KVM: arm/arm64: vgic: Add refcounting for IRQs

In the moment our struct vgic_irq's are statically allocated at guest
creation time. So getting a pointer to an IRQ structure is trivial and
safe. LPIs are more dynamic, they can be mapped and unmapped at any time
during the guest's _runtime_.
In preparation for supporting LPIs we introduce reference counting for
those structures using the kernel's kref infrastructure.
Since private IRQs and SPIs are statically allocated, we avoid actually
refcounting them, since they would never be released anyway.
But we take provisions to increase the refcount when an IRQ gets onto a
VCPU list and decrease it when it gets removed. Also this introduces
vgic_put_irq(), which wraps kref_put and hides the release function from
the callers.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Andre Przywara
2016-07-15 12:43:27 +01:00
committed by Marc Zyngier
parent 8a39d00670
commit 5dd4b924e3
9 changed files with 99 additions and 12 deletions

View File

@@ -96,6 +96,7 @@ struct vgic_irq {
bool active; /* not used for LPIs */
bool enabled;
bool hw; /* Tied to HW IRQ */
struct kref refcount; /* Used for LPIs */
u32 hwintid; /* HW INTID number */
union {
u8 targets; /* GICv2 target VCPUs mask */