Merge branch 'multiarch' into 'main'

install and use multiarch kernels for sibling architectures

See merge request helmutg/debvm!28

1 files changed, 45 insertions, 22 deletions

diff --git a/bin/debvm-run b/bin/debvm-run
index e07ce48..1ac2360 100755
--- a/bin/debvm-run
+++ b/bin/debvm-run
@@ -104,6 +104,14 @@ die() {
 	echo "$*" 1>&2
 	exit 1
 }
+with_set_ex() {
+	echo "+ $*" 1>&2
+	with_set_ex_ret=0
+	"$@" || with_set_ex_ret=$?
+	if test "$with_set_ex_ret" != 0; then
+		die "failed with exit code $with_set_ex_ret"
+	fi
+}
 usage() {
 	die "usage: $0 [-g] [-i image] [-s sshport] [-- qemu options]"
 }
@@ -203,6 +211,23 @@ INITRDNAME=$(/sbin/debugfs "$IMAGE" -R "stat ${BOOTDIR}initrd.img" | sed 's/Fast
 test -n "$INITRDNAME" || die "failed to discover initrd image"
 test "${INITRDNAME#/}" = "$INITRDNAME" && INITRDNAME="$BOOTDIR$INITRDNAME"
 
+with_set_ex /sbin/debugfs "$IMAGE" -R "cat $KERNELNAME" > "$KERNELTMP"
+with_set_ex /sbin/debugfs "$IMAGE" -R "cat $INITRDNAME" > "$INITRDTMP"
+
+# Guess the kernel architecture.
+KERNELARCH=$VMARCH
+if command -v file >/dev/null 2>&1; then
+	case "$VMARCH:$(file -b "$KERNELTMP")" in
+		"arm:Linux kernel ARM64 boot executable Image"*) KERNELARCH=arm64 ;;
+		"armel:Linux kernel ARM64 boot executable Image"*) KERNELARCH=arm64 ;;
+		"armhf:Linux kernel ARM64 boot executable Image"*) KERNELARCH=arm64 ;;
+		# The boot stub looks the same on i386 and amd64, so we
+		# actually inspect the kernel version here, which happens to
+		# include amd64 for Debian kernels.
+		"i386:Linux kernel x86 boot executable bzImage, version "*"-amd64 "*) KERNELARCH=amd64 ;;
+	esac
+fi
+
 KERNEL_CMDLINE="root=LABEL=debvm rw"
 NETDEV="user,id=net0"
 
@@ -216,33 +241,27 @@ set -- \
 	-object rng-random,filename=/dev/urandom,id=rng0 \
 	"$@"
 
-QEMU="qemu-system-$VMARCH"
+QEMU="qemu-system-$KERNELARCH"
 CPU=
 MACHINE=
 MAX_SMP=
 NIC_DEV=virtio-net-pci,netdev=net0
 RNG_DEV=virtio-rng-pci,rng=rng0
 
-case "$VMARCH" in
+case "$KERNELARCH" in
 	amd64)
 		QEMU=qemu-system-x86_64
 		MACHINE="type=q35"
 	;;
-	arm|armel)
+	arm|armel|armhf)
 		CPU=max
 		MACHINE="type=virt"
 		MAX_SMP=8
-		RNG_DEV=
 	;;
 	arm64)
 		QEMU=qemu-system-aarch64
 		CPU=max
-		MACHINE="type=virt"
-	;;
-	armhf)
-		CPU=max
-		MACHINE="type=virt"
-		MAX_SMP=8
+		MACHINE="type=virt,gic-version=max"
 	;;
 	m68k)
 		MACHINE="type=virt"
@@ -273,7 +292,19 @@ case "$VMARCH" in
 	;;
 esac
 
-if test "$ARCHITECTURE" = "$VMARCH"; then
+ENABLE_KVM=no
+if test "$ARCHITECTURE" = "$KERNELARCH"; then
+	ENABLE_KVM=yes
+	case "$VMARCH:$KERNELARCH" in
+		arm:arm64|armel:arm64|armhf:arm64)
+			if ! linux32 true >/dev/null 2>&1; then
+				# This arm64 cannot run 32bit arm, so don't try KVM.
+				ENABLE_KVM=no
+			fi
+		;;
+	esac
+fi
+if test "$ENABLE_KVM" = yes; then
 	if ! command -v "$QEMU" >/dev/null 2>&1; then
 		# Fall back to kvm in case we badly guessed qemu.
 		QEMU=kvm
@@ -284,9 +315,6 @@ if test "$ARCHITECTURE" = "$VMARCH"; then
 	if test -w /dev/kvm; then
 		CPU=host
 	fi
-	if test "$VMARCH" = arm64; then
-		MACHINE="$MACHINE,gic-version=max"
-	fi
 fi
 
 if test -n "$MACHINE"; then
@@ -308,7 +336,7 @@ fi
 
 if test -z "$GRAPHICAL"; then
 	set -- -nographic "$@"
-	case "$VMARCH" in
+	case "$KERNELARCH" in
 		amd64|i386)
 			KERNEL_CMDLINE="$KERNEL_CMDLINE console=ttyS0"
 		;;
@@ -317,7 +345,7 @@ if test -z "$GRAPHICAL"; then
 		KERNEL_CMDLINE="$KERNEL_CMDLINE TERM=$TERM"
 	fi
 else
-	case "$VMARCH" in
+	case "$KERNELARCH" in
 		amd64|i386)
 			set -- -vga virtio "$@"
 		;;
@@ -337,9 +365,4 @@ set -- \
 	-device "$NIC_DEV" \
 	"$@"
 
-set -ex
-
-/sbin/debugfs "$IMAGE" -R "cat $KERNELNAME" > "$KERNELTMP"
-/sbin/debugfs "$IMAGE" -R "cat $INITRDNAME" > "$INITRDTMP"
-
-"$QEMU" "$@"
+with_set_ex "$QEMU" "$@"