irqchip/GICv3: Don't deactivate interrupts forwarded to a guest
Commit 0a4377de3056 ("genirq: Introduce irq_set_vcpu_affinity() to
target an interrupt to a VCPU") added just what we needed at the
lowest level to allow an interrupt to be deactivated by a guest.
When such a request reaches the GIC, it knows it doesn't need to
perform the deactivation anymore, and can safely leave the guest
do its magic. This of course requires additional support in both
VFIO and KVM.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-and-tested-by: Eric Auger <eric.auger@linaro.org>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: kvmarm@lists.cs.columbia.edu
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1440604845-28229-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 5c31cc9..7deed6e 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -70,6 +70,11 @@
return gic_irq(d) < 32;
}
+static inline bool forwarded_irq(struct irq_data *d)
+{
+ return d->handler_data != NULL;
+}
+
static inline void __iomem *gic_dist_base(struct irq_data *d)
{
if (gic_irq_in_rdist(d)) /* SGI+PPI -> SGI_base for this CPU */
@@ -236,6 +241,16 @@
static void gic_eoimode1_mask_irq(struct irq_data *d)
{
gic_mask_irq(d);
+ /*
+ * When masking a forwarded interrupt, make sure it is
+ * deactivated as well.
+ *
+ * This ensures that an interrupt that is getting
+ * disabled/masked will not get "stuck", because there is
+ * noone to deactivate it (guest is being terminated).
+ */
+ if (forwarded_irq(d))
+ gic_poke_irq(d, GICD_ICACTIVER);
}
static void gic_unmask_irq(struct irq_data *d)
@@ -306,9 +321,10 @@
static void gic_eoimode1_eoi_irq(struct irq_data *d)
{
/*
- * No need to deactivate an LPI.
+ * No need to deactivate an LPI, or an interrupt that
+ * is is getting forwarded to a vcpu.
*/
- if (gic_irq(d) >= 8192)
+ if (gic_irq(d) >= 8192 || forwarded_irq(d))
return;
gic_write_dir(gic_irq(d));
}
@@ -339,6 +355,12 @@
return gic_configure_irq(irq, type, base, rwp_wait);
}
+static int gic_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
+{
+ d->handler_data = vcpu;
+ return 0;
+}
+
static u64 gic_mpidr_to_affinity(u64 mpidr)
{
u64 aff;
@@ -703,6 +725,7 @@
.irq_set_affinity = gic_set_affinity,
.irq_get_irqchip_state = gic_irq_get_irqchip_state,
.irq_set_irqchip_state = gic_irq_set_irqchip_state,
+ .irq_set_vcpu_affinity = gic_irq_set_vcpu_affinity,
.flags = IRQCHIP_SET_TYPE_MASKED,
};