kvm-ok

#!/bin/bash
# SPDX-License-Identifier: GPL-2.0-only
#
# Test availability of KVM for vm-run
#
# Copyright (C) 2022-2023 Vitaly Chikunov <vt@altlinux.org>

# ERROR: ld.so: object 'libfakeroot.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
unset LD_PRELOAD

OPTS=''
TMOUT=1
TMOUT_EXIT=2
unset EXPECT
case "$HOSTTYPE" in
	armh | armv7l)
	# Special case for aarch64 host running in aarch32 personality.
	type -p qemu-system-aarch64-bundle >/dev/null && HOSTTYPE=aarch32
	ARMH_KVM_OK=/usr/bin/qemu-system-aarch64-bundle-kvm-ok
	;;
esac
case "$HOSTTYPE" in
	aarch32)
		QEMU=qemu-system-aarch64-bundle
		OPTS=" -M virt,highmem=off -cpu host,aarch64=off"
		# aarch32 will not output anything, so if it reaches timeout we assume QEMU is functional.
		TMOUT_EXIT=0
		TMOUT=.1
		;;
	aarch64)
		QEMU=qemu-system-aarch64
		OPTS=" -M virt,gic-version=host -cpu host"
		# We can add '-bios /usr/share/AAVMF/AAVMF_CODE.fd' and expect for 'UEFI firmware'
		# string, but it's slower.
		TMOUT_EXIT=0
		TMOUT=.1
		;;
	armh | armv7l)
		QEMU=qemu-system-arm
		OPTS=" -M virt"
		# There is no KVM on armh so it shall always fail.
		;;
	i586)   QEMU=qemu-system-i386
		EXPECT="SeaBIOS"
		;;
	powerpc64le)
		QEMU=qemu-system-ppc64
		OPTS=" -M kvm-type="
		# There is still unavoidable warning: 'KVM: Failed to create TCE64 table for liobn 0x80000000'
		# -cpu host is not required (only option for HV, but PR allows other cpu types).
		grep -q -P '^processor\s+:\s[1234567]$' /proc/cpuinfo \
			&& OPTS+="PR,cap-fwnmi=off" || OPTS+="HV"
		OPTS+=",cap-ccf-assist=off"
		EXPECT="QEMU Starting"
		;;
	x86_64) QEMU=qemu-system-x86_64
		EXPECT="SeaBIOS"
		;;
	*)
		# This is not a problem, it just means there is no KVM.
		echo "KVM is not available (Unknown architecture $HOSTTYPE)." >&2
		exit 3
esac

if [ ! -c /dev/kvm ]; then
	echo >&2 "KVM is not available (No /dev/kvm device)."
	exit 4
elif [ ! -w /dev/kvm ]; then
	echo >&2 "KVM is not available (/dev/kvm is not writable)."
	exit 4
elif [ "$HOSTTYPE" = "aarch32" ] && [ -x $ARMH_KVM_OK ]; then
	if ! $ARMH_KVM_OK; then
		echo >&2 "KVM is not available (No KVM kernel driver on aarch64 host)."
		exit 5
	fi
elif ! { true < /dev/kvm; } 2>/dev/null; then
	echo >&2 "KVM is not available (No KVM kernel driver)."
	exit 5
fi
if ! type -p $QEMU >/dev/null; then
	echo >&2 "KVM is not available (No $QEMU binary in PATH)."
	exit 6
fi

RET=1
atexit() {
	kill -9 $QEMU_PID >/dev/null 2>&1
	[ $1 -eq 0 ] && echo "KVM is available." || echo "KVM is not available."
}
coproc $QEMU -nodefaults -nographic -serial stdio -accel kvm $OPTS "$@"
# COPROC_PID will be unset asynchronously.
QEMU_PID=$COPROC_PID
trap 'atexit $?' EXIT
while read -r a || { [ $? -gt 128 ] && exit $TMOUT_EXIT; }; do
	[ -v EXPECT ] && [[ "$a" =~ $EXPECT ]] && exit 0
done <&$COPROC
wait $QEMU_PID