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[Qemu-devel] [PATCH 3/3] virtio-ccw: Wire up guest and host notifies.
From: |
Cornelia Huck |
Subject: |
[Qemu-devel] [PATCH 3/3] virtio-ccw: Wire up guest and host notifies. |
Date: |
Mon, 24 Jun 2013 12:59:05 +0200 |
Guest and host notifiers are needed by vhost. We use ioeventfds for
the guest notifiers, but need to fall back on qemu injecting interrupts
for the host notifiers.
Signed-off-by: Cornelia Huck <address@hidden>
---
hw/s390x/virtio-ccw.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++
hw/s390x/virtio-ccw.h | 1 +
2 files changed, 89 insertions(+)
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 4ad9d9a..faef5dd 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -101,6 +101,7 @@ static void virtio_ccw_start_ioeventfd(VirtioCcwDevice *dev)
int n, r;
if (!(dev->flags & VIRTIO_CCW_FLAG_USE_IOEVENTFD) ||
+ dev->ioeventfd_disabled ||
dev->ioeventfd_started) {
return;
}
@@ -911,6 +912,90 @@ static void virtio_ccw_vmstate_change(DeviceState *d, bool
running)
}
}
+static bool virtio_ccw_query_guest_notifiers(DeviceState *d)
+{
+ VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
+
+ return !!(dev->sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ENA);
+}
+
+static int virtio_ccw_set_host_notifier(DeviceState *d, int n, bool assign)
+{
+ VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
+
+ /* Stop using the generic ioeventfd, we are doing eventfd handling
+ * ourselves below */
+ dev->ioeventfd_disabled = assign;
+ if (assign) {
+ virtio_ccw_stop_ioeventfd(dev);
+ }
+ return virtio_ccw_set_guest2host_notifier(dev, n, assign, false);
+}
+
+static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
+ bool assign, bool with_irqfd)
+{
+ VirtQueue *vq = virtio_get_queue(dev->vdev, n);
+ EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
+ VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(dev->vdev);
+
+ if (assign) {
+ int r = event_notifier_init(notifier, 0);
+
+ if (r < 0) {
+ return r;
+ }
+ virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
+ /* We do not support irqfd for classic I/O interrupts, because the
+ * classic interrupts are intermixed with the subchannel status, that
+ * is queried with test subchannel. We want to use vhost, though.
+ * Lets make sure to have vhost running and wire up the irq fd to
+ * land in qemu (and only the irq fd) in this code.
+ */
+ if (k->guest_notifier_mask) {
+ k->guest_notifier_mask(dev->vdev, n, false);
+ }
+ /* get lost events and re-inject */
+ if (k->guest_notifier_pending &&
+ k->guest_notifier_pending(dev->vdev, n)) {
+ event_notifier_set(notifier);
+ }
+ } else {
+ if (k->guest_notifier_mask) {
+ k->guest_notifier_mask(dev->vdev, n, true);
+ }
+ virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
+ event_notifier_cleanup(notifier);
+ }
+ return 0;
+}
+
+static int virtio_ccw_set_guest_notifiers(DeviceState *d, int nvqs,
+ bool assigned)
+{
+ VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
+ VirtIODevice *vdev = dev->vdev;
+ int r, n;
+
+ for (n = 0; n < nvqs; n++) {
+ if (!virtio_queue_get_num(vdev, n)) {
+ break;
+ }
+ /* false -> true, as soon as irqfd works */
+ r = virtio_ccw_set_guest_notifier(dev, n, assigned, false);
+ if (r < 0) {
+ goto assign_error;
+ }
+ }
+ return 0;
+
+assign_error:
+ while (--n >= 0) {
+ virtio_ccw_set_guest_notifier(dev, n, !assigned, false);
+ }
+ return r;
+}
+
/**************** Virtio-ccw Bus Device Descriptions *******************/
static Property virtio_ccw_net_properties[] = {
@@ -1224,6 +1309,9 @@ static void virtio_ccw_bus_class_init(ObjectClass *klass,
void *data)
k->notify = virtio_ccw_notify;
k->get_features = virtio_ccw_get_features;
k->vmstate_change = virtio_ccw_vmstate_change;
+ k->query_guest_notifiers = virtio_ccw_query_guest_notifiers;
+ k->set_host_notifier = virtio_ccw_set_host_notifier;
+ k->set_guest_notifiers = virtio_ccw_set_guest_notifiers;
}
static const TypeInfo virtio_ccw_bus_info = {
diff --git a/hw/s390x/virtio-ccw.h b/hw/s390x/virtio-ccw.h
index 433f27a..96d6f5d 100644
--- a/hw/s390x/virtio-ccw.h
+++ b/hw/s390x/virtio-ccw.h
@@ -82,6 +82,7 @@ struct VirtioCcwDevice {
uint32_t host_features[VIRTIO_CCW_FEATURE_SIZE];
VirtioBusState bus;
bool ioeventfd_started;
+ bool ioeventfd_disabled;
uint32_t flags;
/* Guest provided values: */
hwaddr indicators;
--
1.7.9.5