KVM: PPC: e500: Add shadow PID support

Dynamically assign host PIDs to guest PIDs, splitting each guest PID into
multiple host (shadow) PIDs based on kernel/user and MSR[IS/DS].  Use
both PID0 and PID1 so that the shadow PIDs for the right mode can be
selected, that correspond both to guest TID = zero and guest TID = guest
PID.

This allows us to significantly reduce the frequency of needing to
invalidate the entire TLB.  When the guest mode or PID changes, we just
update the host PID0/PID1.  And since the allocation of shadow PIDs is
global, multiple guests can share the TLB without conflict.

Note that KVM does not yet support the guest setting PID1 or PID2 to
a value other than zero.  This will need to be fixed for nested KVM
to work.  Until then, we enforce the requirement for guest PID1/PID2
to stay zero by failing the emulation if the guest tries to set them
to something else.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 7 insertions, 4 deletions

diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 4538956daecf..9f2e4a5e1c4d 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -113,15 +113,18 @@ static void kvmppc_vcpu_sync_spe(struct kvm_vcpu *vcpu)
 }
 #endif
 
-/* Helper function for "full" MSR writes. No need to call this if only EE is
- * changing. */
+/*
+ * Helper function for "full" MSR writes.  No need to call this if only
+ * EE/CE/ME/DE/RI are changing.
+ */
 void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr)
 {
-	if ((new_msr & MSR_PR) != (vcpu->arch.shared->msr & MSR_PR))
-		kvmppc_mmu_priv_switch(vcpu, new_msr & MSR_PR);
+	u32 old_msr = vcpu->arch.shared->msr;
 
 	vcpu->arch.shared->msr = new_msr;
 
+	kvmppc_mmu_msr_notify(vcpu, old_msr);
+
 	if (vcpu->arch.shared->msr & MSR_WE) {
 		kvm_vcpu_block(vcpu);
 		kvmppc_set_exit_type(vcpu, EMULATED_MTMSRWE_EXITS);