[PART1 RFC v3 02/12] KVM: x86: Introducing kvm_x86_ops VM init/uninit hooks

[Suravee Suthikulpanit]

Adding function pointers in struct kvm_x86_ops for processor-specific
layer to provide hooks for when KVM initialize and un-initialize VM.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
 arch/x86/include/asm/kvm_host.h |  3 +++
 arch/x86/kvm/x86.c              | 10 +++++++++-
 virt/kvm/kvm_main.c             |  8 ++++----
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 44adbb8..4b0dd0f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -828,6 +828,9 @@ struct kvm_x86_ops {
 	bool (*cpu_has_high_real_mode_segbase)(void);
 	void (*cpuid_update)(struct kvm_vcpu *vcpu);
 
+	int (*vm_init)(struct kvm *kvm);
+	void (*vm_uninit)(struct kvm *kvm);
+
 	/* Create, but do not attach this VCPU */
 	struct kvm_vcpu *(*vcpu_create)(struct kvm *kvm, unsigned id);
 	void (*vcpu_free)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 429c3f5..4d2961d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7700,6 +7700,8 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
 
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
+	int ret = 0;
+
 	if (type)
 		return -EINVAL;
 
@@ -7724,7 +7726,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	INIT_DELAYED_WORK(&kvm->arch.kvmclock_update_work, kvmclock_update_fn);
 	INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn);
 
-	return 0;
+	if (kvm_x86_ops->vm_init)
+		ret = kvm_x86_ops->vm_init(kvm);
+
+	return ret;
 }
 
 static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
@@ -7751,6 +7756,9 @@ static void kvm_free_vcpus(struct kvm *kvm)
 	kvm_for_each_vcpu(i, vcpu, kvm)
 		kvm_arch_vcpu_free(vcpu);
 
+	if (kvm_x86_ops->vm_uninit)
+		kvm_x86_ops->vm_uninit(kvm);
+
 	mutex_lock(&kvm->lock);
 	for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
 		kvm->vcpus[i] = NULL;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 1ca0258..5460325 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -536,10 +536,6 @@ static struct kvm *kvm_create_vm(unsigned long type)
 	if (!kvm)
 		return ERR_PTR(-ENOMEM);
 
-	r = kvm_arch_init_vm(kvm, type);
-	if (r)
-		goto out_err_no_disable;
-
 	r = hardware_enable_all();
 	if (r)
 		goto out_err_no_disable;
@@ -578,6 +574,10 @@ static struct kvm *kvm_create_vm(unsigned long type)
 	atomic_set(&kvm->users_count, 1);
 	INIT_LIST_HEAD(&kvm->devices);
 
+	r = kvm_arch_init_vm(kvm, type);
+	if (r)
+		goto out_err;
+
 	r = kvm_init_mmu_notifier(kvm);
 	if (r)
 		goto out_err;
-- 
1.9.1