From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4BD6E18C33; Tue, 3 Feb 2026 08:09:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770106165; cv=none; b=jPi4RKeaG+5ZqBCpt6GOb69vFSHBOtlTMjw6wXq9uwPOiLf9ot9I/ll6FJponX7fF7MZnmQDUx2HCmqtPbdR6Q/roaoaJ1kvV1z0kR9PCSDCmTv+hPukPWxCeFvjlYRi2K8dEkBgXKqZGcZmFlWW5ZPMjs7KTrOeULNXcQohF6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770106165; c=relaxed/simple; bh=XlCZCTHFs/gfGWT/y4AlgyeEiKxWcKld6JkaIVjZYno=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=C9U6/ko55XWBWUcpaw0Aw8hn5VzoDZBXwI1LFImaktF9Ybk/IhiUfmXJtD2Sp9rc6FhFKHzuZtWwYO1YIQq9YzAbGvSnqhWWmYV7Z8mth92ptIyAmIfEn9aKVQJscx5tdqDmmDF2hPosFnNlkUlGjxql5Jy7V4YEneoe+UArzOY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LS5FGJua; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LS5FGJua" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7200EC116D0; Tue, 3 Feb 2026 08:09:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770106165; bh=XlCZCTHFs/gfGWT/y4AlgyeEiKxWcKld6JkaIVjZYno=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LS5FGJuauA/HjtPQh7tAkMFf95Jwyaxr8BazthGe6dLoplMn5xT2u3qMMkhbTVO9a +M/C/q5OIOK6T8JoFVRd2Iwd121l/EF1MsNuTxQWYGKbsibadQLFuyA5zE2HUyexhc atCpriVwN2ogQQEkB5i6ErVPv1h9Fhy0GeowsNjKQY9gqp5rwXgxxoYEV9l4n+EwIF cTUgGhQxAOU3yXEtITAUj9Qku8CQJ1orc/u0GmB/X9EDB40M4fPSbj7J4ietjUNSPl 4wLY0BV0mRaVjwCcW10DvGl42N8e+ZFQPxGg501IhbZTbwryGcKGL20XaV+DYQr0vk ugY+lmQukUztg== Date: Tue, 3 Feb 2026 10:09:20 +0200 From: Jarkko Sakkinen To: linux-media@vger.kernel.org Cc: jani.nikula@linux.intel.com, anisse@astier.eu, oleksandr@natalenko.name, linux-integrity@vger.kernel.org, Mauro Carvalho Chehab , Hans Verkuil , Laurent Pinchart , Sakari Ailus , Jacopo Mondi , Ricardo Ribalda , open list Subject: Re: [RFC PATCH v2] media: Virtual camera driver Message-ID: References: <20260202204425.2614054-1-jarkko@kernel.org> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260202204425.2614054-1-jarkko@kernel.org> On Mon, Feb 02, 2026 at 10:44:21PM +0200, Jarkko Sakkinen wrote: > Already a quick Google survey backs strongly that OOT drivers (e.g., > v4l2loopback) are the defacto solution for streaming phone cameras in > video conference calls, which puts confidential discussions at risk. > > It can be also claimed that there's enough OOT usage in the wild that > possible security bugs could be considered as potential zerodays for the > benefit of malicious actors. > > The situation has been stagnated for however many years, which is > unsastainable situation, and it further factors potential security > risks. Therefore, a driver is needed to address the popular use case. > > vcam is a DMA-BUF backed virtual camera driver capable of creating video > capture devices to which data can be streamed through /dev/vcam after > calling VCAM_IOC_CREATE. Frames are pushed with VCAM_IOC_QUEUE and recycled > with VCAM_IOC_DEQUEUE. Zero-copy semantics are supported for shared DMA-BUF > between capture and output. > > This enables efficient implementation of software, which can manage network > video streams from phone cameras, and map those streams to video devices. > > PipeWire or any other specific pick of userspace software cannot really > address the issue at scale, as e.g., the use of v4l2loopback is both wide > and scattered. > > Signed-off-by: Jarkko Sakkinen After learning a bit more about the topic and for future updates I will drop YUYV. NV12, MJPEG, and additionally RGBX32 and XRGB32 for testing and GPUs define pretty well the requirements for a software define device, and limit the applicability of "proprietary risk" (as that was the main concern raised). I honestly did not have idea what would be an appropriate subset of formats to constraint the driver initially. In addition, a better name for this module would probably be swcam as it does not mix up with those pre-existing devices starting with the letter 'v'. BR, Jarkko