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Date:   Mon, 4 Apr 2022 22:35:52 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     Christoph Hellwig <hch@infradead.org>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>
Subject: Re: [PATCH 8/8] virtio_ring.h: do not include <stdint.h> from
 exported header
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On Mon, Apr 04, 2022 at 10:04:02AM +0200, Arnd Bergmann wrote:
> The header is shared between kernel and other projects using virtio, such as
> qemu and any boot loaders booting from virtio devices. It's not technically a
> /kernel/ ABI, but it is an ABI and for practical reasons the kernel version is
> maintained as the master copy if I understand it correctly.

Besides that fact that as you correctly states these are not a UAPI at
all, qemu and bootloades are not specific to Linux and can't require a
specific kernel version.  So the same thing we do for file system
formats or network protocols applies here:  just copy the damn header.
And as stated above any reasonably portable userspace needs to have a
copy anyway.

If it is just as a "master copy" it can live in drivers/virtio/, just
like we do for other formats.