Re: [Qemu-devel] [PATCH v4 7/10] qemu-binfmt-conf.sh: generalize CPU to positional TARGETS

[Laurent Vivier <laurent@vivier.eu>]

On 11/03/2019 11:30, Unai Martinez-Corral wrote:
> This breaks brackward compatibility.
> 
> Option '--systemd CPU' allows to register binfmt interpreters for a
> single target architecture or for 'ALL' (of them). This patch
> generalizes the approach to support it in any mode (default, '--debian'
> or '--systemd'). To do so, option 'systemd' is changed to be boolean
> (no args). Then, all the positional arguments are considered to be a
> list of target architectures.
> 
> If no positional arguments are provided, all of the architectures in
> qemu_target_list are registered. Conversely, argument value 'NONE'
> allows to make a 'dry run' of the script. I.e., checks are executed
> according to the mode, but no interpreter is registered.
> 
> Support QEMU_TARGETS environment variable, consistently with 'path',
> 'suffix', 'persistent' and 'credential', The supported formats are
> the same as for positional arguments, which have priority. If both
> the variable and the list of positional arguments are empty, defaults
> to qemu_target_list.
> 
> Signed-off-by: Unai Martinez-Corral <unai.martinezcorral@ehu.eus>
> ---
>  scripts/qemu-binfmt-conf.sh | 80 +++++++++++++++++++++----------------
>  1 file changed, 45 insertions(+), 35 deletions(-)
> 
> diff --git a/scripts/qemu-binfmt-conf.sh b/scripts/qemu-binfmt-conf.sh
> index 13e619794c..fde78517ff 100755
> --- a/scripts/qemu-binfmt-conf.sh
> +++ b/scripts/qemu-binfmt-conf.sh
> @@ -6,6 +6,27 @@ mips mipsel mipsn32 mipsn32el mips64 mips64el \
>  sh4 sh4eb s390x aarch64 aarch64_be hppa riscv32 riscv64 xtensa xtensaeb \
>  microblaze microblazeel or1k x86_64"
> 
> +# check if given TARGETS is/are in the supported target list
> +qemu_check_target_list() {
> +    if [ $# -eq 0 ] ; then
> +      checked_target_list="$qemu_target_list"
> +      return
> +    fi
> +    for target ; do
> +        for cpu in $qemu_target_list ; do
> +            if [ "x$cpu" = "x$target" ] ; then
> +                checked_target_list="$checked_target_list $target"
> +                break
> +            fi
> +        done
> +        if [ "$unknown_target" = "true" ] ; then

           if [ "x$cpu" != "x$target" ] ; then

> +            echo "ERROR: unknown CPU \"$target\"" 1>&2
> +            usage
> +            exit 1
> +        fi
> +    done
> +}
> +
>  i386_magic='\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x03\x00'
>  i386_mask='\xff\xff\xff\xff\xff\xfe\xfe\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff'
>  i386_family=i386
> @@ -167,21 +188,25 @@ qemu_get_family() {
> 
>  usage() {
>      cat <<EOF
> +Usage: qemu-binfmt-conf.sh [options] [TARGETS]
> 
> -Usage: qemu-binfmt-conf.sh [options]
> -
> -Configure binfmt_misc to use qemu interpreter
> +Configure binfmt_misc to use qemu interpreter for the given TARGETS.
> 
>  Options and associated environment variables:
> 
>  Argument             Env-variable     Description
> +TARGETS              QEMU_TARGETS     A single arch name or a list of them (see all names below);
> +                                      if empty, configure all known targets;
> +                                      if 'NONE', no interpreter is configured.
>  -h|--help                             display this usage
>  -Q|--path PATH:      QEMU_PATH        set path to qemu interpreter(s)
>  -F|--suffix SUFFIX:  QEMU_SUFFIX      add a suffix to the default interpreter name
>  -d|--debian:                          don't write into /proc, generate update-binfmts templates
> --s|--systemd CPU:                     don't write into /proc, generate file for
> -                                      systemd-binfmt.service for the given CPU; if CPU is "ALL",
> -                                      generate a file for all known cpus.
> +-s|--systemd:                         don't write into /proc, generate file(s) for
> +                                      systemd-binfmt.service; environment variable HOST_ARCH

why HOST_ARCH appears here?

> +                                      allows to override 'uname' to generate configuration files
> +                                      for a different architecture than the current one.
> +
>  -e|--exportdir PATH: DEBIANDIR        define where to write configuration files
>                       SYSTEMDDIR
>  -c|--credential:     QEMU_CREDENTIAL  (yes) credential and security tokens are calculated according
> @@ -197,14 +222,7 @@ To remove interpreter, use :
> 
>      sudo update-binfmts --package qemu-CPU --remove qemu-CPU $QEMU_PATH
> 
> -With systemd, binfmt files are loaded by systemd-binfmt.service
> -
> -The environment variable HOST_ARCH allows to override 'uname' to generate configuration files for a
> -different architecture than the current one.
> -
> -where CPU is one of:
> -
> -    $qemu_target_list
> +QEMU target list: $qemu_target_list
> 
>  EOF
>  }
> @@ -288,9 +306,15 @@ qemu_set_binfmts() {
>      # probe cpu type
>      host_family=$(qemu_get_family)
> 
> -    # register the interpreter for each cpu except for the native one
> +    # reduce the list of target interpreters to those given in the CLI
> +    [ $# -eq 0 ] && targets="${QEMU_TARGETS:-}" || targets="$@"
> +    if [ "x$targets" = "xNONE" ] ; then
> +      return
> +    fi
> +    qemu_check_target_list $targets
> 
> -    for cpu in ${qemu_target_list} ; do
> +    # register the interpreter for each target except for the native one
> +    for cpu in $checked_target_list ; do
>          magic=$(eval echo \$${cpu}_magic)
>          mask=$(eval echo \$${cpu}_mask)
>          family=$(eval echo \$${cpu}_family)
> @@ -318,12 +342,13 @@ BINFMT_SET=qemu_register_interpreter
>  SYSTEMDDIR="/etc/binfmt.d"
>  DEBIANDIR="/usr/share/binfmts"
> 
> +QEMU_TARGETS="${QEMU_TARGETS:-}"
>  QEMU_PATH="${QEMU_PATH:-/usr/local/bin}"
>  QEMU_SUFFIX="${QEMU_SUFFIX:-}"
>  QEMU_CREDENTIAL="${QEMU_CREDENTIAL:-no}"
>  QEMU_PERSISTENT="${QEMU_PERSISTENT:-no}"
> 
> -options=$(getopt -o ds:Q:S:e:hcp -l debian,systemd:,path:,suffix:,exportdir:,help,credential,persistent -- "$@")
> +options=$(getopt -o dsQ:S:e:hcp -l debian,systemd,path:,suffix:,exportdir:,help,credential,persistent -- "$@")
>  eval set -- "$options"
> 
>  while true ; do
> @@ -337,23 +362,6 @@ while true ; do
>          CHECK=qemu_check_systemd
>          BINFMT_SET=qemu_generate_systemd
>          EXPORTDIR=${EXPORTDIR:-$SYSTEMDDIR}
> -        shift
> -        # check given cpu is in the supported CPU list
> -        if [ "$1" != "ALL" ] ; then
> -            for cpu in ${qemu_target_list} ; do
> -                if [ "$cpu" = "$1" ] ; then
> -                    break
> -                fi
> -            done
> -
> -            if [ "$cpu" = "$1" ] ; then
> -                qemu_target_list="$1"
> -            else
> -                echo "ERROR: unknown CPU \"$1\"" 1>&2
> -                usage
> -                exit 1
> -            fi
> -        fi
>          ;;
>      -Q|--path)
>          shift
> @@ -384,5 +392,7 @@ while true ; do
>      shift
>  done
> 
> +shift
> +
>  $CHECK
> -qemu_set_binfmts
> +qemu_set_binfmts "$@"
> --
> 2.21.0
>