Re: [Qemu-devel] [PATCH 1/4] configure: Add --enable-migration-from-qemu-kvm

[Anthony Liguori]

Cole Robinson <address@hidden> writes:

> This switch will turn on all the migration compat bits needed to
> perform migration from qemu-kvm to qemu. It's just a stub for now.
>
> This compat will break incoming migration from qemu < 1.3, but for
> distros where qemu-kvm was the only shipped package for years it's
> not a big loss (and I don't know any way to avoid it).
>
> Signed-off-by: Cole Robinson <address@hidden>

This can't be a build time option.  It's ugly and just reintroduces a fork.

I assume the issue with making it a run time option is that libvirt
would need to be updated?  Why can't qemu-kvm be a script wrapper that
passes a fixed flag?

Regards,

Anthony Liguori

> ---
>  configure | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/configure b/configure
> index bf5970f..296f488 100755
> --- a/configure
> +++ b/configure
> @@ -170,6 +170,7 @@ xfs=""
>  
>  vhost_net="no"
>  kvm="no"
> +migrate_from_kvm="no"
>  gprof="no"
>  debug_tcg="no"
>  debug="no"
> @@ -759,6 +760,8 @@ for opt do
>    ;;
>    --enable-kvm) kvm="yes"
>    ;;
> +  --enable-migration-from-qemu-kvm) migrate_from_kvm="yes"
> +  ;;
>    --disable-tcg-interpreter) tcg_interpreter="no"
>    ;;
>    --enable-tcg-interpreter) tcg_interpreter="yes"
> @@ -1087,6 +1090,9 @@ echo "  --enable-bluez           enable bluez stack 
> connectivity"
>  echo "  --disable-slirp          disable SLIRP userspace network 
> connectivity"
>  echo "  --disable-kvm            disable KVM acceleration support"
>  echo "  --enable-kvm             enable KVM acceleration support"
> +echo "  --enable-migration-from-qemu-kvm  Allow migration from qemu-kvm."
> +echo "                                    This will break migration from "
> +echo "                                    qemu < 1.3 in most cases"
>  echo "  --enable-tcg-interpreter enable TCG with bytecode interpreter (TCI)"
>  echo "  --disable-nptl           disable usermode NPTL support"
>  echo "  --enable-nptl            enable usermode NPTL support"
> @@ -3334,6 +3340,7 @@ echo "Linux AIO support $linux_aio"
>  echo "ATTR/XATTR support $attr"
>  echo "Install blobs     $blobs"
>  echo "KVM support       $kvm"
> +echo "Migrate from qemu-kvm $migrate_from_kvm"
>  echo "TCG interpreter   $tcg_interpreter"
>  echo "fdt support       $fdt"
>  echo "preadv support    $preadv"
> @@ -3622,6 +3629,9 @@ fi
>  if test "$signalfd" = "yes" ; then
>    echo "CONFIG_SIGNALFD=y" >> $config_host_mak
>  fi
> +if test "$migrate_from_kvm" = "yes"; then
> +  echo "CONFIG_MIGRATE_FROM_QEMU_KVM=y" >> $config_host_mak
> +fi
>  if test "$tcg_interpreter" = "yes" ; then
>    echo "CONFIG_TCG_INTERPRETER=y" >> $config_host_mak
>  fi
> -- 
> 1.8.1.2