Re: [PATCH] kvm: move KVM_CAP_NR_MEMSLOTS to common code

[Sean Christopherson]

On Thu, Mar 28, 2019 at 06:10:00PM +0100, Paolo Bonzini wrote:
> All architectures except MIPS were defining it in the same way,
> and memory slots are handled entirely by common code so there
> is no point in keeping the definition per-architecture.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
>  Documentation/virtual/kvm/api.txt | 5 ++---
>  arch/powerpc/kvm/powerpc.c        | 3 ---
>  arch/s390/kvm/kvm-s390.c          | 3 ---
>  arch/x86/kvm/x86.c                | 3 ---
>  virt/kvm/arm/arm.c                | 3 ---
>  virt/kvm/kvm_main.c               | 2 ++
>  6 files changed, 4 insertions(+), 15 deletions(-)
> 
> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
> index 67068c47c591..b62ad0d94234 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -1117,9 +1117,8 @@ struct kvm_userspace_memory_region {
>  This ioctl allows the user to create, modify or delete a guest physical
>  memory slot.  Bits 0-15 of "slot" specify the slot id and this value
>  should be less than the maximum number of user memory slots supported per
> -VM.  The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS,
> -if this capability is supported by the architecture.  Slots may not
> -overlap in guest physical address space.
> +VM.  The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS.
> +Slots may not overlap in guest physical address space.

Nit: s/may/must in that last sentence while you're at it?

Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

>  
>  If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot"
>  specifies the address space which is being modified.  They must be
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 8885377ec3e0..92910b7c5bcc 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -644,9 +644,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>  		else
>  			r = num_online_cpus();
>  		break;
> -	case KVM_CAP_NR_MEMSLOTS:
> -		r = KVM_USER_MEM_SLOTS;
> -		break;
>  	case KVM_CAP_MAX_VCPUS:
>  		r = KVM_MAX_VCPUS;
>  		break;
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 4638303ba6a8..28f35d2b06cb 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -513,9 +513,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>  		else if (sclp.has_esca && sclp.has_64bscao)
>  			r = KVM_S390_ESCA_CPU_SLOTS;
>  		break;
> -	case KVM_CAP_NR_MEMSLOTS:
> -		r = KVM_USER_MEM_SLOTS;
> -		break;
>  	case KVM_CAP_S390_COW:
>  		r = MACHINE_HAS_ESOP;
>  		break;
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 099b851dabaf..9b64d3359c93 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3073,9 +3073,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>  	case KVM_CAP_MAX_VCPUS:
>  		r = KVM_MAX_VCPUS;
>  		break;
> -	case KVM_CAP_NR_MEMSLOTS:
> -		r = KVM_USER_MEM_SLOTS;
> -		break;
>  	case KVM_CAP_PV_MMU:	/* obsolete */
>  		r = 0;
>  		break;
> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> index 99c37384ba7b..be4ec5f3ba5f 100644
> --- a/virt/kvm/arm/arm.c
> +++ b/virt/kvm/arm/arm.c
> @@ -224,9 +224,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>  	case KVM_CAP_MAX_VCPUS:
>  		r = KVM_MAX_VCPUS;
>  		break;
> -	case KVM_CAP_NR_MEMSLOTS:
> -		r = KVM_USER_MEM_SLOTS;
> -		break;
>  	case KVM_CAP_MSI_DEVID:
>  		if (!kvm)
>  			r = -EINVAL;
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 55fe8e20d8fd..31c28e0b067c 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -3061,6 +3061,8 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
>  #endif
>  	case KVM_CAP_MAX_VCPU_ID:
>  		return KVM_MAX_VCPU_ID;
> +	case KVM_CAP_NR_MEMSLOTS:
> +		return KVM_USER_MEM_SLOTS;
>  	default:
>  		break;
>  	}
> -- 
> 1.8.3.1
>