---

yaml
---
r: 172280
b: refs/heads/master
c: 10474ae
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e8b3433a5c062e94e34cadb6144c10689a497bc3
+refs/heads/master: 10474ae8945ce08622fd1f3464e55bd817bf2376

trunk/arch/ia64/kvm/kvm-ia64.c

@@ -124,7 +124,7 @@ long ia64_pal_vp_create(u64 *vpd, u64 *host_iva, u64 *opt_handler)
 
 static  DEFINE_SPINLOCK(vp_lock);
 
-void kvm_arch_hardware_enable(void *garbage)
+int kvm_arch_hardware_enable(void *garbage)
 {
 	long  status;
 	long  tmp_base;
@@ -137,15 +137,15 @@ void kvm_arch_hardware_enable(void *garbage)
 	slot = ia64_itr_entry(0x3, KVM_VMM_BASE, pte, KVM_VMM_SHIFT);
 	local_irq_restore(saved_psr);
 	if (slot < 0)
-		return;
+		return -EINVAL;
 
 	spin_lock(&vp_lock);
 	status = ia64_pal_vp_init_env(kvm_vsa_base ?
 				VP_INIT_ENV : VP_INIT_ENV_INITALIZE,
 			__pa(kvm_vm_buffer), KVM_VM_BUFFER_BASE, &tmp_base);
 	if (status != 0) {
 		printk(KERN_WARNING"kvm: Failed to Enable VT Support!!!!\n");
-		return ;
+		return -EINVAL;
 	}
 
 	if (!kvm_vsa_base) {
@@ -154,6 +154,8 @@ void kvm_arch_hardware_enable(void *garbage)
 	}
 	spin_unlock(&vp_lock);
 	ia64_ptr_entry(0x3, slot);
+
+	return 0;
 }
 
 void kvm_arch_hardware_disable(void *garbage)

trunk/arch/powerpc/kvm/powerpc.c

@@ -78,8 +78,9 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
 	return r;
 }
 
-void kvm_arch_hardware_enable(void *garbage)
+int kvm_arch_hardware_enable(void *garbage)
 {
+	return 0;
 }
 
 void kvm_arch_hardware_disable(void *garbage)

trunk/arch/s390/kvm/kvm-s390.c

@@ -74,9 +74,10 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 static unsigned long long *facilities;
 
 /* Section: not file related */
-void kvm_arch_hardware_enable(void *garbage)
+int kvm_arch_hardware_enable(void *garbage)
 {
 	/* every s390 is virtualization enabled ;-) */
+	return 0;
 }
 
 void kvm_arch_hardware_disable(void *garbage)

trunk/arch/x86/include/asm/kvm_host.h

@@ -459,7 +459,7 @@ struct descriptor_table {
 struct kvm_x86_ops {
 	int (*cpu_has_kvm_support)(void);          /* __init */
 	int (*disabled_by_bios)(void);             /* __init */
-	void (*hardware_enable)(void *dummy);      /* __init */
+	int (*hardware_enable)(void *dummy);
 	void (*hardware_disable)(void *dummy);
 	void (*check_processor_compatibility)(void *rtn);
 	int (*hardware_setup)(void);               /* __init */

trunk/arch/x86/kvm/svm.c

@@ -316,7 +316,7 @@ static void svm_hardware_disable(void *garbage)
 	cpu_svm_disable();
 }
 
-static void svm_hardware_enable(void *garbage)
+static int svm_hardware_enable(void *garbage)
 {
 
 	struct svm_cpu_data *svm_data;
@@ -325,16 +325,20 @@ static void svm_hardware_enable(void *garbage)
 	struct desc_struct *gdt;
 	int me = raw_smp_processor_id();
 
+	rdmsrl(MSR_EFER, efer);
+	if (efer & EFER_SVME)
+		return -EBUSY;
+
 	if (!has_svm()) {
 		printk(KERN_ERR "svm_cpu_init: err EOPNOTSUPP on %d\n", me);
-		return;
+		return -EINVAL;
 	}
 	svm_data = per_cpu(svm_data, me);
 
 	if (!svm_data) {
 		printk(KERN_ERR "svm_cpu_init: svm_data is NULL on %d\n",
 		       me);
-		return;
+		return -EINVAL;
 	}
 
 	svm_data->asid_generation = 1;
@@ -345,11 +349,12 @@ static void svm_hardware_enable(void *garbage)
 	gdt = (struct desc_struct *)gdt_descr.base;
 	svm_data->tss_desc = (struct kvm_ldttss_desc *)(gdt + GDT_ENTRY_TSS);
 
-	rdmsrl(MSR_EFER, efer);
 	wrmsrl(MSR_EFER, efer | EFER_SVME);
 
 	wrmsrl(MSR_VM_HSAVE_PA,
 	       page_to_pfn(svm_data->save_area) << PAGE_SHIFT);
+
+	return 0;
 }
 
 static void svm_cpu_uninit(int cpu)

trunk/arch/x86/kvm/vmx.c

@@ -1138,12 +1138,15 @@ static __init int vmx_disabled_by_bios(void)
 	/* locked but not enabled */
 }
 
-static void hardware_enable(void *garbage)
+static int hardware_enable(void *garbage)
 {
 	int cpu = raw_smp_processor_id();
 	u64 phys_addr = __pa(per_cpu(vmxarea, cpu));
 	u64 old;
 
+	if (read_cr4() & X86_CR4_VMXE)
+		return -EBUSY;
+
 	INIT_LIST_HEAD(&per_cpu(vcpus_on_cpu, cpu));
 	rdmsrl(MSR_IA32_FEATURE_CONTROL, old);
 	if ((old & (FEATURE_CONTROL_LOCKED |
@@ -1158,6 +1161,10 @@ static void hardware_enable(void *garbage)
 	asm volatile (ASM_VMX_VMXON_RAX
 		      : : "a"(&phys_addr), "m"(phys_addr)
 		      : "memory", "cc");
+
+	ept_sync_global();
+
+	return 0;
 }
 
 static void vmclear_local_vcpus(void)
@@ -4040,8 +4047,6 @@ static int __init vmx_init(void)
 	if (bypass_guest_pf)
 		kvm_mmu_set_nonpresent_ptes(~0xffeull, 0ull);
 
-	ept_sync_global();
-
 	return 0;
 
 out3:

trunk/arch/x86/kvm/x86.c

@@ -4691,9 +4691,9 @@ int kvm_arch_vcpu_reset(struct kvm_vcpu *vcpu)
 	return kvm_x86_ops->vcpu_reset(vcpu);
 }
 
-void kvm_arch_hardware_enable(void *garbage)
+int kvm_arch_hardware_enable(void *garbage)
 {
-	kvm_x86_ops->hardware_enable(garbage);
+	return kvm_x86_ops->hardware_enable(garbage);
 }
 
 void kvm_arch_hardware_disable(void *garbage)

trunk/include/linux/kvm_host.h

@@ -345,7 +345,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu);
 
 int kvm_arch_vcpu_reset(struct kvm_vcpu *vcpu);
-void kvm_arch_hardware_enable(void *garbage);
+int kvm_arch_hardware_enable(void *garbage);
 void kvm_arch_hardware_disable(void *garbage);
 int kvm_arch_hardware_setup(void);
 void kvm_arch_hardware_unsetup(void);

trunk/virt/kvm/kvm_main.c

@@ -69,6 +69,8 @@ DEFINE_SPINLOCK(kvm_lock);
 LIST_HEAD(vm_list);
 
 static cpumask_var_t cpus_hardware_enabled;
+static int kvm_usage_count = 0;
+static atomic_t hardware_enable_failed;
 
 struct kmem_cache *kvm_vcpu_cache;
 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
@@ -79,6 +81,8 @@ struct dentry *kvm_debugfs_dir;
 
 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
 			   unsigned long arg);
+static int hardware_enable_all(void);
+static void hardware_disable_all(void);
 
 static bool kvm_rebooting;
 
@@ -339,13 +343,19 @@ static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
 
 static struct kvm *kvm_create_vm(void)
 {
+	int r = 0;
 	struct kvm *kvm = kvm_arch_create_vm();
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 	struct page *page;
 #endif
 
 	if (IS_ERR(kvm))
 		goto out;
+
+	r = hardware_enable_all();
+	if (r)
+		goto out_err_nodisable;
+
 #ifdef CONFIG_HAVE_KVM_IRQCHIP
 	INIT_HLIST_HEAD(&kvm->mask_notifier_list);
 	INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
@@ -354,24 +364,22 @@ static struct kvm *kvm_create_vm(void)
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 	if (!page) {
-		kfree(kvm);
-		return ERR_PTR(-ENOMEM);
+		r = -ENOMEM;
+		goto out_err;
 	}
 	kvm->coalesced_mmio_ring =
 			(struct kvm_coalesced_mmio_ring *)page_address(page);
 #endif
 
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 	{
-		int err;
 		kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
-		err = mmu_notifier_register(&kvm->mmu_notifier, current->mm);
-		if (err) {
+		r = mmu_notifier_register(&kvm->mmu_notifier, current->mm);
+		if (r) {
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 			put_page(page);
 #endif
-			kfree(kvm);
-			return ERR_PTR(err);
+			goto out_err;
 		}
 	}
 #endif
@@ -395,6 +403,12 @@ static struct kvm *kvm_create_vm(void)
 #endif
 out:
 	return kvm;
+
+out_err:
+	hardware_disable_all();
+out_err_nodisable:
+	kfree(kvm);
+	return ERR_PTR(r);
 }
 
 /*
@@ -453,6 +467,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
 	kvm_arch_flush_shadow(kvm);
 #endif
 	kvm_arch_destroy_vm(kvm);
+	hardware_disable_all();
 	mmdrop(mm);
 }
 
@@ -1644,11 +1659,21 @@ static struct miscdevice kvm_dev = {
 static void hardware_enable(void *junk)
 {
 	int cpu = raw_smp_processor_id();
+	int r;
 
 	if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
 		return;
+
 	cpumask_set_cpu(cpu, cpus_hardware_enabled);
-	kvm_arch_hardware_enable(NULL);
+
+	r = kvm_arch_hardware_enable(NULL);
+
+	if (r) {
+		cpumask_clear_cpu(cpu, cpus_hardware_enabled);
+		atomic_inc(&hardware_enable_failed);
+		printk(KERN_INFO "kvm: enabling virtualization on "
+				 "CPU%d failed\n", cpu);
+	}
 }
 
 static void hardware_disable(void *junk)
@@ -1661,11 +1686,52 @@ static void hardware_disable(void *junk)
 	kvm_arch_hardware_disable(NULL);
 }
 
+static void hardware_disable_all_nolock(void)
+{
+	BUG_ON(!kvm_usage_count);
+
+	kvm_usage_count--;
+	if (!kvm_usage_count)
+		on_each_cpu(hardware_disable, NULL, 1);
+}
+
+static void hardware_disable_all(void)
+{
+	spin_lock(&kvm_lock);
+	hardware_disable_all_nolock();
+	spin_unlock(&kvm_lock);
+}
+
+static int hardware_enable_all(void)
+{
+	int r = 0;
+
+	spin_lock(&kvm_lock);
+
+	kvm_usage_count++;
+	if (kvm_usage_count == 1) {
+		atomic_set(&hardware_enable_failed, 0);
+		on_each_cpu(hardware_enable, NULL, 1);
+
+		if (atomic_read(&hardware_enable_failed)) {
+			hardware_disable_all_nolock();
+			r = -EBUSY;
+		}
+	}
+
+	spin_unlock(&kvm_lock);
+
+	return r;
+}
+
 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
 			   void *v)
 {
 	int cpu = (long)v;
 
+	if (!kvm_usage_count)
+		return NOTIFY_OK;
+
 	val &= ~CPU_TASKS_FROZEN;
 	switch (val) {
 	case CPU_DYING:
@@ -1868,13 +1934,15 @@ static void kvm_exit_debug(void)
 
 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
 {
-	hardware_disable(NULL);
+	if (kvm_usage_count)
+		hardware_disable(NULL);
 	return 0;
 }
 
 static int kvm_resume(struct sys_device *dev)
 {
-	hardware_enable(NULL);
+	if (kvm_usage_count)
+		hardware_enable(NULL);
 	return 0;
 }
 
@@ -1949,7 +2017,6 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
 			goto out_free_1;
 	}
 
-	on_each_cpu(hardware_enable, NULL, 1);
 	r = register_cpu_notifier(&kvm_cpu_notifier);
 	if (r)
 		goto out_free_2;
@@ -1999,7 +2066,6 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
 	unregister_reboot_notifier(&kvm_reboot_notifier);
 	unregister_cpu_notifier(&kvm_cpu_notifier);
 out_free_2:
-	on_each_cpu(hardware_disable, NULL, 1);
 out_free_1:
 	kvm_arch_hardware_unsetup();
 out_free_0a: