KVM: e500: use shadow TLB entry as witness for writability

kvmppc_e500_ref_setup is returning whether the guest TLB entry is writable,
which is than passed to kvm_release_faultin_page.  This makes little sense
for two reasons: first, because the function sets up the private data for
the page and the return value feels like it has been bolted on the side;
second, because what really matters is whether the _shadow_ TLB entry is
writable.  If it is not writable, the page can be released as non-dirty.
Shift from using tlbe_is_writable(gtlbe) to doing the same check on
the shadow TLB entry.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 6824e8139801c2089ebe32d9964cfe378d9a5da6..c266c02f120f867f211b8088e8e217ff4c64c502 100644 (file)
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -242,7 +242,7 @@ static inline int tlbe_is_writable(struct kvm_book3e_206_tlb_entry *tlbe)
        return tlbe->mas7_3 & (MAS3_SW|MAS3_UW);
 }
 
-static inline bool kvmppc_e500_ref_setup(struct tlbe_ref *ref,
+static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref,
                                         struct kvm_book3e_206_tlb_entry *gtlbe,
                                         kvm_pfn_t pfn, unsigned int wimg)
 {
@@ -251,8 +251,6 @@ static inline bool kvmppc_e500_ref_setup(struct tlbe_ref *ref,
 
        /* Use guest supplied MAS2_G and MAS2_E */
        ref->flags |= (gtlbe->mas2 & MAS2_ATTRIB_MASK) | wimg;
-
-       return tlbe_is_writable(gtlbe);
 }
 
 static inline void kvmppc_e500_ref_release(struct tlbe_ref *ref)
@@ -489,9 +487,10 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
        }
        local_irq_restore(flags);
 
-       writable = kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg);
+       kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg);
        kvmppc_e500_setup_stlbe(&vcpu_e500->vcpu, gtlbe, tsize,
                                ref, gvaddr, stlbe);
+       writable = tlbe_is_writable(stlbe);
 
        /* Clear i-cache for new pages */
        kvmppc_mmu_flush_icache(pfn);