Hi Rahul,
On 20/08/2021 11:30, Rahul Singh wrote:
Please add a comment explaining why this just returns 0.
Here is the comment that I will add in next version.
/*
* Return 0 as on ARM there is no pci physical irqs that required cleanup.
*/
In this context, PIRQ means an interrupts that was routed to the guest
and could be mapped to an event channel. We have no such concept on Arm
(see allocate_pirq_struct()).
So I would write "PIRQ event channels are not supported on Arm, so
nothing to do".
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/drivers/passthrough/arm/iommu.c
b/xen/drivers/passthrough/arm/iommu.c
index db3b07a571..fdec1c5547 100644
--- a/xen/drivers/passthrough/arm/iommu.c
+++ b/xen/drivers/passthrough/arm/iommu.c
@@ -135,3 +135,8 @@ void arch_iommu_domain_destroy(struct domain *d)
void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
{
}
+
+bool arch_iommu_use_permitted(const struct domain *d)
+{
+ return true;
+}
Please add a comment explaining why returning true is always fine.
Here is the comment that I will add in next version:
/*
* Return true as iommu use is always permitted if mem-sharing,
* mem-paging, or log-dirty functionality is not enabled.
*/
How about writing "Unlike x86, Arm doesn't support mem-sharing,
mem-paging and log-dirty (yet). So there is no restriction to use the
IOMMU".
This would make clear why you are mentioning mem-sharing, mem-paging & co.
Cheers,
--
Julien Grall
