lkml.org 
[lkml]   [2007]   [Jul]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [kvm-devel] [RFC 0/8]KVM: swap out guest pages
From
Date
On Mon, 2007-07-23 at 13:27 +0300, Avi Kivity wrote:
> Having an address_space (like your patch does) is remarkably simple, and
> requires few hooks from the current vm. However using existing vmas
> mapped by the user has many advantages:
>
> - compatible with s390 requirements
> - allows the user to use hugetlbfs pages, which have a performance
> advantage using ept/npt (but which are unswappable)
> - allows the user to map a file (which can be regarded as way to specify
> the swap device)
> - better ingration with the rest of the vm

You don't need to expose the vmas. You just have userspace point out
the start+len of each region of memory it wants the guest to be able to
access, and the address it wants it to appear in the guest.

This is a slight superset of what lguest does in two ways:

1) my guest address == user address, but I'm looking at adding an offset
so I don't have to link the launcher binary specially.
2) I have only one contiguous region of guest-physical memory, since I
can place device memory immediately above "normal" mem.

But the result is pretty sweet, and doesn't require any new symbols to
be exported.

Cheers,
Rusty.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-07-24 01:13    [W:1.473 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site