Re: [PATCH 3/3] kvm: s390: Exploiting generic userspace interface for cmma\

[Marcelo Tosatti <mtosatti@redhat.com>]

On Wed, Apr 16, 2014 at 09:47:52PM +0200, Alexander Graf wrote:
> 
> On 16.04.14 20:49, Marcelo Tosatti wrote:
> >On Thu, Apr 10, 2014 at 01:16:44PM +0200, Christian Borntraeger wrote:
> >>From: Dominik Dingel <dingel@linux.vnet.ibm.com>
> >>
> >>To enable CMMA and to reset its state we use the vm kvm_device ioctls,
> >>encapsulating attributes within the KVM_S390_VM_MEM_CTRL group.
> >>
> >>Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
> >>Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> >>---
> >>  Documentation/virtual/kvm/devices/vm.txt | 18 ++++++++++++++
> >>  arch/s390/include/uapi/asm/kvm.h         |  7 ++++++
> >>  arch/s390/kvm/kvm-s390.c                 | 42 ++++++++++++++++++++++++++++++++
> >>  3 files changed, 67 insertions(+)
> >Sounds awkward to use these three ioctls for something not
> >returned by KVM_CREATE_DEVICE.
> >
> >/* ioctls for fds returned by KVM_CREATE_DEVICE */
> >#define KVM_SET_DEVICE_ATTR       _IOW(KVMIO,  0xe1, struct kvm_device_attr)
> >#define KVM_GET_DEVICE_ATTR       _IOW(KVMIO,  0xe2, struct kvm_device_attr)
> >#define KVM_HAS_DEVICE_ATTR       _IOW(KVMIO,  0xe3, struct kvm_device_attr)
> >
> >Is that much of a problem to introduce
> >
> >struct kvm_vm_attr and
> >
> >/* ioctls for fds returned by KVM_CREATE_VM */
> >#define KVM_SET_VM_ATTR       _IOW(KVMIO,  0xa, struct kvm_vm_attr)
> >#define KVM_GET_VM_ATTR       _IOW(KVMIO,  0xb, struct kvm_vm_attr)
> >#define KVM_HAS_VM_ATTR       _IOW(KVMIO,  0xc, struct kvm_vm_attr)
> >
> >?
> 
> We could just alias them, no?
> 
> #define KVM_SET_VM_ATTR KVM_SET_DEVICE_ATTR
> 
> But I don't feel strongly either way.

Ok not a huge deal.

Assuming the series will be resubmitted with 
improved virtual/kvm/devices/vm.txt.