From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Coquelin Subject: Re: [04/12] vhost: introduce postcopy's advise message Date: Fri, 28 Sep 2018 15:49:14 +0200 Message-ID: References: <20180926072705.22641-1-maxime.coquelin@redhat.com> <20180926072705.22641-5-maxime.coquelin@redhat.com> <20180927082608eucas1p17cd1d99e54134fb2a6de3151e52048f3~YNErH8Swu2138421384eucas1p1G@eucas1p1.samsung.com> <20180928103815eucas1p1ddb4141bea8b9ef965073a4706ccdaea~YihUJIT9-2460124601eucas1p1Z@eucas1p1.samsung.com> <20180928121334.GA6880@bricha3-MOBL.ger.corp.intel.com> <20180928131524eucas1p174f4057454f99c035b2025c4a7c7dec1~YkqhekGjc3150031500eucas1p1X@eucas1p1.samsung.com> <20180928132426.GA20200@bricha3-MOBL.ger.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: dev@dpdk.org, tiwei.bie@intel.com, zhihong.wang@intel.com, jfreimann@redhat.com, dgilbert@redhat.com, Thomas Monjalon To: Bruce Richardson , Ilya Maximets Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 8E3511B4CF for ; Fri, 28 Sep 2018 15:49:22 +0200 (CEST) In-Reply-To: <20180928132426.GA20200@bricha3-MOBL.ger.corp.intel.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 09/28/2018 03:24 PM, Bruce Richardson wrote: > On Fri, Sep 28, 2018 at 04:17:34PM +0300, Ilya Maximets wrote: >> On 28.09.2018 15:13, Bruce Richardson wrote: >>> On Fri, Sep 28, 2018 at 01:40:25PM +0300, Ilya Maximets wrote: >>>> On 27.09.2018 11:28, Ilya Maximets wrote: >>>>> On 26.09.2018 10:26, Maxime Coquelin wrote: >>>>>> This patch opens a userfaultfd and sends it back to Qemu's >>>>>> VHOST_USER_POSTCOPY_ADVISE request. >>>>>> >>>>>> Signed-off-by: Dr. David Alan Gilbert >>>>>> Signed-off-by: Maxime Coquelin >>>>>> --- >>>>>> lib/librte_vhost/vhost.h | 2 ++ >>>>>> lib/librte_vhost/vhost_user.c | 37 +++++++++++++++++++++++++++++++++++ >>>>>> lib/librte_vhost/vhost_user.h | 3 ++- >>>>>> 3 files changed, 41 insertions(+), 1 deletion(-) >>>>>> >>>>>> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h >>>>>> index 25ffd7614..21722d8a8 100644 >>>>>> --- a/lib/librte_vhost/vhost.h >>>>>> +++ b/lib/librte_vhost/vhost.h >>>>>> @@ -363,6 +363,8 @@ struct virtio_net { >>>>>> int slave_req_fd; >>>>>> rte_spinlock_t slave_req_lock; >>>>>> >>>>>> + int postcopy_ufd; >>>>>> + >>>>>> /* >>>>>> * Device id to identify a specific backend device. >>>>>> * It's set to -1 for the default software implementation. >>>>>> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c >>>>>> index a9b429598..bdfe2cac0 100644 >>>>>> --- a/lib/librte_vhost/vhost_user.c >>>>>> +++ b/lib/librte_vhost/vhost_user.c >>>>>> @@ -24,9 +24,13 @@ >>>>>> #include >>>>>> #include >>>>>> #include >>>>>> +#include >>>>>> +#include >>>>> >>>>> Maybe we need compile time check for this header existence? >>>>> Otherwise, this will bump minimal kernel version for default linux build >>>>> to something like 4.3. >>>> >>>> We'll need a config option here (disabled by default) and guard all >>>> the postcopy related code. >>>> Meson build will be able to detect the header file and enable >>>> the config if possible. Like this: >>>> >>>> lib/librte_vhost/meson.build: >>>> if cc.has_header('linux/userfaultfd.h') >>>> dpdk_conf.set10('RTE_LIBRTE_VHOST_POSTCOPY', true) >>> >>> Are you sure you want 'set10' rather than 'set'. Set is probably easier >>> because it ensures no define on false, while set10 has a define of 0. This >>> has caught me out before. >>> >>> FYI, you can also avoid the if by putting the condition into the define: >>> >>> dpdk_conf.set('RTE_LIBRTE_VHOST_POSTCOPY', cc.has_header('...')) >> >> Sure, this variant looks better. Thanks for suggestions. >> I just copied my version from the similar code for 'RTE_HAS_LIBNUMA'. >> Thanks Ilya & Bruce for the hint! I'll do this in next version. > Yes, looking at that code, it could do with a clean-up to shorten it too. > [It's true that nothing embarasses a programmer more than their own code 6 > months layer :-)] :) Maxime > /Bruce >