Re: [patch 14/31] x86/fpu: Replace KVMs homebrewn FPU copy from user

[Paolo Bonzini]

On 13/10/21 16:57, Sean Christopherson wrote:
> > > +int fpu_copy_kvm_uabi_to_vcpu(struct fpu *fpu, const void *buf, u64 xcr0,
> > > +			      u32 *vpkru)
> > Right, except that there's no @vcpu in the args of that function. I
> > guess you could call it
> >
> > fpu_copy_kvm_uabi_to_buf()
> >
> > and that @buf can be
> >
> > vcpu->arch.guest_fpu
> But the existing @buf is the userspace pointer, which semantically makes sense
> because the userspace pointer is the "buffer" and the destination @fpu (and @prku)
> is vCPU state, not a buffer.
>
> That said, I also struggled with the lack of @vcpu.  What about prepending vcpu_
> to fpu and to pkru?  E.g.
>
>    int fpu_copy_kvm_uabi_to_vcpu(struct fpu *vcpu_fpu, const void *buf, u64 xcr0,
>    				u32 *vcpu_pkru)

It doesn't matter much that the source is somehow related to a vCPU, as 
long as the FPU is concerned.  If anything I would even drop the "v" 
from vpkru, but that's really nitpicking.

Paolo