diff options
Diffstat (limited to 'virt/kvm')
| -rw-r--r-- | virt/kvm/kvm_main.c | 90 |
1 files changed, 78 insertions, 12 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 38e4d2c34ac..70c8cbea0a9 100644 --- a/virt/kvm/kvm_main.c +++ b/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; @@ -339,6 +343,7 @@ 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; @@ -346,6 +351,11 @@ static struct kvm *kvm_create_vm(void) 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); @@ -354,8 +364,8 @@ 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); @@ -363,15 +373,13 @@ static struct kvm *kvm_create_vm(void) #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 @@ out_free_3: 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: |