KVM: PPC: e500: Mark "struct page" pfn accessed before dropping mmu_lock

Mark pages accessed before dropping mmu_lock when faulting in guest memory
so that shadow_map() can convert to kvm_release_faultin_page() without
tripping its lockdep assertion on mmu_lock being held.  Marking pages
accessed outside of mmu_lock is ok (not great, but safe), but marking
pages _dirty_ outside of mmu_lock can make filesystems unhappy.

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: <20241010182427.1434605-54-seanjc@google.com>

diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 5c2adfd19e123018bb7b549a3b8e765330a72e8a..334dd96f8081470ed05858ee576ee90d4c78df99 100644 (file)
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -498,11 +498,9 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
        kvmppc_mmu_flush_icache(pfn);
 
 out:
-       spin_unlock(&kvm->mmu_lock);
-
        /* Drop refcount on page, so that mmu notifiers can clear it */
        kvm_release_pfn_clean(pfn);
-
+       spin_unlock(&kvm->mmu_lock);
        return ret;
 }