[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [RFC PATCH 30/49] ARM: new VGIC: Add ENABLE registers handlers

On 19/02/18 12:41, Andre Przywara wrote:


On 16/02/18 16:57, Julien Grall wrote:
On 09/02/18 14:39, Andre Przywara wrote:
+    spin_lock_irqsave(&desc->lock, flags);
+    if ( enable )
+    {
+        gic_set_irq_type(desc, irq_type == VGIC_CONFIG_LEVEL ?

Indentation and I would prefer a helper to convert between the vgic
value and the IRQ_TYPE. This would make the code easier to read.

Also, this code does not replicate correctly the current vGIC.
gic_set_irq_type is only allowed to be used when
irq_set_type_by_domain(d) returns true. If you consider this change
valid, then I would like to know why.

So what is/was the rationale for not allowing IRQ type changes for
non-privileged guests? If you allow to pass through an hardware IRQ to a
guest (which is the case this function handles), then I don't see why a
guest would not be allowed to change the configuration? It seems rather
odd, I guess it's up to the guest to know which type of IRQ this is?

If you can answer the question on top of irq_type_set_by_domain (i.e "See whether it is possible to let any domain configure the type) then we can remove it. We decided to only allow for the hardware domain because we trust it.


Julien Grall

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.