From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DCE64C4360F for ; Fri, 5 Apr 2019 08:24:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADDF6217D7 for ; Fri, 5 Apr 2019 08:24:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="D+wqOj5H" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730236AbfDEIYv (ORCPT ); Fri, 5 Apr 2019 04:24:51 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:35683 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725955AbfDEIYv (ORCPT ); Fri, 5 Apr 2019 04:24:51 -0400 Received: by mail-wr1-f67.google.com with SMTP id w1so6933801wrp.2; Fri, 05 Apr 2019 01:24:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=vcAGVwffkChWM3GNFoyXAhcxCqnVacQuIbvdyotZLKw=; b=D+wqOj5H9LMk8ePCJOpYioa0Rw7DTfNr134f0UMxZiN6itl3HfgnDONtTWOEVPFEDe jjyehrvnr2abkKv6oB5lIplC8M81SQYjpOkJEcssFESGL14zFnS+2o3Y/XRi0MavlBen lJY6/frQncqiu14cZ/AlB2xECf96arwccJGT/PQej7P5QoZzICWpkXOrgHTmIdXFRc1l HWy6gcPMXfb6hulFuPwN8pwcXqquH71Fxso/mDNwGfEtsWv+Q7jcJ2EnGq60j2cPDucP AJgoTU2EJDXZmOJ8lI0bKg5/3RForJDH7uylOTm2VnErGt4h+dQ6I8la8zQRyR2q/UlK GMRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=vcAGVwffkChWM3GNFoyXAhcxCqnVacQuIbvdyotZLKw=; b=ICgGecQt1AahT/CSw/mK8N9mshCscziNxd49oBp7B/c2a82As7WrN9szdHjfRp3kI5 shfd4Vb3Kzs80wV8YqVC+A8Q1lQ+RKyCcvu1RoBbtnKVEVYbTGsSBdx/z405bmDQN7sM 6CdJR0TBp4DaqG4AbxAIHpKGf3SfyG7t+KEsVNUvEDI9ORY6xBeHFMWUYEWB2ofEOQvM LdJf/ROUbk1svYEgeFA+DZ7V95H0jVSNpS0G3bj1vN7qpCQnNddJCmy0iY7V7wZV3taZ qk/x1kDXCykqWoRFoAat/Of2c4cE46jXEkYZlsqP47M1cl+1haadOe+RG8jCaRZERbre s7Ag== X-Gm-Message-State: APjAAAXYZKyKmG5hlXxariJ8TxIsCiO1ro8zbzXm4Qe1GJLkZOM8i6r8 tzxUEq6PBAbDPfTA6XatEWQ= X-Google-Smtp-Source: APXvYqzttcSB9L8/xHbgT9hliJXljIF7JaZ8SPAcN/UvUB9ScDaXc7l+aMjrsrFfsk/udvI4sja8cg== X-Received: by 2002:a5d:4683:: with SMTP id u3mr7535881wrq.200.1554452689218; Fri, 05 Apr 2019 01:24:49 -0700 (PDT) Received: from localhost ([51.15.41.238]) by smtp.gmail.com with ESMTPSA id w14sm15943843wrr.16.2019.04.05.01.24.48 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 05 Apr 2019 01:24:48 -0700 (PDT) Date: Fri, 5 Apr 2019 09:24:47 +0100 From: Stefan Hajnoczi To: Stefano Garzarella Cc: netdev@vger.kernel.org, Jason Wang , "Michael S. Tsirkin" , Stefan Hajnoczi , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, "David S. Miller" Subject: Re: [PATCH RFC 3/4] vsock/virtio: change the maximum packet size allowed Message-ID: <20190405082447.GD25152@stefanha-x1.localdomain> References: <20190404105838.101559-1-sgarzare@redhat.com> <20190404105838.101559-4-sgarzare@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="yudcn1FV7Hsu/q59" Content-Disposition: inline In-Reply-To: <20190404105838.101559-4-sgarzare@redhat.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --yudcn1FV7Hsu/q59 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Apr 04, 2019 at 12:58:37PM +0200, Stefano Garzarella wrote: > Since now we are able to split packets, we can avoid limiting > their sizes to VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE. > Instead, we can use VIRTIO_VSOCK_MAX_PKT_BUF_SIZE as the max > packet size. >=20 > Signed-off-by: Stefano Garzarella > --- > net/vmw_vsock/virtio_transport_common.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) >=20 > diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virt= io_transport_common.c > index f32301d823f5..822e5d07a4ec 100644 > --- a/net/vmw_vsock/virtio_transport_common.c > +++ b/net/vmw_vsock/virtio_transport_common.c > @@ -167,8 +167,8 @@ static int virtio_transport_send_pkt_info(struct vsoc= k_sock *vsk, > vvs =3D vsk->trans; > =20 > /* we can send less than pkt_len bytes */ > - if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE) > - pkt_len =3D VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; > + if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) > + pkt_len =3D VIRTIO_VSOCK_MAX_PKT_BUF_SIZE; The next line limits pkt_len based on available credits: /* virtio_transport_get_credit might return less than pkt_len credit */ pkt_len =3D virtio_transport_get_credit(vvs, pkt_len); I think drivers/vhost/vsock.c:vhost_transport_do_send_pkt() now works correctly even with pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE. The other ->send_pkt() callback is net/vmw_vsock/virtio_transport.c:virtio_transport_send_pkt_work() and it can already send any size packet. Do you remember why VIRTIO_VSOCK_MAX_PKT_BUF_SIZE still needs to be the limit? I'm wondering if we can get rid of it now and just limit packets to the available credits. Stefan --yudcn1FV7Hsu/q59 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJcpxDPAAoJEJykq7OBq3PIkwEIAKUcFcpFXgBx1Gbs5mSd4ypd Yi7a6mc4wSbq/FLNhVo0xVjJA+7hSNxiUvsqbwr1ajpudAHbMoV9LEuVZqtRLBmM pj9GmjHssqWgFr83oW1zlti/BNcArOoYl0csKoqfWXMA8sBb4o0ENdjlXwPvy+rm aQE78BhRi0vHSpFlOs+Zc/KHaaeQuH0fufyjLSi4vFhWnOC4jpoXuPhCT2NAVCJA MEdGNJZ2ZxtPBD8cUJH/ZTziNOArXsnOc6a9YIW72JnUOywqokVvgvsBtimaKN95 lbBsBCmPxd0rY4n3OTAssfnHbUVVNwYaVoysD39pWBwwd1ZL0J3kqpP2zPh/O7g= =xs/A -----END PGP SIGNATURE----- --yudcn1FV7Hsu/q59--