1 files changed, 17 insertions, 89 deletions

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index ecc5958e27fe..418014998f18 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -53,11 +53,6 @@ static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
 unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];
 DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
 
-/* The VMID used in the VTTBR */
-static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1);
-static u32 kvm_next_vmid;
-static DEFINE_SPINLOCK(kvm_vmid_lock);
-
 static bool vgic_present;
 
 static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);
@@ -422,6 +417,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 	kvm_timer_vcpu_put(vcpu);
 	kvm_vgic_put(vcpu);
 	kvm_vcpu_pmu_restore_host(vcpu);
+	kvm_arm_vmid_clear_active();
 
 	vcpu->cpu = -1;
 }
@@ -489,87 +485,6 @@ unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
 }
 #endif
 
-/* Just ensure a guest exit from a particular CPU */
-static void exit_vm_noop(void *info)
-{
-}
-
-void force_vm_exit(const cpumask_t *mask)
-{
-	preempt_disable();
-	smp_call_function_many(mask, exit_vm_noop, NULL, true);
-	preempt_enable();
-}
-
-/**
- * need_new_vmid_gen - check that the VMID is still valid
- * @vmid: The VMID to check
- *
- * return true if there is a new generation of VMIDs being used
- *
- * The hardware supports a limited set of values with the value zero reserved
- * for the host, so we check if an assigned value belongs to a previous
- * generation, which requires us to assign a new value. If we're the first to
- * use a VMID for the new generation, we must flush necessary caches and TLBs
- * on all CPUs.
- */
-static bool need_new_vmid_gen(struct kvm_vmid *vmid)
-{
-	u64 current_vmid_gen = atomic64_read(&kvm_vmid_gen);
-	smp_rmb(); /* Orders read of kvm_vmid_gen and kvm->arch.vmid */
-	return unlikely(READ_ONCE(vmid->vmid_gen) != current_vmid_gen);
-}
-
-/**
- * update_vmid - Update the vmid with a valid VMID for the current generation
- * @vmid: The stage-2 VMID information struct
- */
-static void update_vmid(struct kvm_vmid *vmid)
-{
-	if (!need_new_vmid_gen(vmid))
-		return;
-
-	spin_lock(&kvm_vmid_lock);
-
-	/*
-	 * We need to re-check the vmid_gen here to ensure that if another vcpu
-	 * already allocated a valid vmid for this vm, then this vcpu should
-	 * use the same vmid.
-	 */
-	if (!need_new_vmid_gen(vmid)) {
-		spin_unlock(&kvm_vmid_lock);
-		return;
-	}
-
-	/* First user of a new VMID generation? */
-	if (unlikely(kvm_next_vmid == 0)) {
-		atomic64_inc(&kvm_vmid_gen);
-		kvm_next_vmid = 1;
-
-		/*
-		 * On SMP we know no other CPUs can use this CPU's or each
-		 * other's VMID after force_vm_exit returns since the
-		 * kvm_vmid_lock blocks them from reentry to the guest.
-		 */
-		force_vm_exit(cpu_all_mask);
-		/*
-		 * Now broadcast TLB + ICACHE invalidation over the inner
-		 * shareable domain to make sure all data structures are
-		 * clean.
-		 */
-		kvm_call_hyp(__kvm_flush_vm_context);
-	}
-
-	WRITE_ONCE(vmid->vmid, kvm_next_vmid);
-	kvm_next_vmid++;
-	kvm_next_vmid &= (1 << kvm_get_vmid_bits()) - 1;
-
-	smp_wmb();
-	WRITE_ONCE(vmid->vmid_gen, atomic64_read(&kvm_vmid_gen));
-
-	spin_unlock(&kvm_vmid_lock);
-}
-
 static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
 {
 	return vcpu->arch.target >= 0;
@@ -793,7 +708,6 @@ static bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu, int *ret)
 	}
 
 	return kvm_request_pending(vcpu) ||
-			need_new_vmid_gen(&vcpu->arch.hw_mmu->vmid) ||
 			xfer_to_guest_mode_work_pending();
 }
 
@@ -855,8 +769,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		if (!ret)
 			ret = 1;
 
-		update_vmid(&vcpu->arch.hw_mmu->vmid);
-
 		check_vcpu_requests(vcpu);
 
 		/*
@@ -866,6 +778,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		 */
 		preempt_disable();
 
+		/*
+		 * The VMID allocator only tracks active VMIDs per
+		 * physical CPU, and therefore the VMID allocated may not be
+		 * preserved on VMID roll-over if the task was preempted,
+		 * making a thread's VMID inactive. So we need to call
+		 * kvm_arm_vmid_update() in non-premptible context.
+		 */
+		kvm_arm_vmid_update(&vcpu->arch.hw_mmu->vmid);
+
 		kvm_pmu_flush_hwstate(vcpu);
 
 		local_irq_disable();
@@ -2161,6 +2082,12 @@ int kvm_arch_init(void *opaque)
 	if (err)
 		return err;
 
+	err = kvm_arm_vmid_alloc_init();
+	if (err) {
+		kvm_err("Failed to initialize VMID allocator.\n");
+		return err;
+	}
+
 	if (!in_hyp_mode) {
 		err = init_hyp_mode();
 		if (err)
@@ -2200,6 +2127,7 @@ out_hyp:
 	if (!in_hyp_mode)
 		teardown_hyp_mode();
 out_err:
+	kvm_arm_vmid_alloc_free();
 	return err;
 }