The Microsoft ADV180002, talk about the speculative execution side-channel vulnerabilities.
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV180002
There are 3 vulnerabilities:
CVE-2017-5753 - Bounds check bypass
CVE-2017-5715 - Branch target injection
CVE-2017-5754 - Rogue data cache load
If you update for your Microsoft OS, and your Antivirus, you only are protected for
CVE-2017-5753 - Bounds check bypass
CVE-2017-5754 - Rogue data cache load
You really need your firmware update to be protected for
CVE-2017-5715 - Branch target injection
Having say that, for Win 2016 Hyper V host there is a way to mitigate this vulnerability CVE-2017-5715 - Branch target injection, until your OEM release firmware.
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/CVE-2017-5715-and-hyper-v-hosts
Just to clarify, with this vulnerability a VM van read data from another VM, or even the host. You can imagine how bad that can be, specially with companies that host VM from other companies.
Now, what this doc recommends to do is to assign CPU to VM, isolating data.
Be VERY careful!. Test before you go to production servers.
For our company, after several talks, we decided to wait for the firmware.
So, its up to you if you want to give it a go.
Happy Patching!