On Wed, Nov 29, 2017 at 02:33:59AM +0000, Gonglei (Arei) wrote: > > > -----Original Message----- > > From: Paolo Bonzini [mailto:pbonz...@redhat.com] > > Sent: Tuesday, November 28, 2017 7:20 PM > > To: Gonglei (Arei); qemu-devel@nongnu.org > > Cc: m...@redhat.com; Huangweidong (C); stefa...@redhat.com; Zhoujian > > (jay); pa...@linux.vnet.ibm.com; longpeng; xin.z...@intel.com; > > roy.fan.zh...@intel.com > > Subject: Re: [PATCH 3/4] cryptodev-vhost-user: add crypto session handler > > > > On 28/11/2017 12:06, Gonglei (Arei) wrote: > > >>> You mean we can share control virtqueue to DPDK as well? Like data > > queues? > > >> I don't know :) but why not? > > >> > > > Current there are two main reasons for this design: > > > > > > 1) we should use another cpu to polling the control virtqueue, which is > > expensive. > > > > IIRC DPDK also supports interrupt mode, doesn't it? Is it possible to > > do interrupt mode for some virtqueues and poll mode for others? > > > > The intel guy Tan (Ccing) said to me: > > " Interrupt mode for vhost-user is still not supported in current > implementation. But we are evaluating the necessity now.
That's more or less a spec violation. Guest must get interrupts if it does not disable them. And it must notify host if host does not disable notifications. > And yes, the mode (polling or interrupt) can be different for different > queues." > > > > 2) we should copy the logic of parsing control message to DPDK, which > > > break > > > current layered architecture . > > > > But isn't it already a layering violation that you're adding *some* > > control messages to the vhost-user protocol? I am not sure why only > > these two are necessary. > > > Sorry, but I don't think this is layering violation, just like > "vhost_net_set_mtu" > for vhost-net and "vhost_vsock_set_guest_cid_op" for vhost_vsock. They're all > device-specific messages. Aren't they? > > Thanks, > -Gonglei > > > Paolo > > > > > I'm not sure if there are any other hidden issues for future scalability, > > > such as > > > using Qemu to manage some control messages, avoiding D-Dos attack etc. > > > > > > Thanks, > > > -Gonglei >
