Messages in this thread | | | Date | Thu, 15 Mar 2018 14:07:23 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 05/10] iommu/amd: remove the special case from get_irq_table() |
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On Thu, Mar 15, 2018 at 02:01:53PM +0100, Sebastian Andrzej Siewior wrote: > On 2018-03-15 13:53:42 [+0100], Joerg Roedel wrote: > > 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. > > Which part any why? The !->min_index part plus extending(setting to 32)?
In particular the set_allocated part, when get_irq_table() returns the table is visible to other users as well. I have not checked the irq-layer locking to be sure that can happen, though.
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