KVM: MIPS: Drop vm_init() callback

Now that the commpage doesn't use wired TLB entries, the per-CPU
vm_init() callback is the only work done by kvm_mips_init_vm_percpu().

The trap & emulate implementation doesn't actually need to do anything
from vm_init(), and the future VZ implementation would be better served
by a kvm_arch_hardware_enable callback anyway.

Therefore drop the vm_init() callback entirely, allowing the
kvm_mips_init_vm_percpu() function to also be dropped, along with the
kvm_mips_instance atomic counter.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org

arch/mips/include/asm/kvm_host.h

@@ -121,8 +121,6 @@ static inline bool kvm_is_error_hva(unsigned long addr)
 	return IS_ERR_VALUE(addr);
 }
 
-extern atomic_t kvm_mips_instance;
-
 struct kvm_vm_stat {
 	ulong remote_tlb_flush;
 };
@@ -528,7 +526,6 @@ struct kvm_mips_callbacks {
 	int (*handle_msa_fpe)(struct kvm_vcpu *vcpu);
 	int (*handle_fpe)(struct kvm_vcpu *vcpu);
 	int (*handle_msa_disabled)(struct kvm_vcpu *vcpu);
-	int (*vm_init)(struct kvm *kvm);
 	int (*vcpu_init)(struct kvm_vcpu *vcpu);
 	void (*vcpu_uninit)(struct kvm_vcpu *vcpu);
 	int (*vcpu_setup)(struct kvm_vcpu *vcpu);

arch/mips/kvm/mips.c

@@ -92,22 +92,8 @@ void kvm_arch_check_processor_compat(void *rtn)
 	*(int *)rtn = 0;
 }
 
-static void kvm_mips_init_vm_percpu(void *arg)
-{
-	struct kvm *kvm = (struct kvm *)arg;
-
-	kvm_mips_callbacks->vm_init(kvm);
-
-}
-
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
-	if (atomic_inc_return(&kvm_mips_instance) == 1) {
-		kvm_debug("%s: 1st KVM instance, setup host TLB parameters\n",
-			  __func__);
-		on_each_cpu(kvm_mips_init_vm_percpu, kvm, 1);
-	}
-
 	return 0;
 }
 
@@ -150,8 +136,6 @@ void kvm_mips_free_vcpus(struct kvm *kvm)
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	kvm_mips_free_vcpus(kvm);
-
-	atomic_dec(&kvm_mips_instance);
 }
 
 long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl,

arch/mips/kvm/tlb.c

@@ -33,9 +33,6 @@
 #define KVM_GUEST_PC_TLB    0
 #define KVM_GUEST_SP_TLB    1
 
-atomic_t kvm_mips_instance;
-EXPORT_SYMBOL_GPL(kvm_mips_instance);
-
 static u32 kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
 {
 	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;

arch/mips/kvm/trap_emul.c

@@ -429,11 +429,6 @@ static int kvm_trap_emul_handle_msa_disabled(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
-static int kvm_trap_emul_vm_init(struct kvm *kvm)
-{
-	return 0;
-}
-
 static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)
 {
 	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
@@ -847,7 +842,6 @@ static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
 	.handle_fpe = kvm_trap_emul_handle_fpe,
 	.handle_msa_disabled = kvm_trap_emul_handle_msa_disabled,
 
-	.vm_init = kvm_trap_emul_vm_init,
 	.vcpu_init = kvm_trap_emul_vcpu_init,
 	.vcpu_uninit = kvm_trap_emul_vcpu_uninit,
 	.vcpu_setup = kvm_trap_emul_vcpu_setup,