From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
KVM/X86 can change those callbacks without worrying about breaking other
archs.
Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
arch/x86/kvm/x86.c | 166 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 161 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f5ebb69996d5..b15eb59096b6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11960,6 +11960,167 @@ void kvm_arch_hardware_disable(void)
drop_user_return_notifiers();
}
+static cpumask_t cpus_hardware_enabled = CPU_MASK_NONE;
+
+int kvm_arch_post_init_vm(struct kvm *kvm)
+{
+ return kvm_mmu_post_init_vm(kvm);
+}
+
+static int __hardware_enable(void)
+{
+ int cpu = raw_smp_processor_id();
+ int r;
+
+ WARN_ON_ONCE(preemptible());
+
+ if (cpumask_test_cpu(cpu, &cpus_hardware_enabled))
+ return 0;
+ r = kvm_arch_hardware_enable();
+ if (r)
+ pr_warn("kvm: enabling virtualization on CPU%d failed during %pSb\n",
+ cpu, __builtin_return_address(0));
+ else
+ cpumask_set_cpu(cpu, &cpus_hardware_enabled);
+ return r;
+}
+
+static void hardware_enable(void *arg)
+{
+ atomic_t *failed = arg;
+
+ if (__hardware_enable())
+ atomic_inc(failed);
+}
+
+static void hardware_disable(void *junk)
+{
+ int cpu = raw_smp_processor_id();
+
+ WARN_ON_ONCE(preemptible());
+
+ if (!cpumask_test_cpu(cpu, &cpus_hardware_enabled))
+ return;
+ cpumask_clear_cpu(cpu, &cpus_hardware_enabled);
+ kvm_arch_hardware_disable();
+}
+
+/*
+ * Called after the VM is otherwise initialized, but just before adding it to
+ * the vm_list.
+ */
+int kvm_arch_add_vm(struct kvm *kvm, int usage_count)
+{
+ atomic_t failed;
+ int r = 0;
+
+ if (usage_count != 1)
+ return 0;
+
+ atomic_set(&failed, 0);
+ on_each_cpu(hardware_enable, &failed, 1);
+
+ if (atomic_read(&failed)) {
+ r = -EBUSY;
+ goto err;
+ }
+
+ r = kvm_arch_post_init_vm(kvm);
+err:
+ if (r)
+ on_each_cpu(hardware_disable, NULL, 1);
+ return r;
+}
+
+int kvm_arch_del_vm(int usage_count)
+{
+ if (usage_count)
+ return 0;
+
+ on_each_cpu(hardware_disable, NULL, 1);
+ return 0;
+}
+
+static void check_processor_compat(void *rtn)
+{
+ *(int *)rtn = kvm_arch_check_processor_compat();
+}
+
+int kvm_arch_check_processor_compat_all(void)
+{
+ int cpu;
+ int r;
+
+ for_each_online_cpu(cpu) {
+ smp_call_function_single(cpu, check_processor_compat, &r, 1);
+ if (r < 0)
+ return r;
+ }
+ return 0;
+}
+
+int kvm_arch_online_cpu(unsigned int cpu, int usage_count)
+{
+ int ret;
+
+ ret = kvm_arch_check_processor_compat();
+ if (ret)
+ return ret;
+
+ if (!usage_count)
+ return 0;
+
+ /*
+ * arch callback kvm_arch_hardware_eanble() assumes that
+ * preemption is disabled for historical reason. Disable
+ * preemption until all arch callbacks are fixed.
+ */
+ preempt_disable();
+ /*
+ * Abort the CPU online process if hardware virtualization cannot
+ * be enabled. Otherwise running VMs would encounter unrecoverable
+ * errors when scheduled to this CPU.
+ */
+ ret = __hardware_enable();
+ preempt_enable();
+
+ return ret;
+}
+
+int kvm_arch_offline_cpu(unsigned int cpu, int usage_count)
+{
+ if (usage_count) {
+ /*
+ * arch callback kvm_arch_hardware_disable() assumes that
+ * preemption is disabled for historical reason. Disable
+ * preemption until all arch callbacks are fixed.
+ */
+ preempt_disable();
+ hardware_disable(NULL);
+ preempt_enable();
+ }
+ return 0;
+}
+
+int kvm_arch_reboot(int val)
+{
+ on_each_cpu(hardware_disable, NULL, 1);
+ return NOTIFY_OK;
+}
+
+int kvm_arch_suspend(int usage_count)
+{
+ if (usage_count)
+ hardware_disable(NULL);
+ return 0;
+}
+
+void kvm_arch_resume(int usage_count)
+{
+ if (usage_count)
+ (void)__hardware_enable();
+}
+
static inline void kvm_ops_update(struct kvm_x86_init_ops *ops)
{
memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops));
@@ -12140,11 +12301,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
return ret;
}
-int kvm_arch_post_init_vm(struct kvm *kvm)
-{
- return kvm_mmu_post_init_vm(kvm);
-}
-
static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
{
vcpu_load(vcpu);
--
2.25.1
