On Wed, 28 Oct 2020, Alex Bennée wrote:
> Xen is supported on aarch64 although weirdly using the i386-softmmu
> model. Checking based on the host CPU meant we never enabled Xen
> support. It would be nice to enable CONFIG_XEN for aarch64-softmmu to
> make it not seem weird but that will require further build surgery.
>
> Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
> Cc: Masami Hiramatsu <masami.hirama...@linaro.org>
> Cc: Stefano Stabellini <sstabell...@kernel.org>
> Cc: Anthony Perard <anthony.per...@citrix.com>
> Cc: Paul Durrant <p...@xen.org>
> Fixes: 8a19980e3f ("configure: move accelerator logic to meson")
> ---
> meson.build | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/meson.build b/meson.build
> index 835424999d..f1fcbfed4c 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -81,6 +81,8 @@ if cpu in ['x86', 'x86_64']
> 'CONFIG_HVF': ['x86_64-softmmu'],
> 'CONFIG_WHPX': ['i386-softmmu', 'x86_64-softmmu'],
> }
> +elif cpu in [ 'arm', 'aarch64' ]
> + accelerator_targets += { 'CONFIG_XEN': ['i386-softmmu'] }
> endif
This looks very reasonable -- the patch makes sense.
However I have two questions, mostly for my own understanding. I tried
to repro the aarch64 build problem but it works at my end, even without
this patch. I wonder why. I suspect it works thanks to these lines in
meson.build:
if not get_option('xen').disabled() and 'CONFIG_XEN_BACKEND' in config_host
accelerators += 'CONFIG_XEN'
have_xen_pci_passthrough = not get_option('xen_pci_passthrough').disabled()
and targetos == 'linux'
else
have_xen_pci_passthrough = false
endif
But I am not entirely sure who is adding CONFIG_XEN_BACKEND to
config_host.
The other question is: does it make sense to print the value of
CONFIG_XEN as part of the summary? Something like:
diff --git a/meson.build b/meson.build
index 47e32e1fcb..c6e7832dc9 100644
--- a/meson.build
+++ b/meson.build
@@ -2070,6 +2070,7 @@ summary_info += {'KVM support':
config_all.has_key('CONFIG_KVM')}
summary_info += {'HAX support': config_all.has_key('CONFIG_HAX')}
summary_info += {'HVF support': config_all.has_key('CONFIG_HVF')}
summary_info += {'WHPX support': config_all.has_key('CONFIG_WHPX')}
+summary_info += {'XEN support': config_all.has_key('CONFIG_XEN')}
summary_info += {'TCG support': config_all.has_key('CONFIG_TCG')}
if config_all.has_key('CONFIG_TCG')
summary_info += {'TCG debug enabled':
config_host.has_key('CONFIG_DEBUG_TCG')}
But I realize there is already:
summary_info += {'xen support': config_host.has_key('CONFIG_XEN_BACKEND')}
so it would be a bit of a duplicate
