Messages in this thread | | | Subject | Re: [PATCH] KVM: VMX: Enable Notify VM exit | From | Paolo Bonzini <> | Date | Mon, 2 Nov 2020 19:25:37 +0100 |
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On 02/11/20 19:01, Andy Lutomirski wrote: > What's the point? Surely the kernel should reliably mitigate the > flaw, and the kernel should decide how to do so.
There is some slowdown in trapping #DB and #AC unconditionally. Though for these two cases nobody should care so I agree with keeping the code simple and keeping the workaround.
Also, why would this trigger after more than a few hundred cycles, something like the length of the longest microcode loop? HZ*10 seems like a very generous estimate already.
Paolo
>>> I also think you should print a loud warning >> I'm not so sure on this one, e.g. userspace could just spin up a new instance >> if its malicious guest and spam the kernel log. > pr_warn_once()? If this triggers, it's a *bug*, right? Kernel or CPU. >
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