2 files changed, 131 insertions, 75 deletions

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 2ca4535..73358d2 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -90,7 +90,7 @@ irqfd_shutdown(struct work_struct *work)
 	 * We know no new events will be scheduled at this point, so block
 	 * until all previously outstanding events have completed
 	 */
-	flush_work(&irqfd->inject);
+	flush_work_sync(&irqfd->inject);
 
 	/*
 	 * It is now safe to release the object's resources
@@ -313,8 +313,9 @@ kvm_irqfd_deassign(struct kvm *kvm, int fd, int gsi)
 		if (irqfd->eventfd == eventfd && irqfd->gsi == gsi) {
 			/*
 			 * This rcu_assign_pointer is needed for when
-			 * another thread calls kvm_irqfd_update before
-			 * we flush workqueue below.
+			 * another thread calls kvm_irq_routing_update before
+			 * we flush workqueue below (we synchronize with
+			 * kvm_irq_routing_update using irqfds.lock).
 			 * It is paired with synchronize_rcu done by caller
 			 * of that function.
 			 */
@@ -577,7 +578,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 
 	mutex_lock(&kvm->slots_lock);
 
-	/* Verify that there isnt a match already */
+	/* Verify that there isn't a match already */
 	if (ioeventfd_check_collision(kvm, p)) {
 		ret = -EEXIST;
 		goto unlock_fail;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f29abeb..6330653 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -30,7 +30,7 @@
 #include <linux/debugfs.h>
 #include <linux/highmem.h>
 #include <linux/file.h>
-#include <linux/sysdev.h>
+#include <linux/syscore_ops.h>
 #include <linux/cpu.h>
 #include <linux/sched.h>
 #include <linux/cpumask.h>
@@ -52,7 +52,6 @@
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
-#include <asm-generic/bitops/le.h>
 
 #include "coalesced_mmio.h"
 #include "async_pf.h"
@@ -69,7 +68,7 @@ MODULE_LICENSE("GPL");
  * 		kvm->lock --> kvm->slots_lock --> kvm->irq_lock
  */
 
-DEFINE_SPINLOCK(kvm_lock);
+DEFINE_RAW_SPINLOCK(kvm_lock);
 LIST_HEAD(vm_list);
 
 static cpumask_var_t cpus_hardware_enabled;
@@ -137,6 +136,14 @@ void vcpu_load(struct kvm_vcpu *vcpu)
 	int cpu;
 
 	mutex_lock(&vcpu->mutex);
+	if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) {
+		/* The thread running this VCPU changed. */
+		struct pid *oldpid = vcpu->pid;
+		struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
+		rcu_assign_pointer(vcpu->pid, newpid);
+		synchronize_rcu();
+		put_pid(oldpid);
+	}
 	cpu = get_cpu();
 	preempt_notifier_register(&vcpu->preempt_notifier);
 	kvm_arch_vcpu_load(vcpu, cpu);
@@ -165,13 +172,16 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
 
 	zalloc_cpumask_var(&cpus, GFP_ATOMIC);
 
-	raw_spin_lock(&kvm->requests_lock);
-	me = smp_processor_id();
+	me = get_cpu();
 	kvm_for_each_vcpu(i, vcpu, kvm) {
-		if (kvm_make_check_request(req, vcpu))
-			continue;
+		kvm_make_request(req, vcpu);
 		cpu = vcpu->cpu;
-		if (cpus != NULL && cpu != -1 && cpu != me)
+
+		/* Set ->requests bit before we read ->mode */
+		smp_mb();
+
+		if (cpus != NULL && cpu != -1 && cpu != me &&
+		      kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE)
 			cpumask_set_cpu(cpu, cpus);
 	}
 	if (unlikely(cpus == NULL))
@@ -180,7 +190,7 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
 		smp_call_function_many(cpus, ack_flush, NULL, 1);
 	else
 		called = false;
-	raw_spin_unlock(&kvm->requests_lock);
+	put_cpu();
 	free_cpumask_var(cpus);
 	return called;
 }
@@ -209,6 +219,7 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 	vcpu->cpu = -1;
 	vcpu->kvm = kvm;
 	vcpu->vcpu_id = id;
+	vcpu->pid = NULL;
 	init_waitqueue_head(&vcpu->wq);
 	kvm_async_pf_vcpu_init(vcpu);
 
@@ -233,6 +244,7 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_init);
 
 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
 {
+	put_pid(vcpu->pid);
 	kvm_arch_vcpu_uninit(vcpu);
 	free_page((unsigned long)vcpu->run);
 }
@@ -463,15 +475,14 @@ static struct kvm *kvm_create_vm(void)
 	kvm->mm = current->mm;
 	atomic_inc(&kvm->mm->mm_count);
 	spin_lock_init(&kvm->mmu_lock);
-	raw_spin_lock_init(&kvm->requests_lock);
 	kvm_eventfd_init(kvm);
 	mutex_init(&kvm->lock);
 	mutex_init(&kvm->irq_lock);
 	mutex_init(&kvm->slots_lock);
 	atomic_set(&kvm->users_count, 1);
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 	list_add(&kvm->vm_list, &vm_list);
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 
 	return kvm;
 
@@ -544,9 +555,9 @@ static void kvm_destroy_vm(struct kvm *kvm)
 	struct mm_struct *mm = kvm->mm;
 
 	kvm_arch_sync_events(kvm);
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 	list_del(&kvm->vm_list);
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 	kvm_free_irq_routing(kvm);
 	for (i = 0; i < KVM_NR_BUSES; i++)
 		kvm_io_bus_destroy(kvm->buses[i]);
@@ -588,6 +599,7 @@ static int kvm_vm_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+#ifndef CONFIG_S390
 /*
  * Allocation size is twice as large as the actual dirty bitmap size.
  * This makes it possible to do double buffering: see x86's
@@ -608,6 +620,7 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
 	memslot->dirty_bitmap_head = memslot->dirty_bitmap;
 	return 0;
 }
+#endif /* !CONFIG_S390 */
 
 /*
  * Allocate some memory and give it an address in the guest physical address
@@ -621,7 +634,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
 			    struct kvm_userspace_memory_region *mem,
 			    int user_alloc)
 {
-	int r, flush_shadow = 0;
+	int r;
 	gfn_t base_gfn;
 	unsigned long npages;
 	unsigned long i;
@@ -741,8 +754,6 @@ skip_lpage:
 		if (kvm_create_dirty_bitmap(&new) < 0)
 			goto out_free;
 		/* destroy any largepage mappings for dirty tracking */
-		if (old.npages)
-			flush_shadow = 1;
 	}
 #else  /* not defined CONFIG_S390 */
 	new.user_alloc = user_alloc;
@@ -813,9 +824,6 @@ skip_lpage:
 	kvm_free_physmem_slot(&old, &new);
 	kfree(old_memslots);
 
-	if (flush_shadow)
-		kvm_arch_flush_shadow(kvm);
-
 	return 0;
 
 out_free:
@@ -1029,6 +1037,26 @@ static pfn_t get_fault_pfn(void)
 	return fault_pfn;
 }
 
+int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
+	unsigned long start, int write, struct page **page)
+{
+	int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
+
+	if (write)
+		flags |= FOLL_WRITE;
+
+	return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
+}
+
+static inline int check_user_page_hwpoison(unsigned long addr)
+{
+	int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
+
+	rc = __get_user_pages(current, current->mm, addr, 1,
+			      flags, NULL, NULL, NULL);
+	return rc == -EHWPOISON;
+}
+
 static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
 			bool *async, bool write_fault, bool *writable)
 {
@@ -1053,7 +1081,14 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
 		if (writable)
 			*writable = write_fault;
 
-		npages = get_user_pages_fast(addr, 1, write_fault, page);
+		if (async) {
+			down_read(&current->mm->mmap_sem);
+			npages = get_user_page_nowait(current, current->mm,
+						     addr, write_fault, page);
+			up_read(&current->mm->mmap_sem);
+		} else
+			npages = get_user_pages_fast(addr, 1, write_fault,
+						     page);
 
 		/* map read fault as writable if possible */
 		if (unlikely(!write_fault) && npages == 1) {
@@ -1076,7 +1111,8 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
 			return get_fault_pfn();
 
 		down_read(&current->mm->mmap_sem);
-		if (is_hwpoison_address(addr)) {
+		if (npages == -EHWPOISON ||
+			(!async && check_user_page_hwpoison(addr))) {
 			up_read(&current->mm->mmap_sem);
 			get_page(hwpoison_page);
 			return page_to_pfn(hwpoison_page);
@@ -1421,7 +1457,7 @@ void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
 	if (memslot && memslot->dirty_bitmap) {
 		unsigned long rel_gfn = gfn - memslot->base_gfn;
 
-		generic___set_le_bit(rel_gfn, memslot->dirty_bitmap);
+		__set_bit_le(rel_gfn, memslot->dirty_bitmap);
 	}
 }
 
@@ -1466,18 +1502,55 @@ void kvm_resched(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvm_resched);
 
-void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu)
+void kvm_vcpu_on_spin(struct kvm_vcpu *me)
 {
-	ktime_t expires;
-	DEFINE_WAIT(wait);
-
-	prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
-
-	/* Sleep for 100 us, and hope lock-holder got scheduled */
-	expires = ktime_add_ns(ktime_get(), 100000UL);
-	schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
+	struct kvm *kvm = me->kvm;
+	struct kvm_vcpu *vcpu;
+	int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
+	int yielded = 0;
+	int pass;
+	int i;
 
-	finish_wait(&vcpu->wq, &wait);
+	/*
+	 * We boost the priority of a VCPU that is runnable but not
+	 * currently running, because it got preempted by something
+	 * else and called schedule in __vcpu_run.  Hopefully that
+	 * VCPU is holding the lock that we need and will release it.
+	 * We approximate round-robin by starting at the last boosted VCPU.
+	 */
+	for (pass = 0; pass < 2 && !yielded; pass++) {
+		kvm_for_each_vcpu(i, vcpu, kvm) {
+			struct task_struct *task = NULL;
+			struct pid *pid;
+			if (!pass && i < last_boosted_vcpu) {
+				i = last_boosted_vcpu;
+				continue;
+			} else if (pass && i > last_boosted_vcpu)
+				break;
+			if (vcpu == me)
+				continue;
+			if (waitqueue_active(&vcpu->wq))
+				continue;
+			rcu_read_lock();
+			pid = rcu_dereference(vcpu->pid);
+			if (pid)
+				task = get_pid_task(vcpu->pid, PIDTYPE_PID);
+			rcu_read_unlock();
+			if (!task)
+				continue;
+			if (task->flags & PF_VCPU) {
+				put_task_struct(task);
+				continue;
+			}
+			if (yield_to(task, 1)) {
+				put_task_struct(task);
+				kvm->last_boosted_vcpu = i;
+				yielded = 1;
+				break;
+			}
+			put_task_struct(task);
+		}
+	}
 }
 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
 
@@ -2122,9 +2195,9 @@ static void hardware_enable_nolock(void *junk)
 
 static void hardware_enable(void *junk)
 {
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 	hardware_enable_nolock(junk);
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 }
 
 static void hardware_disable_nolock(void *junk)
@@ -2139,9 +2212,9 @@ static void hardware_disable_nolock(void *junk)
 
 static void hardware_disable(void *junk)
 {
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 	hardware_disable_nolock(junk);
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 }
 
 static void hardware_disable_all_nolock(void)
@@ -2155,16 +2228,16 @@ static void hardware_disable_all_nolock(void)
 
 static void hardware_disable_all(void)
 {
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 	hardware_disable_all_nolock();
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 }
 
 static int hardware_enable_all(void)
 {
 	int r = 0;
 
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 
 	kvm_usage_count++;
 	if (kvm_usage_count == 1) {
@@ -2177,7 +2250,7 @@ static int hardware_enable_all(void)
 		}
 	}
 
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 
 	return r;
 }
@@ -2339,10 +2412,10 @@ static int vm_stat_get(void *_offset, u64 *val)
 	struct kvm *kvm;
 
 	*val = 0;
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 	list_for_each_entry(kvm, &vm_list, vm_list)
 		*val += *(u32 *)((void *)kvm + offset);
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 	return 0;
 }
 
@@ -2356,12 +2429,12 @@ static int vcpu_stat_get(void *_offset, u64 *val)
 	int i;
 
 	*val = 0;
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 	list_for_each_entry(kvm, &vm_list, vm_list)
 		kvm_for_each_vcpu(i, vcpu, kvm)
 			*val += *(u32 *)((void *)vcpu + offset);
 
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 	return 0;
 }
 
@@ -2392,33 +2465,26 @@ static void kvm_exit_debug(void)
 	debugfs_remove(kvm_debugfs_dir);
 }
 
-static int kvm_suspend(struct sys_device *dev, pm_message_t state)
+static int kvm_suspend(void)
 {
 	if (kvm_usage_count)
 		hardware_disable_nolock(NULL);
 	return 0;
 }
 
-static int kvm_resume(struct sys_device *dev)
+static void kvm_resume(void)
 {
 	if (kvm_usage_count) {
-		WARN_ON(spin_is_locked(&kvm_lock));
+		WARN_ON(raw_spin_is_locked(&kvm_lock));
 		hardware_enable_nolock(NULL);
 	}
-	return 0;
 }
 
-static struct sysdev_class kvm_sysdev_class = {
-	.name = "kvm",
+static struct syscore_ops kvm_syscore_ops = {
 	.suspend = kvm_suspend,
 	.resume = kvm_resume,
 };
 
-static struct sys_device kvm_sysdev = {
-	.id = 0,
-	.cls = &kvm_sysdev_class,
-};
-
 struct page *bad_page;
 pfn_t bad_pfn;
 
@@ -2502,14 +2568,6 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 		goto out_free_2;
 	register_reboot_notifier(&kvm_reboot_notifier);
 
-	r = sysdev_class_register(&kvm_sysdev_class);
-	if (r)
-		goto out_free_3;
-
-	r = sysdev_register(&kvm_sysdev);
-	if (r)
-		goto out_free_4;
-
 	/* A kmem cache lets us meet the alignment requirements of fx_save. */
 	if (!vcpu_align)
 		vcpu_align = __alignof__(struct kvm_vcpu);
@@ -2517,7 +2575,7 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 					   0, NULL);
 	if (!kvm_vcpu_cache) {
 		r = -ENOMEM;
-		goto out_free_5;
+		goto out_free_3;
 	}
 
 	r = kvm_async_pf_init();
@@ -2534,6 +2592,8 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 		goto out_unreg;
 	}
 
+	register_syscore_ops(&kvm_syscore_ops);
+
 	kvm_preempt_ops.sched_in = kvm_sched_in;
 	kvm_preempt_ops.sched_out = kvm_sched_out;
 
@@ -2545,10 +2605,6 @@ out_unreg:
 	kvm_async_pf_deinit();
 out_free:
 	kmem_cache_destroy(kvm_vcpu_cache);
-out_free_5:
-	sysdev_unregister(&kvm_sysdev);
-out_free_4:
-	sysdev_class_unregister(&kvm_sysdev_class);
 out_free_3:
 	unregister_reboot_notifier(&kvm_reboot_notifier);
 	unregister_cpu_notifier(&kvm_cpu_notifier);
@@ -2576,8 +2632,7 @@ void kvm_exit(void)
 	misc_deregister(&kvm_dev);
 	kmem_cache_destroy(kvm_vcpu_cache);
 	kvm_async_pf_deinit();
-	sysdev_unregister(&kvm_sysdev);
-	sysdev_class_unregister(&kvm_sysdev_class);
+	unregister_syscore_ops(&kvm_syscore_ops);
 	unregister_reboot_notifier(&kvm_reboot_notifier);
 	unregister_cpu_notifier(&kvm_cpu_notifier);
 	on_each_cpu(hardware_disable_nolock, NULL, 1);