libvmi: Fix out of box build failure with xen disabled

vbd was added for xen based VMs since
bdee00fac9b4 ("Disk reading interface for Xen based VMs and example")
and should be built only when xen is enabled, otherwise there would not be
necessary xen headers and cause the following failure.

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

recipes-extended/libvmi/files/0001-Build-vbd-only-when-xen-is-enabled.patch

@@ -0,0 +1,76 @@
+From fb7a1493c7d4a30ae930d8cb7dcb84c83c0cacce Mon Sep 17 00:00:00 2001
+From: He Zhe <zhe.he@windriver.com>
+Date: Wed, 13 Apr 2022 09:26:01 +0000
+Subject: [PATCH] Build vbd only when xen is enabled
+
+vbd was added for xen based VMs since
+bdee00fac9b4 ("Disk reading interface for Xen based VMs and example")
+and should be built only when xen is enabled, otherwise there would not be
+necessary xen headers and cause the following failure.
+
+xen_private.h:38:10: fatal error: xenctrl.h: No such file or directory
+
+Upstream-Status: Pending
+
+Signed-off-by: He Zhe <zhe.he@windriver.com>
+---
+ Makefile.am           | 8 ++++----
+ libvmi/CMakeLists.txt | 2 +-
+ 2 files changed, 5 insertions(+), 5 deletions(-)
+
+diff --git a/Makefile.am b/Makefile.am
+index 097c23c..c560a1d 100644
+--- a/Makefile.am
++++ b/Makefile.am
+@@ -17,8 +17,7 @@ h_private = \
+     libvmi/os/os_interface.h \
+     libvmi/driver/driver_interface.h \
+     libvmi/driver/driver_wrapper.h \
+-    libvmi/driver/memory_cache.h \
+-    libvmi/disk/vbd_private.h
++    libvmi/driver/memory_cache.h
+ 
+ c_sources = \
+     libvmi/accessors.c \
+@@ -39,8 +38,7 @@ c_sources = \
+     libvmi/arch/ept.c \
+     libvmi/driver/driver_interface.c \
+     libvmi/driver/memory_cache.c \
+-    libvmi/os/os_interface.c \
+-    libvmi/disk/vbd.c
++    libvmi/os/os_interface.c
+ 
+ if ENABLE_ADDRESS_CACHE
+     c_sources   += libvmi/cache.c
+@@ -104,6 +102,8 @@ if WITH_XEN
+                    libvmi/driver/xen/libxc_wrapper.h \
+                    libvmi/driver/xen/libxs_wrapper.c \
+                    libvmi/driver/xen/libxs_wrapper.h
++    h_private   += libvmi/disk/vbd_private.h
++    c_sources   += libvmi/disk/vbd.c
+ endif
+ 
+ if WITH_BAREFLANK
+diff --git a/libvmi/CMakeLists.txt b/libvmi/CMakeLists.txt
+index ac57d79..7e87751 100644
+--- a/libvmi/CMakeLists.txt
++++ b/libvmi/CMakeLists.txt
+@@ -18,7 +18,6 @@ set(libvmi_src
+     driver/driver_interface.c
+     driver/memory_cache.c
+     os/os_interface.c
+-    disk/vbd.c
+ )
+ 
+ add_library(vmi OBJECT ${libvmi_src})
+@@ -169,6 +168,7 @@ add_subdirectory(os)
+ 
+ 
+ if (ENABLE_XEN)
++    list(APPEND libvmi_src disk/vbd.c)
+     find_package(Xen REQUIRED)
+     list(APPEND VMI_PUBLIC_HEADERS events.h)
+     # CMAKE_DL_LIBS -> dlopen* lib
+-- 
+2.32.0
+

recipes-extended/libvmi/libvmi_git.bb

@@ -9,6 +9,7 @@ PV = "0.14.0+git${SRCPV}"
 DEPENDS = "libvirt libcheck bison fuse byacc-native"
 
 SRC_URI = "git://github.com/libvmi/libvmi.git;branch=master;protocol=https \
+           file://0001-Build-vbd-only-when-xen-is-enabled.patch \
 "
 
 SRCREV = "41600b602815a9c42620cd5a96c5b88739fc6d9b"