Re: [PATCH v2 17/54] KVM: arm/arm64: vgic-new: Add GICv2 world switch backend

[Marc Zyngier <marc.zyngier@arm.com>]

On Thu, 28 Apr 2016 17:45:36 +0100
Andre Przywara <andre.przywara@arm.com> wrote:

> From: Marc Zyngier <marc.zyngier@arm.com>
> 
> Processing maintenance interrupts and accessing the list registers
> are dependent on the host's GIC version.
> Introduce vgic-v2.c to contain GICv2 specific functions.
> Implement the GICv2 specific code for syncing the emulation state
> into the VGIC registers.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> Changelog RFC..v1:
> - remove explicit LR_STATE clearing on maintenance interrupt handling
> - improve documentation for vgic_v2_populate_lr()
> - remove WARN_ON on non-edge IRQs in maintenance interrupts
> - simplify multi-CPU source SGI handling
> 
> Changelog v1 .. v2:
> - inject the IRQ priority into the list register
> 
>  include/linux/irqchip/arm-gic.h |   1 +
>  virt/kvm/arm/vgic/vgic-v2.c     | 178 ++++++++++++++++++++++++++++++++++++++++
>  virt/kvm/arm/vgic/vgic.c        |  19 ++---
>  virt/kvm/arm/vgic/vgic.h        |   6 ++
>  4 files changed, 194 insertions(+), 10 deletions(-)
>  create mode 100644 virt/kvm/arm/vgic/vgic-v2.c
> 

[...]

> @@ -441,14 +447,12 @@ static int compute_ap_list_depth(struct kvm_vcpu *vcpu)
>  static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
>  {
>  	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
> -	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
> -	u32 model = dist->vgic_model;
>  	struct vgic_irq *irq;
>  	int count = 0;
>  
>  	DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(vgic_cpu->ap_list_lock));
>  
> -	if (unlikely(!dist->enabled))
> +	if (unlikely(!vcpu->kvm->arch.vgic.enabled))
>  		goto out_clean;
>  
>  	if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr) {
> @@ -466,14 +470,9 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
>  		 * If we get an SGI with multiple sources, try to get
>  		 * them in all at once.
>  		 */
> -		if (model == KVM_DEV_TYPE_ARM_VGIC_V2 &&
> -		    vgic_irq_is_sgi(irq->intid)) {
> -			while (irq->source &&
> -			       count < kvm_vgic_global_state.nr_lr)
> -				vgic_populate_lr(vcpu, irq, count++);
> -		} else {
> +		do {
>  			vgic_populate_lr(vcpu, irq, count++);
> -		}
> +		} while (irq->source && count < kvm_vgic_global_state.nr_lr);
>  
>  next:

Most, if not all of the changes in this function should be folded in the
previous patch, as we only have generic code in this file (this looks
like a leftover from an earlier rework).

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny.