On Tue, Dec 06, 2016 at 02:30:24PM +0800, Lan Tianyu wrote: [...]
> >> 2. How to restore GPA->HPA mapping when IOVA is disabled by guest. > >> When guest enables IOVA for device, vIOMMU will invalidate all previous > >> GPA->HPA mapping and update IOVA->HPA mapping to pIOMMU via iommu > >> notifier. But if IOVA is disabled, I think we should restore GPA->HPA > >> mapping for the device otherwise the device won't work again in the VM. > > > > If we can have a workable replay mechanism, this problem will be > > solved IMHO. > > Basic idea is to replay related memory regions to restore GPA->HPA > mapping when guest disables IOVA. Btw, could you help elaborate in what case we will trigger such a condition? Or, can we dynamically enable/disable an IOMMU? Thanks, -- peterx
