qemu: Use common helper when probing qemu capabilities

QEMU binary is called several times when we probe different kinds of
capabilities the binary supports. This patch introduces new common
helper so that all probes use a consistent way of invoking qemu.

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 3d1fb43f5540fa2d00bda6611e30939d7b320389..6e5165bfb857df12feabfb06ce03f7ec9c38df6d 100644 (file)
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -289,6 +289,7 @@ qemuCapsParseMachineTypesStr(const char *output,
 
 int
 qemuCapsProbeMachineTypes(const char *binary,
+                          virBitmapPtr qemuCaps,
                           virCapsGuestMachinePtr **machines,
                           int *nmachines)
 {
@@ -306,10 +307,9 @@ qemuCapsProbeMachineTypes(const char *binary,
         return -1;
     }
 
-    cmd = virCommandNewArgList(binary, "-M", "?", NULL);
-    virCommandAddEnvPassCommon(cmd);
+    cmd = qemuCapsProbeCommand(binary, qemuCaps);
+    virCommandAddArgList(cmd, "-M", "?", NULL);
     virCommandSetOutputBuffer(cmd, &output);
-    virCommandClearCaps(cmd);
 
     /* Ignore failure from older qemu that did not understand '-M ?'.  */
     if (virCommandRun(cmd, &status) < 0)
@@ -599,12 +599,9 @@ qemuCapsProbeCPUModels(const char *qemu,
         return 0;
     }
 
-    cmd = virCommandNewArgList(qemu, "-cpu", "?", NULL);
-    if (qemuCapsGet(qemuCaps, QEMU_CAPS_NODEFCONFIG))
-        virCommandAddArg(cmd, "-nodefconfig");
-    virCommandAddEnvPassCommon(cmd);
+    cmd = qemuCapsProbeCommand(qemu, qemuCaps);
+    virCommandAddArgList(cmd, "-cpu", "?", NULL);
     virCommandSetOutputBuffer(cmd, &output);
-    virCommandClearCaps(cmd);
 
     if (virCommandRun(cmd, NULL) < 0)
         goto cleanup;
@@ -730,7 +727,8 @@ qemuCapsInitGuest(virCapsPtr caps,
                                             info->wordsize, binary, binary_mtime,
                                             old_caps, &machines, &nmachines);
         if (probe &&
-            qemuCapsProbeMachineTypes(binary, &machines, &nmachines) < 0)
+            qemuCapsProbeMachineTypes(binary, qemuCaps,
+                                      &machines, &nmachines) < 0)
             goto error;
     }
 
@@ -798,7 +796,8 @@ qemuCapsInitGuest(virCapsPtr caps,
                                                     kvmbin, binary_mtime,
                                                     old_caps, &machines, &nmachines);
                 if (probe &&
-                    qemuCapsProbeMachineTypes(kvmbin, &machines, &nmachines) < 0)
+                    qemuCapsProbeMachineTypes(kvmbin, qemuCaps,
+                                              &machines, &nmachines) < 0)
                     goto error;
             }
 
@@ -1366,17 +1365,16 @@ qemuCapsExtractDeviceStr(const char *qemu,
      * understand '-device name,?', and always exits with status 1 for
      * the simpler '-device ?', so this function is really only useful
      * if -help includes "device driver,?".  */
-    cmd = virCommandNewArgList(qemu,
-                               "-device", "?",
-                               "-device", "pci-assign,?",
-                               "-device", "virtio-blk-pci,?",
-                               "-device", "virtio-net-pci,?",
-                               "-device", "scsi-disk,?",
-                               NULL);
-    virCommandAddEnvPassCommon(cmd);
+    cmd = qemuCapsProbeCommand(qemu, flags);
+    virCommandAddArgList(cmd,
+                         "-device", "?",
+                         "-device", "pci-assign,?",
+                         "-device", "virtio-blk-pci,?",
+                         "-device", "virtio-net-pci,?",
+                         "-device", "scsi-disk,?",
+                         NULL);
     /* qemu -help goes to stdout, but qemu -device ? goes to stderr.  */
     virCommandSetErrorBuffer(cmd, &output);
-    virCommandClearCaps(cmd);
 
     if (virCommandRun(cmd, NULL) < 0)
         goto cleanup;
@@ -1485,10 +1483,9 @@ int qemuCapsExtractVersionInfo(const char *qemu, const char *arch,
         return -1;
     }
 
-    cmd = virCommandNewArgList(qemu, "-help", NULL);
-    virCommandAddEnvPassCommon(cmd);
+    cmd = qemuCapsProbeCommand(qemu, NULL);
+    virCommandAddArgList(cmd, "-help", NULL);
     virCommandSetOutputBuffer(cmd, &help);
-    virCommandClearCaps(cmd);
 
     if (virCommandRun(cmd, NULL) < 0)
         goto cleanup;
@@ -1628,3 +1625,21 @@ qemuCapsGet(virBitmapPtr caps,
     else
         return b;
 }
+
+
+virCommandPtr
+qemuCapsProbeCommand(const char *qemu,
+                     virBitmapPtr qemuCaps)
+{
+    virCommandPtr cmd = virCommandNew(qemu);
+
+    if (qemuCaps) {
+        if (qemuCapsGet(qemuCaps, QEMU_CAPS_NODEFCONFIG))
+            virCommandAddArg(cmd, "-nodefconfig");
+    }
+
+    virCommandAddEnvPassCommon(cmd);
+    virCommandClearCaps(cmd);
+
+    return cmd;
+}

diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 7279cdb90186229b73a582ffa3261caccac603d2..7a6c5a067004a4e4ea47051c971aae4b46ec3029 100644 (file)
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -26,6 +26,7 @@
 
 # include "bitmap.h"
 # include "capabilities.h"
+# include "command.h"
 
 /* Internal flags to keep track of qemu command line capabilities */
 enum qemuCapsFlags {
@@ -150,6 +151,7 @@ bool qemuCapsGet(virBitmapPtr caps,
 virCapsPtr qemuCapsInit(virCapsPtr old_caps);
 
 int qemuCapsProbeMachineTypes(const char *binary,
+                              virBitmapPtr qemuCaps,
                               virCapsGuestMachinePtr **machines,
                               int *nmachines);
 
@@ -175,6 +177,9 @@ int qemuCapsParseHelpStr(const char *qemu,
 int qemuCapsParseDeviceStr(const char *str,
                            virBitmapPtr qemuCaps);
 
+virCommandPtr qemuCapsProbeCommand(const char *qemu,
+                                   virBitmapPtr qemuCaps);
+
 VIR_ENUM_DECL(qemuCaps);
 
 #endif /* __QEMU_CAPABILITIES_H__*/

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 65de52cbb0a4758ab9b3708fb324b4f84ca1d43a..ce31e0928defb282a2b2f1305e0bd57d77683ab4 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4867,7 +4867,14 @@ qemudCanonicalizeMachineDirect(virDomainDefPtr def, char **canonical)
     virCapsGuestMachinePtr *machines = NULL;
     int i, nmachines = 0;
 
-    if (qemuCapsProbeMachineTypes(def->emulator, &machines, &nmachines) < 0)
+    /* XXX we should be checking emulator capabilities and pass them instead
+     * of NULL so that -nodefconfig is properly added when
+     * probing machine types. Luckily, qemu does not support specifying new
+     * machine types in its configuration files yet, which means passing this
+     * additional parameter makes no difference now.
+     */
+    if (qemuCapsProbeMachineTypes(def->emulator, NULL,
+                                  &machines, &nmachines) < 0)
         return -1;
 
     for (i = 0; i < nmachines; i++) {