virtio-pci: decouple the single vector from the interrupt process

To reuse the interrupt process in configure interrupt
Need to decouple the single vector from the interrupt process.
We add new function kvm_virtio_pci_vector_use_one and _release_one.
These functions are used for the single vector, the whole process will
finish in the loop with vq number.

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20221222070451.936503-4-lulu@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 73 insertions, 58 deletions

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 68d04928db..d7e29b1cdc 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -784,7 +784,6 @@ static uint32_t virtio_read_config(PCIDevice *pci_dev,
 }
 
 static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy *proxy,
-                                        unsigned int queue_no,
                                         unsigned int vector)
 {
     VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
@@ -849,87 +848,103 @@ static int virtio_pci_get_notifier(VirtIOPCIProxy *proxy, int queue_no,
     return 0;
 }
 
-static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy, int nvqs)
+static int kvm_virtio_pci_vector_use_one(VirtIOPCIProxy *proxy, int queue_no)
 {
+    unsigned int vector;
+    int ret;
+    EventNotifier *n;
     PCIDevice *dev = &proxy->pci_dev;
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
-    unsigned int vector;
-    int ret, queue_no;
-    EventNotifier *n;
-    for (queue_no = 0; queue_no < nvqs; queue_no++) {
-        if (!virtio_queue_get_num(vdev, queue_no)) {
-            break;
-        }
-        ret = virtio_pci_get_notifier(proxy, queue_no, &n, &vector);
-        if (ret < 0) {
-            break;
-        }
-        if (vector >= msix_nr_vectors_allocated(dev)) {
-            continue;
-        }
-        ret = kvm_virtio_pci_vq_vector_use(proxy, queue_no, vector);
+
+    ret = virtio_pci_get_notifier(proxy, queue_no, &n, &vector);
+    if (ret < 0) {
+        return ret;
+    }
+    if (vector >= msix_nr_vectors_allocated(dev)) {
+        return 0;
+    }
+    ret = kvm_virtio_pci_vq_vector_use(proxy, vector);
+    if (ret < 0) {
+        goto undo;
+    }
+    /*
+     * If guest supports masking, set up irqfd now.
+     * Otherwise, delay until unmasked in the frontend.
+     */
+    if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) {
+        ret = kvm_virtio_pci_irqfd_use(proxy, n, vector);
         if (ret < 0) {
+            kvm_virtio_pci_vq_vector_release(proxy, vector);
             goto undo;
         }
-        /* If guest supports masking, set up irqfd now.
-         * Otherwise, delay until unmasked in the frontend.
-         */
-        if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) {
-            ret = kvm_virtio_pci_irqfd_use(proxy, n, vector);
-            if (ret < 0) {
-                kvm_virtio_pci_vq_vector_release(proxy, vector);
-                goto undo;
-            }
-        }
     }
-    return 0;
 
+    return 0;
 undo:
-    while (--queue_no >= 0) {
-        vector = virtio_queue_vector(vdev, queue_no);
-        if (vector >= msix_nr_vectors_allocated(dev)) {
-            continue;
+
+    vector = virtio_queue_vector(vdev, queue_no);
+    if (vector >= msix_nr_vectors_allocated(dev)) {
+        return ret;
+    }
+    if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) {
+        ret = virtio_pci_get_notifier(proxy, queue_no, &n, &vector);
+        if (ret < 0) {
+            return ret;
         }
-        if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) {
-            ret = virtio_pci_get_notifier(proxy, queue_no, &n, &vector);
-            if (ret < 0) {
-                break;
-            }
-            kvm_virtio_pci_irqfd_release(proxy, n, vector);
+        kvm_virtio_pci_irqfd_release(proxy, n, vector);
+    }
+    return ret;
+}
+static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy, int nvqs)
+{
+    int queue_no;
+    int ret = 0;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
+    for (queue_no = 0; queue_no < nvqs; queue_no++) {
+        if (!virtio_queue_get_num(vdev, queue_no)) {
+            return -1;
         }
-        kvm_virtio_pci_vq_vector_release(proxy, vector);
+        ret = kvm_virtio_pci_vector_use_one(proxy, queue_no);
     }
     return ret;
 }
 
-static void kvm_virtio_pci_vector_release(VirtIOPCIProxy *proxy, int nvqs)
+
+static void kvm_virtio_pci_vector_release_one(VirtIOPCIProxy *proxy,
+                                              int queue_no)
 {
-    PCIDevice *dev = &proxy->pci_dev;
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     unsigned int vector;
-    int queue_no;
-    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
     EventNotifier *n;
-    int ret ;
+    int ret;
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    PCIDevice *dev = &proxy->pci_dev;
+
+    ret = virtio_pci_get_notifier(proxy, queue_no, &n, &vector);
+    if (ret < 0) {
+        return;
+    }
+    if (vector >= msix_nr_vectors_allocated(dev)) {
+        return;
+    }
+    if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) {
+        kvm_virtio_pci_irqfd_release(proxy, n, vector);
+    }
+    kvm_virtio_pci_vq_vector_release(proxy, vector);
+}
+
+static void kvm_virtio_pci_vector_release(VirtIOPCIProxy *proxy, int nvqs)
+{
+    int queue_no;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
     for (queue_no = 0; queue_no < nvqs; queue_no++) {
         if (!virtio_queue_get_num(vdev, queue_no)) {
             break;
         }
-        ret = virtio_pci_get_notifier(proxy, queue_no, &n, &vector);
-        if (ret < 0) {
-            break;
-        }
-        if (vector >= msix_nr_vectors_allocated(dev)) {
-            continue;
-        }
-        /* If guest supports masking, clean up irqfd now.
-         * Otherwise, it was cleaned when masked in the frontend.
-         */
-        if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) {
-            kvm_virtio_pci_irqfd_release(proxy, n, vector);
-        }
-        kvm_virtio_pci_vq_vector_release(proxy, vector);
+        kvm_virtio_pci_vector_release_one(proxy, queue_no);
     }
 }