On Fri, Jul 30, 2021 at 06:04:49PM -0400, Peter Xu wrote:
> Allow archs to create arch-specific nodes under kvm->debugfs_dentry directory
> besides the stats fields. The new interface kvm_arch_create_vm_debugfs() is
> defined but not yet used. It's called after kvm->debugfs_dentry is created, so
> it can be referenced directly in kvm_arch_create_vm_debugfs(). Arch should
> define their own versions when they want to create extra debugfs nodes.
>
> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
> ---
> include/linux/kvm_host.h | 1 +
> virt/kvm/kvm_main.c | 20 +++++++++++++++++++-
> 2 files changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 9d6b4ad407b8..a3ec3271c4c8 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -1067,6 +1067,7 @@ 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);
>
> #ifndef __KVM_HAVE_ARCH_VM_ALLOC
> /*
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index a96cbe24c688..327f8fae80a5 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -915,7 +915,7 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
> char dir_name[ITOA_MAX_LEN * 2];
> struct kvm_stat_data *stat_data;
> const struct _kvm_stats_desc *pdesc;
> - int i;
> + int i, ret;
> int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
> kvm_vcpu_stats_header.num_desc;
>
> @@ -960,6 +960,13 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
> kvm->debugfs_dentry, stat_data,
> &stat_fops_per_vm);
> }
> +
> + ret = kvm_arch_create_vm_debugfs(kvm);
> + if (ret) {
> + kvm_destroy_vm_debugfs(kvm);
> + return i;
> + }
> +
> return 0;
> }
>
> @@ -980,6 +987,17 @@ void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm)
> {
> }
>
> +/*
> + * Called after per-vm debugfs created. When called kvm->debugfs_dentry should
> + * be setup already, so we can create arch-specific debugfs entries under it.
> + * 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)
This should be a void function, nothing should matter if creating
debugfs files succeeds or not.
As proof, your one implementation always returned 0 :)
thanks,
greg k-h
