Re: A proposal - binary

Bill Rugolsky Jr.
2006-08-04T21:40:49Z

On Fri, Aug 04, 2006 at 02:26:20PM -0700, Jeremy Fitzhardinge wrote:
> >I also am missing something here. how can a system be compiled to do
> >several different things for the same privilaged opcode (including
> >running that opcode) without turning that area of code into a
> >performance pig as it checks for each possible hypervisor being present?
>
> Conceptually, the paravirtops structure is a structure of pointers to
> functions which get filled in at runtime to support whatever hypervisor
> we're running over. But it also has the means to patch inline versions
> of the appropriate code sequences for performance-critical operations.

Perhaps Ulrich and Jakub should join this discussion, as the whole
thing sounds like a rehash of the userland ld.so + glibc versioned ABI.
glibc has weathered 64-bit LFS changes to open(), SYSENTER, and vdso.

Isn't this discussion entirely analogous (except for the patching of
performance critical sections, perhaps) to taking a binary compiled
against glibc-2.0 back on Linux-2.2 and running it on glibc-2.4 + 2.6.17?
Or OpenSolaris, for that matter?

Bill Rugolsky