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;
}
/*
* This function handles both assigning the ioeventfd handler and
* registering it with the kernel.
* assign: register/deregister ioeventfd with the kernel
* set_handler: use the generic ioeventfd handler
*/
static int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
int n, bool assign, bool set_handler)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(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);
r = k->ioeventfd_assign(proxy, notifier, n, assign);
if (r < 0) {
error_report("%s: unable to assign ioeventfd: %d", __func__, r);
virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
return r;
}
} else {
k->ioeventfd_assign(proxy, notifier, n, assign);
virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
}
return r;
}
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 && vdev->use_guest_notifier_mask) {
vdc->guest_notifier_mask(vdev, n, !assign);
}
return 0;
}
int virtio_bus_start_ioeventfd(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
int r;
if (!k->ioeventfd_assign || !k->ioeventfd_enabled(proxy)) {
return -ENOSYS;
}
if (bus->ioeventfd_started) {
return 0;
}
/* Only set our notifier if we have ownership. */
if (!bus->ioeventfd_grabbed) {
r = vdc->start_ioeventfd(vdev);
if (r < 0) {
error_report("%s: failed. Fallback to userspace (slower).", __func__);
return r;
}
}
bus->ioeventfd_started = true;
return 0;
}
/* Reset the virtio_bus */
void virtio_bus_reset(VirtioBusState *bus)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
DPRINTF("%s: reset device.\n", BUS(bus)->name);
if (vdev != NULL) {
virtio_reset(vdev);
}
}
/* Get the features of the plugged device. */
uint32_t virtio_bus_get_vdev_features(VirtioBusState *bus,
uint32_t requested_features)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioDeviceClass *k;
assert(vdev != NULL);
k = VIRTIO_DEVICE_GET_CLASS(vdev);
assert(k->get_features != NULL);
return k->get_features(vdev, requested_features);
}
/* Set config of the plugged device. */
void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioDeviceClass *k;
assert(vdev != NULL);
k = VIRTIO_DEVICE_GET_CLASS(vdev);
if (k->set_config != NULL) {
k->set_config(vdev, config);
}
}
static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
{
VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
int level;
if (!vdev) {
return;
}
level = (atomic_read(&vdev->isr) != 0);
DPRINTF("virtio_mmio setting IRQ %d\n", level);
qemu_set_irq(proxy->irq, level);
}
/* Get bad features of the plugged device. */
uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioDeviceClass *k;
assert(vdev != NULL);
k = VIRTIO_DEVICE_GET_CLASS(vdev);
if (k->bad_features != NULL) {
return k->bad_features(vdev);
} else {
return 0;
}
}
void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
{
VirtIODevice *vdev;
VirtioDeviceClass *vdc;
if (!bus->ioeventfd_started) {
return;
}
vdev = virtio_bus_get_device(bus);
vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
vdc->stop_ioeventfd(vdev);
bus->ioeventfd_started = false;
}
void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
{
VirtIODevice *vdev;
VirtioDeviceClass *vdc;
if (!bus->ioeventfd_started) {
return;
}
/* Only remove our notifier if we have ownership. */
if (!bus->ioeventfd_grabbed) {
vdev = virtio_bus_get_device(bus);
vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
vdc->stop_ioeventfd(vdev);
}
bus->ioeventfd_started = false;
}
/*
* This function switches ioeventfd on/off in the device.
* The caller must set or clear the handlers for the EventNotifier.
*/
int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtQueue *vq = virtio_get_queue(vdev, n);
EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
int r = 0;
if (!k->ioeventfd_assign) {
return -ENOSYS;
}
if (assign) {
assert(!bus->ioeventfd_started);
r = event_notifier_init(notifier, 1);
if (r < 0) {
error_report("%s: unable to init event notifier: %s (%d)",
__func__, strerror(-r), r);
return r;
}
r = k->ioeventfd_assign(proxy, notifier, n, true);
if (r < 0) {
error_report("%s: unable to assign ioeventfd: %d", __func__, r);
goto cleanup_event_notifier;
}
return 0;
} else {
if (!bus->ioeventfd_started) {
return 0;
}
k->ioeventfd_assign(proxy, notifier, n, false);
}
cleanup_event_notifier:
/* Test and clear notifier after disabling event,
* in case poll callback didn't have time to run.
*/
virtio_queue_host_notifier_read(notifier);
event_notifier_cleanup(notifier);
return r;
}
void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtIODevice *vdev;
int n, r;
if (!k->ioeventfd_started || !k->ioeventfd_started(proxy)) {
return;
}
vdev = virtio_bus_get_device(bus);
for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
r = set_host_notifier_internal(proxy, bus, n, false, false);
assert(r >= 0);
}
k->ioeventfd_set_started(proxy, false, false);
}
void virtio_bus_start_ioeventfd(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtIODevice *vdev;
int n, r;
if (!k->ioeventfd_started || k->ioeventfd_started(proxy)) {
return;
}
if (k->ioeventfd_disabled(proxy)) {
return;
}
vdev = virtio_bus_get_device(bus);
for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
r = set_host_notifier_internal(proxy, bus, n, true, true);
if (r < 0) {
goto assign_error;
}
}
k->ioeventfd_set_started(proxy, true, false);
return;
assign_error:
while (--n >= 0) {
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
r = set_host_notifier_internal(proxy, bus, n, false, false);
assert(r >= 0);
}
k->ioeventfd_set_started(proxy, false, true);
error_report("%s: failed. Fallback to userspace (slower).", __func__);
}
/* Get the device id of the plugged device. */
uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
assert(vdev != NULL);
return vdev->device_id;
}
/* Get the config_len field of the plugged device. */
size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
assert(vdev != NULL);
return vdev->config_len;
}
static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
{
VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);
if (!vdev) {
/* If no backend is present, we treat most registers as
* read-as-zero, except for the magic number, version and
* vendor ID. This is not strictly sanctioned by the virtio
* spec, but it allows us to provide transports with no backend
* plugged in which don't confuse Linux's virtio code: the
* probe won't complain about the bad magic number, but the
* device ID of zero means no backend will claim it.
*/
switch (offset) {
case VIRTIO_MMIO_MAGIC:
return VIRT_MAGIC;
case VIRTIO_MMIO_VERSION:
return VIRT_VERSION;
case VIRTIO_MMIO_VENDORID:
return VIRT_VENDOR;
default:
return 0;
}
}
if (offset >= VIRTIO_MMIO_CONFIG) {
offset -= VIRTIO_MMIO_CONFIG;
switch (size) {
case 1:
return virtio_config_readb(vdev, offset);
case 2:
return virtio_config_readw(vdev, offset);
case 4:
return virtio_config_readl(vdev, offset);
default:
abort();
}
}
if (size != 4) {
DPRINTF("wrong size access to register!\n");
return 0;
}
switch (offset) {
case VIRTIO_MMIO_MAGIC:
return VIRT_MAGIC;
case VIRTIO_MMIO_VERSION:
return VIRT_VERSION;
case VIRTIO_MMIO_DEVICEID:
return vdev->device_id;
case VIRTIO_MMIO_VENDORID:
return VIRT_VENDOR;
case VIRTIO_MMIO_HOSTFEATURES:
if (proxy->host_features_sel) {
return 0;
}
return vdev->host_features;
case VIRTIO_MMIO_QUEUENUMMAX:
if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
return 0;
}
return VIRTQUEUE_MAX_SIZE;
case VIRTIO_MMIO_QUEUEPFN:
return virtio_queue_get_addr(vdev, vdev->queue_sel)
>> proxy->guest_page_shift;
case VIRTIO_MMIO_INTERRUPTSTATUS:
return atomic_read(&vdev->isr);
case VIRTIO_MMIO_STATUS:
return vdev->status;
case VIRTIO_MMIO_HOSTFEATURESSEL:
case VIRTIO_MMIO_GUESTFEATURES:
case VIRTIO_MMIO_GUESTFEATURESSEL:
case VIRTIO_MMIO_GUESTPAGESIZE:
case VIRTIO_MMIO_QUEUESEL:
case VIRTIO_MMIO_QUEUENUM:
case VIRTIO_MMIO_QUEUEALIGN:
case VIRTIO_MMIO_QUEUENOTIFY:
case VIRTIO_MMIO_INTERRUPTACK:
DPRINTF("read of write-only register\n");
return 0;
default:
DPRINTF("bad register offset\n");
return 0;
}
return 0;
}
static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
unsigned size)
{
VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",
(int)offset, value);
if (!vdev) {
/* If no backend is present, we just make all registers
* write-ignored. This allows us to provide transports with
* no backend plugged in.
*/
return;
}
if (offset >= VIRTIO_MMIO_CONFIG) {
offset -= VIRTIO_MMIO_CONFIG;
switch (size) {
case 1:
virtio_config_writeb(vdev, offset, value);
break;
case 2:
virtio_config_writew(vdev, offset, value);
break;
case 4:
virtio_config_writel(vdev, offset, value);
break;
default:
abort();
}
return;
}
if (size != 4) {
DPRINTF("wrong size access to register!\n");
return;
}
switch (offset) {
case VIRTIO_MMIO_HOSTFEATURESSEL:
proxy->host_features_sel = value;
break;
case VIRTIO_MMIO_GUESTFEATURES:
if (!proxy->guest_features_sel) {
virtio_set_features(vdev, value);
}
break;
case VIRTIO_MMIO_GUESTFEATURESSEL:
proxy->guest_features_sel = value;
break;
case VIRTIO_MMIO_GUESTPAGESIZE:
proxy->guest_page_shift = ctz32(value);
if (proxy->guest_page_shift > 31) {
proxy->guest_page_shift = 0;
}
DPRINTF("guest page size %" PRIx64 " shift %d\n", value,
proxy->guest_page_shift);
break;
case VIRTIO_MMIO_QUEUESEL:
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:
if (value == 0) {
virtio_reset(vdev);
} else {
virtio_queue_set_addr(vdev, vdev->queue_sel,
value << proxy->guest_page_shift);
}
break;
case VIRTIO_MMIO_QUEUENOTIFY:
if (value < VIRTIO_QUEUE_MAX) {
virtio_queue_notify(vdev, value);
}
break;
case VIRTIO_MMIO_INTERRUPTACK:
atomic_and(&vdev->isr, ~value);
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);
}
break;
case VIRTIO_MMIO_MAGIC:
case VIRTIO_MMIO_VERSION:
case VIRTIO_MMIO_DEVICEID:
case VIRTIO_MMIO_VENDORID:
case VIRTIO_MMIO_HOSTFEATURES:
case VIRTIO_MMIO_QUEUENUMMAX:
case VIRTIO_MMIO_INTERRUPTSTATUS:
DPRINTF("write to readonly register\n");
break;
default:
DPRINTF("bad register offset\n");
}
}