @@ qemuBuildMachineArgStr(virCommandPtr cmd,
                        const virDomainDefPtr def,
                        virQEMUCapsPtr qemuCaps)
 {
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+
     /* This should *never* be NULL, since we always provide
      * a machine in the capabilities data for QEMU. So this
      * check is just here as a safety in case the unexpected
@@ -4621,27 +4623,39 @@ qemuBuildMachineArgStr(virCommandPtr cmd,
     if (!def->os.machine)
         return 0;
 
-    if (!def->mem.dump_core) {
+    if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MACH_OPT)) {
         /* if no parameter to the machine type is needed, we still use
          * '-M' to keep the most of the compatibility with older versions.
          */
         virCommandAddArgList(cmd, "-M", def->os.machine, NULL);
     } else {
-        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DUMP_GUEST_CORE)) {
-            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
-                           "%s", _("dump-guest-core is not available "
-                                   " with this QEMU binary"));
-            return -1;
-        }
 
         /* However, in case there is a parameter to be added, we need to
          * use the "-machine" parameter because qemu is not parsing the
          * "-M" correctly */
+
         virCommandAddArg(cmd, "-machine");
-        virCommandAddArgFormat(cmd,
-                               "%s,dump-guest-core=%s",
-                               def->os.machine,
-                               virDomainMemDumpTypeToString(def->mem.dump_core));
+        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_USB_OPT))
+            virBufferAsprintf(&buf, ",usb=off");
+
+        if (def->mem.dump_core) {
+            if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DUMP_GUEST_CORE)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               "%s", _("dump-guest-core is not available "
+                                " with this QEMU binary"));
+                return -1;
+            }
+
+            virBufferAsprintf(&buf, ",dump-guest-core=%s",
+                              virDomainMemDumpTypeToString(def->mem.dump_core));
+        }
+
+        virCommandAddArg(cmd, virBufferContentAndReset(&buf));
     }
 
     return 0;
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 4357068..296503b 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -361,8 +361,8 @@ mymain(void)
     DO_TEST("minimal-s390", QEMU_CAPS_NAME);
     DO_TEST("machine-aliases1", NONE);
     DO_TEST("machine-aliases2", QEMU_CAPS_KVM);
-    DO_TEST("machine-core-on", QEMU_CAPS_DUMP_GUEST_CORE);
-    DO_TEST("machine-core-off", QEMU_CAPS_DUMP_GUEST_CORE);
+    DO_TEST("machine-core-on", QEMU_CAPS_MACH_OPT, QEMU_CAPS_DUMP_GUEST_CORE);
+    DO_TEST("machine-core-off", QEMU_CAPS_MACH_OPT, QEMU_CAPS_DUMP_GUEST_CORE);
     DO_TEST_FAILURE("machine-core-on", NONE);
     DO_TEST("boot-cdrom", NONE);
     DO_TEST("boot-network", NONE);
-- 
1.7.10.1