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path: root/hw/virtio/virtio-pci.c
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Diffstat (limited to 'hw/virtio/virtio-pci.c')
-rw-r--r--hw/virtio/virtio-pci.c37
1 files changed, 35 insertions, 2 deletions
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index cb6940fc0e..cb159fd078 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1424,6 +1424,38 @@ static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
return offset;
}
+static void virtio_pci_set_vector(VirtIODevice *vdev,
+ VirtIOPCIProxy *proxy,
+ int queue_no, uint16_t old_vector,
+ uint16_t new_vector)
+{
+ bool kvm_irqfd = (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+ msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled();
+
+ if (new_vector == old_vector) {
+ return;
+ }
+
+ /*
+ * If the device uses irqfd and the vector changes after DRIVER_OK is
+ * set, we need to release the old vector and set up the new one.
+ * Otherwise just need to set the new vector on the device.
+ */
+ if (kvm_irqfd && old_vector != VIRTIO_NO_VECTOR) {
+ kvm_virtio_pci_vector_release_one(proxy, queue_no);
+ }
+ /* Set the new vector on the device. */
+ if (queue_no == VIRTIO_CONFIG_IRQ_IDX) {
+ vdev->config_vector = new_vector;
+ } else {
+ virtio_queue_set_vector(vdev, queue_no, new_vector);
+ }
+ /* If the new vector changed need to set it up. */
+ if (kvm_irqfd && new_vector != VIRTIO_NO_VECTOR) {
+ kvm_virtio_pci_vector_use_one(proxy, queue_no);
+ }
+}
+
int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy,
uint8_t bar, uint64_t offset, uint64_t length,
uint8_t id)
@@ -1570,7 +1602,8 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
} else {
val = VIRTIO_NO_VECTOR;
}
- vdev->config_vector = val;
+ virtio_pci_set_vector(vdev, proxy, VIRTIO_CONFIG_IRQ_IDX,
+ vdev->config_vector, val);
break;
case VIRTIO_PCI_COMMON_STATUS:
if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) {
@@ -1610,7 +1643,7 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
} else {
val = VIRTIO_NO_VECTOR;
}
- virtio_queue_set_vector(vdev, vdev->queue_sel, val);
+ virtio_pci_set_vector(vdev, proxy, vdev->queue_sel, vector, val);
break;
case VIRTIO_PCI_COMMON_Q_ENABLE:
if (val == 1) {