Re: [RFC v12 51/65] target/arm: cpu-sve: split TCG and KVM functionality

[Richard Henderson]

On 3/26/21 1:36 PM, Claudio Fontana wrote:
> +++ b/target/arm/kvm/kvm-sve.h
> @@ -0,0 +1,30 @@
> +/*
> + * QEMU AArch64 CPU SVE KVM interface
> + *
> + * Copyright 2021 SUSE LLC
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#ifndef KVM_SVE_H
> +#define KVM_SVE_H
> +
> +/* note: SVE is an AARCH64-only option, only include this for TARGET_AARCH64 */

A pointless comment given that kvm itself is aarch64-only.

> -void cpu_sve_finalize_features(ARMCPU *cpu, Error **errp)
> +bool cpu_sve_finalize_features(ARMCPU *cpu, Error **errp)

The commit message does not mention the interface change here.

I'm not sure about the rest of this patch.  It saves a miniscule amount of code 
in a kvm-only build, but I don't know that it clarifies things at all.

As yet, the other arm hw accelerators do not support SVE, but I assume that's 
only a matter of time.  The ARM Neoverse cpus support SVE, and will require Xen 
to have an answer soon.  (Apple will do whatever Apple does, given that it fabs 
its own ARM cpus, but I expect they won't delay SVE forever.)

It's not clear to me what bits of the kvm code here is really kvm specific, or 
if we'll have to move it back.

I'm tempted to leave it alone for now.


r~