[PATCH v3 7/9] vfio: add infrastructure to commit the deferred kvm routing

["Longpeng(Mike)" <longpeng2@huawei.com>]

'defer_kvm_irq_routing' indicates whether we should defer to commit
the kvm routing.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
---
 hw/vfio/pci.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
 hw/vfio/pci.h |  1 +
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 8e97ca93cf..8fe238b11d 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -423,12 +423,24 @@ static void vfio_add_kvm_msi_virq(VFIOPCIDevice *vdev, VFIOMSIVector *vector,
         return;
     }
 
-    virq = kvm_irqchip_add_msi_route(kvm_state, vector_n, &vdev->pdev);
+    virq = kvm_irqchip_add_deferred_msi_route(kvm_state, vector_n, &vdev->pdev);
     if (virq < 0) {
         event_notifier_cleanup(&vector->kvm_interrupt);
         return;
     }
 
+    if (vdev->defer_kvm_irq_routing) {
+        /*
+         * Hold the allocated virq in vector->virq temporarily, will
+         * reset it to -1 when we fail to add the corresponding irqfd
+         * in vfio_commit_kvm_msi_virq().
+         */
+        vector->virq = virq;
+        return;
+    }
+
+    kvm_irqchip_commit_routes(kvm_state);
+
     if (kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, &vector->kvm_interrupt,
                                        NULL, virq) < 0) {
         kvm_irqchip_release_virq(kvm_state, virq);
@@ -567,6 +579,35 @@ static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr)
     }
 }
 
+/* TODO: invoked when enclabe msi/msix vectors */
+static __attribute__((unused)) void vfio_commit_kvm_msi_virq(VFIOPCIDevice *vdev)
+{
+    int i;
+    VFIOMSIVector *vector;
+
+    if (!vdev->defer_kvm_irq_routing || !vdev->nr_vectors) {
+        return;
+    }
+
+    kvm_irqchip_commit_routes(kvm_state);
+
+    for (i = 0; i < vdev->nr_vectors; i++) {
+        vector = &vdev->msi_vectors[i];
+
+        if (!vector->use || vector->virq < 0) {
+            continue;
+        }
+
+        if (kvm_irqchip_add_irqfd_notifier_gsi(kvm_state,
+                                               &vector->kvm_interrupt,
+                                               NULL, vector->virq) < 0) {
+            kvm_irqchip_release_virq(kvm_state, vector->virq);
+            event_notifier_cleanup(&vector->kvm_interrupt);
+            vector->virq = -1;
+        }
+    }
+}
+
 static void vfio_msix_enable(VFIOPCIDevice *vdev)
 {
     PCIDevice *pdev = &vdev->pdev;
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 64777516d1..d3c5177d37 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -171,6 +171,7 @@ struct VFIOPCIDevice {
     bool no_kvm_ioeventfd;
     bool no_vfio_ioeventfd;
     bool enable_ramfb;
+    bool defer_kvm_irq_routing;
     VFIODisplay *dpy;
     Notifier irqchip_change_notifier;
 };
-- 
2.23.0