um: virtio/pci: enable suspend/resume
The UM virtual PCI devices currently cannot be suspended properly
since the virtio driver already disables VQs well before the PCI
bus's suspend_noirq wants to complete the transition by writing to
PCI config space.
After trying around for a long time with moving the devices on the
DPM list, trying to create dependencies between them, etc. I gave
up and instead added UML specific cross-driver API that lets the
virt-pci code enable not suspending/resuming VQs for its devices.
This then allows the PCI bus suspend_noirq to still talk to the
device, and suspend/resume works properly.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c
index 91ddf74..4412d6f 100644
--- a/arch/um/drivers/virtio_uml.c
+++ b/arch/um/drivers/virtio_uml.c
@@ -56,6 +56,7 @@ struct virtio_uml_device {
u8 status;
u8 registered:1;
u8 suspended:1;
+ u8 no_vq_suspend:1;
u8 config_changed_irq:1;
uint64_t vq_irq_vq_map;
@@ -1098,6 +1099,19 @@ static void virtio_uml_release_dev(struct device *d)
kfree(vu_dev);
}
+void virtio_uml_set_no_vq_suspend(struct virtio_device *vdev,
+ bool no_vq_suspend)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+
+ if (WARN_ON(vdev->config != &virtio_uml_config_ops))
+ return;
+
+ vu_dev->no_vq_suspend = no_vq_suspend;
+ dev_info(&vdev->dev, "%sabled VQ suspend\n",
+ no_vq_suspend ? "dis" : "en");
+}
+
/* Platform device */
static int virtio_uml_probe(struct platform_device *pdev)
@@ -1302,13 +1316,16 @@ MODULE_DEVICE_TABLE(of, virtio_uml_match);
static int virtio_uml_suspend(struct platform_device *pdev, pm_message_t state)
{
struct virtio_uml_device *vu_dev = platform_get_drvdata(pdev);
- struct virtqueue *vq;
- virtio_device_for_each_vq((&vu_dev->vdev), vq) {
- struct virtio_uml_vq_info *info = vq->priv;
+ if (!vu_dev->no_vq_suspend) {
+ struct virtqueue *vq;
- info->suspended = true;
- vhost_user_set_vring_enable(vu_dev, vq->index, false);
+ virtio_device_for_each_vq((&vu_dev->vdev), vq) {
+ struct virtio_uml_vq_info *info = vq->priv;
+
+ info->suspended = true;
+ vhost_user_set_vring_enable(vu_dev, vq->index, false);
+ }
}
if (!device_may_wakeup(&vu_dev->vdev.dev)) {
@@ -1322,13 +1339,16 @@ static int virtio_uml_suspend(struct platform_device *pdev, pm_message_t state)
static int virtio_uml_resume(struct platform_device *pdev)
{
struct virtio_uml_device *vu_dev = platform_get_drvdata(pdev);
- struct virtqueue *vq;
- virtio_device_for_each_vq((&vu_dev->vdev), vq) {
- struct virtio_uml_vq_info *info = vq->priv;
+ if (!vu_dev->no_vq_suspend) {
+ struct virtqueue *vq;
- info->suspended = false;
- vhost_user_set_vring_enable(vu_dev, vq->index, true);
+ virtio_device_for_each_vq((&vu_dev->vdev), vq) {
+ struct virtio_uml_vq_info *info = vq->priv;
+
+ info->suspended = false;
+ vhost_user_set_vring_enable(vu_dev, vq->index, true);
+ }
}
vu_dev->suspended = false;