run_qemu.sh: allow setting MMDEBSTRAP_TESTS_DEBUG and add auto-detection for amlogic a311d bananapi

run_qemu.sh

@@ -4,6 +4,7 @@ set -eu
 
 : "${DEFAULT_DIST:=unstable}"
 : "${cachedir:=./shared/cache}"
+: "${MMDEBSTRAP_TESTS_DEBUG:=no}"
 tmpdir="$(mktemp -d)"
 
 cleanup() {
@@ -29,20 +30,42 @@ fi
 touch shared/output.txt
 setpriv --pdeathsig TERM tail -f shared/output.txt &
 
+set -- timeout --foreground 40m \
+	debvm-run --image="$(realpath "$cachedir")/debian-$DEFAULT_DIST.ext4" \
+	--
+cpuname=$(lscpu | awk '/Model name:/ {print $3}' | tr '\n' '+')
+ncpu=$(lscpu | awk '/Core\(s\) per socket:/ {print $4}' | tr '\n' '+')
+if [ "$cpuname" = "Cortex-A53+Cortex-A73+" ] && [ "$ncpu" = "2+4+" ]; then
+	# crude detection of the big.LITTLE heterogeneous setup of cores on the
+	# amlogic a311d bananapi
+	#
+	# https://lists.nongnu.org/archive/html/qemu-devel/2020-10/msg08494.html
+	# https://gitlab.com/qemu-project/qemu/-/issues/239
+	# https://segments.zhan.science/posts/kvm_on_pinehone_pro/#trouble-with-heterogeneous-architecture
+	set -- taskset --cpu-list 2,3,4,5 "$@" -smp 4
+fi
+
+set -- "$@" -nic none -m 4G -snapshot
+
+if [ "$MMDEBSTRAP_TESTS_DEBUG" = "no" ]; then
 	# to connect to serial use:
 	#   minicom -D 'unix#/tmp/ttyS0'
-#
 	# or this (quit with ctrl+q):
 	#   socat stdin,raw,echo=0,escape=0x11 unix-connect:/tmp/ttyS0
-ret=0
-timeout --foreground 40m debvm-run --image="$(realpath "$cachedir")/debian-$DEFAULT_DIST.ext4" -- \
-	-nic none \
-	-m 4G -snapshot \
+	set -- "$@" \
 	-monitor unix:/tmp/monitor,server,nowait \
 	-serial unix:/tmp/ttyS0,server,nowait \
-	-serial unix:/tmp/ttyS1,server,nowait \
-	-virtfs local,id=mmdebstrap,path="$(pwd)/shared",security_model=none,mount_tag=mmdebstrap \
-	>"$tmpdir/log" 2>&1 || ret=$?
+	-serial unix:/tmp/ttyS1,server,nowait
+fi
+
+set -- "$@" -virtfs local,id=mmdebstrap,path="$(pwd)/shared",security_model=none,mount_tag=mmdebstrap
+
+ret=0
+if [ "$MMDEBSTRAP_TESTS_DEBUG" = "no" ]; then
+	"$@" >"$tmpdir/log" 2>&1 || ret=$?
+else
+	"$@" 2>&1 | tee "$tmpdir/log" || ret=$?
+fi
 if [ "$ret" -ne 0 ]; then
 	cat "$tmpdir/log"
 	exit $ret