From 58cd577ff157cfaf7506bba135db58e75c330ff0 Mon Sep 17 00:00:00 2001

From: Cindy Lu <lulu@redhat.com>

Date: Thu, 22 Dec 2022 15:04:44 +0800

Subject: [PATCH 03/31] virtio-pci: decouple the single vector from the

 interrupt process

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RH-Author: Cindy Lu <lulu@redhat.com>

RH-MergeRequest: 132: vhost-vdpa: support config interrupt in vhost-vdpa

RH-Bugzilla: 1905805

RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

RH-Acked-by: Eugenio Pérez <eperezma@redhat.com>

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

RH-Commit: [3/10] 2c79cb678f005fb2f53b2db0f237347634ab3422 (lulu6/qemu-kvm3)

https://bugzilla.redhat.com/show_bug.cgi?id=1905805

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>

(cherry picked from commit ee3b8dc6cc496ba7f4e27aed4493275c706a7942)

Signed-off-by: Cindy Lu <lulu@redhat.com>

---

 hw/virtio/virtio-pci.c | 131 +++++++++++++++++++++++------------------

 1 file changed, 73 insertions(+), 58 deletions(-)

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c

index 52c7692fff..ec816ea367 100644

--- a/hw/virtio/virtio-pci.c

+++ b/hw/virtio/virtio-pci.c

@@ -699,7 +699,6 @@ 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];

@@ -764,87 +763,103 @@ 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);

     }

 }

-- 

2.31.1