Re: [PATCH 08/17] vmx: nest: L1 <-> L2 context switch

[Qing He <qing.he@intel.com>]

On Thu, 2010-05-20 at 19:11 +0800, Tim Deegan wrote:
> At 10:41 +0100 on 22 Apr (1271932880), Qing He wrote:
> > This patch adds mode switch between L1 and L2, many controls
> > and states handling may need additioinal scrutiny.
> 
> Yep - this clearly needs some more work.  I'm going to wait for a later
> version that's got the additional scrutiny. :)

Hmm, I'll scrutinize it, but meanwhile, can you share some of
your thoughts?

I mean, the code doesn't seem to organize well, partly because there
are many different states to cover, and some tricks are used to
work with the current code, vmx_set_host_env would be a good example
of such kind of tricks. Do you have any suggestions on a better code
orgnization?

Another issue is that 64 shadow on 64 shadow is the only case that
doesn't work, I'm curious about it, I had some initial investigation
but didn't come with something, do you have some ideas?

Thanks,
Qing
> 
> Cheers,
> 
> Tim.
> 
> > Roughly, at virtual VMEntry time, sVMCS is loaded, L2 control
> > is combined from controls of L0 and vVMCS, L2 state from vVMCS
> > guest state.
> > when virtual VMExit, host VMCS is loaded, L1 control is from L0,
> > L1 state from vVMCS host state.
> > 
> > Signed-off-by: Qing He <qing.he@intel.com>
> 
> -- 
> Tim Deegan <Tim.Deegan@citrix.com>
> Principal Software Engineer, XenServer Engineering
> Citrix Systems UK Ltd.  (Company #02937203, SL9 0BG)