[libvirt] [PATCH 4/9] conf: introduce parser feature flags

[Peter Krempa]

To avoid having to forbid new features added to domain XML in post parse
callbacks for individual hypervisor drivers the feature flag mechanism
will allow to add a central check that will be disabled for the drivers
that will add support.

As a first example flag, the 'hasWideSCSIBus' is converted to the new
bitmap.
---
 src/conf/domain_conf.c | 13 ++++++++-----
 src/conf/domain_conf.h |  7 ++++++-
 src/vmx/vmx.c          |  2 +-
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 5bb0616..705a796 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -4040,18 +4040,21 @@ virDomainHostdevAssignAddress(virDomainXMLOptionPtr xmlopt,
 {
     int next_unit = 0;
     unsigned controller = 0;
+    unsigned int max_unit;
     size_t i;
     int ret;

+    if (xmlopt->config.features & VIR_DOMAIN_DEF_FEATURE_WIDE_SCSI)
+        max_unit = SCSI_WIDE_BUS_MAX_CONT_UNIT;
+    else
+        max_unit = SCSI_NARROW_BUS_MAX_CONT_UNIT;
+
     for (i = 0; i < def->ncontrollers; i++) {
         if (def->controllers[i]->type != VIR_DOMAIN_CONTROLLER_TYPE_SCSI)
             continue;

         controller++;
-        ret = virDomainControllerSCSINextUnit(def,
-                                              xmlopt->config.hasWideSCSIBus ?
-                                              SCSI_WIDE_BUS_MAX_CONT_UNIT :
-                                              SCSI_NARROW_BUS_MAX_CONT_UNIT,
+        ret = virDomainControllerSCSINextUnit(def, max_unit,
                                               def->controllers[i]->idx);
         if (ret >= 0) {
             next_unit = ret;
@@ -5863,7 +5866,7 @@ virDomainDiskDefAssignAddress(virDomainXMLOptionPtr xmlopt,

         def->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_DRIVE;

-        if (xmlopt->config.hasWideSCSIBus) {
+        if (xmlopt->config.features & VIR_DOMAIN_DEF_FEATURE_WIDE_SCSI) {
             /* For a wide SCSI bus we define the default mapping to be
              * 16 units per bus, 1 bus per controller, many controllers.
              * Unit 7 is the SCSI controller itself. Therefore unit 7
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index c1e63e4..223ce2d 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2403,6 +2403,11 @@ typedef bool (*virDomainObjListACLFilter)(virConnectPtr conn,
                                           virDomainDefPtr def);


+typedef enum {
+    VIR_DOMAIN_DEF_FEATURE_WIDE_SCSI = (1 << 0),
+} virDomainDefFeatures;
+
+
 /* This structure holds various callbacks and data needed
  * while parsing and creating domain XMLs */
 typedef struct _virDomainXMLOption virDomainXMLOption;
@@ -2434,7 +2439,7 @@ struct _virDomainDefParserConfig {
     virFreeCallback privFree;

     /* data */
-    bool hasWideSCSIBus;
+    unsigned int features; /* virDomainDefFeatures */
     unsigned char macPrefix[VIR_MAC_PREFIX_BUFLEN];
 };

diff --git a/src/vmx/vmx.c b/src/vmx/vmx.c
index 4fd0a1d..cbd6633 100644
--- a/src/vmx/vmx.c
+++ b/src/vmx/vmx.c
@@ -548,10 +548,10 @@ virVMXDomainDevicesDefPostParse(virDomainDeviceDefPtr dev ATTRIBUTE_UNUSED,
 }

 static virDomainDefParserConfig virVMXDomainDefParserConfig = {
-    .hasWideSCSIBus = true,
     .macPrefix = {0x00, 0x0c, 0x29},
     .devicesPostParseCallback = virVMXDomainDevicesDefPostParse,
     .domainPostParseCallback = virVMXDomainDefPostParse,
+    .features = VIR_DOMAIN_DEF_FEATURE_WIDE_SCSI,
 };

 static void
-- 
2.6.2