Re: [PATCH v2 00/13] perf: KVM: Fix, optimize, and clean up callbacks

[Marc Zyngier <maz@xxxxxxxxxx>]

On Mon, 20 Sep 2021 13:05:25 +0100,
Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
> 
> On 17/09/21 09:28, Peter Zijlstra wrote:
> >> In theory, I like the idea of burying intel_pt inside x86 (and even in
> >> Intel+VMX code for the most part), but the actual implementation is a
> >> bit gross.  Because of the whole "KVM can be a module" thing,
> > 
> > ARGH!! we should really fix that. I've heard other archs have made much
> > better choices here.
> 
> I think that's only ARM, and even then it is only because of
> limitations of the hardware which mostly apply only if VHE is not in
> use.
> 
> If anything, it's ARM that should support module build in VHE mode
> (Linux would still need to know whether it will be running at EL1 or
> EL2, but KVM's functionality is as self-contained as on x86 in the VHE
> case).

I don't see this happening anytime soon. At least not before we
declare the arm64 single kernel image policy to be obsolete.

        M.

-- 
Without deviation from the norm, progress is not possible.