Introduce per-hypervisor virtual RPMs

Introduce a set sub-RPMs, one per hypervisor, which can be used
as dependency targets by applications wishing to pull in the
full stack of packages required for a specific hypervisor. This
avoids the application needing to know what the hypervisor specific
package set is.

ie, applications should not need to know that using the libvirt
Xen hypervisor requires the 'xen' RPM - libvirt should take care
of that knowledge. All the application wants is 'libvirt-daemon-xen'

There are 5 sub-RPMs:

  libvirt-daemon-qemu - non-native TCG based emulators
  libvirt-daemon-kvm  - native KVM hypervisor
  libvirt-daemon-uml  - User Mode linux
  libvirt-daemon-xen  - Xen, either via XenD or libxl
  libvirt-daemon-lxc  - Linux native containers

When driver modules get turned on, these sub-RPMs will also
gain dependencies on the appropriate driver module .so files

libvirt.spec.in

@@ -52,6 +52,14 @@
 %define with_libxl         0%{!?_without_libxl:%{server_drivers}}
 %define with_vmware        0%{!?_without_vmware:%{server_drivers}}
 
+%define with_qemu_tcg      %{with_qemu}
+# Change if we ever provide qemu-kvm binaries on non-x86 hosts
+%ifarch %{ix86} x86_64
+%define with_qemu_kvm      %{with_qemu}
+%else
+%define with_qemu_kvm      0
+%endif
+
 # Then the hypervisor drivers that talk via a native remote protocol
 %define with_phyp          0%{!?_without_phyp:1}
 %define with_esx           0%{!?_without_esx:1}
@@ -125,8 +133,10 @@
 
 # RHEL-5 has restricted QEMU to x86_64 only and is too old for LXC
 %if 0%{?rhel} == 5
+%define with_qemu_tcg 0
 %ifnarch x86_64
 %define with_qemu 0
+%define with_qemu_kvm 0
 %endif
 %define with_lxc 0
 %endif
@@ -134,8 +144,10 @@
 # RHEL-6 has restricted QEMU to x86_64 only, stopped including Xen
 # on all archs. Other archs all have LXC available though
 %if 0%{?rhel} >= 6
+%define with_qemu_tcg 0
 %ifnarch x86_64
 %define with_qemu 0
+%define with_qemu_kvm 0
 %endif
 %define with_xen 0
 %endif
@@ -206,7 +218,7 @@
 %define with_storage_disk 0
 %endif
 
-%if %{with_qemu}
+%if %{with_qemu} || %{with_lxc} || %{with_uml}
 %define with_nwfilter 0%{!?_without_nwfilter:%{server_drivers}}
 # Enable libpcap library
 %define with_libpcap  0%{!?_without_libpcap:%{server_drivers}}
@@ -586,6 +598,78 @@ Requires: libvirt-daemon = %{version}-%{release}
 %description daemon-config-nwfilter
 Network filter configuration files for cleaning guest traffic
 %endif
+
+# XXX when we turn on driver modules, we will need to
+# create daemon-drv-XXX sub-RPMs and add them as deps
+# to all of the following  daemon-XXX RPMs
+
+%if %{with_qemu_tcg}
+%package daemon-qemu
+Summary: Server side daemon & driver required to run QEMU guests
+Group: Development/Libraries
+
+Requires: libvirt-daemon = %{version}-%{release}
+Requires: qemu
+
+%description daemon-qemu
+Server side daemon and driver required to manage the virtualization
+capabilities of the QEMU TCG emulators
+%endif
+
+
+%if %{with_qemu_kvm}
+%package daemon-kvm
+Summary: Server side daemon & driver required to run KVM guests
+Group: Development/Libraries
+
+Requires: libvirt-daemon = %{version}-%{release}
+Requires: qemu-kvm
+
+%description daemon-kvm
+Server side daemon and driver required to manage the virtualization
+capabilities of the KVM hypervisor
+%endif
+
+
+%if %{with_lxc}
+%package daemon-lxc
+Summary: Server side daemon & driver required to run LXC guests
+Group: Development/Libraries
+
+Requires: libvirt-daemon = %{version}-%{release}
+
+%description daemon-lxc
+Server side daemon and driver required to manage the virtualization
+capabilities of LXC
+%endif
+
+
+%if %{with_uml}
+%package daemon-uml
+Summary: Server side daemon & driver required to run UML guests
+Group: Development/Libraries
+
+Requires: libvirt-daemon = %{version}-%{release}
+# There are no UML kernel RPMs in Fedora/RHEL to depend on.
+
+%description daemon-uml
+Server side daemon and driver required to manage the virtualization
+capabilities of UML
+%endif
+
+
+%if %{with_xen} || %{with_libxl}
+%package daemon-xen
+Summary: Server side daemon & driver required to run XEN guests
+Group: Development/Libraries
+
+Requires: libvirt-daemon = %{version}-%{release}
+Requires: xen
+
+%description daemon-xen
+Server side daemon and driver required to manage the virtualization
+capabilities of XEN
+%endif
 %endif
 
 %package client
@@ -1250,6 +1334,31 @@ rm -f $RPM_BUILD_ROOT%{_sysconfdir}/sysctl.d/libvirtd
 %defattr(-, root, root)
 %{_sysconfdir}/libvirt/nwfilter/*.xml
 %endif
+
+%if %{with_qemu_tcg}
+%files daemon-qemu
+%defattr(-, root, root)
+%endif
+
+%if %{with_qemu_kvm}
+%files daemon-kvm
+%defattr(-, root, root)
+%endif
+
+%if %{with_lxc}
+%files daemon-lxc
+%defattr(-, root, root)
+%endif
+
+%if %{with_uml}
+%files daemon-uml
+%defattr(-, root, root)
+%endif
+
+%if %{with_xen} || %{with_libxl}
+%files daemon-xen
+%defattr(-, root, root)
+%endif
 %endif
 
 %if %{with_sanlock}