Use the newly added function support in the IDL to generate the function
definitions for the device add, remove, and destroy functions. The
content of the generated functions is taken from the device fuction
macro framework in libxl_internal.h.

For now, the definitions are not actually written out to a .c file, but
are invoked to ensure there is no build regression introduced. A later
commit will replace the existing macros with this generated code.

Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
---
 tools/libs/light/gentypes.py | 91 +++++++++++++++++++++++++++++++++++-
 1 file changed, 90 insertions(+), 1 deletion(-)

diff --git a/tools/libs/light/gentypes.py b/tools/libs/light/gentypes.py
index f9957b79a2..9f1856399a 100644
--- a/tools/libs/light/gentypes.py
+++ b/tools/libs/light/gentypes.py
@@ -584,6 +584,85 @@ def libxl_C_enum_from_string(ty, str, e, indent = "    "):
         s = indent + s
     return s.replace("\n", "\n%s" % indent).rstrip(indent)
 
+def libxl_func_define_device_add(func):
+    s = ''
+
+    return_type = func.return_type.typename
+    if isinstance(func.return_type, idl.Enumeration):
+        return_type = idl.integer.typename
+
+    params = ', '.join([ ty.make_arg(name) for (name,ty) in func.params ])
+
+    s += '{0} {1}({2})\n'.format(return_type, func.name, params)
+    s += '{\n'
+    s += '\tAO_CREATE(ctx, domid, ao_how);\n'
+    s += '\tlibxl__ao_device *aodev;\n\n'
+    s += '\tGCNEW(aodev);\n'
+    s += '\tlibxl__prepare_ao_device(ao, aodev);\n'
+    s += '\taodev->action = LIBXL__DEVICE_ACTION_ADD;\n'
+    s += '\taodev->callback = device_addrm_aocomplete;\n'
+    s += '\taodev->update_json = true;\n'
+    s += '\tlibxl__{0}(egc, domid, type, aodev);\n\n'.format(func.rawname)
+    s += '\treturn AO_INPROGRESS;\n'
+    s += '}\n'
+
+    return s
+
+def libxl_func_define_device_remove_ext(func, action=None):
+    s = ''
+
+    flag = None
+    if action == 'remove':
+        flag = 'LIBXL__FORCE_AUTO'
+    elif action == 'destroy':
+        flag = 'LIBXL__FORCE_ON'
+    else:
+        raise Exception('Unsupported action %s' % action)
+
+    # This is used to formulate the function name libxl__device_from_<devtype>
+    devtype = func.device_param[1].rawname.replace('device_','')
+
+    remtype = 'generic'
+    if func.custom_remove is not None:
+        remtype = func.custom_remove
+
+    return_type = func.return_type.typename
+    if isinstance(func.return_type, idl.Enumeration):
+        return_type = idl.integer.typename
+
+    params = ', '.join([ ty.make_arg(name) for (name,ty) in func.params ])
+
+    s += '{0} {1}({2})\n'.format(return_type, func.name, params)
+    s += '{\n'
+    s += '\tAO_CREATE(ctx, domid, ao_how);\n'
+    s += '\tlibxl__device *device;\n'
+    s += '\tlibxl__ao_device *aodev;\n'
+    s += '\tint rc;\n'
+    s += '\n'
+    s += '\tGCNEW(device);\n'
+    s += '\trc = libxl__device_from_{0}(gc, domid, type, device);\n'.format(devtype)
+    s += '\tif (rc != 0) goto out;\n'
+    s += '\n'
+    s += '\tGCNEW(aodev);\n'
+    s += '\tlibxl__prepare_ao_device(ao, aodev);\n'
+    s += '\taodev->action = LIBXL__DEVICE_ACTION_REMOVE;\n'
+    s += '\taodev->dev = device;\n'
+    s += '\taodev->callback = device_addrm_aocomplete;\n'
+    s += '\taodev->force.flag = {0};\n'.format(flag)
+    s += '\tlibxl__initiate_device_{0}_remove(egc, aodev);\n'.format(remtype)
+    s += '\n'
+    s += 'out:\n'
+    s += '\tif (rc) return AO_CREATE_FAIL(rc);\n'
+    s += '\treturn AO_INPROGRESS;\n'
+    s += '}\n'
+
+    return s
+
+def libxl_func_define_device_remove(func):
+    return libxl_func_define_device_remove_ext(func, action='remove')
+
+def libxl_func_define_device_destroy(func):
+    return libxl_func_define_device_remove_ext(func, action='destroy')
 
 if __name__ == '__main__':
     if len(sys.argv) != 6:
@@ -592,7 +671,7 @@ if __name__ == '__main__':
 
     (_, idlname, header, header_private, header_json, impl) = sys.argv
 
-    (builtins,types,_) = idl.parse(idlname)
+    (builtins,types,funcs) = idl.parse(idlname)
 
     print("outputting libxl type definitions to %s" % header)
 
@@ -794,4 +873,14 @@ if __name__ == '__main__':
         f.write("}\n")
         f.write("\n")
 
+    for func in funcs:
+        if type(func) is idl.DeviceAddFunction:
+            _ = libxl_func_define_device_add(func)
+        elif type(func) is idl.DeviceRemoveFunction:
+            _ = libxl_func_define_device_remove(func)
+        elif type(func) is idl.DeviceDestroyFunction:
+            _ = libxl_func_define_device_destroy(func)
+        else:
+            raise Exception("Unexpected Function class %s" % type(func))
+
     f.close()
-- 
2.17.1

On Tue, Mar 02, 2021 at 08:46:18PM -0500, Nick Rosbrook wrote:
> +def libxl_func_define_device_add(func):
> +    s = ''
> +
> +    return_type = func.return_type.typename
> +    if isinstance(func.return_type, idl.Enumeration):
> +        return_type = idl.integer.typename
> +
> +    params = ', '.join([ ty.make_arg(name) for (name,ty) in func.params ])
> +
> +    s += '{0} {1}({2})\n'.format(return_type, func.name, params)
> +    s += '{\n'
> +    s += '\tAO_CREATE(ctx, domid, ao_how);\n'
> +    s += '\tlibxl__ao_device *aodev;\n\n'
> +    s += '\tGCNEW(aodev);\n'
> +    s += '\tlibxl__prepare_ao_device(ao, aodev);\n'
> +    s += '\taodev->action = LIBXL__DEVICE_ACTION_ADD;\n'
> +    s += '\taodev->callback = device_addrm_aocomplete;\n'
> +    s += '\taodev->update_json = true;\n'
> +    s += '\tlibxl__{0}(egc, domid, type, aodev);\n\n'.format(func.rawname)
> +    s += '\treturn AO_INPROGRESS;\n'
> +    s += '}\n'

That's kind of hard to read, I think we could use python's triple-quote
(or triple double-quote) ''' or """ to have a multi-line string and
remove all those \t \n
Something like:

    s = '''
    {ret} {func}({params})
    {{
        return ERROR_FAIL;
        libxl__{rawname}(gc);
    }}
    '''.format(ret=return_type, func=func.name, params=params,
               rawname=func.rawname)

That would produce some extra indentation in the generated C file, but
that doesn't matter to me. They could be removed with textwrap.dedent()
if needed.

Thanks,

-- 
Anthony PERARD

On Tue, May 04, 2021 at 04:02:55PM +0100, Anthony PERARD wrote:
> On Tue, Mar 02, 2021 at 08:46:18PM -0500, Nick Rosbrook wrote:
> > +def libxl_func_define_device_add(func):
> > +    s = ''
> > +
> > +    return_type = func.return_type.typename
> > +    if isinstance(func.return_type, idl.Enumeration):
> > +        return_type = idl.integer.typename
> > +
> > +    params = ', '.join([ ty.make_arg(name) for (name,ty) in func.params ])
> > +
> > +    s += '{0} {1}({2})\n'.format(return_type, func.name, params)
> > +    s += '{\n'
> > +    s += '\tAO_CREATE(ctx, domid, ao_how);\n'
> > +    s += '\tlibxl__ao_device *aodev;\n\n'
> > +    s += '\tGCNEW(aodev);\n'
> > +    s += '\tlibxl__prepare_ao_device(ao, aodev);\n'
> > +    s += '\taodev->action = LIBXL__DEVICE_ACTION_ADD;\n'
> > +    s += '\taodev->callback = device_addrm_aocomplete;\n'
> > +    s += '\taodev->update_json = true;\n'
> > +    s += '\tlibxl__{0}(egc, domid, type, aodev);\n\n'.format(func.rawname)
> > +    s += '\treturn AO_INPROGRESS;\n'
> > +    s += '}\n'
> 
> That's kind of hard to read, I think we could use python's triple-quote
> (or triple double-quote) ''' or """ to have a multi-line string and
> remove all those \t \n
> Something like:
> 
>     s = '''
>     {ret} {func}({params})
>     {{
>         return ERROR_FAIL;
>         libxl__{rawname}(gc);
>     }}
>     '''.format(ret=return_type, func=func.name, params=params,
>                rawname=func.rawname)
> 
> That would produce some extra indentation in the generated C file, but
> that doesn't matter to me. They could be removed with textwrap.dedent()
> if needed.
> 
That sounds good to me.

Thanks,
NR