[PATCH 09/10] KVM: arm/arm64: vgic: Implement forwarding setting

Eric Auger
2017-05-24T20:10:40Z

Implements kvm_vgic_[set|unset]_forwarding.

Handle low-level VGIC programming and consistent irqchip
programming.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
---
include/kvm/arm_vgic.h | 5 +++
virt/kvm/arm/vgic/vgic.c | 105 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 110 insertions(+)

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 695ebc7..7ddac8a 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -343,4 +343,9 @@ int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi);
*/
int kvm_vgic_setup_default_irq_routing(struct kvm *kvm);

+int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int irq,
+ unsigned int virt_irq);
+void kvm_vgic_unset_forwarding(struct kvm *kvm, unsigned int irq,
+ unsigned int virt_irq);
+
#endif /* __KVM_ARM_VGIC_H */
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index aa0618c..c2add8d 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -17,6 +17,8 @@
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/list_sort.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>

#include "vgic.h"

@@ -771,3 +773,106 @@ bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int virt_irq)
return map_is_active;
}

+/**
+ * kvm_vgic_set_forwarding - Set IRQ forwarding
+ *
+ * @kvm: kvm handle
+ * @host_irq: the host linux IRQ
+ * @vintid: the virtual INTID
+ *
+ * This function must be called when the IRQ is not active:
+ * ie. not active at GIC level and not currently under injection
+ * into the guest using the unforwarded mode. The physical IRQ must
+ * be disabled and all vCPUs must have been exited and prevented
+ * from being re-entered.
+ */
+int kvm_vgic_set_forwarding(struct kvm *kvm, unsigned int host_irq,
+ unsigned int vintid)
+{
+ struct kvm_vcpu *vcpu;
+ struct vgic_irq *irq;
+ struct irq_desc *desc;
+ struct irq_data *data;
+ unsigned int pintid;
+ int ret = 0;
+
+
+ kvm_debug("%s host linux irq=%d vintid=%d\n",
+ __func__, host_irq, vintid);
+
+ if (!vgic_valid_spi(kvm, vintid))
+ return 0;
+
+ /* find the INTID corresponding to @host_irq */
+ desc = irq_to_desc(host_irq);
+ if (!desc) {
+ kvm_err("%s: no interrupt descriptor\n", __func__);
+ return -EINVAL;
+ }
+
+ data = irq_desc_get_irq_data(desc);
+ while (data->parent_data)
+ data = data->parent_data;
+
+ pintid = data->hwirq;
+
+ irq = vgic_get_irq(kvm, NULL, vintid);
+
+ spin_lock(&irq->irq_lock);
+
+ vcpu = irq->target_vcpu;
+
+ if (!vcpu) {
+ ret = -EAGAIN;
+ goto unlock;
+ }
+
+ irq_set_vcpu_affinity(host_irq, vcpu);
+
+ irq->hw = true;
+ irq->hwintid = pintid;
+ irq->host_irq = host_irq;
+
+unlock:
+ spin_unlock(&irq->irq_lock);
+ vgic_put_irq(kvm, irq);
+ return ret;
+}
+
+/**
+ * kvm_vgic_unset_forwarding - Unset IRQ forwarding
+ *
+ * @kvm: KVM handle
+ * @host_irq: the host Linux IRQ number
+ * @vintid: virtual INTID
+ *
+ * This function must be called when the host irq is disabled and
+ * all vCPUs have been exited and prevented from being re-entered.
+ */
+void kvm_vgic_unset_forwarding(struct kvm *kvm,
+ unsigned int host_irq,
+ unsigned int vintid)
+{
+ struct vgic_irq *irq;
+ bool active;
+
+ kvm_debug("%s host_irq=%d virt_irq=%d\n", __func__, host_irq, vintid);
+
+ irq_get_irqchip_state(host_irq, IRQCHIP_STATE_ACTIVE, &active);
+
+ irq = vgic_get_irq(kvm, NULL, vintid);
+ spin_lock(&irq->irq_lock);
+
+ if (!is_unshared_mapped(irq))
+ goto unlock;
+
+ if (active)
+ irq_set_irqchip_state(host_irq, IRQCHIP_STATE_ACTIVE, false);
+
+ irq->hw = false;
+ irq_set_vcpu_affinity(host_irq, NULL);
+
+unlock:
+ spin_unlock(&irq->irq_lock);
+}
+
--
2.5.5