Re: [Qemu-devel] [PATCH v3 6/7] virtio-net: cleanup: use QOM cast.

[Anthony Liguori <aliguori@us.ibm.com>]

KONRAD Frédéric <fred.konrad@greensocs.com> writes:

> On 18/04/2013 10:41, Michael S. Tsirkin wrote:
>> BTW this is data path so was supposed to use the faster non-QOM casts.
>> Also in other places below.  This was applied meanwhile, but maybe we
>> could revert the relevant chunks?  Or maybe everyone who cares about
>> speed uses vhost-net anyway so we don't care ...
>>
>> I point datapath below in case it's useful.
>
> Which faster non-QOM casts?
>
> In virtio-pci there is this one:
>
> static inline VirtIOPCIProxy *to_virtio_pci_proxy_fast(DeviceState *d)
> {
>      return container_of(d, VirtIOPCIProxy, pci_dev.qdev);
> }
>
> Is that what you want?

Nack.  "Faster non-QOM casts" is FUD.

Regards,

Anthony Liguori

>
>>
>>> @@ -629,7 +626,7 @@ static int virtio_net_can_receive(NetClientState *nc)
>>>       }
>>>   
>>>       if (!virtio_queue_ready(q->rx_vq) ||
>>> -        !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
>>> +        !(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
>>>           return 0;
>>>       }
>>>   
>>> @@ -759,6 +756,7 @@ static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t
>>>   {
>>>       VirtIONet *n = qemu_get_nic_opaque(nc);
>>>       VirtIONetQueue *q = virtio_net_get_subqueue(nc);
>>> +    VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>>       struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
>>>       struct virtio_net_hdr_mrg_rxbuf mhdr;
>>>       unsigned mhdr_cnt = 0;
>> datapath
>>
>>> @@ -792,7 +790,7 @@ static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t
>>>                       "i %zd mergeable %d offset %zd, size %zd, "
>>>                       "guest hdr len %zd, host hdr len %zd guest features 0x%x",
>>>                       i, n->mergeable_rx_bufs, offset, size,
>>> -                    n->guest_hdr_len, n->host_hdr_len, n->vdev.guest_features);
>>> +                    n->guest_hdr_len, n->host_hdr_len, vdev->guest_features);
>>>               exit(1);
>>>           }
>>>   
>>> @@ -849,7 +847,7 @@ static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t
>>>       }
>>>   
>>>       virtqueue_flush(q->rx_vq, i);
>>> -    virtio_notify(&n->vdev, q->rx_vq);
>>> +    virtio_notify(vdev, q->rx_vq);
>>>   
>>>       return size;
>>>   }
>>> @@ -860,9 +858,10 @@ static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
>>>   {
>>>       VirtIONet *n = qemu_get_nic_opaque(nc);
>>>       VirtIONetQueue *q = virtio_net_get_subqueue(nc);
>>> +    VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>>   
>>>       virtqueue_push(q->tx_vq, &q->async_tx.elem, 0);
>>> -    virtio_notify(&n->vdev, q->tx_vq);
>>> +    virtio_notify(vdev, q->tx_vq);
>>>   
>>>       q->async_tx.elem.out_num = q->async_tx.len = 0;
>>>
>> datapath
>>    
>>> @@ -874,14 +873,15 @@ static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
>>>   static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
>>>   {
>>>       VirtIONet *n = q->n;
>>> +    VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>>       VirtQueueElement elem;
>>>       int32_t num_packets = 0;
>>>       int queue_index = vq2q(virtio_get_queue_index(q->tx_vq));
>>> -    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
>>> +    if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
>>>           return num_packets;
>>>       }
>>>   
>>> -    assert(n->vdev.vm_running);
>>> +    assert(vdev->vm_running);
>>>   
>>>       if (q->async_tx.elem.out_num) {
>>>           virtio_queue_set_notification(q->tx_vq, 0);
>>
>> datapath
>>
>>> @@ -930,7 +930,7 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
>>>           len += ret;
>>>   
>>>           virtqueue_push(q->tx_vq, &elem, 0);
>>> -        virtio_notify(&n->vdev, q->tx_vq);
>>> +        virtio_notify(vdev, q->tx_vq);
>>>   
>>>           if (++num_packets >= n->tx_burst) {
>>>               break;
>>> @@ -941,11 +941,11 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
>>>   
>>>   static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
>>>   {
>>> -    VirtIONet *n = to_virtio_net(vdev);
>>> +    VirtIONet *n = VIRTIO_NET(vdev);
>>>       VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
>>>   
>>>       /* This happens when device was stopped but VCPU wasn't. */
>>> -    if (!n->vdev.vm_running) {
>>> +    if (!vdev->vm_running) {
>>>           q->tx_waiting = 1;
>>>           return;
>>>       }
>>
>> datapath
>>
>>> @@ -965,7 +965,7 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
>>>   
>>>   static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
>>>   {
>>> -    VirtIONet *n = to_virtio_net(vdev);
>>> +    VirtIONet *n = VIRTIO_NET(vdev);
>>>       VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
>>>   
>>>       if (unlikely(q->tx_waiting)) {
>> datapath
>>
>>> @@ -973,7 +973,7 @@ static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
>>>       }
>>>       q->tx_waiting = 1;
>>>       /* This happens when device was stopped but VCPU wasn't. */
>>> -    if (!n->vdev.vm_running) {
>>> +    if (!vdev->vm_running) {
>>>           return;
>>>       }
>>>       virtio_queue_set_notification(vq, 0);
>>> @@ -984,13 +984,15 @@ static void virtio_net_tx_timer(void *opaque)
>>>   {
>>>       VirtIONetQueue *q = opaque;
>>>       VirtIONet *n = q->n;
>>> -    assert(n->vdev.vm_running);
>>> +    VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>> +    assert(vdev->vm_running);
>>>   
>>>       q->tx_waiting = 0;
>>>   
>>>       /* Just in case the driver is not ready on more */
>>> -    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
>>> +    if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
>>>           return;
>>> +    }
>>>   
>>>       virtio_queue_set_notification(q->tx_vq, 1);
>>>       virtio_net_flush_tx(q);
>> datapath
>>
>>> @@ -1000,15 +1002,17 @@ static void virtio_net_tx_bh(void *opaque)
>>>   {
>>>       VirtIONetQueue *q = opaque;
>>>       VirtIONet *n = q->n;
>>> +    VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>>       int32_t ret;
>>>   
>>> -    assert(n->vdev.vm_running);
>>> +    assert(vdev->vm_running);
>>>   
>>>       q->tx_waiting = 0;
>>>   
>>>       /* Just in case the driver is not ready on more */
>>> -    if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))
>>> +    if (unlikely(!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))) {
>>>           return;
>>> +    }
>>>   
>>>       ret = virtio_net_flush_tx(q);
>>>       if (ret == -EBUSY) {
>> datapath
>>
>>> @@ -1036,7 +1040,7 @@ static void virtio_net_tx_bh(void *opaque)
>>>   
>>>   static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue, int ctrl)
>>>   {
>>> -    VirtIODevice *vdev = &n->vdev;
>>> +    VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>>       int i, max = multiqueue ? n->max_queues : 1;
>>>   
>>>       n->multiqueue = multiqueue;
>>> @@ -1074,11 +1078,12 @@ static void virtio_net_save(QEMUFile *f, void *opaque)
>>>   {
>>>       int i;
>>>       VirtIONet *n = opaque;
>>> +    VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>>   
>>>       /* At this point, backend must be stopped, otherwise
>>>        * it might keep writing to memory. */
>>>       assert(!n->vhost_started);
>>> -    virtio_save(&n->vdev, f);
>>> +    virtio_save(vdev, f);
>>>   
>>>       qemu_put_buffer(f, n->mac, ETH_ALEN);
>>>       qemu_put_be32(f, n->vqs[0].tx_waiting);
>>> @@ -1109,12 +1114,13 @@ static void virtio_net_save(QEMUFile *f, void *opaque)
>>>   static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>>>   {
>>>       VirtIONet *n = opaque;
>>> +    VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>>       int ret, i, link_down;
>>>   
>>>       if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
>>>           return -EINVAL;
>>>   
>>> -    ret = virtio_load(&n->vdev, f);
>>> +    ret = virtio_load(vdev, f);
>>>       if (ret) {
>>>           return ret;
>>>       }
>>> @@ -1163,11 +1169,11 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>>>   
>>>           if (n->has_vnet_hdr) {
>>>               tap_set_offload(qemu_get_queue(n->nic)->peer,
>>> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
>>> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
>>> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
>>> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
>>> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
>>> +                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
>>> +                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
>>> +                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
>>> +                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
>>> +                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
>>>           }
>>>       }
>>>   
>>> @@ -1240,7 +1246,7 @@ static NetClientInfo net_virtio_info = {
>>>   
>>>   static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
>>>   {
>>> -    VirtIONet *n = to_virtio_net(vdev);
>>> +    VirtIONet *n = VIRTIO_NET(vdev);
>>>       NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
>>>       assert(n->vhost_started);
>>>       return vhost_net_virtqueue_pending(tap_get_vhost_net(nc->peer), idx);
>>> @@ -1249,7 +1255,7 @@ static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
>>>   static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
>>>                                              bool mask)
>>>   {
>>> -    VirtIONet *n = to_virtio_net(vdev);
>>> +    VirtIONet *n = VIRTIO_NET(vdev);
>>>       NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
>>>       assert(n->vhost_started);
>>>       vhost_net_virtqueue_mask(tap_get_vhost_net(nc->peer),
>> kind of datapath
>>
>>> @@ -1273,6 +1279,7 @@ static VirtIODevice *virtio_net_common_init(DeviceState *dev, NICConf *conf,
>>>                                               VirtIONet **pn)
>>>   {
>>>       VirtIONet *n = *pn;
>>> +    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
>>>       int i, config_size = 0;
>>>   
>>>       /*
>>> @@ -1295,18 +1302,18 @@ static VirtIODevice *virtio_net_common_init(DeviceState *dev, NICConf *conf,
>>>                                                       n->config_size);
>>>       }
>>>   
>>> -    n->vdev.get_config = virtio_net_get_config;
>>> -    n->vdev.set_config = virtio_net_set_config;
>>> -    n->vdev.get_features = virtio_net_get_features;
>>> -    n->vdev.set_features = virtio_net_set_features;
>>> -    n->vdev.bad_features = virtio_net_bad_features;
>>> -    n->vdev.reset = virtio_net_reset;
>>> -    n->vdev.set_status = virtio_net_set_status;
>>> -    n->vdev.guest_notifier_mask = virtio_net_guest_notifier_mask;
>>> -    n->vdev.guest_notifier_pending = virtio_net_guest_notifier_pending;
>>> +    vdev->get_config = virtio_net_get_config;
>>> +    vdev->set_config = virtio_net_set_config;
>>> +    vdev->get_features = virtio_net_get_features;
>>> +    vdev->set_features = virtio_net_set_features;
>>> +    vdev->bad_features = virtio_net_bad_features;
>>> +    vdev->reset = virtio_net_reset;
>>> +    vdev->set_status = virtio_net_set_status;
>>> +    vdev->guest_notifier_mask = virtio_net_guest_notifier_mask;
>>> +    vdev->guest_notifier_pending = virtio_net_guest_notifier_pending;
>>>       n->max_queues = MAX(conf->queues, 1);
>>>       n->vqs = g_malloc0(sizeof(VirtIONetQueue) * n->max_queues);
>>> -    n->vqs[0].rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
>>> +    n->vqs[0].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
>>>       n->curr_queues = 1;
>>>       n->vqs[0].n = n;
>>>       n->tx_timeout = net->txtimer;
>>> @@ -1319,16 +1326,16 @@ static VirtIODevice *virtio_net_common_init(DeviceState *dev, NICConf *conf,
>>>       }
>>>   
>>>       if (net->tx && !strcmp(net->tx, "timer")) {
>>> -        n->vqs[0].tx_vq = virtio_add_queue(&n->vdev, 256,
>>> +        n->vqs[0].tx_vq = virtio_add_queue(vdev, 256,
>>>                                              virtio_net_handle_tx_timer);
>>>           n->vqs[0].tx_timer = qemu_new_timer_ns(vm_clock, virtio_net_tx_timer,
>>>                                                  &n->vqs[0]);
>>>       } else {
>>> -        n->vqs[0].tx_vq = virtio_add_queue(&n->vdev, 256,
>>> +        n->vqs[0].tx_vq = virtio_add_queue(vdev, 256,
>>>                                              virtio_net_handle_tx_bh);
>>>           n->vqs[0].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[0]);
>>>       }
>>> -    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
>>> +    n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
>>>       qemu_macaddr_default_if_unset(&conf->macaddr);
>>>       memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
>>>       n->status = VIRTIO_NET_S_LINK_UP;
>>> @@ -1361,7 +1368,7 @@ static VirtIODevice *virtio_net_common_init(DeviceState *dev, NICConf *conf,
>>>   
>>>       add_boot_device_path(conf->bootindex, dev, "/ethernet-phy@0");
>>>   
>>> -    return &n->vdev;
>>> +    return vdev;
>>>   }
>>>   
>>>   VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>>> @@ -1373,7 +1380,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>>>   
>>>   void virtio_net_exit(VirtIODevice *vdev)
>>>   {
>>> -    VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
>>> +    VirtIONet *n = VIRTIO_NET(vdev);
>>>       int i;
>>>   
>>>       /* This will stop vhost backend if appropriate. */
>>> @@ -1400,7 +1407,7 @@ void virtio_net_exit(VirtIODevice *vdev)
>>>   
>>>       g_free(n->vqs);
>>>       qemu_del_nic(n->nic);
>>> -    virtio_cleanup(&n->vdev);
>>> +    virtio_cleanup(vdev);
>>>   }
>>>   
>>>   static int virtio_net_device_init(VirtIODevice *vdev)
>>> @@ -1449,7 +1456,7 @@ static int virtio_net_device_exit(DeviceState *qdev)
>>>   
>>>       g_free(n->vqs);
>>>       qemu_del_nic(n->nic);
>>> -    virtio_common_cleanup(&n->vdev);
>>> +    virtio_common_cleanup(vdev);
>>>   
>>>       return 0;
>>>   }
>>> diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
>>> index 9fbb506..ce4ab50 100644
>>> --- a/include/hw/virtio/virtio-net.h
>>> +++ b/include/hw/virtio/virtio-net.h
>>> @@ -153,7 +153,7 @@ typedef struct VirtIONetQueue {
>>>   } VirtIONetQueue;
>>>   
>>>   typedef struct VirtIONet {
>>> -    VirtIODevice vdev;
>>> +    VirtIODevice parent_obj;
>>>       uint8_t mac[ETH_ALEN];
>>>       uint16_t status;
>>>       VirtIONetQueue *vqs;
>>> -- 
>>> 1.8.1.4
>>>