3 files changed, 20 insertions, 22 deletions

diff --git a/arch/powerpc/include/asm/kvm_44x.h b/arch/powerpc/include/asm/kvm_44x.h
index dece0935071..72e593914ad 100644
--- a/arch/powerpc/include/asm/kvm_44x.h
+++ b/arch/powerpc/include/asm/kvm_44x.h
@@ -44,4 +44,6 @@ static inline struct kvmppc_vcpu_44x *to_44x(struct kvm_vcpu *vcpu)
         return container_of(vcpu, struct kvmppc_vcpu_44x, vcpu);
 }
 
+void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 new_pid);
+
 #endif /* __ASM_44X_H__ */
diff --git a/arch/powerpc/kvm/44x_emulate.c b/arch/powerpc/kvm/44x_emulate.c
index 9bc50cebf9e..9ef79c78ede 100644
--- a/arch/powerpc/kvm/44x_emulate.c
+++ b/arch/powerpc/kvm/44x_emulate.c
@@ -21,6 +21,7 @@
 #include <asm/dcr.h>
 #include <asm/dcr-regs.h>
 #include <asm/disassemble.h>
+#include <asm/kvm_44x.h>
 
 #include "booke.h"
 #include "44x_tlb.h"
@@ -38,14 +39,6 @@
 #define XOP_ICCCI   966
 #define XOP_TLBWE   978
 
-static inline void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 new_pid)
-{
-        if (vcpu->arch.pid != new_pid) {
-                vcpu->arch.pid = new_pid;
-                vcpu->arch.swap_pid = 1;
-        }
-}
-
 static void kvmppc_emul_rfi(struct kvm_vcpu *vcpu)
 {
         vcpu->arch.pc = vcpu->arch.srr0;
diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c
index 6fadbd69602..ee2461860bc 100644
--- a/arch/powerpc/kvm/44x_tlb.c
+++ b/arch/powerpc/kvm/44x_tlb.c
@@ -268,31 +268,34 @@ static void kvmppc_mmu_invalidate(struct kvm_vcpu *vcpu, gva_t eaddr,
         }
 }
 
-/* Invalidate all mappings on the privilege switch after PID has been changed.
- * The guest always runs with PID=1, so we must clear the entire TLB when
- * switching address spaces. */
 void kvmppc_mmu_priv_switch(struct kvm_vcpu *vcpu, int usermode)
 {
+        vcpu->arch.shadow_pid = !usermode;
+}
+
+void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 new_pid)
+{
         struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
         int i;
 
-        if (vcpu->arch.swap_pid) {
-                /* XXX Replace loop with fancy data structures. */
-                for (i = 0; i <= tlb_44x_hwater; i++) {
-                        struct kvmppc_44x_tlbe *stlbe = &vcpu_44x->shadow_tlb[i];
+        if (unlikely(vcpu->arch.pid == new_pid))
+                return;
+
+        vcpu->arch.pid = new_pid;
+
+        /* Guest userspace runs with TID=0 mappings and PID=0, to make sure it
+         * can't access guest kernel mappings (TID=1). When we switch to a new
+         * guest PID, which will also use host PID=0, we must discard the old guest
+         * userspace mappings. */
+        for (i = 0; i < ARRAY_SIZE(vcpu_44x->shadow_tlb); i++) {
+                struct kvmppc_44x_tlbe *stlbe = &vcpu_44x->shadow_tlb[i];
 
-                        /* Future optimization: clear only userspace mappings. */
+                if (get_tlb_tid(stlbe) == 0) {
                         kvmppc_44x_shadow_release(vcpu, i);
                         stlbe->word0 = 0;
                         kvmppc_tlbe_set_modified(vcpu, i);
-                        KVMTRACE_5D(STLB_INVAL, vcpu, i,
-                                    stlbe->tid, stlbe->word0, stlbe->word1,
-                                    stlbe->word2, handler);
                 }
-                vcpu->arch.swap_pid = 0;
         }
-
-        vcpu->arch.shadow_pid = !usermode;
 }
 
 static int tlbe_is_host_safe(const struct kvm_vcpu *vcpu,