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. Thanks, Tetsuya > > Regards, > Changchun > >> -----Original Message----- >> From: Tetsuya.Mukawa [mailto:mukawa at igel.co.jp] >> Sent: Wednesday, August 27, 2014 12:39 PM >> To: Ouyang, Changchun; dev at dpdk.org >> Cc: Xie, Huawei; Katsuya MATSUBARA; nakajima.yoshihiro at lab.ntt.co.jp; >> 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 at dpdk.org] On Behalf Of Xie, Huawei >>> Sent: Tuesday, August 26, 2014 7:06 PM >>> To: dev at dpdk.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
