Darrell Ball <[email protected]> writes: > On 6/4/17, 9:15 AM, "Aaron Conole" <[email protected]> wrote: > > Darrell Ball <[email protected]> writes: > > > On 5/26/17, 7:12 AM, "[email protected] on behalf of > Stephen Finucane" <[email protected] on behalf of > [email protected]> wrote: > > > > Apparently dpdkvhostuser interfaces are inferior to > dpdkvhostuserclient. > > Explain why. > > > > Signed-off-by: Stephen Finucane <[email protected]> > > Cc: Ciara Loftus <[email protected]> > > Cc: Kevin Traynor <[email protected]> > > --- > > I'd like to note what happens to traffic when OVS or a VM is > restarted > > for both port types. If someone knows the answer to this, please > feel > > free to take ownership of that patch/ask me for a v2. > > --- > > Documentation/topics/dpdk/vhost-user.rst | 8 ++++++-- > > 1 file changed, 6 insertions(+), 2 deletions(-) > > > > diff --git a/Documentation/topics/dpdk/vhost-user.rst > b/Documentation/topics/dpdk/vhost-user.rst > > index ba22684..2e2396b 100644 > > --- a/Documentation/topics/dpdk/vhost-user.rst > > +++ b/Documentation/topics/dpdk/vhost-user.rst > > @@ -54,8 +54,12 @@ vHost User sockets, and the client connects to > the server. Depending on which > > port type you use, ``dpdkvhostuser`` or ``dpdkvhostuserclient``, a > different > > configuration of the client-server model is used. > > > > -For vhost-user ports, Open vSwitch acts as the server and QEMU the > client. For > > -vhost-user-client ports, Open vSwitch acts as the client and QEMU > the server. > > +For vhost-user ports, Open vSwitch acts as the server and QEMU the > client. This > > +means if OVS dies, all VMs **must** be restarted. On the other > hand, for > > +vhost-user-client ports, OVS acts as the client and QEMU the > server. This means > > +OVS can die and be restarted without issue, > > > > > > “ and it is also possible to restart > > +an instance itself.” > > > > Restart a VM instance ?; if so, it seems already implied. > > Or OVS instance ? > > > > For this reason, vhost-user-client ports are the preferred > > +type for most use cases. > > > > At one point, because I am helping to support OVS-DPDK, I had both > > vhostuser and vhostuserclient ports configured on our performance > servers, > > because I thought I should have both, so I could support both. Then, I > realized I > > just did not want to use vhostuser ports, due to the > permissions/security > > issues, noticed on OVS restart. > > > > So, what are the use cases (besides self-flagellation) for using > vhostuser ports in lieu of > > vhostuserclient ports ? > > At the time they were introduced, deployed versions of qemu couldn't > support the vhostuserclient mode. I'm less sure what the state of that > world looks like today. I know that RHEL 7.3 doesn't ship a QEMU that > supports client-mode ports. > > I understand about the qemu version requirements; I really wanted to make sure > that there were no specific use cases for server mode, per this patch text. > > Do you know if there are any issues with RHEL 7.3 supporting QEMU 2.7 ?
The current RHEV qemu version is 2.6, so it will have problems. By the time 7.4 releases the RHEV qemu will at least be 2.9, so it's probably okay. > > If the answer is none, can we deprecate them in OVS 2.8 (update NEWS > etc) and > > remove them in OVS 2.9 ? > > I'm all for deprecating them as long as the major vendors (RH, Debian, > SUSE) support the newer QEMU. 2.9 may be too aggressive for removal - > perhaps the release after? Just to be sure there is a path to migration > for existing users. > > Agreed; ideally, qemu should be upgradable to 2.7 on recent versions of > common/important distros such RHEL/centos, SLES and debian. Yep. > Many people have a national holiday today, so let us see when they get back. > > If we can deprecate, then: For these two: > 1) We might deprecate now and say in an upcoming release, vhostuserserver > port code > will be removed. > 2) We can add a log warning to that effect on configuration. Good idea. I just submitted a patch to do this: https://mail.openvswitch.org/pipermail/ovs-dev/2017-June/333609.html > 3) We can add text here to suggest upgrading to qemu 2.7 if at all possible > and using client mode. qemu 2.9 is out, upgrade to 2.7 should be > possible in many (most ?) cases, for those > serious about using ovs-dpdk with VM connectivity. I'm not sure how the upgrade utility would work, since the location of the vhostuser socket is important part of this. > Maybe I'm off my rocker, though. > > > .. _dpdk-vhost-user: > > > > -- > > 2.9.4 > > > > _______________________________________________ > > dev mailing list > > [email protected] > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__mail.openvswitch.org_mailman_listinfo_ovs-2Ddev&d=DwICAg&c=uilaK90D4TOVoH58JNXRgQ&r=BVhFA09CGX7JQ5Ih-uZnsw&m=hjj87k1Hqw8FflJQ7cRgAFD8O4-t89ARPxN1qb1XrZs&s=LCybNvXe55JKD-bmxLDouYfRUdKhk7qHQFv2Wsk7UsA&e= > > > > > > > _______________________________________________ > > dev mailing list > > [email protected] > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__mail.openvswitch.org_mailman_listinfo_ovs-2Ddev&d=DwIFaQ&c=uilaK90D4TOVoH58JNXRgQ&r=BVhFA09CGX7JQ5Ih-uZnsw&m=McRcrdQlkt_TY30rKe-4vvoXejvWEZkHpXG9whN4bt8&s=_9m8xG0PLIC2m9gKAjZ2FJKtW7XIRDhVqQmqOtPUgo0&e= > > > > > > _______________________________________________ > dev mailing list > [email protected] > https://mail.openvswitch.org/mailman/listinfo/ovs-dev _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
