From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 4B3C4595A for ; Mon, 2 Mar 2015 09:58:03 +0100 (CET) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP; 02 Mar 2015 00:58:02 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,674,1418112000"; d="scan'208";a="673752284" Received: from shvmail01.sh.intel.com ([10.239.29.42]) by fmsmga001.fm.intel.com with ESMTP; 02 Mar 2015 00:58:01 -0800 Received: from shecgisg004.sh.intel.com (shecgisg004.sh.intel.com [10.239.29.89]) by shvmail01.sh.intel.com with ESMTP id t228vwsq027213; Mon, 2 Mar 2015 16:57:58 +0800 Received: from shecgisg004.sh.intel.com (localhost [127.0.0.1]) by shecgisg004.sh.intel.com (8.13.6/8.13.6/SuSE Linux 0.8) with ESMTP id t228vteB017528; Mon, 2 Mar 2015 16:57:57 +0800 Received: (from couyang@localhost) by shecgisg004.sh.intel.com (8.13.6/8.13.6/Submit) id t228vtpD017524; Mon, 2 Mar 2015 16:57:55 +0800 From: Ouyang Changchun To: dev@dpdk.org Date: Mon, 2 Mar 2015 16:57:54 +0800 Message-Id: <1425286674-17495-1-git-send-email-changchun.ouyang@intel.com> X-Mailer: git-send-email 1.7.12.2 Subject: [dpdk-dev] [PATCH] doc: Update doc for vhost sample X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Mar 2015 08:58:03 -0000 Add some contents for vhost sample. Signed-off-by: Changchun Ouyang --- doc/guides/sample_app_ug/vhost.rst | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/doc/guides/sample_app_ug/vhost.rst b/doc/guides/sample_app_ug/vhost.rst index fa53db6..756838c 100644 --- a/doc/guides/sample_app_ug/vhost.rst +++ b/doc/guides/sample_app_ug/vhost.rst @@ -654,6 +654,35 @@ The number of free hugepages can be checked as follows: The command above indicates how many hugepages are free to support QEMU's allocation request. +**Can user space VHOST work properly with the guest with 2M sized hug pages?** + +Yes, it can. The guest may have 2M or 1G sized huge pages file, the user space VHOST can work properly in both cases. + +**Can user space VHOST work with QEMU without '-mem-prealloc' option?** +The current implementation work properly only when the guest memory is pre-allocated, so you are required to use the +correct QEMU version(e.g. 1.6) which supports '-mem-prealloc'; And the option '-mem-prealloc' is required to be specified +explicitly in QEMU command line. + +**Can user space VHOST work with QEMU version without shared memory mapping?** +No, it can't, shared memory mapping is mandatory for user space VHOST to work properly with guest as user space VHOST +need access the shared memory from guest to receive and transmit packets. You are required to make sure the QEMU version +support shared memory mapping. + +**When using libvirt "virsh create" the qemu-wrap.py spawns a new process to run "qemu-kvm". This impacts the behavior +of the "virsh destroy" which kills the process running "qemu-wrap.py" without actually destroying the VM (leaves the +"qemu-kvm" process running).** +This patch can fix this issue: http://dpdk.org/ml/archives/dev/2014-June/003607.html + +**On Ubuntu environment, QEMU fail to start a new guest normally with user space VHOST due to hug pages can't be +allocated for the new guest.** +The solution for this issue could be adding "-boot c" into QEMU command line to make sure the huge pages are allocated +properly and then the guest startup normally. You may use "cat /proc/meminfo" to check if there is any change in value +of HugePages_Total and HugePages_Free after the guest startup. + +**Why I get this logging message: "eventfd_link: module verification failed: signature and/or required key missing - tainting kernel"?** +You can ignore the above logging message. The message occurs due to the new module eventfd_link is not a standard +module of Linux, but it is necessary for user space VHOST current implementation(CUSE-based) to communicate with guest. + Running DPDK in the Virtual Machine ----------------------------------- -- 1.8.4.2