[meta-virtualization][PATCH v2 2/4] xen, xen-tools: fix build and passing of CFLAGS via Xen vars

["Christopher Clark" <christopher.w.clark@gmail.com>]

Ensure that the Xen build system variables EXTRA_CFLAGS_XEN_CORE and
EXTRA_CFLAGS_XEN_TOOLS are passed into the compile steps.

Update the hypervisor compilation to avoid passing in most compile flags
from the build environment via EXTRA_CFLAGS_XEN_CORE -- prefer the
compiler defaults and the flags set by the Xen build system, so only the
debug prefix flags are provided.

Observeration derived from the prior commit e99974aa, so:
Reported-by: Diego Sueiro <diego.sueiro@arm.com>
Signed-off-by: Christopher Clark <christopher.w.clark@gmail.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
---
 recipes-extended/xen/xen-hypervisor.inc |  3 ++-
 recipes-extended/xen/xen-tools.inc      |  3 ++-
 recipes-extended/xen/xen.inc            | 12 ++++++++++--
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/recipes-extended/xen/xen-hypervisor.inc b/recipes-extended/xen/xen-hypervisor.inc
index 916bd3c..9b96d91 100644
--- a/recipes-extended/xen/xen-hypervisor.inc
+++ b/recipes-extended/xen/xen-hypervisor.inc
@@ -49,7 +49,8 @@ do_configure() {
 }
 
 do_compile() {
-    oe_runmake xen PYTHON="${PYTHON}"
+    oe_runmake xen PYTHON="${PYTHON}" \
+                   EXTRA_CFLAGS_XEN_CORE="${EXTRA_CFLAGS_XEN_CORE}"
 }
 
 do_install() {
diff --git a/recipes-extended/xen/xen-tools.inc b/recipes-extended/xen/xen-tools.inc
index 3560e79..2930097 100644
--- a/recipes-extended/xen/xen-tools.inc
+++ b/recipes-extended/xen/xen-tools.inc
@@ -727,7 +727,8 @@ do_configure() {
 
 do_compile() {
     cd ${S}
-    oe_runmake tools PYTHON="${PYTHON}"
+    oe_runmake tools PYTHON="${PYTHON}" \
+                     EXTRA_CFLAGS_XEN_TOOLS="${EXTRA_CFLAGS_XEN_TOOLS}"
 }
 
 do_install() {
diff --git a/recipes-extended/xen/xen.inc b/recipes-extended/xen/xen.inc
index 2fbdb3a..5aa2d5a 100644
--- a/recipes-extended/xen/xen.inc
+++ b/recipes-extended/xen/xen.inc
@@ -92,6 +92,16 @@ export LDFLAGS=""
 
 # Pass through the Yocto distro compiler flags via the Xen-provided variables.
 # Special handling:
+# - The Yocto distro compiler flags are typically set to be appropriate for
+#   user-space software rather than for generation of a hypervisor binary, so
+#   only pass the debug prefix map to the hypervisor build:
+EXTRA_CFLAGS_XEN_CORE="${DEBUG_PREFIX_MAP}"
+
+# - The Xen tools build for x86 systems with HVM-mode enabled includes hvmloader
+#   which fails to build when "-m64" is included in flags set via the
+#   EXTRA_CFLAGS_XEN_TOOLS: so clear TUNE_CCARGS on x86 to prevent that.
+TUNE_CCARGS_x86-64=""
+
 # - Yocto supplies the _FORTIFY_SOURCE flag via CC/CPP/CXX but then passes the
 #   optimization -O via C*FLAGS which is problematic when the CFLAGS are cleared
 #   within the build because compilation fails with the compiler stating
@@ -102,12 +112,10 @@ export LDFLAGS=""
 #   explicitly clears CFLAGS to ensure that, so such options must not be passed
 #   in via the tool variable. hvmloader is required to run HVM-mode guest VMs.
 CC="${CCACHE}${HOST_PREFIX}gcc ${TOOLCHAIN_OPTIONS} ${CC_REPRODUCIBLE_OPTIONS}"
-EXTRA_CFLAGS_XEN_CORE="${HOST_CC_ARCH} ${CFLAGS}"
 EXTRA_CFLAGS_XEN_TOOLS="${HOST_CC_ARCH} ${CFLAGS}"
 # 32-bit ARM needs the TUNE_CCARGS component of HOST_CC_ARCH to be passed
 # in CC to ensure that configure can compile binaries for the right arch.
 CC_arm="${CCACHE}${HOST_PREFIX}gcc ${TUNE_CCARGS} ${TOOLCHAIN_OPTIONS} ${CC_REPRODUCIBLE_OPTIONS}"
-EXTRA_CFLAGS_XEN_CORE_arm="${SECURITY_CFLAGS} ${CFLAGS}"
 EXTRA_CFLAGS_XEN_TOOLS_arm="${SECURITY_CFLAGS} ${CFLAGS}"
 
 # There are no Xen-provided variables for C++, so append to the tool variables:
-- 
2.25.1