* src/driver.h src/libvirt.c src/openvz_driver.c src/qemu_driver.c

  src/remote_internal.c src/test.c src/util.c src/util.h
  src/xen_unified.c: added probe interface at the driver level,
  use that to improve default hypervisor selection in the absence
  of a given URI when connecting
Daniel

diff --git a/ChangeLog b/ChangeLog
index 3d8bb994a2cf7136ff489836e362bb91d449606a..c24edc6ab46f178adcabe7be7fef3ea637b38107 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Tue Feb 26 08:02:57 CET 2008 Daniel Veillard <veillard@redhat.com>
+
+       * src/driver.h src/libvirt.c src/openvz_driver.c src/qemu_driver.c
+         src/remote_internal.c src/test.c src/util.c src/util.h
+         src/xen_unified.c: added probe interface at the driver level,
+         use that to improve default hypervisor selection in the absence
+         of a given URI when connecting
+
 Mon Feb 25 14:53:59 CET 2008 Daniel Veillard <veillard@redhat.com>
 
        * src/Makefile.am src/util-lib.h: fix done with Jim to allow

diff --git a/src/driver.h b/src/driver.h
index 4db972b455dbeb6ead5d46921a2173989ff9f443..6e0df332a62dcab8e04f68ac083688772e2e8738 100644 (file)
--- a/src/driver.h
+++ b/src/driver.h
@@ -69,6 +69,8 @@ typedef enum {
 #define VIR_DRV_SUPPORTS_FEATURE(drv,conn,feature)                      \
     ((drv)->supports_feature ? (drv)->supports_feature((conn),(feature)) : 0)
 
+typedef const char *
+       (*virDrvProbe)                  (void);
 typedef virDrvOpenStatus
        (*virDrvOpen)                   (virConnectPtr conn,
                              xmlURIPtr uri,
@@ -277,62 +279,63 @@ typedef unsigned long long
  *  - close
  */
 struct _virDriver {
-       int            no;      /* the number virDrvNo */
-       const char * name;      /* the name of the driver */
-       unsigned long ver;      /* the version of the backend */
-       virDrvOpen                      open;
-       virDrvClose                     close;
+    int               no;      /* the number virDrvNo */
+    const char * name; /* the name of the driver */
+    unsigned long ver; /* the version of the backend */
+    virDrvProbe                        probe;
+    virDrvOpen                 open;
+    virDrvClose                        close;
     virDrvSupportsFeature   supports_feature;
-       virDrvGetType                   type;
-       virDrvGetVersion                version;
+    virDrvGetType                      type;
+    virDrvGetVersion           version;
     virDrvGetHostname       getHostname;
     virDrvGetURI            getURI;
-       virDrvGetMaxVcpus               getMaxVcpus;
-       virDrvNodeGetInfo               nodeGetInfo;
-       virDrvGetCapabilities           getCapabilities;
-       virDrvListDomains               listDomains;
-       virDrvNumOfDomains              numOfDomains;
-       virDrvDomainCreateLinux         domainCreateLinux;
-       virDrvDomainLookupByID          domainLookupByID;
-       virDrvDomainLookupByUUID        domainLookupByUUID;
-       virDrvDomainLookupByName        domainLookupByName;
-       virDrvDomainSuspend             domainSuspend;
-       virDrvDomainResume              domainResume;
-       virDrvDomainShutdown            domainShutdown;
-       virDrvDomainReboot              domainReboot;
-       virDrvDomainDestroy             domainDestroy;
-       virDrvDomainGetOSType           domainGetOSType;
-       virDrvDomainGetMaxMemory        domainGetMaxMemory;
-       virDrvDomainSetMaxMemory        domainSetMaxMemory;
-       virDrvDomainSetMemory           domainSetMemory;
-       virDrvDomainGetInfo             domainGetInfo;
-       virDrvDomainSave                domainSave;
-       virDrvDomainRestore             domainRestore;
-       virDrvDomainCoreDump            domainCoreDump;
-       virDrvDomainSetVcpus            domainSetVcpus;
-       virDrvDomainPinVcpu             domainPinVcpu;
-       virDrvDomainGetVcpus            domainGetVcpus;
-       virDrvDomainGetMaxVcpus         domainGetMaxVcpus;
-       virDrvDomainDumpXML             domainDumpXML;
-       virDrvListDefinedDomains        listDefinedDomains;
-       virDrvNumOfDefinedDomains       numOfDefinedDomains;
-       virDrvDomainCreate              domainCreate;
-       virDrvDomainDefineXML           domainDefineXML;
-       virDrvDomainUndefine            domainUndefine;
-       virDrvDomainAttachDevice        domainAttachDevice;
-       virDrvDomainDetachDevice        domainDetachDevice;
-       virDrvDomainGetAutostart        domainGetAutostart;
-       virDrvDomainSetAutostart        domainSetAutostart;
-       virDrvDomainGetSchedulerType    domainGetSchedulerType;
-       virDrvDomainGetSchedulerParameters domainGetSchedulerParameters;
-       virDrvDomainSetSchedulerParameters domainSetSchedulerParameters;
+    virDrvGetMaxVcpus          getMaxVcpus;
+    virDrvNodeGetInfo          nodeGetInfo;
+    virDrvGetCapabilities              getCapabilities;
+    virDrvListDomains          listDomains;
+    virDrvNumOfDomains         numOfDomains;
+    virDrvDomainCreateLinux            domainCreateLinux;
+    virDrvDomainLookupByID             domainLookupByID;
+    virDrvDomainLookupByUUID   domainLookupByUUID;
+    virDrvDomainLookupByName   domainLookupByName;
+    virDrvDomainSuspend                domainSuspend;
+    virDrvDomainResume         domainResume;
+    virDrvDomainShutdown               domainShutdown;
+    virDrvDomainReboot         domainReboot;
+    virDrvDomainDestroy                domainDestroy;
+    virDrvDomainGetOSType              domainGetOSType;
+    virDrvDomainGetMaxMemory   domainGetMaxMemory;
+    virDrvDomainSetMaxMemory   domainSetMaxMemory;
+    virDrvDomainSetMemory              domainSetMemory;
+    virDrvDomainGetInfo                domainGetInfo;
+    virDrvDomainSave           domainSave;
+    virDrvDomainRestore                domainRestore;
+    virDrvDomainCoreDump               domainCoreDump;
+    virDrvDomainSetVcpus               domainSetVcpus;
+    virDrvDomainPinVcpu                domainPinVcpu;
+    virDrvDomainGetVcpus               domainGetVcpus;
+    virDrvDomainGetMaxVcpus            domainGetMaxVcpus;
+    virDrvDomainDumpXML                domainDumpXML;
+    virDrvListDefinedDomains   listDefinedDomains;
+    virDrvNumOfDefinedDomains  numOfDefinedDomains;
+    virDrvDomainCreate         domainCreate;
+    virDrvDomainDefineXML           domainDefineXML;
+    virDrvDomainUndefine            domainUndefine;
+    virDrvDomainAttachDevice   domainAttachDevice;
+    virDrvDomainDetachDevice   domainDetachDevice;
+    virDrvDomainGetAutostart   domainGetAutostart;
+    virDrvDomainSetAutostart   domainSetAutostart;
+    virDrvDomainGetSchedulerType       domainGetSchedulerType;
+    virDrvDomainGetSchedulerParameters domainGetSchedulerParameters;
+    virDrvDomainSetSchedulerParameters domainSetSchedulerParameters;
     virDrvDomainMigratePrepare domainMigratePrepare;
     virDrvDomainMigratePerform domainMigratePerform;
     virDrvDomainMigrateFinish  domainMigrateFinish;
     virDrvDomainBlockStats      domainBlockStats;
     virDrvDomainInterfaceStats  domainInterfaceStats;
-       virDrvNodeGetCellsFreeMemory    nodeGetCellsFreeMemory;
-       virDrvNodeGetFreeMemory         getFreeMemory;
+    virDrvNodeGetCellsFreeMemory       nodeGetCellsFreeMemory;
+    virDrvNodeGetFreeMemory            getFreeMemory;
 };
 
 typedef int

diff --git a/src/libvirt.c b/src/libvirt.c
index 897a953bc8a240891e699173c816a8f63f04f6e8..29dba0a7af9f9e62f0f724db5f67112d963a209c 100644 (file)
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -632,9 +632,47 @@ do_open (const char *name,
     virConnectPtr ret = NULL;
     xmlURIPtr uri;
 
-    /* Convert NULL or "" to xen:/// for back compat */
-    if (!name || name[0] == '\0')
-        name = "xen:///";
+    /*
+     *  If no URI is passed, then check for an environment string if not
+     *  available probe the compiled in drivers to find a default hypervisor
+     *  if detectable.
+     */
+    if (!name || name[0] == '\0') {
+        char *defname = getenv("LIBVIRT_DEFAULT_URI");
+        if (defname && *defname) {
+           DEBUG("Using LIBVIRT_DEFAULT_URI %s", defname);
+            name = defname;
+        } else {
+           const char *use = NULL;
+           const char *latest;
+           int probes = 0;
+           for (i = 0; i < virNetworkDriverTabCount; i++) {
+               if ((virDriverTab[i]->probe != NULL) &&
+                   ((latest = virDriverTab[i]->probe()) != NULL)) {
+                   probes++;
+
+                   DEBUG("Probed %s", latest);
+                   /*
+                    * if running a xen kernel, give it priority over
+                    * QEmu emultation
+                    */
+                   if (STREQ(latest, "xen:///")) 
+                       use = latest;
+                   else if (use == NULL)
+                       use = latest;
+               }
+           }
+           if (use == NULL) {
+               name = "xen:///";
+               DEBUG("Could not probe any hypervisor defaulting to %s",
+                     name);
+           } else {
+               name = use;
+               DEBUG("Using %s as default URI, %d hypervisor found",
+                     use, probes);
+           }
+       }
+    }
 
     /* Convert xen -> xen:/// for back compat */
     if (!strcasecmp(name, "xen"))

diff --git a/src/openvz_driver.c b/src/openvz_driver.c
index c1b506a99e6fb377e50d6997ce054c843b6787ca..29cb24494eb564e46a4c2ddf694eeba0c7bbcf7c 100644 (file)
--- a/src/openvz_driver.c
+++ b/src/openvz_driver.c
@@ -546,6 +546,15 @@ bail_out5:
     return ret;
 }
 
+static const char *openvzProbe(void)
+{
+#ifdef __linux__
+    if ((getuid() == 0) && (virFileExists("/proc/vz")))
+        return("openvz:///");
+#endif
+    return(NULL);
+}
+
 static virDrvOpenStatus openvzOpen(virConnectPtr conn,
                                  xmlURIPtr uri,
                                  virConnectAuthPtr auth ATTRIBUTE_UNUSED,
@@ -694,6 +703,7 @@ static virDriver openvzDriver = {
     VIR_DRV_OPENVZ,
     "OPENVZ",
     LIBVIR_VERSION_NUMBER,
+    openvzProbe, /* probe */
     openvzOpen, /* open */
     openvzClose, /* close */
     NULL, /* supports_feature */

diff --git a/src/qemu_driver.c b/src/qemu_driver.c
index 9a3964424596270e185aa32e966af9b3be0d459c..b711dc1f0f00a88be6077a4f5838bad2e6a0b678 100644 (file)
--- a/src/qemu_driver.c
+++ b/src/qemu_driver.c
@@ -1388,6 +1388,25 @@ static int qemudMonitorCommand(struct qemud_driver *driver ATTRIBUTE_UNUSED,
     return -1;
 }
 
+/**
+ * qemudProbe:
+ *
+ * Probe for the availability of the qemu driver, assume the
+ * presence of QEmu emulation if the binaries are installed
+ */
+static const char *qemudProbe(void)
+{
+    if ((virFileExists("/usr/bin/qemu")) ||
+        (virFileExists("/usr/bin/qemu-kvm")) ||
+       (virFileExists("/usr/bin/xenner"))) {
+        if (getuid() == 0) {
+           return("qemu:///system");
+       } else {
+           return("qemu:///session");
+       }
+    }
+    return(NULL);
+}
 
 static virDrvOpenStatus qemudOpen(virConnectPtr conn,
                                   xmlURIPtr uri,
@@ -2859,6 +2878,7 @@ static virDriver qemuDriver = {
     VIR_DRV_QEMU,
     "QEMU",
     LIBVIR_VERSION_NUMBER,
+    qemudProbe, /* probe */
     qemudOpen, /* open */
     qemudClose, /* close */
     NULL, /* supports_feature */

diff --git a/src/remote_internal.c b/src/remote_internal.c
index 9e569ae9a7d014f36828437359b63bb5d14535a2..11d299ba37f20cab02b1d3869b41917ce40cbed3 100644 (file)
--- a/src/remote_internal.c
+++ b/src/remote_internal.c
@@ -4599,6 +4599,7 @@ static virDriver driver = {
     .no = VIR_DRV_REMOTE,
     .name = "remote",
     .ver = REMOTE_PROTOCOL_VERSION,
+    .probe = NULL,
     .open = remoteOpen,
     .close = remoteClose,
     .supports_feature = remoteSupportsFeature,

diff --git a/src/test.c b/src/test.c
index 1d064d3c416829e491d34ced2d5ddab4dc989fb3..ce8cea8f8f4700465f4534f0dbdd68fbcac48377 100644 (file)
--- a/src/test.c
+++ b/src/test.c
@@ -1939,6 +1939,7 @@ static virDriver testDriver = {
     VIR_DRV_TEST,
     "Test",
     LIBVIR_VERSION_NUMBER,
+    NULL, /* probe */
     testOpen, /* open */
     testClose, /* close */
     NULL, /* supports_feature */

diff --git a/src/util.c b/src/util.c
index 67cb0b816ea92fcd55c33b580725344878ce3deb..da1610a0363f6219d09b0810575134d218152f0b 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -463,6 +463,15 @@ virFileLinkPointsTo (const char *checkLink ATTRIBUTE_UNUSED,
 
 #endif /*! __MINGW32__ */
 
+int virFileExists(const char *path)
+{
+    struct stat st;
+
+    if (stat(path, &st) >= 0)
+        return(1);
+    return(0);
+}
+
 int virFileMakePath(const char *path)
 {
     struct stat st;

diff --git a/src/util.h b/src/util.h
index 23a016de5c68ee577872e443dcdec0e25d103762..4ababaecf39f465f4e5bbc7036725fcd8c735d0d 100644 (file)
--- a/src/util.h
+++ b/src/util.h
@@ -47,6 +47,9 @@ int virFileHasSuffix(const char *str,
 
 int virFileLinkPointsTo(const char *checkLink,
                         const char *checkDest);
+
+int virFileExists(const char *path);
+
 int virFileMakePath(const char *path);
 
 int virFileBuildPath(const char *dir,

diff --git a/src/xen_unified.c b/src/xen_unified.c
index 8dd82c45cafccae895993099e15b0a6623768d64..50d49b6d3a2587451f69d7f20a5d19d58536d292 100644 (file)
--- a/src/xen_unified.c
+++ b/src/xen_unified.c
@@ -39,6 +39,7 @@
 #include "xs_internal.h"
 #include "xm_internal.h"
 #include "xml.h"
+#include "util.h"
 
 #define DEBUG(fmt,...) VIR_DEBUG(__FILE__, fmt,__VA_ARGS__)
 
@@ -217,6 +218,24 @@ done:
  * in the low level drivers directly.
  */
 
+static const char *
+xenUnifiedProbe (void)
+{
+#ifdef __linux__
+    if (virFileExists("/proc/xen"))
+        return("xen:///");
+#endif
+#ifdef __sun__
+    FILE *fh;
+
+    if (fh = fopen("/dev/xen/domcaps", "r")) {
+       fclose(fh);
+        return("xen:///");
+    }
+#endif
+    return(NULL);
+}
+
 static int
 xenUnifiedOpen (virConnectPtr conn, xmlURIPtr uri, virConnectAuthPtr auth, int flags)
 {
@@ -1198,6 +1217,7 @@ static virDriver xenUnifiedDriver = {
     .no = VIR_DRV_XEN_UNIFIED,
     .name = "Xen",
     .ver = HV_VERSION,
+    .probe                     = xenUnifiedProbe,
     .open                      = xenUnifiedOpen,
     .close                     = xenUnifiedClose,
     .supports_feature   = xenUnifiedSupportsFeature,