Re: [PATCH v2] KVM: arm/arm64 : add lpi info in vgic-debug

From: Marc Zyngier
Date: Fri Mar 23 2018 - 11:27:19 EST


On 23/03/18 23:01, Peng Hao wrote:
> Add lpi debug info to vgic-stat.
> the printed info like this:
> SPI 287 0 000001 0 0 0 160 -1
> LPI 8192 2 000100 0 0 0 160 -1
>
> Signed-off-by: Peng Hao <peng.hao2@xxxxxxxxxx>
> ---
> virt/kvm/arm/vgic/vgic-debug.c | 56 ++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 51 insertions(+), 5 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-debug.c b/virt/kvm/arm/vgic/vgic-debug.c
> index 10b3817..cb85550 100644
> --- a/virt/kvm/arm/vgic/vgic-debug.c
> +++ b/virt/kvm/arm/vgic/vgic-debug.c
> @@ -36,9 +36,12 @@
> struct vgic_state_iter {
> int nr_cpus;
> int nr_spis;
> + int nr_lpis;
> int dist_id;
> int vcpu_id;
> int intid;
> + int lpi_print_count;
> + struct vgic_irq **lpi_irqs;
> };
>
> static void iter_next(struct vgic_state_iter *iter)
> @@ -52,6 +55,35 @@ static void iter_next(struct vgic_state_iter *iter)
> if (iter->intid == VGIC_NR_PRIVATE_IRQS &&
> ++iter->vcpu_id < iter->nr_cpus)
> iter->intid = 0;
> +
> + if (iter->intid >= VGIC_NR_PRIVATE_IRQS + iter->nr_spis) {
> + if (iter->lpi_print_count < iter->nr_lpis)
> + iter->intid = iter->lpi_irqs[iter->lpi_print_count]->intid;
> + iter->lpi_print_count++;
> + }
> +}
> +
> +static void vgic_debug_get_lpis(struct kvm *kvm, struct vgic_state_iter *iter)
> +{
> + struct vgic_dist *dist = &kvm->arch.vgic;
> + int i = 0;
> + struct vgic_irq *irq = NULL, **lpi_irqs;
> +
> + iter->nr_lpis = dist->lpi_list_count;
> + lpi_irqs = kmalloc_array(iter->nr_lpis, sizeof(irq), GFP_KERNEL);
> + if (!lpi_irqs) {
> + iter->nr_lpis = 0;
> + return;
> + }
> + spin_lock(&dist->lpi_list_lock);
> + list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
> + vgic_get_irq_kref(irq);
> + if (i < iter->nr_lpis)
> + lpi_irqs[i++] = irq;
> + }
> + iter->nr_lpis = i;
> + spin_unlock(&dist->lpi_list_lock);
> + iter->lpi_irqs = lpi_irqs;

I've already explained why I didn't like this construct.

I still don't like it.

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