Re: [Qemu-devel] [RFC PATCH 0/3] Balloon inhibit enhancements

[Michael S. Tsirkin]

On Mon, Jul 30, 2018 at 08:39:39AM -0600, Alex Williamson wrote:
> This is more
> compatible with the IOMMU mappings,

Precisely. These are at page granularity.

> but I don't think it can be done
> atomically with respect to inflight DMA of a physical device where we
> cannot halt the device without interfering with its state.

Guests never add pages to the balloon if they are under DMA,
so that's fine - there's never an in-flight DMA, if
there is guest is buggy and it's ok to crash it.

-- 
MST