Re: [PATCH v4 16/20] KVM: arm64: GICv4.1: Allow SGIs to switch between HW and SW interrupts

[Zenghui Yu]

Hi Marc,

On 2020/2/14 22:57, Marc Zyngier wrote:
> In order to let a guest buy in the new, active-less SGIs, we
> need to be able to switch between the two modes.
>
> Handle this by stopping all guest activity, transfer the state
> from one mode to the other, and resume the guest.
>
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>

[...]

> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 1bc09b523486..2c9fc13e2c59 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -540,6 +540,8 @@ int vgic_v3_map_resources(struct kvm *kvm)
>   		goto out;
>   	}
>   
> +	if (kvm_vgic_global_state.has_gicv4_1)
> +		vgic_v4_configure_vsgis(kvm);
>   	dist->ready = true;
>   
>   out:

Is there any reason to invoke vgic_v4_configure_vsgis() here?
This is called on the first VCPU run, through kvm_vgic_map_resources().
Shouldn't the vSGI configuration only driven by a GICD_CTLR.nASSGIreq
writing (from guest, or from userspace maybe)?


Thanks,
Zenghui