Re: [PATCH 02/26] KVM: PPC: Convert MSR to shared page

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

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

But either way, you can take a look at both - documentation and code,  
yes.

What I really meant here is that the list of registers we patch should  
be taken from the patch code. I didn't want to write out all of them  
in the description.


Alex