3 files changed, 66 insertions, 5 deletions

diff --git a/arch/powerpc/include/asm/kvm_44x.h b/arch/powerpc/include/asm/kvm_44x.h
index e770ea2bbb1..f49031b632c 100644
--- a/arch/powerpc/include/asm/kvm_44x.h
+++ b/arch/powerpc/include/asm/kvm_44x.h
@@ -42,6 +42,10 @@ struct kvmppc_vcpu_44x {
         /* References to guest pages in the hardware TLB. */
         struct kvmppc_44x_shadow_ref shadow_refs[PPC44x_TLB_SIZE];
 
+        /* State of the shadow TLB at guest context switch time. */
+        struct kvmppc_44x_tlbe shadow_tlb[PPC44x_TLB_SIZE];
+        u8 shadow_tlb_mod[PPC44x_TLB_SIZE];
+
         struct kvm_vcpu vcpu;
 };
 
@@ -51,5 +55,7 @@ static inline struct kvmppc_vcpu_44x *to_44x(struct kvm_vcpu *vcpu)
 }
 
 void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 new_pid);
+void kvmppc_44x_tlb_put(struct kvm_vcpu *vcpu);
+void kvmppc_44x_tlb_load(struct kvm_vcpu *vcpu);
 
 #endif /* __ASM_44X_H__ */
diff --git a/arch/powerpc/kvm/44x.c b/arch/powerpc/kvm/44x.c
index 05d72fc8b47..a66bec57265 100644
--- a/arch/powerpc/kvm/44x.c
+++ b/arch/powerpc/kvm/44x.c
@@ -96,15 +96,12 @@ void kvmppc_core_load_guest_debugstate(struct kvm_vcpu *vcpu)
 
 void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
+        kvmppc_44x_tlb_load(vcpu);
 }
 
 void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
 {
-        /* XXX Since every guest uses TS=1 TID=0/1 mappings, we can't leave any TLB
-         * entries around when we're descheduled, so we must completely flush the
-         * TLB of all guest mappings. On the other hand, if there is only one
-         * guest, this flush is completely unnecessary. */
-        _tlbia();
+        kvmppc_44x_tlb_put(vcpu);
 }
 
 int kvmppc_core_check_processor_compat(void)
diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c
index 2981ebea3d1..ff16d0e3843 100644
--- a/arch/powerpc/kvm/44x_tlb.c
+++ b/arch/powerpc/kvm/44x_tlb.c
@@ -73,6 +73,25 @@ static inline void kvmppc_44x_tlbie(unsigned int index)
         );
 }
 
+static inline void kvmppc_44x_tlbre(unsigned int index,
+                                    struct kvmppc_44x_tlbe *tlbe)
+{
+        asm volatile(
+                "tlbre %[word0], %[index], 0\n"
+                "mfspr %[tid], %[sprn_mmucr]\n"
+                "andi. %[tid], %[tid], 0xff\n"
+                "tlbre %[word1], %[index], 1\n"
+                "tlbre %[word2], %[index], 2\n"
+                : [word0] "=r"(tlbe->word0),
+                  [word1] "=r"(tlbe->word1),
+                  [word2] "=r"(tlbe->word2),
+                  [tid]   "=r"(tlbe->tid)
+                : [index] "r"(index),
+                  [sprn_mmucr] "i"(SPRN_MMUCR)
+                : "cc"
+        );
+}
+
 static inline void kvmppc_44x_tlbwe(unsigned int index,
                                     struct kvmppc_44x_tlbe *stlbe)
 {
@@ -116,6 +135,44 @@ static u32 kvmppc_44x_tlb_shadow_attrib(u32 attrib, int usermode)
         return attrib;
 }
 
+/* Load shadow TLB back into hardware. */
+void kvmppc_44x_tlb_load(struct kvm_vcpu *vcpu)
+{
+        struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+        int i;
+
+        for (i = 0; i <= tlb_44x_hwater; i++) {
+                struct kvmppc_44x_tlbe *stlbe = &vcpu_44x->shadow_tlb[i];
+
+                if (get_tlb_v(stlbe) && get_tlb_ts(stlbe))
+                        kvmppc_44x_tlbwe(i, stlbe);
+        }
+}
+
+static void kvmppc_44x_tlbe_set_modified(struct kvmppc_vcpu_44x *vcpu_44x,
+                                         unsigned int i)
+{
+        vcpu_44x->shadow_tlb_mod[i] = 1;
+}
+
+/* Save hardware TLB to the vcpu, and invalidate all guest mappings. */
+void kvmppc_44x_tlb_put(struct kvm_vcpu *vcpu)
+{
+        struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+        int i;
+
+        for (i = 0; i <= tlb_44x_hwater; i++) {
+                struct kvmppc_44x_tlbe *stlbe = &vcpu_44x->shadow_tlb[i];
+
+                if (vcpu_44x->shadow_tlb_mod[i])
+                        kvmppc_44x_tlbre(i, stlbe);
+
+                if (get_tlb_v(stlbe) && get_tlb_ts(stlbe))
+                        kvmppc_44x_tlbie(i);
+        }
+}
+
+
 /* Search the guest TLB for a matching entry. */
 int kvmppc_44x_tlb_index(struct kvm_vcpu *vcpu, gva_t eaddr, unsigned int pid,
                          unsigned int as)
@@ -283,6 +340,7 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 gvaddr, gpa_t gpaddr, u64 asid,
         ref->tid = stlbe.tid;
 
         /* Insert shadow mapping into hardware TLB. */
+        kvmppc_44x_tlbe_set_modified(vcpu_44x, victim);
         kvmppc_44x_tlbwe(victim, &stlbe);
         KVMTRACE_5D(STLB_WRITE, vcpu, victim, stlbe.tid, stlbe.word0, stlbe.word1,
                     stlbe.word2, handler);