@@ -23,6 +23,7 @@
#include "hw/virtio/virtio.h"
#include "qemu/host-utils.h"
#include "hw/virtio/virtio-bus.h"
+#include "qemu/error-report.h"
/* #define DEBUG_VIRTIO_MMIO */
@@ -87,11 +88,61 @@ typedef struct {
uint32_t guest_page_shift;
/* virtio-bus */
VirtioBusState bus;
+ bool ioeventfd_disabled;
+ bool ioeventfd_started;
} VirtIOMMIOProxy;
static void virtio_mmio_bus_new(VirtioBusState *bus, size_t bus_size,
VirtIOMMIOProxy *dev);
+static int virtio_mmio_set_host_notifier_internal(VirtIOMMIOProxy *proxy,
+ int n, bool assign, bool set_handler)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+ VirtQueue *vq = virtio_get_queue(vdev, n);
+ EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
+ int r = 0;
+
+ if (assign) {
+ r = event_notifier_init(notifier, 1);
+ if (r < 0) {
+ error_report("%s: unable to init event notifier: %d",
+ __func__, r);
+ return r;
+ }
+ virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler);
+ memory_region_add_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
+ true, n, notifier);
+ } else {
+ memory_region_del_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
+ true, n, notifier);
+ virtio_queue_set_host_notifier_fd_handler(vq, false, false);
+ event_notifier_cleanup(notifier);
+ }
+ return r;
+}
+
+static void virtio_mmio_stop_ioeventfd(VirtIOMMIOProxy *proxy)
+{
+ int r;
+ int n;
+ VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
+ if (!proxy->ioeventfd_started) {
+ return;
+ }
+
+ for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
+ if (!virtio_queue_get_num(vdev, n)) {
+ continue;
+ }
+
+ r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false);
+ assert(r >= 0);
+ }
+ proxy->ioeventfd_started = false;
+}
+
static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
{
VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
@@ -345,6 +396,24 @@ static void virtio_mmio_reset(DeviceState *d)
proxy->guest_page_shift = 0;
}
+static int virtio_mmio_set_host_notifier(DeviceState *opaque, int n, bool assign)
+{
+ VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
+
+ /* Stop using ioeventfd for virtqueue kick if the device starts using host
+ * notifiers. This makes it easy to avoid stepping on each others' toes.
+ */
+ proxy->ioeventfd_disabled = assign;
+ if (assign) {
+ virtio_mmio_stop_ioeventfd(proxy);
+ }
+ /* We don't need to start here: it's not needed because backend
+ * currently only stops on status change away from ok,
+ * reset, vmstop and such. If we do add code to start here,
+ * need to check vmstate, device state etc. */
+ return virtio_mmio_set_host_notifier_internal(proxy, n, assign, false);
+}
+
/* virtio-mmio device */
/* This is called by virtio-bus just after the device is plugged. */
@@ -406,6 +475,7 @@ static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data)
k->notify = virtio_mmio_update_irq;
k->save_config = virtio_mmio_save_config;
k->load_config = virtio_mmio_load_config;
+ k->set_host_notifier = virtio_mmio_set_host_notifier;
k->get_features = virtio_mmio_get_features;
k->device_plugged = virtio_mmio_device_plugged;
k->has_variable_vring_alignment = true;
set_host_notifier() is introduced into virtio-mmio now. Most of codes came from virtio-pci. Signed-off-by: Ying-Shiuan Pan <yspan@itri.org.tw> --- hw/virtio/virtio-mmio.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+)