KVM: Get rid of return value from kvm_arch_create_vm_debugfs()

The general expectation with debugfs is that any initialization failure is nonfatal. Nevertheless, kvm_arch_create_vm_debugfs() allows implementations to return an error and kvm_create_vm_debugfs() allows that to fail VM creation. Change to a void return to discourage architectures from making debugfs failures fatal for the VM. Seems like everyone already had the right idea, as all implementations already return 0 unconditionally. Acked-by: Marc Zyngier <[email protected]> Acked-by: Paolo Bonzini <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Oliver Upton <[email protected]>
torvalds · Feb 23, 2024 · 284851e · 284851e
1 parent 8cdc71f
commit 284851e
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Showing 4 changed files with 5 additions and 11 deletions.
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
@@ -2538,9 +2538,8 @@ void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_
  vcpu->kvm->arch.kvm_ops->create_vcpu_debugfs(vcpu, debugfs_dentry);
 }
 
-int kvm_arch_create_vm_debugfs(struct kvm *kvm)
+void kvm_arch_create_vm_debugfs(struct kvm *kvm)
 {
  if (kvm->arch.kvm_ops->create_vm_debugfs)
  kvm->arch.kvm_ops->create_vm_debugfs(kvm);
- return 0;
 }
diff --git a/arch/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c
@@ -189,9 +189,8 @@ static const struct file_operations mmu_rmaps_stat_fops = {
  .release = kvm_mmu_rmaps_stat_release,
 };
 
-int kvm_arch_create_vm_debugfs(struct kvm *kvm)
+void kvm_arch_create_vm_debugfs(struct kvm *kvm)
 {
  debugfs_create_file("mmu_rmaps_stat", 0644, kvm->debugfs_dentry, kvm,
  &mmu_rmaps_stat_fops);
- return 0;
 }
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
@@ -1507,7 +1507,7 @@ bool kvm_arch_dy_runnable(struct kvm_vcpu *vcpu);
 bool kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu);
 int kvm_arch_post_init_vm(struct kvm *kvm);
 void kvm_arch_pre_destroy_vm(struct kvm *kvm);
-int kvm_arch_create_vm_debugfs(struct kvm *kvm);
+void kvm_arch_create_vm_debugfs(struct kvm *kvm);
 
 #ifndef __KVM_HAVE_ARCH_VM_ALLOC
 /*

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
@@ -1150,10 +1150,7 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, const char *fdname)
  &stat_fops_per_vm);
  }
 
- ret = kvm_arch_create_vm_debugfs(kvm);
- if (ret)
- goto out_err;
-
+ kvm_arch_create_vm_debugfs(kvm);
  return 0;
 out_err:
  kvm_destroy_vm_debugfs(kvm);
@@ -1183,9 +1180,8 @@ void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm)
  * Cleanup should be automatic done in kvm_destroy_vm_debugfs() recursively, so
  * a per-arch destroy interface is not needed.
  */
-int __weak kvm_arch_create_vm_debugfs(struct kvm *kvm)
+void __weak kvm_arch_create_vm_debugfs(struct kvm *kvm)
 {
- return 0;
 }
 
 static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)