KVM: MIPS: Invalidate TLB by regenerating ASIDs

[cascardo/linux.git] / arch / mips / kvm / mips.c

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index a6ea084..ad1b15b 100644 (file)
--- 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.