#include "hw/sysbus.h"
#include "hw/virtio/virtio.h"
#include "qemu/host-utils.h"
+#include "sysemu/kvm.h"
#include "hw/virtio/virtio-bus.h"
+#include "qemu/error-report.h"
/* #define DEBUG_VIRTIO_MMIO */
SysBusDevice parent_obj;
MemoryRegion iomem;
qemu_irq irq;
- uint32_t host_features;
/* Guest accessible state needing migration and reset */
uint32_t host_features_sel;
uint32_t guest_features_sel;
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_start_ioeventfd(VirtIOMMIOProxy *proxy)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+ int n, r;
+
+ if (!kvm_eventfds_enabled() ||
+ proxy->ioeventfd_disabled ||
+ proxy->ioeventfd_started) {
+ return;
+ }
+
+ for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
+ if (!virtio_queue_get_num(vdev, n)) {
+ continue;
+ }
+
+ r = virtio_mmio_set_host_notifier_internal(proxy, n, true, true);
+ if (r < 0) {
+ goto assign_error;
+ }
+ }
+ proxy->ioeventfd_started = true;
+ return;
+
+assign_error:
+ while (--n >= 0) {
+ 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;
+ error_report("%s: failed. Fallback to a userspace (slower).", __func__);
+}
+
+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_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)
{
if (proxy->host_features_sel) {
return 0;
}
- return proxy->host_features;
+ return vdev->host_features;
case VIRTIO_MMIO_QUEUENUMMAX:
if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
return 0;
proxy->guest_page_shift);
break;
case VIRTIO_MMIO_QUEUESEL:
- if (value < VIRTIO_PCI_QUEUE_MAX) {
+ if (value < VIRTIO_QUEUE_MAX) {
vdev->queue_sel = value;
}
break;
case VIRTIO_MMIO_QUEUENUM:
DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE);
virtio_queue_set_num(vdev, vdev->queue_sel, value);
+ /* Note: only call this function for legacy devices */
+ virtio_queue_update_rings(vdev, vdev->queue_sel);
break;
case VIRTIO_MMIO_QUEUEALIGN:
+ /* Note: this is only valid for legacy devices */
virtio_queue_set_align(vdev, vdev->queue_sel, value);
break;
case VIRTIO_MMIO_QUEUEPFN:
}
break;
case VIRTIO_MMIO_QUEUENOTIFY:
- if (value < VIRTIO_PCI_QUEUE_MAX) {
+ if (value < VIRTIO_QUEUE_MAX) {
virtio_queue_notify(vdev, value);
}
break;
virtio_update_irq(vdev);
break;
case VIRTIO_MMIO_STATUS:
+ if (!(value & VIRTIO_CONFIG_S_DRIVER_OK)) {
+ virtio_mmio_stop_ioeventfd(proxy);
+ }
+
virtio_set_status(vdev, value & 0xff);
+
+ if (value & VIRTIO_CONFIG_S_DRIVER_OK) {
+ virtio_mmio_start_ioeventfd(proxy);
+ }
+
if (vdev->status == 0) {
virtio_reset(vdev);
}
qemu_set_irq(proxy->irq, level);
}
-static unsigned int virtio_mmio_get_features(DeviceState *opaque)
-{
- VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
-
- return proxy->host_features;
-}
-
static int virtio_mmio_load_config(DeviceState *opaque, QEMUFile *f)
{
VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
{
VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
+ virtio_mmio_stop_ioeventfd(proxy);
virtio_bus_reset(&proxy->bus);
proxy->host_features_sel = 0;
proxy->guest_features_sel = 0;
proxy->guest_page_shift = 0;
}
-/* virtio-mmio device */
+static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
+ bool with_irqfd)
+{
+ VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
+ VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+ VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
+ VirtQueue *vq = virtio_get_queue(vdev, n);
+ EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
+
+ 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);
+ } else {
+ virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
+ event_notifier_cleanup(notifier);
+ }
+
+ if (vdc->guest_notifier_mask) {
+ vdc->guest_notifier_mask(vdev, n, !assign);
+ }
-/* This is called by virtio-bus just after the device is plugged. */
-static void virtio_mmio_device_plugged(DeviceState *opaque)
+ return 0;
+}
+
+static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
+ bool assign)
+{
+ VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
+ VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+ /* TODO: need to check if kvm-arm supports irqfd */
+ bool with_irqfd = false;
+ int r, n;
+
+ nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX);
+
+ for (n = 0; n < nvqs; n++) {
+ if (!virtio_queue_get_num(vdev, n)) {
+ break;
+ }
+
+ r = virtio_mmio_set_guest_notifier(d, n, assign, with_irqfd);
+ if (r < 0) {
+ goto assign_error;
+ }
+ }
+
+ return 0;
+
+assign_error:
+ /* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */
+ assert(assign);
+ while (--n >= 0) {
+ virtio_mmio_set_guest_notifier(d, n, !assign, false);
+ }
+ return r;
+}
+
+static int virtio_mmio_set_host_notifier(DeviceState *opaque, int n,
+ bool assign)
{
VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
- proxy->host_features |= (0x1 << VIRTIO_F_NOTIFY_ON_EMPTY);
- proxy->host_features = virtio_bus_get_vdev_features(&proxy->bus,
- proxy->host_features);
+ /* 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 */
+
static void virtio_mmio_realizefn(DeviceState *d, Error **errp)
{
VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
SysBusDevice *sbd = SYS_BUS_DEVICE(d);
- virtio_mmio_bus_new(&proxy->bus, sizeof(proxy->bus), proxy);
+ qbus_create_inplace(&proxy->bus, sizeof(proxy->bus), TYPE_VIRTIO_MMIO_BUS,
+ d, NULL);
sysbus_init_irq(sbd, &proxy->irq);
memory_region_init_io(&proxy->iomem, OBJECT(d), &virtio_mem_ops, proxy,
TYPE_VIRTIO_MMIO, 0x200);
sysbus_init_mmio(sbd, &proxy->iomem);
}
-static Property virtio_mmio_properties[] = {
- DEFINE_VIRTIO_COMMON_FEATURES(VirtIOMMIOProxy, host_features),
- DEFINE_PROP_END_OF_LIST(),
-};
-
static void virtio_mmio_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
- dc->props = virtio_mmio_properties;
dc->realize = virtio_mmio_realizefn;
dc->reset = virtio_mmio_reset;
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
/* virtio-mmio-bus. */
-static void virtio_mmio_bus_new(VirtioBusState *bus, size_t bus_size,
- VirtIOMMIOProxy *dev)
-{
- DeviceState *qdev = DEVICE(dev);
- BusState *qbus;
-
- qbus_create_inplace(bus, bus_size, TYPE_VIRTIO_MMIO_BUS, qdev, NULL);
- qbus = BUS(bus);
- qbus->allow_hotplug = 0;
-}
-
static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data)
{
BusClass *bus_class = BUS_CLASS(klass);
k->notify = virtio_mmio_update_irq;
k->save_config = virtio_mmio_save_config;
k->load_config = virtio_mmio_load_config;
- k->get_features = virtio_mmio_get_features;
- k->device_plugged = virtio_mmio_device_plugged;
+ k->set_host_notifier = virtio_mmio_set_host_notifier;
+ k->set_guest_notifiers = virtio_mmio_set_guest_notifiers;
k->has_variable_vring_alignment = true;
bus_class->max_dev = 1;
}
projects / qemu.git / blobdiff