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Peter Anvin" , David Woodhouse , Shuah Khan , kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Mon, Jan 15, 2024, Paul Durrant wrote: > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 7e7fd25b09b3..f3bb9e0a81fe 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -1399,6 +1399,17 @@ int kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, unsigned long len); > */ > void kvm_gpc_deactivate(struct gfn_to_pfn_cache *gpc); > > +/** > + * kvm_gpc_mark_dirty - mark a cached page as dirty. > + * > + * @gpc: struct gfn_to_pfn_cache object. > + */ > +static inline void kvm_gpc_mark_dirty(struct gfn_to_pfn_cache *gpc) > +{ > + lockdep_assert_held(&gpc->lock); > + mark_page_dirty_in_slot(gpc->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT); Can you opportunistically have this pre-check gpc->memslot? __kvm_gpc_refresh() should nullify gpc->memslot when using an hva. That way, you don't need to explicitly check for the "invalid gfn" case here (or you could, but WARN_ON_ONCE() if the memslot is non-NULL and the gfn is invalid?).