From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755901AbbGFTsW (ORCPT ); Mon, 6 Jul 2015 15:48:22 -0400 Received: from p3plsmtps2ded02.prod.phx3.secureserver.net ([208.109.80.59]:41701 "EHLO p3plsmtps2ded02.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755856AbbGFTsR (ORCPT ); Mon, 6 Jul 2015 15:48:17 -0400 x-originating-ip: 72.167.245.219 From: Haiyang Zhang To: davem@davemloft.net, netdev@vger.kernel.org Cc: haiyangz@microsoft.com, kys@microsoft.com, olaf@aepfle.de, jasowang@redhat.com, linux-kernel@vger.kernel.org, driverdev-devel@linuxdriverproject.org Subject: [PATCH net-next,v2] hv_netvsc: Add support to set MTU reservation from guest side Date: Mon, 6 Jul 2015 14:11:37 -0700 Message-Id: <1436217097-31102-1-git-send-email-haiyangz@microsoft.com> X-Mailer: git-send-email 1.7.4.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When packet encapsulation is in use, the MTU needs to be reduced for headroom reservation. The existing code takes the updated MTU value only from the host side. But vSwitch extensions, such as Open vSwitch, require the flexibility to change the MTU to different values from within a guest during the lifecycle of a vNIC, when the encapsulation protocol is changed. The patch supports this kind of MTU changes. Signed-off-by: Haiyang Zhang Reviewed-by: K. Y. Srinivasan --- drivers/net/hyperv/hyperv_net.h | 1 + drivers/net/hyperv/netvsc_drv.c | 3 +-- drivers/net/hyperv/rndis_filter.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h index dd45440..26cd14c 100644 --- a/drivers/net/hyperv/hyperv_net.h +++ b/drivers/net/hyperv/hyperv_net.h @@ -589,6 +589,7 @@ struct nvsp_message { #define NETVSC_MTU 65536 +#define NETVSC_MTU_MIN 68 #define NETVSC_RECEIVE_BUFFER_SIZE (1024*1024*16) /* 16MB */ #define NETVSC_RECEIVE_BUFFER_SIZE_LEGACY (1024*1024*15) /* 15MB */ diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 358475e..b855ba9 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -743,8 +743,7 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu) if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2) limit = NETVSC_MTU - ETH_HLEN; - /* Hyper-V hosts don't support MTU < ETH_DATA_LEN (1500) */ - if (mtu < ETH_DATA_LEN || mtu > limit) + if (mtu < NETVSC_MTU_MIN || mtu > limit) return -EINVAL; nvdev->start_remove = true; diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c index 006c1b8..172824e 100644 --- a/drivers/net/hyperv/rndis_filter.c +++ b/drivers/net/hyperv/rndis_filter.c @@ -1053,7 +1053,7 @@ int rndis_filter_device_add(struct hv_device *dev, ret = rndis_filter_query_device(rndis_device, RNDIS_OID_GEN_MAXIMUM_FRAME_SIZE, &mtu, &size); - if (ret == 0 && size == sizeof(u32)) + if (ret == 0 && size == sizeof(u32) && mtu < net_device->ndev->mtu) net_device->ndev->mtu = mtu; /* Get the mac address */ -- 1.7.4.1