[PATCH v4 12/16] libqos: add MSI-X callbacks to QVirtioPCIDevice

[Stefan Hajnoczi <stefanha@redhat.com>]

The MSI-X vectors are programmed differently in the VIRTIO 1.0 and
Legacy interfaces.  Introduce callbacks so different implementations can
be used depending on the interface version.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 tests/libqos/virtio-pci.h | 12 ++++++++++++
 tests/libqos/virtio-pci.c | 37 ++++++++++++++++++++++++++++---------
 2 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/tests/libqos/virtio-pci.h b/tests/libqos/virtio-pci.h
index 728b4715f1..4299efc023 100644
--- a/tests/libqos/virtio-pci.h
+++ b/tests/libqos/virtio-pci.h
@@ -14,16 +14,28 @@
 #include "libqos/pci.h"
 #include "libqos/qgraph.h"
 
+typedef struct QVirtioPCIMSIXOps QVirtioPCIMSIXOps;
+
 typedef struct QVirtioPCIDevice {
     QOSGraphObject obj;
     QVirtioDevice vdev;
     QPCIDevice *pdev;
     QPCIBar bar;
+    const QVirtioPCIMSIXOps *msix_ops;
     uint16_t config_msix_entry;
     uint64_t config_msix_addr;
     uint32_t config_msix_data;
 } QVirtioPCIDevice;
 
+struct QVirtioPCIMSIXOps {
+    /* Set the Configuration Vector for MSI-X */
+    void (*set_config_vector)(QVirtioPCIDevice *d, uint16_t entry);
+
+    /* Set the Queue Vector for MSI-X */
+    void (*set_queue_vector)(QVirtioPCIDevice *d, uint16_t vq_idx,
+                             uint16_t entry);
+};
+
 typedef struct QVirtQueuePCI {
     QVirtQueue vq;
     uint16_t msix_entry;
diff --git a/tests/libqos/virtio-pci.c b/tests/libqos/virtio-pci.c
index e4fa318dcc..0725777a8d 100644
--- a/tests/libqos/virtio-pci.c
+++ b/tests/libqos/virtio-pci.c
@@ -281,6 +281,31 @@ const QVirtioBus qvirtio_pci = {
     .virtqueue_kick = qvirtio_pci_virtqueue_kick,
 };
 
+static void qvirtio_pci_set_config_vector(QVirtioPCIDevice *d, uint16_t entry)
+{
+    uint16_t vector;
+
+    qpci_io_writew(d->pdev, d->bar, VIRTIO_MSI_CONFIG_VECTOR, entry);
+    vector = qpci_io_readw(d->pdev, d->bar, VIRTIO_MSI_CONFIG_VECTOR);
+    g_assert_cmphex(vector, !=, VIRTIO_MSI_NO_VECTOR);
+}
+
+static void qvirtio_pci_set_queue_vector(QVirtioPCIDevice *d, uint16_t vq_idx,
+                                         uint16_t entry)
+{
+    uint16_t vector;
+
+    qvirtio_pci_queue_select(&d->vdev, vq_idx);
+    qpci_io_writew(d->pdev, d->bar, VIRTIO_MSI_QUEUE_VECTOR, entry);
+    vector = qpci_io_readw(d->pdev, d->bar, VIRTIO_MSI_QUEUE_VECTOR);
+    g_assert_cmphex(vector, !=, VIRTIO_MSI_NO_VECTOR);
+}
+
+static const QVirtioPCIMSIXOps qvirtio_pci_msix_ops_legacy = {
+    .set_config_vector = qvirtio_pci_set_config_vector,
+    .set_queue_vector = qvirtio_pci_set_queue_vector,
+};
+
 void qvirtio_pci_device_enable(QVirtioPCIDevice *d)
 {
     qpci_device_enable(d->pdev);
@@ -295,7 +320,6 @@ void qvirtio_pci_device_disable(QVirtioPCIDevice *d)
 void qvirtqueue_pci_msix_setup(QVirtioPCIDevice *d, QVirtQueuePCI *vqpci,
                                         QGuestAllocator *alloc, uint16_t entry)
 {
-    uint16_t vector;
     uint32_t control;
     uint64_t off;
 
@@ -321,16 +345,12 @@ void qvirtqueue_pci_msix_setup(QVirtioPCIDevice *d, QVirtQueuePCI *vqpci,
                    off + PCI_MSIX_ENTRY_VECTOR_CTRL,
                    control & ~PCI_MSIX_ENTRY_CTRL_MASKBIT);
 
-    qvirtio_pci_queue_select(&d->vdev, vqpci->vq.index);
-    qpci_io_writew(d->pdev, d->bar, VIRTIO_MSI_QUEUE_VECTOR, entry);
-    vector = qpci_io_readw(d->pdev, d->bar, VIRTIO_MSI_QUEUE_VECTOR);
-    g_assert_cmphex(vector, !=, VIRTIO_MSI_NO_VECTOR);
+    d->msix_ops->set_queue_vector(d, vqpci->vq.index, entry);
 }
 
 void qvirtio_pci_set_msix_configuration_vector(QVirtioPCIDevice *d,
                                         QGuestAllocator *alloc, uint16_t entry)
 {
-    uint16_t vector;
     uint32_t control;
     uint64_t off;
 
@@ -358,9 +378,7 @@ void qvirtio_pci_set_msix_configuration_vector(QVirtioPCIDevice *d,
                    off + PCI_MSIX_ENTRY_VECTOR_CTRL,
                    control & ~PCI_MSIX_ENTRY_CTRL_MASKBIT);
 
-    qpci_io_writew(d->pdev, d->bar, VIRTIO_MSI_CONFIG_VECTOR, entry);
-    vector = qpci_io_readw(d->pdev, d->bar, VIRTIO_MSI_CONFIG_VECTOR);
-    g_assert_cmphex(vector, !=, VIRTIO_MSI_NO_VECTOR);
+    d->msix_ops->set_config_vector(d, entry);
 }
 
 void qvirtio_pci_destructor(QOSGraphObject *obj)
@@ -383,6 +401,7 @@ static void qvirtio_pci_init_from_pcidev(QVirtioPCIDevice *dev, QPCIDevice *pci_
     dev->vdev.device_type = qpci_config_readw(pci_dev, PCI_SUBSYSTEM_ID);
 
     dev->config_msix_entry = -1;
+    dev->msix_ops = &qvirtio_pci_msix_ops_legacy;
 
     dev->vdev.bus = &qvirtio_pci;
     dev->vdev.big_endian = qvirtio_pci_is_big_endian(dev);
-- 
2.21.0