From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 63B3B12DDA9 for ; Thu, 11 Jul 2024 14:59:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720709976; cv=none; b=DM69nbBk2GqKn3uG7CX6G/qKU9fxIP/Sj/J8oYGeHDUOBrnVMaov7vc4BnjaL68OU/DgdiFQ9eiNRhU4I6tVOGVcQ1EZ8xqbEKPexirDViFJPiESpM+g4pk7+ueq3g8WiqPHSt/Ab+tUxFazBz7q3J4DlHDMTBveV8GbMSOsxzs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720709976; c=relaxed/simple; bh=4CuytYGWxop9eAcIa6p/8qpsPWZV/sx6JByCVnWLnEs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=g7QYUj007Pgf36ffcm0PKuFLNl5F/2wMCai/m+KCEaet0n3AI0kB0NnMydy/4ai7EHMpfZYzotIenxgC31+bz4cRpttspB4dIt+hkrEZPTSwLOSnVz8y2i8xstqfDqbMNv7O35XBwsyGnEQeduvhPT/Cj23zD/UaNeT37Z9l8iU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=QRaToxQB; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QRaToxQB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1720709974; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4CuytYGWxop9eAcIa6p/8qpsPWZV/sx6JByCVnWLnEs=; b=QRaToxQBfUcqArUzL3XocZEJHzvLk/4FiLslFqpkm5mGnyrY4OGg94c++5BN0jNyR0GyUy Lq668b4J+uBOX9ImNEN8RZMueFqzazZAqWMCcsuTjERO8AX6eSrojTp1cc+dSvFAkPkw6n VAJNNcCCI3rvrJnKGTMhCmj8yF0Tyn4= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-132-w4XqLiviM-6OVXuYYX5ZAA-1; Thu, 11 Jul 2024 10:59:26 -0400 X-MC-Unique: w4XqLiviM-6OVXuYYX5ZAA-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 22950196CE02; Thu, 11 Jul 2024 14:59:25 +0000 (UTC) Received: from localhost (unknown [10.22.32.66]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3A6EB195606C; Thu, 11 Jul 2024 14:59:23 +0000 (UTC) From: Cornelia Huck To: "Michael S. Tsirkin" Cc: Viresh Kumar , virtio-comment@lists.linux.dev, Vincent Guittot , Alex =?utf-8?Q?Benn=C3=A9e?= , Manos Pitsidianakis , Parav Pandit , Matias Ezequiel Vara Larsen Subject: Re: [PATCH V7] virtio-transport: Add a new section to clarify transport requirements In-Reply-To: <20240711104702-mutt-send-email-mst@kernel.org> Organization: "Red Hat GmbH, Sitz: Werner-von-Siemens-Ring 12, D-85630 Grasbrunn, Handelsregister: Amtsgericht =?utf-8?Q?M=C3=BCnchen=2C?= HRB 153243, =?utf-8?Q?Gesch=C3=A4ftsf=C3=BChrer=3A?= Ryan Barnhart, Charles Cachera, Michael O'Neill, Amy Ross" References: <279db14c105666b4e2c9c71dede31592947dd9f5.1720683975.git.viresh.kumar@linaro.org> <20240711070740-mutt-send-email-mst@kernel.org> <87zfqob184.fsf@redhat.com> <20240711074942-mutt-send-email-mst@kernel.org> <87wmlsb0m1.fsf@redhat.com> <20240711103014-mutt-send-email-mst@kernel.org> <87ttgwasyg.fsf@redhat.com> <20240711104702-mutt-send-email-mst@kernel.org> User-Agent: Notmuch/0.38.3 (https://notmuchmail.org) Date: Thu, 11 Jul 2024 16:59:21 +0200 Message-ID: <87r0c0asae.fsf@redhat.com> Precedence: bulk X-Mailing-List: virtio-comment@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Thu, Jul 11 2024, "Michael S. Tsirkin" wrote: > On Thu, Jul 11, 2024 at 04:44:55PM +0200, Cornelia Huck wrote: >> On Thu, Jul 11 2024, "Michael S. Tsirkin" wrote: >>=20 >> > On Thu, Jul 11, 2024 at 01:59:34PM +0200, Cornelia Huck wrote: >> >> On Thu, Jul 11 2024, "Michael S. Tsirkin" wrote: >> >>=20 >> >> > On Thu, Jul 11, 2024 at 01:46:19PM +0200, Cornelia Huck wrote: >> >> >> On Thu, Jul 11 2024, "Michael S. Tsirkin" wrote: >> >> >>=20 >> >> >> > On Thu, Jul 11, 2024 at 01:18:18PM +0530, Viresh Kumar wrote: >> >> >> >> The virtio documentation currently doesn't define any generic >> >> >> >> requirements that are applicable to all transports. They can be= useful >> >> >> >> while adding support for a new transport. >> >> >> >>=20 >> >> >> >> This commit tries to define the same under a new Appendix secti= on. >> >> >> >>=20 >> >> >> >> Reviewed-by: Alex Benn=C3=A9e >> >> >> >> Signed-off-by: Viresh Kumar >> >> >> >> --- >> >> >> > >> >> >> > I am not sure what is this supposed doing - just listing basic t= hings >> >> >> > transport does or all things it can do? >> >> >> > >> >> >> > If the later, this ignores several things that transports can do= , >> >> >> > such as shared memory, data in notification, etc. >> >> >>=20 >> >> >> Maybe split this up? >> >> >>=20 >> >> >> A transport needs to implement the following: >> >> >> >> >> >>=20 >> >> >> A transport is encouraged to implement the following: >> >> >> >> >> > >> >> > Some things just depend on feature bits, and a transport >> >> > can make a feature bit mandatory if it wants to. >> >>=20 >> >> I wasn't thinking about mandatory for a device/driver, but mandatory = for >> >> a transport (e.g. stuff like per-queue reset which is not mandatory f= or >> >> a transport to implement.) >> > >> > Same thing really. >> > For example, queue reset is controlled by VIRTIO_F_RING_RESET >>=20 >> Well, it is -- but a transport can choose not to implement the feature >> bit. I guess what I'd like to do is to set expectations: every transport >> needs e.g. some way to do notifications, but it can skip some other >> things like "device discovery", for example. I think the appendix is >> intended as a reference for someone wanting to design a transport, and >> some kind of laundry list would help there. > > Yes. I am however a little worried that if we include optional features > we have just increased the cost of adding any new transport feature - > it now has to be added in this appendix, too. > > So maybe stick to just the basics? WDYT? I'd be happy with the basics only -- the features are documented anyway, and the important part is being able to figure out what is not optional.