3 files changed, 47 insertions, 5 deletions

diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index 43853ec6e160..8dc9e64346e6 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -1170,15 +1170,23 @@ enum emulation_result kvm_mips_emulate_CP0(union mips_instruction inst,
 							& KVM_ENTRYHI_ASID,
 						nasid);
 
+					/*
+					 * Regenerate/invalidate kernel MMU
+					 * context.
+					 * The user MMU context will be
+					 * regenerated lazily on re-entry to
+					 * guest user if the guest ASID actually
+					 * changes.
+					 */
 					preempt_disable();
-					/* Blow away the shadow host TLBs */
-					kvm_mips_flush_host_tlb(1);
 					cpu = smp_processor_id();
+					kvm_get_new_mmu_context(&vcpu->arch.guest_kernel_mm,
+								cpu, vcpu);
+					vcpu->arch.guest_kernel_asid[cpu] =
+						vcpu->arch.guest_kernel_mm.context.asid[cpu];
 					for_each_possible_cpu(i)
-						if (i != cpu) {
-							vcpu->arch.guest_user_asid[i] = 0;
+						if (i != cpu)
 							vcpu->arch.guest_kernel_asid[i] = 0;
-						}
 					preempt_enable();
 				}
 				kvm_write_c0_guest_entryhi(cop0,
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index a6ea084b4d9d..ad1b15ba5907 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -411,6 +411,31 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 	return -ENOIOCTLCMD;
 }
 
+/* Must be called with preemption disabled, just before entering guest */
+static void kvm_mips_check_asids(struct kvm_vcpu *vcpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	int cpu = smp_processor_id();
+	unsigned int gasid;
+
+	/*
+	 * Lazy host ASID regeneration for guest user mode.
+	 * If the guest ASID has changed since the last guest usermode
+	 * execution, regenerate the host ASID so as to invalidate stale TLB
+	 * entries.
+	 */
+	if (!KVM_GUEST_KERNEL_MODE(vcpu)) {
+		gasid = kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID;
+		if (gasid != vcpu->arch.last_user_gasid) {
+			kvm_get_new_mmu_context(&vcpu->arch.guest_user_mm, cpu,
+						vcpu);
+			vcpu->arch.guest_user_asid[cpu] =
+				vcpu->arch.guest_user_mm.context.asid[cpu];
+			vcpu->arch.last_user_gasid = gasid;
+		}
+	}
+}
+
 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
 	int r = 0;
@@ -438,6 +463,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	htw_stop();
 
 	trace_kvm_enter(vcpu);
+
+	kvm_mips_check_asids(vcpu);
+
 	r = vcpu->arch.vcpu_run(run, vcpu);
 	trace_kvm_out(vcpu);
 
@@ -1551,6 +1579,8 @@ skip_emul:
 	if (ret == RESUME_GUEST) {
 		trace_kvm_reenter(vcpu);
 
+		kvm_mips_check_asids(vcpu);
+
 		/*
 		 * If FPU / MSA are enabled (i.e. the guest's FPU / MSA context
 		 * is live), restore FCR31 / MSACSR.
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index c1f8758f5323..8e1f2bffcf0f 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -260,9 +260,13 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 
 	if ((vcpu->arch.guest_user_asid[cpu] ^ asid_cache(cpu)) &
 						asid_version_mask(cpu)) {
+		u32 gasid = kvm_read_c0_guest_entryhi(vcpu->arch.cop0) &
+				KVM_ENTRYHI_ASID;
+
 		kvm_get_new_mmu_context(&vcpu->arch.guest_user_mm, cpu, vcpu);
 		vcpu->arch.guest_user_asid[cpu] =
 		    vcpu->arch.guest_user_mm.context.asid[cpu];
+		vcpu->arch.last_user_gasid = gasid;
 		newasid++;
 
 		kvm_debug("[%d]: cpu_context: %#lx\n", cpu,