On Mon, Feb 18, 2019 at 07:52:27PM +0000, Dave Martin wrote:
> -static bool __hyp_text __hyp_switch_fpsimd(struct kvm_vcpu *vcpu)
> +/* Check for an FPSIMD/SVE trap and handle as appropriate */
> +static bool __hyp_text __hyp_handle_fpsimd(struct kvm_vcpu *vcpu)
> {
> - struct user_fpsimd_state *host_fpsimd = vcpu->arch.host_fpsimd_state;
> + bool vhe, sve_guest, sve_host;
> + u8 trap_class;
Nit: elsewhere in kvm, this gets called hsr_ec. Can we use the same name
here?
>
> - if (has_vhe())
> - write_sysreg(read_sysreg(cpacr_el1) | CPACR_EL1_FPEN,
> - cpacr_el1);
> - else
> + if (!system_supports_fpsimd())
> + return false;
> +
> + if (system_supports_sve()) {
> + sve_guest = vcpu_has_sve(vcpu);
> + sve_host = vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE;
> + vhe = true;
> + } else {
> + sve_guest = false;
> + sve_host = false;
> + vhe = has_vhe();
> + }
> +
> + trap_class = kvm_vcpu_trap_get_class(vcpu);
> + if (trap_class != ESR_ELx_EC_FP_ASIMD &&
> + (!sve_guest || trap_class != ESR_ELx_EC_SVE))
> + return false;
This is somewhat painful to decipher, but I couldn't come up with
something that was both succint and legible.
Maybe it's worth duplicating the SVE check, i.e.
if (hsr_ec != ESR_ELx_EC_FP_ASIMD &&
hsr_ec != ESR_ELx_EC_SVE)
return false;
if (!sve_guest && hsr_ec == ESR_ELx_EC_SVE)
return false;
... ?
Thanks,
Mark.
