Re: [PATCH v4 01/13] hw/arm/virt-acpi-build.c: Migrate fw_cfg creation to common location

[Andrew Jones]

On Thu, Oct 26, 2023 at 01:37:01AM +0530, Sunil V L wrote:
...
> diff --git a/hw/nvram/fw_cfg-acpi.c b/hw/nvram/fw_cfg-acpi.c
> new file mode 100644
> index 0000000000..eddaffc09b
> --- /dev/null
> +++ b/hw/nvram/fw_cfg-acpi.c
> @@ -0,0 +1,44 @@
> +/*
> + * Add fw_cfg device in DSDT
> + *
> + * Copyright (C) 2008-2010  Kevin O'Connor <kevin@koconnor.net>
> + * Copyright (C) 2006 Fabrice Bellard
> + * Copyright (C) 2013 Red Hat Inc
> + *
> + * Author: Michael S. Tsirkin <mst@redhat.com>
> + *
> + * Copyright (c) 2015 HUAWEI TECHNOLOGIES CO.,LTD.
> + *
> + * Author: Shannon Zhao <zhaoshenglong@huawei.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> +
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> +
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.

I don't recommend creating new files with the long form GPL instead of an
SPDX. I can't find a QEMU SPDX policy to point at, but pretty much every
project I work on has been moving towards SPDX, and usually with a format
policy. I presume QEMU will either slowly work its way there too or
someday do a mass change. New files can participate in an unofficial slow
transition now, rather than have to be touched again in a mass change.

...
> diff --git a/include/hw/nvram/fw_cfg_acpi.h b/include/hw/nvram/fw_cfg_acpi.h
> new file mode 100644
> index 0000000000..1c863df329
> --- /dev/null
> +++ b/include/hw/nvram/fw_cfg_acpi.h
> @@ -0,0 +1,15 @@
> +/*
> + * ACPI support for fw_cfg
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */

While QEMU doesn't appear to have an SPDX policy with formatting rules,
I would format this as

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * ACPI support for fw_cfg
 */

And the source file above as

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Add fw_cfg device in DSDT
 *
 * ...
 */

as that is the recommended format for many projects (I think starting
with Linux which documents[1] it) and tools have already learned that
formatting. QEMU's checkpatch will accept the C99 comment style[2].

[1] 
https://www.kernel.org/doc/html/latest/process/license-rules.html#license-identifier-syntax
[2] commit 8d061278d385 ("checkpatch: allow SPDX-License-Identifier")

Thanks,
drew