KVM: Make kvm_follow_pfn.refcounted_page a required field

Now that the legacy gfn_to_pfn() APIs are gone, and all callers of
hva_to_pfn() pass in a refcounted_page pointer, make it a required field
to ensure all future usage in KVM plays nice.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241010182427.1434605-82-seanjc@google.com>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b2c8d429442d3ec7f4c5197aba7935bfe79cc94b..a483da96f4be3300d1c0eb0e2323f5af04a38447 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2834,8 +2834,7 @@ static kvm_pfn_t kvm_resolve_pfn(struct kvm_follow_pfn *kfp, struct page *page,
                pfn = page_to_pfn(page);
        }
 
-       if (kfp->refcounted_page)
-               *kfp->refcounted_page = page;
+       *kfp->refcounted_page = page;
 
        return pfn;
 }
@@ -2986,6 +2985,9 @@ kvm_pfn_t hva_to_pfn(struct kvm_follow_pfn *kfp)
 
        might_sleep();
 
+       if (WARN_ON_ONCE(!kfp->refcounted_page))
+               return KVM_PFN_ERR_FAULT;
+
        if (hva_to_pfn_fast(kfp, &pfn))
                return pfn;