xenserver: Use kernel uname version for XenServer 6.5

In XenServer 6.5, multiple kernel packages with different
rpm versions can have the same uname.  So, it is not
necessary for openvswitch kernel module to require the
exact rpm version.  Instead, the kernel module package
should check the uname version.

This commit will add a new variable %{kernel_uname} to
specify whether to use kernel uname version or kernel
rpm version as requirement.

When %{kernel_name} is used, openvswitch-module will have
"Requires: kernel-uname-r = <uname version>" set instead of
"Requires: kernel = <version>".

Reported-by: Gosen Chien <astgosen@ccu.edu.tw>
Signed-off-by: Edwin Chiu <echiu@vmware.com>
Signed-off-by: Alex Wang <alexw@nicira.com>

INSTALL.XenServer.md

@@ -81,26 +81,16 @@ where:
     the crashdump kernel flavor. Commonly, one would specify "xen" here.
 
 For XenServer 6.5 or above, the kernel version naming no longer contains
-KERNEL_FLAVOR.  Correspondingly, the the final "rpmbuild" step changes to:
+KERNEL_FLAVOR.  In fact, only providing the `uname -r` output is enough.
+So, the final "rpmbuild" step changes to:
 
    ```
-   VERSION=<Open vSwitch version>
-   KERNEL_NAME=<Xen Kernel name>
-   KERNEL_VERSION=<Xen Kernel version>
-   XEN_VERSION=<Xen Kernel flavor(suffix) >
+   KERNEL_UNAME=<`uname -r` output>
    rpmbuild \
-        -D "openvswitch_version $VERSION" \
-        -D "kernel_name $KERNEL_NAME" \
-        -D "kernel_version $KERNEL_VERSION" \
-        -D "xen_version $XEN_VERSION" \
+        -D "kenel_uname $KERNEL_UNAME" \
         -bb xenserver/openvswitch-xen.spec
    ```
 
-where:
-
-    `<Xen Version>` is the output of `uname -r`.  Since XenServer 6.5, the
-    directory name in 'lib/modules/' becomes a shortened expression of the
-    KERNEL_VERSION.
 
 Installing Open vSwitch for XenServer
 -------------------------------------

xenserver/openvswitch-xen.spec.in

@@ -18,14 +18,12 @@
 #      -D "kernel_flavor xen"
 #      -bb /usr/src/redhat/SPECS/openvswitch-xen.spec
 #
-# For XenServer version >= 6.5, replace kernel_flavor with xen_version which
-# should be the `uname -r` output.
+# For XenServer version >= 6.5, use kernel_uname which should be
+# the `uname -r` output.
 # for example:
 #
 #    rpmbuild -D "openvswitch_version 2.3.0+build123"
-#      -D "kernel_name  NAME-xen"
-#      -D "kernel_version 3.10.41-323.380416"
-#      -D "xen_version 3.10.0+2"
+#      -D "kernel_uname  3.10.0+2"
 #      -bb /usr/src/redhat/SPECS/openvswitch-xen.spec
 #
 # If tests have to be skipped while building, specify the '--without check'
@@ -36,6 +34,11 @@
 %define openvswitch_version @VERSION@
 %endif
 
+%if %{?kernel_uname:1}%{!?kernel_uname:0}
+%define kernel_name kernel
+%define kernel_version %{kernel_uname}
+%endif
+
 %if %{?kernel_name:0}%{!?kernel_name:1}
 %define kernel %(rpm -qa 'kernel*xen-devel' | head -1)
 %define kernel_name %(rpm -q --queryformat "%%{Name}" %{kernel} | sed 's/-devel//' | sed 's/kernel-//')
@@ -44,7 +47,7 @@
 %endif
 
 %if %{?xen_version:0}%{!?xen_version:1}
-%define xen_version %{kernel_version}%{kernel_flavor}
+%define xen_version %{kernel_version}%{?kernel_flavor:%{kernel_flavor}}
 %endif
 
 # bump this when breaking compatibility with userspace
@@ -78,7 +81,12 @@ Summary: Open vSwitch kernel module
 Group: System Environment/Kernel
 License: GPLv2
 Provides: %{name}-modules%{?kernel_flavor:-%{kernel_flavor}} = %{kernel_version}, openvswitch.ko.%{module_abi_version}
+%if %{?kernel_uname:0}%{!?kernel_uname:1}
 Requires: kernel%{?kernel_flavor:-%{kernel_flavor}} = %{kernel_version}
+%endif
+%if %{?kernel_uname:1}%{!?kernel_uname:0}
+Requires: kernel-uname-r = %{kernel_version}
+%endif
 
 %description %{module_package}
 Open vSwitch Linux kernel module compiled against kernel version