Messages in this thread | | | Date | Wed, 7 Oct 2009 10:40:47 +0530 | From | Amit Shah <> | Subject | Re: [Alacrityvm-devel] [PATCH v2 2/4] KVM: introduce "xinterface" API for external interaction with guests |
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On (Tue) Oct 06 2009 [11:18:59], Ira W. Snyder wrote: > > The limitation I have is that memory made available from the host system > (PCI card) as PCI BAR1 must not be migrated around in memory. I can only > change the address decoding to hit a specific physical address. AFAIK, > this means it cannot be userspace memory (since the underlying physical > page could change, or it could be in swap), and must be allocated with > something like __get_free_pages() or dma_alloc_coherent().
If the dma area is just one page in size, that page can be pinned by the host (via a hypercall by the guest). If it's more, there is a reserve-ram patch by Andrea. That'll reserve some RAM area for the guest that's 1-1 mapped in the host address space. There was a patch posted on the list sometime back.
Amit
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