Re: [PATCH 1/6] KVM: Open code kvm_set_memory_region() into its sole caller (ioctl() API)

[Tao Su <tao1.su@linux.intel.com>]

On Fri, Aug 02, 2024 at 01:49:58PM -0700, Sean Christopherson wrote:
> Open code kvm_set_memory_region() into its sole caller in preparation for
> adding a dedicated API for setting internal memslots.
> 
> Oppurtunistically use the fancy new guard(mutex) to avoid a local 'r'
> variable.
> 
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  include/linux/kvm_host.h |  2 --
>  virt/kvm/kvm_main.c      | 15 ++-------------
>  2 files changed, 2 insertions(+), 15 deletions(-)
> 
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 689e8be873a7..b341d00aae37 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -1179,8 +1179,6 @@ enum kvm_mr_change {
>  	KVM_MR_FLAGS_ONLY,
>  };
>  
> -int kvm_set_memory_region(struct kvm *kvm,
> -			  const struct kvm_userspace_memory_region2 *mem);
>  int __kvm_set_memory_region(struct kvm *kvm,
>  			    const struct kvm_userspace_memory_region2 *mem);
>  void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot);
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index d0788d0a72cc..0557d663b69b 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2105,25 +2105,14 @@ int __kvm_set_memory_region(struct kvm *kvm,
>  }
>  EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
>  
> -int kvm_set_memory_region(struct kvm *kvm,
> -			  const struct kvm_userspace_memory_region2 *mem)
> -{
> -	int r;
> -
> -	mutex_lock(&kvm->slots_lock);
> -	r = __kvm_set_memory_region(kvm, mem);
> -	mutex_unlock(&kvm->slots_lock);
> -	return r;
> -}
> -EXPORT_SYMBOL_GPL(kvm_set_memory_region);
> -
>  static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
>  					  struct kvm_userspace_memory_region2 *mem)
>  {
>  	if ((u16)mem->slot >= KVM_USER_MEM_SLOTS)
>  		return -EINVAL;
>  
> -	return kvm_set_memory_region(kvm, mem);
> +	guard(mutex)(&kvm->slots_lock);
> +	return  __kvm_set_memory_region(kvm, mem);
              ^^
Two spaces are introduced here.

>  }
>  
>  #ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
> -- 
> 2.46.0.rc2.264.g509ed76dc8-goog
> 
>