[23/42] KVM: Activate Virtualization On Demand

Message ID	1258373983-8693-24-git-send-email-avi@redhat.com (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id nAGCTktL020988 for <patchwork-kvm@patchwork.kernel.org>; Mon, 16 Nov 2009 12:29:48 GMT From: Avi Kivity <avi@redhat.com> To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org Subject: [PATCH 23/42] KVM: Activate Virtualization On Demand Date: Mon, 16 Nov 2009 14:19:24 +0200 Message-Id: <1258373983-8693-24-git-send-email-avi@redhat.com> In-Reply-To: <1258373983-8693-1-git-send-email-avi@redhat.com> References: <1258373983-8693-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index f6471c8..5fdeec5 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/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; @@ -137,7 +137,7 @@ 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 ? @@ -145,7 +145,7 @@ void kvm_arch_hardware_enable(void *garbage) __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) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 95af622..5902bbc 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/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) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 00e2ce8..5445058 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/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) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a46e2dd..295c7c4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/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 */ diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index f54c4f9..59fe4d5 100644 --- a/arch/x86/kvm/svm.c +++ b/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) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 73cb5dd..a187570 100644 --- a/arch/x86/kvm/vmx.c +++ b/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: diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 829e306..3d83de8 100644 --- a/arch/x86/kvm/x86.c +++ b/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) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index c0a1cc3..b985a29 100644 --- a/include/linux/kvm_host.h +++ b/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); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 38e4d2c..70c8cbe 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:

[23/42] KVM: Activate Virtualization On Demand

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