2 files changed, 32 insertions, 37 deletions

diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 1ed1e4f5d51c..d93af5390341 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -30,6 +30,7 @@ config KVM_X86
 	select HAVE_KVM_IRQ_BYPASS
 	select HAVE_KVM_IRQ_ROUTING
 	select HAVE_KVM_READONLY_MEM
+	select VHOST_TASK
 	select KVM_ASYNC_PF
 	select USER_RETURN_NOTIFIER
 	select KVM_MMIO
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index d7b391fe2c23..22e7ad235123 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -7162,7 +7162,7 @@ static int set_nx_huge_pages(const char *val, const struct kernel_param *kp)
 			kvm_mmu_zap_all_fast(kvm);
 			mutex_unlock(&kvm->slots_lock);
 
-			wake_up_process(kvm->arch.nx_huge_page_recovery_thread);
+			vhost_task_wake(kvm->arch.nx_huge_page_recovery_thread);
 		}
 		mutex_unlock(&kvm_lock);
 	}
@@ -7291,7 +7291,7 @@ static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel
 		mutex_lock(&kvm_lock);
 
 		list_for_each_entry(kvm, &vm_list, vm_list)
-			wake_up_process(kvm->arch.nx_huge_page_recovery_thread);
+			vhost_task_wake(kvm->arch.nx_huge_page_recovery_thread);
 
 		mutex_unlock(&kvm_lock);
 	}
@@ -7394,62 +7394,56 @@ static void kvm_recover_nx_huge_pages(struct kvm *kvm)
 	srcu_read_unlock(&kvm->srcu, rcu_idx);
 }
 
-static long get_nx_huge_page_recovery_timeout(u64 start_time)
+static void kvm_nx_huge_page_recovery_worker_kill(void *data)
 {
-	bool enabled;
-	uint period;
-
-	enabled = calc_nx_huge_pages_recovery_period(&period);
-
-	return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64()
-		       : MAX_SCHEDULE_TIMEOUT;
 }
 
-static int kvm_nx_huge_page_recovery_worker(struct kvm *kvm, uintptr_t data)
+static bool kvm_nx_huge_page_recovery_worker(void *data)
 {
-	u64 start_time;
+	struct kvm *kvm = data;
+	bool enabled;
+	uint period;
 	long remaining_time;
 
-	while (true) {
-		start_time = get_jiffies_64();
-		remaining_time = get_nx_huge_page_recovery_timeout(start_time);
-
-		set_current_state(TASK_INTERRUPTIBLE);
-		while (!kthread_should_stop() && remaining_time > 0) {
-			schedule_timeout(remaining_time);
-			remaining_time = get_nx_huge_page_recovery_timeout(start_time);
-			set_current_state(TASK_INTERRUPTIBLE);
-		}
-
-		set_current_state(TASK_RUNNING);
-
-		if (kthread_should_stop())
-			return 0;
+	enabled = calc_nx_huge_pages_recovery_period(&period);
+	if (!enabled)
+		return false;
 
-		kvm_recover_nx_huge_pages(kvm);
+	remaining_time = kvm->arch.nx_huge_page_last + msecs_to_jiffies(period)
+		- get_jiffies_64();
+	if (remaining_time > 0) {
+		schedule_timeout(remaining_time);
+		/* check for signals and come back */
+		return true;
 	}
+
+	__set_current_state(TASK_RUNNING);
+	kvm_recover_nx_huge_pages(kvm);
+	kvm->arch.nx_huge_page_last = get_jiffies_64();
+	return true;
 }
 
 int kvm_mmu_post_init_vm(struct kvm *kvm)
 {
-	int err;
-
 	if (nx_hugepage_mitigation_hard_disabled)
 		return 0;
 
-	err = kvm_vm_create_worker_thread(kvm, kvm_nx_huge_page_recovery_worker, 0,
-					  "kvm-nx-lpage-recovery",
-					  &kvm->arch.nx_huge_page_recovery_thread);
-	if (!err)
-		kthread_unpark(kvm->arch.nx_huge_page_recovery_thread);
+	kvm->arch.nx_huge_page_last = get_jiffies_64();
+	kvm->arch.nx_huge_page_recovery_thread = vhost_task_create(
+		kvm_nx_huge_page_recovery_worker, kvm_nx_huge_page_recovery_worker_kill,
+		kvm, "kvm-nx-lpage-recovery");
 
-	return err;
+	if (!kvm->arch.nx_huge_page_recovery_thread)
+		return -ENOMEM;
+
+	vhost_task_start(kvm->arch.nx_huge_page_recovery_thread);
+	return 0;
 }
 
 void kvm_mmu_pre_destroy_vm(struct kvm *kvm)
 {
 	if (kvm->arch.nx_huge_page_recovery_thread)
-		kthread_stop(kvm->arch.nx_huge_page_recovery_thread);
+		vhost_task_stop(kvm->arch.nx_huge_page_recovery_thread);
 }
 
 #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES