From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Tetsuya.Mukawa" Subject: Re: [RFC] lib/librte_vhost: qemu vhost-user support into DPDK vhost library Date: Wed, 27 Aug 2014 14:58:28 +0900 Message-ID: <53FD7384.3050209@igel.co.jp> References: <53FD60FD.5090903@igel.co.jp> <53FD6C4E.5040907@igel.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Katsuya MATSUBARA , "nakajima.yoshihiro-Zyj7fXuS5i5L9jVzuh4AOg@public.gmane.org" , Hitoshi Masutani To: "Ouyang, Changchun" , "dev-VfR2kkLFssw@public.gmane.org" Return-path: In-Reply-To: <53FD6C4E.5040907-AlSX/UN32fvPDbFq/vQRIQ@public.gmane.org> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" (2014/08/27 14:27), Tetsuya.Mukawa wrote: > Hi Changchun, > > (2014/08/27 14:01), Ouyang, Changchun wrote: >> Agree with you, the performance should be same as the data path (RX/TX) is not affected, >> The difference between implementation only exists in the virtio device creation and destroy stage. > Yes, I agree. Also There may be the difference, if a virtio-net driver > on a guest isn't poll mode like a virtio-net device driver in the > kernel. In the case, existing vhost implementation uses the eventfd > kernel module, and vhost-user implementation uses eventfd to kick the > driver. So I guess there will be the difference. > > Anyway, about device creation and destruction, the difference will come > from transmission speed between unix domain socket and CUSE. I am not > sure which is faster. Thank for pointing out my misleading expression. Correct: transmission latency Incorrect: transmission speed Tetsuya, > > Thanks, > Tetsuya > > >> Regards, >> Changchun >> >>> -----Original Message----- >>> From: Tetsuya.Mukawa [mailto:mukawa-AlSX/UN32fvPDbFq/vQRIQ@public.gmane.org] >>> Sent: Wednesday, August 27, 2014 12:39 PM >>> To: Ouyang, Changchun; dev-VfR2kkLFssw@public.gmane.org >>> Cc: Xie, Huawei; Katsuya MATSUBARA; nakajima.yoshihiro-Zyj7fXuS5i5L9jVzuh4AOg@public.gmane.org; >>> Hitoshi Masutani >>> Subject: Re: [dpdk-dev] [RFC] lib/librte_vhost: qemu vhost-user support into >>> DPDK vhost library >>> >>> >>> (2014/08/27 9:43), Ouyang, Changchun wrote: >>>> Do we have performance comparison between both implementation? >>> Hi Changchun, >>> >>> If DPDK applications are running on both guest and host side, the >>> performance should be almost same, because while transmitting data virt >>> queues are accessed by virtio-net PMD and libvhost. In libvhost, the existing >>> vhost implementation and a vhost-user implementation will shares or uses >>> same code to access virt queues. So I guess the performance will be almost >>> same. >>> >>> Thanks, >>> Tetsuya >>> >>> >>>> Thanks >>>> Changchun >>>> >>>> >>>> -----Original Message----- >>>> From: dev [mailto:dev-bounces-VfR2kkLFssw@public.gmane.org] On Behalf Of Xie, Huawei >>>> Sent: Tuesday, August 26, 2014 7:06 PM >>>> To: dev-VfR2kkLFssw@public.gmane.org >>>> Subject: Re: [dpdk-dev] [RFC] lib/librte_vhost: qemu vhost-user >>>> support into DPDK vhost library >>>> >>>> Hi all: >>>> We are implementing qemu official vhost-user interface into DPDK vhost >>> library, so there would be two coexisting implementations for user space >>> vhost backend. >>>> Pro and cons in my mind: >>>> Existing solution: >>>> Pros: works with qemu version before 2.1; Cons: depends on eventfd >>> proxy kernel module and extra maintenance effort Qemu vhost-user: >>>> Pros: qemu official us-vhost interface; Cons: only available after >>> qemu 2.1 >>>> BR. >>>> huawei