Re: [PATCH] virtio-balloon spec: provide a version of the "silentdeflate" feature that works

From: Paolo Bonzini
Date: Mon Sep 10 2012 - 01:51:42 EST

Il 10/09/2012 03:43, Rusty Russell ha scritto:
>> Now that vfio is upstream and work on qemu integration
>> is being worked on, we might finally see people using this bit
>> to allow memory overcommit with device assignment.
> That was left-field.... so you're saying some guest might pull a page
> from the balloon and DMA to it, and the vfio device needs to know in
> advance that it's going to do it?

Not the vfio device, but the page needs to be pinned with mlock so the
effect is the same.

> But what will we do if the guest doesn't ack the bit?

Just pin the whole memory.


> ie. I don't think it can really be optional.

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