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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham 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 7337DC04AA7 for ; Mon, 13 May 2019 12:46:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D4DA208C2 for ; Mon, 13 May 2019 12:46:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729496AbfEMMq3 (ORCPT ); Mon, 13 May 2019 08:46:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41316 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728820AbfEMMq2 (ORCPT ); Mon, 13 May 2019 08:46:28 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 524E630832CC; Mon, 13 May 2019 12:46:28 +0000 (UTC) Received: from [10.72.12.49] (ovpn-12-49.pek2.redhat.com [10.72.12.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id 551F36A48A; Mon, 13 May 2019 12:46:21 +0000 (UTC) Subject: Re: [PATCH v2 8/8] vsock/virtio: make the RX buffer size tunable From: Jason Wang To: Stefano Garzarella , netdev@vger.kernel.org Cc: "David S. Miller" , "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Stefan Hajnoczi References: <20190510125843.95587-1-sgarzare@redhat.com> <20190510125843.95587-9-sgarzare@redhat.com> Message-ID: <8e72ef5e-cf6a-a635-3f76-bdeac95761b8@redhat.com> Date: Mon, 13 May 2019 20:46:19 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Mon, 13 May 2019 12:46:28 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/5/13 下午6:05, Jason Wang wrote: > > On 2019/5/10 下午8:58, Stefano Garzarella wrote: >> The RX buffer size determines the memory consumption of the >> vsock/virtio guest driver, so we make it tunable through >> a module parameter. >> >> The size allowed are between 4 KB and 64 KB in order to be >> compatible with old host drivers. >> >> Suggested-by: Stefan Hajnoczi >> Signed-off-by: Stefano Garzarella > > > I don't see much value of doing this through kernel command line. We > should deal with them automatically like what virtio-net did. Or even > a module parameter is better. > > Thanks Sorry, I misread the patch. But even module parameter is something not flexible enough. We should deal with them transparently. Thanks > > >> --- >>   include/linux/virtio_vsock.h     |  1 + >>   net/vmw_vsock/virtio_transport.c | 27 ++++++++++++++++++++++++++- >>   2 files changed, 27 insertions(+), 1 deletion(-) >> >> diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h >> index 5a9d25be72df..b9f8c3d91f80 100644 >> --- a/include/linux/virtio_vsock.h >> +++ b/include/linux/virtio_vsock.h >> @@ -13,6 +13,7 @@ >>   #define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE    (1024 * 64) >>   #define VIRTIO_VSOCK_MAX_BUF_SIZE        0xFFFFFFFFUL >>   #define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE        (1024 * 64) >> +#define VIRTIO_VSOCK_MIN_PKT_BUF_SIZE        (1024 * 4) >>     enum { >>       VSOCK_VQ_RX     = 0, /* for host to guest data */ >> diff --git a/net/vmw_vsock/virtio_transport.c >> b/net/vmw_vsock/virtio_transport.c >> index af1d2ce12f54..732398b4e28f 100644 >> --- a/net/vmw_vsock/virtio_transport.c >> +++ b/net/vmw_vsock/virtio_transport.c >> @@ -66,6 +66,31 @@ struct virtio_vsock { >>       u32 guest_cid; >>   }; >>   +static unsigned int rx_buf_size = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; >> + >> +static int param_set_rx_buf_size(const char *val, const struct >> kernel_param *kp) >> +{ >> +    unsigned int size; >> +    int ret; >> + >> +    ret = kstrtouint(val, 0, &size); >> +    if (ret) >> +        return ret; >> + >> +    if (size < VIRTIO_VSOCK_MIN_PKT_BUF_SIZE || >> +        size > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) >> +        return -EINVAL; >> + >> +    return param_set_uint(val, kp); >> +}; >> + >> +static const struct kernel_param_ops param_ops_rx_buf_size = { >> +    .set = param_set_rx_buf_size, >> +    .get = param_get_uint, >> +}; >> + >> +module_param_cb(rx_buf_size, ¶m_ops_rx_buf_size, &rx_buf_size, >> 0644); >> + >>   static struct virtio_vsock *virtio_vsock_get(void) >>   { >>       return the_virtio_vsock; >> @@ -261,7 +286,7 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk) >>     static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) >>   { >> -    int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; >> +    int buf_len = rx_buf_size; >>       struct virtio_vsock_pkt *pkt; >>       struct scatterlist hdr, buf, *sgs[2]; >>       struct virtqueue *vq;