rcutorture: Add basic ARM64 support to run scripts

This commit adds support of the qemu command qemu-system-aarch64
to rcutorture.

Signed-off-by: Lihao Liang <[e-mail]>
Signed-off-by: Paul E. McKenney <[e-mail]>

tools/testing/selftests/rcutorture/bin/functions.sh

···
 		qemu-system-x86_64|qemu-system-i386)
 			echo arch/x86/boot/bzImage
 			;;
+		qemu-system-aarch64)
+			echo arch/arm64/boot/Image
+			;;
 		*)
 			echo vmlinux
 			;;
···
 	elif echo $u | grep -q "Intel 80386"
 	then
 		echo qemu-system-i386
+	elif echo $u | grep -q aarch64
+	then
+		echo qemu-system-aarch64
 	elif uname -a | grep -q ppc64
 	then
 		echo qemu-system-ppc64
···
 # Output arguments for the qemu "-append" string based on CPU type
 # and the TORTURE_QEMU_INTERACTIVE environment variable.
 identify_qemu_append () {
+	local console=ttyS0
 	case "$1" in
 	qemu-system-x86_64|qemu-system-i386)
 		echo noapic selinux=0 initcall_debug debug
+		;;
+	qemu-system-aarch64)
+		console=ttyAMA0
 		;;
 	esac
 	if test -n "$TORTURE_QEMU_INTERACTIVE"
 	then
 		echo root=/dev/sda
 	else
-		echo console=ttyS0
+		echo console=$console
 	fi
 }
 
···
 identify_qemu_args () {
 	case "$1" in
 	qemu-system-x86_64|qemu-system-i386)
+		;;
+	qemu-system-aarch64)
+		echo -machine virt,gic-version=host -cpu host
 		;;
 	qemu-system-ppc64)
 		echo -enable-kvm -M pseries -nodefaults
···
 		echo $2
 	else
 		case "$1" in
-		qemu-system-x86_64|qemu-system-i386)
+		qemu-system-x86_64|qemu-system-i386|qemu-system-aarch64)
 			echo $2 -smp $3
 			;;
 		qemu-system-ppc64)