Re: [PATCH 05/10] iommu/amd: remove the special case from get_irq_table()

[Joerg Roedel]

On Fri, Feb 23, 2018 at 11:27:31PM +0100, Sebastian Andrzej Siewior wrote:
> @@ -4103,10 +4093,26 @@ static int irq_remapping_alloc(struct irq_domain *domain, unsigned int virq,
>  		return ret;
>  
>  	if (info->type == X86_IRQ_ALLOC_TYPE_IOAPIC) {
> -		if (get_irq_table(devid, true))
> +		struct irq_remap_table *table;
> +		struct amd_iommu *iommu;
> +
> +		table = get_irq_table(devid);
> +		if (table) {
> +			if (!table->min_index) {
> +				/*
> +				 * Keep the first 32 indexes free for IOAPIC
> +				 * interrupts.
> +				 */
> +				table->min_index = 32;
> +				iommu = amd_iommu_rlookup_table[devid];
> +				for (i = 0; i < 32; ++i)
> +					iommu->irte_ops->set_allocated(table, i);
> +			}

I think this needs to be protected by the table->lock.