package/libvirt: do not use 'qemu' user if not defined

Commit ed12e2fbed3d (package/libvirt: add lxc and qemu options)
introduced the definition of the 'qemu' user when the libvirt daemon
is enabled, but unconditionally uses that user in its permissions
table.

When enabling libvirt without its qemu support, for example with the
commands:

    cat <<EOF >.config
    BR2_aarch64=y
    BR2_PACKAGE_LIBVIRT=y
    BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_EUDEV=y
    BR2_TARGET_ROOTFS_EXT2=y
    BR2_TOOLCHAIN_EXTERNAL=y
    EOF
    make olddefconfig
    make

The build fails with output:

    >>>   Generating filesystem image rootfs.ext2
    ...
    makedevs: unknown user name: qemu

Move the permissions needing the 'qemu' user under the same condition
the 'qemu' user is defined under. It means that a few permissions
needing root must also be moved, as they belong under a directory
needing the 'qemu' user. It also moves a few qemu-related permissions
introduced in that same commit. The list of qemu permissions is
reordered alphabetically (the others are left unchanged).

Of course, it also requires that the qemu-related directory and symlink
be moved under the same condition as well.

Reported-by: Alessandro <alex@0x65c.net>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Jared Bents <jared.bents@rockwellcollins.com>
[Julien: add the commands to reproduce the issue]
Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit da9adec1491eefc618aab610615fe293899845fd)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libvirt/libvirt.mk

@@ -250,6 +250,36 @@ define LIBVIRT_INSTALL_UDEV_RULES
 endef
 LIBVIRT_POST_INSTALL_TARGET_HOOKS += LIBVIRT_INSTALL_UDEV_RULES
 
+ifeq ($(BR2_PACKAGE_LIBVIRT_QEMU),y)
+define LIBVIRT_USERS_QEMU
+	qemu -1 kvm -1 * - - - Libvirt qemu/kvm daemon
+endef
+define LIBVIRT_PERMISSIONS_QEMU
+	/var/cache/libvirt/qemu                  d  750  qemu  kvm   -  -  -  -  -
+	/var/cache/libvirt/qemu/capabilities     d  755  root  root  -  -  -  -  -
+	/var/lib/libvirt/qemu                    d  751  qemu  kvm   -  -  -  -  -
+	/var/lib/libvirt/qemu/autostart          d  700  root  root  -  -  -  -  -
+	/var/lib/libvirt/qemu/channel            d  755  qemu  kvm   -  -  -  -  -
+	/var/lib/libvirt/qemu/channel/target     d  755  qemu  kvm   -  -  -  -  -
+	/var/lib/libvirt/qemu/dump               d  755  qemu  kvm   -  -  -  -  -
+	/var/lib/libvirt/qemu/networks           d  700  root  root  -  -  -  -  -
+	/var/lib/libvirt/qemu/networks/autostart d  700  root  root  -  -  -  -  -
+	/var/lib/libvirt/qemu/nvram              d  755  qemu  kvm   -  -  -  -  -
+	/var/lib/libvirt/qemu/save               d  755  qemu  kvm   -  -  -  -  -
+	/var/lib/libvirt/qemu/snapshot           d  755  qemu  kvm   -  -  -  -  -
+	/var/log/libvirt/qemu                    d  750  root  root  -  -  -  -  -
+	/var/log/swtpm/libvirt/qemu              d  711  root  root  -  -  -  -  -
+endef
+define LIBVIRT_CREATE_SYMLINKS_QEMU
+	$(INSTALL) -m 751 -d $(TARGET_DIR)/var/lib/libvirt/qemu
+	ln -s -f ../../var/lib/libvirt/qemu $(TARGET_DIR)/etc/libvirt/
+endef
+endif
+
+define LIBVIRT_USERS
+	$(LIBVIRT_USERS_QEMU)
+endef
+
 # Adjust directory ownerships and permissions. Notice /var/log is a symlink to
 # /tmp in the default sysvinit skeleton, so some directories may disappear at
 # run-time. Set the permissions anyway, since they are valid for the default
@@ -263,29 +293,16 @@ define LIBVIRT_PERMISSIONS
 	/var/lib/libvirt/filesystems             d  711  root  root  -  -  -  -  -
 	/var/lib/libvirt/images                  d  711  root  root  -  -  -  -  -
 	/var/lib/libvirt/network                 d  700  root  root  -  -  -  -  -
-	/var/lib/libvirt/qemu                    d  751  qemu  kvm   -  -  -  -  -
-	/var/lib/libvirt/qemu/autostart          d  700  root  root  -  -  -  -  -
-	/var/lib/libvirt/qemu/networks           d  700  root  root  -  -  -  -  -
-	/var/lib/libvirt/qemu/networks/autostart d  700  root  root  -  -  -  -  -
-	/var/lib/libvirt/qemu/channel            d  755  qemu  kvm   -  -  -  -  -
-	/var/lib/libvirt/qemu/channel/target     d  755  qemu  kvm   -  -  -  -  -
-	/var/lib/libvirt/qemu/dump               d  755  qemu  kvm   -  -  -  -  -
-	/var/lib/libvirt/qemu/nvram              d  755  qemu  kvm   -  -  -  -  -
-	/var/lib/libvirt/qemu/save               d  755  qemu  kvm   -  -  -  -  -
-	/var/lib/libvirt/qemu/snapshot           d  755  qemu  kvm   -  -  -  -  -
 	/var/lib/libvirt/secrets                 d  700  root  root  -  -  -  -  -
 	/var/lib/libvirt/storage                 d  755  root  root  -  -  -  -  -
 	/var/lib/libvirt/storage/autostart       d  755  root  root  -  -  -  -  -
 	/var/cache/libvirt                       d  711  root  root  -  -  -  -  -
 	/var/cache/libvirt/lxc                   d  750  root  root  -  -  -  -  -
-	/var/cache/libvirt/qemu                  d  750  qemu  kvm   -  -  -  -  -
-	/var/cache/libvirt/qemu/capabilities     d  755  root  root  -  -  -  -  -
 	/var/log/libvirt                         d  700  root  root  -  -  -  -  -
 	/var/log/libvirt/lxc                     d  750  root  root  -  -  -  -  -
-	/var/log/libvirt/qemu                    d  750  root  root  -  -  -  -  -
 	/var/log/swtpm                           d  755  root  root  -  -  -  -  -
 	/var/log/swtpm/libvirt                   d  755  root  root  -  -  -  -  -
-	/var/log/swtpm/libvirt/qemu              d  711  root  root  -  -  -  -  -
+	$(LIBVIRT_PERMISSIONS_QEMU)
 endef
 
 # libvirt may need to create persistent files (e.g. VM definitions) in these
@@ -296,22 +313,15 @@ endef
 define LIBVIRT_CREATE_SYMLINKS
 	$(INSTALL) -m 700 -d $(TARGET_DIR)/etc/libvirt
 	$(INSTALL) -m 755 -d $(TARGET_DIR)/var/lib/libvirt
-	$(INSTALL) -m 751 -d $(TARGET_DIR)/var/lib/libvirt/qemu
 	$(INSTALL) -m 700 -d $(TARGET_DIR)/var/lib/libvirt/secrets
 	$(INSTALL) -m 755 -d $(TARGET_DIR)/var/lib/libvirt/storage
-	ln -s -f ../../var/lib/libvirt/qemu $(TARGET_DIR)/etc/libvirt/
 	ln -s -f ../../var/lib/libvirt/secrets $(TARGET_DIR)/etc/libvirt/
 	ln -s -f ../../var/lib/libvirt/storage $(TARGET_DIR)/etc/libvirt/
+	$(LIBVIRT_CREATE_SYMLINKS_QEMU)
 endef
 
 LIBVIRT_PRE_INSTALL_TARGET_HOOKS += LIBVIRT_CREATE_SYMLINKS
 
-ifeq ($(BR2_PACKAGE_LIBVIRT_QEMU),y)
-define LIBVIRT_USERS
-	qemu -1 kvm -1 * - - - Libvirt qemu/kvm daemon
-endef
-endif
-
 ifeq ($(BR2_PACKAGE_LIBVIRT_DAEMON),y)
 define LIBVIRT_INSTALL_INIT_SYSV
 	$(INSTALL) -D -m 0755 package/libvirt/S91virtlogd $(TARGET_DIR)/etc/init.d/S91virtlogd