Messages in this thread | | | From | Dexuan Cui <> | Subject | RE: [PATCH 6/7] Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation | Date | Wed, 31 Jul 2019 00:16:17 +0000 |
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> From: Michael Kelley <mikelley@microsoft.com> > Sent: Tuesday, July 30, 2019 4:26 PM > From: Dexuan Cui <decui@microsoft.com> Sent: Monday, July 8, 2019 10:30 > PM > > > > This is needed when we resume the old kernel from the "current" kernel. > > Perhaps a bit more descriptive commit message could be supplied?
I'll use this as the new changelog:
Before Linux enters hibernation, it sends the CHANNELMSG_UNLOAD message to the host so all the offers are gone. After hibernation, Linux needs to re-negotiate with the host using the same vmbus protocol version (which was in use before hibernation), and ask the host to re-offer the vmbus devices.
> > + > > + ret = vmbus_negotiate_version(msginfo, vmbus_proto_version); > > I think this code answers my earlier question: Upon resume, we negotiate > the same > VMbus protocol version we had at time of hibernation, even if running on a > newer > version of Hyper-V that might support newer protocol versions. Hence the > offer > messages should not have any previously reserved fields now being used. A > comment to this effect would be useful.
Ok, let me add a comment before the line.
I'll post a v2 of the patchset, including the "[PATCH 4/7]", which needs a small change.
Thanks, -- Dexuan
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