Off the top of my head: the VM executes either HLT or MWAIT, and those instructi... | Hacker News

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amluto on Oct 30, 2014 | parent | context | favorite | on: What Does an Idle CPU Do?

Off the top of my head: the VM executes either HLT or MWAIT, and those instructions are generally programmed to cause a VM exit, so the hypervisor can take action. The hypervisor will deschedule the VM and possibly go idle itself.

TBH, I have no idea how MONITOR works in a VM. It might be quite messy.

Edit: Here's a really nice explanation: http://www.contrib.andrew.cmu.edu/~somlo/OSXKVM/mwait.html

hderms on Oct 30, 2014 [–]

Does it reinitiate VM execution by waiting for the hypervisor to be scheduled again which schedules out to its constituent vms?

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