> -----Original Message-----
> From: Stefano Garzarella [mailto:sgarz...@redhat.com]
> Sent: Wednesday, January 19, 2022 7:31 PM
> To: Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
> <longpe...@huawei.com>
> Cc: stefa...@redhat.com; m...@redhat.com; coh...@redhat.com;
> pbonz...@redhat.com; Gonglei (Arei) <arei.gong...@huawei.com>; Yechuan
> <yech...@huawei.com>; Huangzhichao <huangzhic...@huawei.com>;
> qemu-devel@nongnu.org
> Subject: Re: [PATCH v2 05/10] vdpa-dev: implement the realize interface
>
> On Mon, Jan 17, 2022 at 08:43:26PM +0800, Longpeng(Mike) via wrote:
> >From: Longpeng <longpe...@huawei.com>
> >
> >Implements the .realize interface.
> >
> >Signed-off-by: Longpeng <longpe...@huawei.com>
> >---
> > hw/virtio/vdpa-dev.c | 101 +++++++++++++++++++++++++++++++++++
> > include/hw/virtio/vdpa-dev.h | 8 +++
> > 2 files changed, 109 insertions(+)
> >
> >diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
> >index b103768f33..bd28cf7a15 100644
> >--- a/hw/virtio/vdpa-dev.c
> >+++ b/hw/virtio/vdpa-dev.c
> >@@ -27,9 +27,109 @@ uint32_t vhost_vdpa_device_get_u32(int fd, unsigned long
> int cmd, Error **errp)
> > return val;
> > }
> >
> >+static void
> >+vhost_vdpa_device_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> >+{
> >+ /* Nothing to do */
> >+}
> >+
> > static void vhost_vdpa_device_realize(DeviceState *dev, Error **errp)
> > {
> >+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> >+ VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
> >+ uint32_t vdev_id, max_queue_size;
> >+ struct vhost_virtqueue *vqs;
> >+ int i, ret;
> >+
> >+ if (s->vdpa_dev_fd == -1) {
> >+ s->vdpa_dev_fd = qemu_open(s->vdpa_dev, O_RDWR, errp);
>
> So, here we are re-opening the `vdpa_dev` again (without checking if it
> is NULL).
>
> And we re-do the same ioctls already done in
> vhost_vdpa_device_pci_realize(), so I think we should do them in a
> single place, and that place should be here.
>
> So, what about doing all the ioctls here, setting appropriate fields in
> VhostVdpaDevice, then using that fields in
> vhost_vdpa_device_pci_realize() after qdev_realize() to set
> `class_code`, `trans_devid`, and `nvectors`?
>
vhost_vdpa_device_pci_realize()
qdev_realize()
virtio_device_realize()
vhost_vdpa_device_realize()
virtio_bus_device_plugged()
virtio_pci_device_plugged()
These three fields would be used in virtio_pci_device_plugged(), so it's too
late to set them after qdev_realize(). And they belong to VirtIOPCIProxy, so
we cannot set them in vhost_vdpa_device_realize() which is transport layer
independent.
> >+ if (*errp) {
> >+ return;
> >+ }
> >+ }
> >+ s->vdpa.device_fd = s->vdpa_dev_fd;
> >+
> >+ max_queue_size = vhost_vdpa_device_get_u32(s->vdpa_dev_fd,
> >+ VHOST_VDPA_GET_VRING_NUM,
> >errp);
> >+ if (*errp) {
> >+ goto out;
> >+ }
> >+
> >+ if (s->queue_size > max_queue_size) {
> >+ error_setg(errp, "vhost-vdpa-device: invalid queue_size: %d
> (max:%d)",
> >+ s->queue_size, max_queue_size);
> >+ goto out;
> >+ } else if (!s->queue_size) {
> >+ s->queue_size = max_queue_size;
> >+ }
> >+
> >+ s->num_queues = vhost_vdpa_device_get_u32(s->vdpa_dev_fd,
> >+ VHOST_VDPA_GET_VQS_NUM, errp);
> ^
> VHOST_VDPA_GET_VQS_COUNT
>
OK, thanks :)
> >+ if (*errp) {
> >+ goto out;
> >+ }
> >+
> >+ if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) {
> >+ error_setg(errp, "invalid number of virtqueues: %u (max:%u)",
> >+ s->num_queues, VIRTIO_QUEUE_MAX);
> >+ goto out;
> >+ }
> >+
> >+ s->dev.nvqs = s->num_queues;
> >+ vqs = g_new0(struct vhost_virtqueue, s->dev.nvqs);
> >+ s->dev.vqs = vqs;
> >+ s->dev.vq_index = 0;
> >+ s->dev.vq_index_end = s->dev.nvqs;
> >+ s->dev.backend_features = 0;
> >+ s->started = false;
> >+
> >+ ret = vhost_dev_init(&s->dev, &s->vdpa, VHOST_BACKEND_TYPE_VDPA, 0,
> NULL);
> >+ if (ret < 0) {
> >+ error_setg(errp, "vhost-vdpa-device: vhost initialization
> failed: %s",
> >+ strerror(-ret));
> >+ goto free_vqs;
> >+ }
> >+
> >+ vdev_id = vhost_vdpa_device_get_u32(s->vdpa_dev_fd,
> >+ VHOST_VDPA_GET_DEVICE_ID, errp);
> >+ if (ret < 0) {
> >+ error_setg(errp, "vhost-vdpa-device: vhost get device id failed:
> >%s",
> >+ strerror(-ret));
> >+ goto vhost_cleanup;
> >+ }
> >+
> >+ s->config_size = vhost_vdpa_device_get_u32(s->vdpa_dev_fd,
> >+ VHOST_VDPA_GET_CONFIG_SIZE,
> errp);
> >+ if (*errp) {
> >+ goto vhost_cleanup;
> >+ }
> >+ s->config = g_malloc0(s->config_size);
> >+
> >+ ret = vhost_dev_get_config(&s->dev, s->config, s->config_size, NULL);
> >+ if (ret < 0) {
> >+ error_setg(errp, "vhost-vdpa-device: get config failed");
> >+ goto free_config;
> >+ }
> >+
> >+ virtio_init(vdev, "vhost-vdpa", vdev_id, s->config_size);
> >+
> >+ s->virtqs = g_new0(VirtQueue *, s->dev.nvqs);
> >+ for (i = 0; i < s->dev.nvqs; i++) {
> >+ s->virtqs[i] = virtio_add_queue(vdev, s->queue_size,
> >+
> vhost_vdpa_device_dummy_handle_output);
> >+ }
> >+
> > return;
> >+
> >+free_config:
> >+ g_free(s->config);
> >+vhost_cleanup:
> >+ vhost_dev_cleanup(&s->dev);
> >+free_vqs:
> >+ g_free(vqs);
> >+out:
> >+ qemu_close(s->vdpa_dev_fd);
> >+ s->vdpa_dev_fd = -1;
> > }
> >
> > static void vhost_vdpa_device_unrealize(DeviceState *dev)
> >@@ -64,6 +164,7 @@ static void vhost_vdpa_device_set_status(VirtIODevice
> >*vdev,
> uint8_t status)
> > static Property vhost_vdpa_device_properties[] = {
> > DEFINE_PROP_STRING("vdpa-dev", VhostVdpaDevice, vdpa_dev),
> > DEFINE_PROP_INT32("vdpa-dev-fd", VhostVdpaDevice, vdpa_dev_fd, -1),
> >+ DEFINE_PROP_UINT16("queue-size", VhostVdpaDevice, queue_size, 0),
> > DEFINE_PROP_END_OF_LIST(),
> > };
> >
> >diff --git a/include/hw/virtio/vdpa-dev.h b/include/hw/virtio/vdpa-dev.h
> >index e7ad349113..e0482035cf 100644
> >--- a/include/hw/virtio/vdpa-dev.h
> >+++ b/include/hw/virtio/vdpa-dev.h
> >@@ -14,6 +14,14 @@ struct VhostVdpaDevice {
> > char *vdpa_dev;
> > int vdpa_dev_fd;
> > int32_t bootindex;
> >+ struct vhost_dev dev;
> >+ struct vhost_vdpa vdpa;
> >+ VirtQueue **virtqs;
> >+ uint8_t *config;
> >+ int config_size;
> >+ uint32_t num_queues;
> >+ uint16_t queue_size;
> >+ bool started;
> > };
> >
> > uint32_t vhost_vdpa_device_get_u32(int fd, unsigned long int cmd, Error
> **errp);
> >--
> >2.23.0
> >
> >
