Re: [PATCH v12 11/31] LoongArch: KVM: Implement fpu related operations for vcpu

[bibo, mao]

Reviewed-by: Bibo, Mao <maobibo@xxxxxxxxxxx>

在 2023/5/30 09:52, Tianrui Zhao 写道:
> Implement LoongArch fpu related interface for vcpu, such as get fpu, set
> fpu, own fpu and lose fpu, etc.
> 
> Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
> ---
>  arch/loongarch/kvm/vcpu.c | 60 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
> 
> diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
> index 5a88f815c412..60213f7f7bac 100644
> --- a/arch/loongarch/kvm/vcpu.c
> +++ b/arch/loongarch/kvm/vcpu.c
> @@ -244,6 +244,66 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
>  	return r;
>  }
>  
> +int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
> +{
> +	int i = 0;
> +
> +	/* no need vcpu_load and vcpu_put */
> +	fpu->fcsr = vcpu->arch.fpu.fcsr;
> +	fpu->fcc = vcpu->arch.fpu.fcc;
> +	for (i = 0; i < NUM_FPU_REGS; i++)
> +		memcpy(&fpu->fpr[i], &vcpu->arch.fpu.fpr[i], FPU_REG_WIDTH / 64);
> +
> +	return 0;
> +}
> +
> +int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
> +{
> +	int i = 0;
> +
> +	/* no need vcpu_load and vcpu_put */
> +	vcpu->arch.fpu.fcsr = fpu->fcsr;
> +	vcpu->arch.fpu.fcc = fpu->fcc;
> +	for (i = 0; i < NUM_FPU_REGS; i++)
> +		memcpy(&vcpu->arch.fpu.fpr[i], &fpu->fpr[i], FPU_REG_WIDTH / 64);
> +
> +	return 0;
> +}
> +
> +/* Enable FPU for guest and restore context */
> +void kvm_own_fpu(struct kvm_vcpu *vcpu)
> +{
> +	preempt_disable();
> +
> +	/*
> +	 * Enable FPU for guest
> +	 */
> +	set_csr_euen(CSR_EUEN_FPEN);
> +
> +	kvm_restore_fpu(&vcpu->arch.fpu);
> +	vcpu->arch.aux_inuse |= KVM_LARCH_FPU;
> +	trace_kvm_aux(vcpu, KVM_TRACE_AUX_RESTORE, KVM_TRACE_AUX_FPU);
> +
> +	preempt_enable();
> +}
> +
> +/* Save and disable FPU */
> +void kvm_lose_fpu(struct kvm_vcpu *vcpu)
> +{
> +	preempt_disable();
> +
> +	if (vcpu->arch.aux_inuse & KVM_LARCH_FPU) {
> +		kvm_save_fpu(&vcpu->arch.fpu);
> +		vcpu->arch.aux_inuse &= ~KVM_LARCH_FPU;
> +		trace_kvm_aux(vcpu, KVM_TRACE_AUX_SAVE, KVM_TRACE_AUX_FPU);
> +
> +		/* Disable FPU */
> +		clear_csr_euen(CSR_EUEN_FPEN);
> +	}
> +
> +	preempt_enable();
> +}
> +
>  int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
>  {
>  	return 0;