KVM: x86: define SVM/VMX specific kvm_arch_[alloc|free]_vm

Define kvm_arch_[alloc|free]_vm in x86 as pass through functions
to new kvm_x86_ops vm_alloc and vm_free, and move the current
allocation logic as-is to SVM and VMX.  Vendor specific alloc/free
functions set the stage for SVM/VMX wrappers of 'struct kvm',
which will allow us to move the growing number of SVM/VMX specific
member variables out of 'struct kvm_arch'.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -948,6 +948,8 @@ struct kvm_x86_ops {
 	bool (*cpu_has_high_real_mode_segbase)(void);
 	void (*cpuid_update)(struct kvm_vcpu *vcpu);
 
+	struct kvm *(*vm_alloc)(void);
+	void (*vm_free)(struct kvm *);
 	int (*vm_init)(struct kvm *kvm);
 	void (*vm_destroy)(struct kvm *kvm);
 
@@ -1121,6 +1123,17 @@ struct kvm_arch_async_pf {
 
 extern struct kvm_x86_ops *kvm_x86_ops;
 
+#define __KVM_HAVE_ARCH_VM_ALLOC
+static inline struct kvm *kvm_arch_alloc_vm(void)
+{
+	return kvm_x86_ops->vm_alloc();
+}
+
+static inline void kvm_arch_free_vm(struct kvm *kvm)
+{
+	return kvm_x86_ops->vm_free(kvm);
+}
+
 int kvm_mmu_module_init(void);
 void kvm_mmu_module_exit(void);
 

arch/x86/kvm/svm.c

@@ -1717,6 +1717,16 @@ static void __unregister_enc_region_locked(struct kvm *kvm,
 	kfree(region);
 }
 
+static struct kvm *svm_vm_alloc(void)
+{
+	return kzalloc(sizeof(struct kvm), GFP_KERNEL);
+}
+
+static void svm_vm_free(struct kvm *kvm)
+{
+	kfree(kvm);
+}
+
 static void sev_vm_destroy(struct kvm *kvm)
 {
 	struct kvm_sev_info *sev = &kvm->arch.sev_info;
@@ -6881,6 +6891,8 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.vcpu_free = svm_free_vcpu,
 	.vcpu_reset = svm_vcpu_reset,
 
+	.vm_alloc = svm_vm_alloc,
+	.vm_free = svm_vm_free,
 	.vm_init = avic_vm_init,
 	.vm_destroy = svm_vm_destroy,
 

arch/x86/kvm/vmx.c

@@ -9763,6 +9763,16 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
 }
 STACK_FRAME_NON_STANDARD(vmx_vcpu_run);
 
+static struct kvm *vmx_vm_alloc(void)
+{
+	return kzalloc(sizeof(struct kvm), GFP_KERNEL);
+}
+
+static void vmx_vm_free(struct kvm *kvm)
+{
+	kfree(kvm);
+}
+
 static void vmx_switch_vmcs(struct kvm_vcpu *vcpu, struct loaded_vmcs *vmcs)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -12430,6 +12440,8 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_high_real_mode_segbase = vmx_has_high_real_mode_segbase,
 
 	.vm_init = vmx_vm_init,
+	.vm_alloc = vmx_vm_alloc,
+	.vm_free = vmx_vm_free,
 
 	.vcpu_create = vmx_create_vcpu,
 	.vcpu_free = vmx_free_vcpu,