[kvm-unit-tests PATCH v4 3/3] arm/run: introduce usingkvm var and use it

["Alex Bennée" <alex.bennee@linaro.org>]

This makes the script a little cleaner by only checking for KVM support
in one place. If KVM isn't available we can fall back to TCG emulation
and echo the fact to the screen rather than let QEMU complain.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>

---
v2
  - rm redundant M= statement
v3
  - make usingkvm use "yes"
  - merge patches 3/4 into one
v4
  - use single quotes consistently
  - add r-b tag
---
 arm/run | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arm/run b/arm/run
index 6b42a2e..6b3d558 100755
--- a/arm/run
+++ b/arm/run
@@ -8,6 +8,15 @@ fi
 source config.mak
 processor="$PROCESSOR"
 
+# Default to using KVM if available and on the right ARM host
+if [ -c /dev/kvm ]; then
+	if [ "$HOST" = "arm" ] && [ "$ARCH" = "arm" ]; then
+		usingkvm=yes
+	elif [ "$HOST" = "aarch64" ]; then
+		usingkvm=yes
+	fi
+fi
+
 qemu="${QEMU:-qemu-system-$ARCH_NAME}"
 qpath=$(which $qemu 2>/dev/null)
 
@@ -22,6 +31,12 @@ if ! $qemu -machine '?' 2>&1 | grep 'ARM Virtual Machine' > /dev/null; then
 fi
 
 M='-machine virt'
+if [ "$usingkvm" = "yes" ]; then
+	M+=',accel=kvm'
+else
+	echo "Running with TCG"
+	M+=',accel=tcg'
+fi
 
 if ! $qemu $M -device '?' 2>&1 | grep virtconsole > /dev/null; then
 	echo "$qpath doesn't support virtio-console for chr-testdev. Exiting."
@@ -34,12 +49,11 @@ if $qemu $M -chardev testdev,id=id -initrd . 2>&1 \
 	exit 2
 fi
 
-M='-machine virt,accel=kvm:tcg'
 chr_testdev='-device virtio-serial-device'
 chr_testdev+=' -device virtconsole,chardev=ctd -chardev testdev,id=ctd'
 
 # arm64 must use '-cpu host' with kvm
-if [ "$(arch)" = "aarch64" ] && [ "$ARCH" = "arm64" ] && [ -c /dev/kvm ]; then
+if [ "$usingkvm" = "yes" ] && [ "$ARCH" = "arm64" ]; then
 	processor="host"
 fi
 
-- 
2.4.5