Re: [Qemu-devel] Re: [PATCH 2 of 5] add can_dma/post_dma for direct IO

Ian Jackson
2008-12-22T16:44:36Z

Avi Kivity writes ("[Qemu-devel] Re: [PATCH 2 of 5] add can_dma/post_dma for direct IO"):
> Newer Xen shouldn't have this problem though; it runs qemu in kernel
> mode in a dedicated 64-bit domain.

This is not yet the default configuration and there are still various
reasons why you might not want to use it. I expect we'll retain the
dom0 user process option for a while yet.

I think there is continued value in being able to emulate a guest
whose physical address space exceeds the virtual address space in the
host. The whole assumption that all guest accessible RAM is mapped at
once, contiguously, is I think wrong.

Ian.