Re: [PATCH v2 11/13] kvm/dirty_ring: Add arch-generic interface for hw-accelerated dirty-ring cleaning

[Leonardo Bras <leo.bras@arm.com>]

On Mon, Jun 29, 2026 at 11:49:03AM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] Hardware-accelerated dirty ring reset completely bypasses the reset tracepoint.
> --
> 
> commit 8d48fca1a0a1a0e2a8d66dd93d79ffc96e524e83
> Author: Leonardo Bras <leo.bras@arm.com>
> 
> kvm/dirty_ring: Add arch-generic interface for hw-accelerated dirty-ring cleaning
> 
> This commit introduces kvm_arch_dirty_ring_clear() to allow architectures
> to implement hardware-accelerated dirty-ring routines. It adds a call to
> this new function in kvm_dirty_ring_reset(), which will fall back to the
> software version if the hardware version is not implemented or fails.
> 
> [ ... ]
> 
> > diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c
> > index 42de1a511037a..fe4e7da6cc4a6 100644
> > --- a/virt/kvm/dirty_ring.c
> > +++ b/virt/kvm/dirty_ring.c
> > @@ -133,6 +134,9 @@ int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring,
> >  	 */
> >  	lockdep_assert_held(&kvm->slots_lock);
> >  
> > +	if (kvm_arch_dirty_ring_clear(kvm, ring, nr_entries_reset) >= 0)
> > +		return 0;
> 
> [Severity: Medium]
> Does this early return bypass the trace_kvm_dirty_ring_reset() tracepoint
> at the bottom of the function?
> 
> When hardware-accelerated dirty ring cleaning succeeds, returning early here
> skips the tracepoint entirely. This could break observability tools and
> scripts that rely on this tracepoint to monitor KVM dirty ring resets.

Ok, sure, I can goto-out to before the tracing, then.

> 
> -- 
> Sashiko AI review · https://sashiko.dev/#/patchset/20260629111820.1873540-1-leo.bras@arm.com?part=11