diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6d9f763a7bb9d5db422ea5625b2c28420bd14f26..427d1daf06d06a028e80417ee8c78524cc927992 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -26,6 +26,7 @@
#include <linux/irqbypass.h>
#include <linux/hyperv.h>
#include <linux/kfifo.h>
+#include <linux/sched/vhost_task.h>
#include <asm/apic.h>
#include <asm/pvclock-abi.h>
@@ -1443,7 +1444,8 @@ struct kvm_arch {
bool sgx_provisioning_allowed;
struct kvm_x86_pmu_event_filter __rcu *pmu_event_filter;
- struct task_struct *nx_huge_page_recovery_thread;
+ struct vhost_task *nx_huge_page_recovery_thread;
+ u64 nx_huge_page_last;
#ifdef CONFIG_X86_64
/* The number of TDP MMU pages across all roots. */
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index f09f13c01c6bbd28fa37fdf50547abf4403658c9..b387d61af44f182731ab6239e64e4869bedbaaa4 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -29,6 +29,7 @@ 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 8e853a5fc867b742321a78076d5bd81764abbc55..3e353ed1f767361220c85888ba1dd00afbb30d30 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -7281,7 +7281,7 @@ 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);
}
@@ -7427,7 +7427,7 @@ 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);
}
@@ -7530,62 +7530,56 @@ 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
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 45be36e5285ffb5de3c161ff450275997aac7232..85fe9d0ebb9152c02d4e253326d04b694b4ab1c1 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2382,12 +2382,6 @@ static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
}
#endif /* CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE */
-typedef int (*kvm_vm_thread_fn_t)(struct kvm *kvm, uintptr_t data);
-
-int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
- uintptr_t data, const char *name,
- struct task_struct **thread_ptr);
-
#ifdef CONFIG_KVM_XFER_TO_GUEST_WORK
static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu)
{
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 6ca7a1045bbb75dfbd9195b348c3d03a83578a86..279e03029ce149b90745707ff3063aec50d41b4b 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -6561,106 +6561,3 @@ void kvm_exit(void)
kvm_irqfd_exit();
}
EXPORT_SYMBOL_GPL(kvm_exit);
-
-struct kvm_vm_worker_thread_context {
- struct kvm *kvm;
- struct task_struct *parent;
- struct completion init_done;
- kvm_vm_thread_fn_t thread_fn;
- uintptr_t data;
- int err;
-};
-
-static int kvm_vm_worker_thread(void *context)
-{
- /*
- * The init_context is allocated on the stack of the parent thread, so
- * we have to locally copy anything that is needed beyond initialization
- */
- struct kvm_vm_worker_thread_context *init_context = context;
- struct task_struct *parent;
- struct kvm *kvm = init_context->kvm;
- kvm_vm_thread_fn_t thread_fn = init_context->thread_fn;
- uintptr_t data = init_context->data;
- int err;
-
- err = kthread_park(current);
- /* kthread_park(current) is never supposed to return an error */
- WARN_ON(err != 0);
- if (err)
- goto init_complete;
-
- err = cgroup_attach_task_all(init_context->parent, current);
- if (err) {
- kvm_err("%s: cgroup_attach_task_all failed with err %d\n",
- __func__, err);
- goto init_complete;
- }
-
- set_user_nice(current, task_nice(init_context->parent));
-
-init_complete:
- init_context->err = err;
- complete(&init_context->init_done);
- init_context = NULL;
-
- if (err)
- goto out;
-
- /* Wait to be woken up by the spawner before proceeding. */
- kthread_parkme();
-
- if (!kthread_should_stop())
- err = thread_fn(kvm, data);
-
-out:
- /*
- * Move kthread back to its original cgroup to prevent it lingering in
- * the cgroup of the VM process, after the latter finishes its
- * execution.
- *
- * kthread_stop() waits on the 'exited' completion condition which is
- * set in exit_mm(), via mm_release(), in do_exit(). However, the
- * kthread is removed from the cgroup in the cgroup_exit() which is
- * called after the exit_mm(). This causes the kthread_stop() to return
- * before the kthread actually quits the cgroup.
- */
- rcu_read_lock();
- parent = rcu_dereference(current->real_parent);
- get_task_struct(parent);
- rcu_read_unlock();
- cgroup_attach_task_all(parent, current);
- put_task_struct(parent);
-
- return err;
-}
-
-int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
- uintptr_t data, const char *name,
- struct task_struct **thread_ptr)
-{
- struct kvm_vm_worker_thread_context init_context = {};
- struct task_struct *thread;
-
- *thread_ptr = NULL;
- init_context.kvm = kvm;
- init_context.parent = current;
- init_context.thread_fn = thread_fn;
- init_context.data = data;
- init_completion(&init_context.init_done);
-
- thread = kthread_run(kvm_vm_worker_thread, &init_context,
- "%s-%d", name, task_pid_nr(current));
- if (IS_ERR(thread))
- return PTR_ERR(thread);
-
- /* kthread_run is never supposed to return NULL */
- WARN_ON(thread == NULL);
-
- wait_for_completion(&init_context.init_done);
-
- if (!init_context.err)
- *thread_ptr = thread;
-
- return init_context.err;
-}