Re: [PATCH v3 1/7] configure: option to disable host block devices

[Joelle van Dyne <j@getutm.app>]

On Wed, Oct 28, 2020 at 4:22 AM Stefan Hajnoczi <stefanha@gmail.com> wrote:
>
> On Tue, Oct 27, 2020 at 08:06:55PM -0700, Joelle van Dyne wrote:
> > Some hosts (iOS) have a sandboxed filesystem and do not provide low-level
> > APIs for interfacing with host block devices.
> >
> > Signed-off-by: Joelle van Dyne <j@getutm.app>
> > ---
> >  configure          | 4 ++++
> >  meson.build        | 1 +
> >  block/file-posix.c | 8 +++++++-
> >  3 files changed, 12 insertions(+), 1 deletion(-)
>
> A change along these lines is needed in qapi/block-core.json:
>
>   { 'enum': 'BlockdevDriver',
>     ...
>     { 'name': 'host_device', 'if': 'defined(CONFIG_HOST_BLOCK_DEVICE)' }
>
> That way the QAPI schema reflects the QEMU binary's actual features.
Will do.

>
> >
> > diff --git a/configure b/configure
> > index 71bbe82ac5..4e68a5fefe 100755
> > --- a/configure
> > +++ b/configure
> > @@ -448,6 +448,7 @@ ninja=""
> >  skip_meson=no
> >  gettext=""
> >  mirror_jit="no"
> > +host_block_device_support="yes"
> >
> >  bogus_os="no"
> >  malloc_trim="auto"
> > @@ -5901,6 +5902,9 @@ if test "$default_devices" = "yes" ; then
> >  else
> >    echo "CONFIG_MINIKCONF_MODE=--allnoconfig" >> $config_host_mak
> >  fi
> > +if test "$host_block_device_support" = "yes" ; then
> > +  echo "CONFIG_HOST_BLOCK_DEVICE=y" >> $config_host_mak
> > +fi
> >  if test "$debug_tcg" = "yes" ; then
> >    echo "CONFIG_DEBUG_TCG=y" >> $config_host_mak
> >  fi
>
> How do you disable CONFIG_HOST_BLOCK_DEVICE? There is no ./configure
> --disable-host-block-device option.
I don't see a value in disabling as an option. It's always enabled by
default and automatically disabled for iOS.

-j