On 06/27/2010 12:38 PM, Alexander Graf wrote:

Am 27.06.2010 um 10:16 schrieb Avi Kivity [off-list ref]:

quoted

On 06/26/2010 02:24 AM, Alexander Graf wrote:

quoted

One of the most obvious registers to share with the guest directly 
is the
MSR. The MSR contains the "interrupts enabled" flag which the guest 
has to
toggle in critical sections.

So in order to bring the overhead of interrupt en- and disabling 
down, let's
put msr into the shared page. Keep in mind that even though you can 
fully read
its contents, writing to it doesn't always update all state. There 
are a few
safe fields that don't require hypervisor interaction. See the guest
implementation that follows later for reference.

You mean, see the documentation for reference.

It should be possible to write the guest code looking only at the 
documentation.

*shrug* since we're writing open source I don't mind telling people to 
read code for a reference implemenration. 

It's impossible to infer from the source what's a guaranteed part of the 
interface and what is just an implementation artifact.  So people rely 
on implementation artifacts (or even bugs) and that reduces our ability 
to change things.

If well written, that's more comprehensible than documentation anyways 
:).

If the documentation is poorly written, yes.

-- 
error compiling committee.c: too many arguments to function