Re: [PATCH v6 7/9] virtio-pci: add support for configure interrupt

[Jason Wang]

在 2021/4/27 上午11:39, Cindy Lu 写道:
Add support for configure interrupt, use kvm_irqfd_assign and set the
gsi to kernel. When the configure notifier was eventfd_signal by host
kernel, this will finally inject an msix interrupt to guest
---
  hw/virtio/virtio-pci.c | 186 ++++++++++++++++++++++++++---------------
  1 file changed, 120 insertions(+), 66 deletions(-)

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 2b7e6cc0d9..07d28dd367 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -664,12 +664,10 @@ 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];
      int ret;
-


Unnecessary changes.


      if (irqfd->users == 0) {
          ret = kvm_irqchip_add_msi_route(kvm_state, vector, &proxy->pci_dev);
          if (ret < 0) {
@@ -708,93 +706,120 @@ static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy 
*proxy,
      ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, irqfd->virq);
      assert(ret == 0);
  }
-


So did here.


-static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy, int nvqs)
+ static int virtio_pci_get_notifier(VirtIOPCIProxy *proxy, int queue_no,
+                                      EventNotifier **n, unsigned int *vector)


The indentation looks not correct.


  {
      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;
      VirtQueue *vq;
-    EventNotifier *n;
-    for (queue_no = 0; queue_no < nvqs; queue_no++) {
+
+    if (queue_no == -1) {
+        *n = virtio_get_config_notifier(vdev);
+        *vector = vdev->config_vector;
+    } else {
          if (!virtio_queue_get_num(vdev, queue_no)) {
-            break;
-        }
-        vector = virtio_queue_vector(vdev, queue_no);
-        if (vector >= msix_nr_vectors_allocated(dev)) {
-            continue;
-        }
-        ret = kvm_virtio_pci_vq_vector_use(proxy, queue_no, 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) {
-            vq = virtio_get_queue(vdev, queue_no);
-            n = virtio_queue_get_guest_notifier(vq);
-            ret = kvm_virtio_pci_irqfd_use(proxy, n, vector);
-            if (ret < 0) {
-                kvm_virtio_pci_vq_vector_release(proxy, vector);
-                goto undo;
-            }
+            return -1;
          }
+        *vector = virtio_queue_vector(vdev, queue_no);
+        vq = virtio_get_queue(vdev, queue_no);
+        *n = virtio_queue_get_guest_notifier(vq);
+    }
+    if (*vector >= msix_nr_vectors_allocated(dev)) {
+        return -1;
      }
      return 0;
+}
  
+static int kvm_virtio_pci_vector_use_one(VirtIOPCIProxy *proxy, int queue_no)
+{


Let's use separate patch for the introducing of 
kvm_virtio_pci_vector_user/release_one().

And then do the config interrupt support on top.

Thanks