Re: [PATCH v3 05/10] vdpa-dev: implement the realize interface

[Stefano Garzarella]

On Sat, Mar 19, 2022 at 03:20:07PM +0800, Longpeng(Mike) wrote:
>From: Longpeng <longpeng2@huawei.com>
>
>Implements the .realize interface.
>
>Signed-off-by: Longpeng <longpeng2@huawei.com>
>---
> hw/virtio/vdpa-dev-pci.c     |  18 ++++-
> hw/virtio/vdpa-dev.c         | 132 +++++++++++++++++++++++++++++++++++
> include/hw/virtio/vdpa-dev.h |  10 +++
> 3 files changed, 159 insertions(+), 1 deletion(-)
>
>diff --git a/hw/virtio/vdpa-dev-pci.c b/hw/virtio/vdpa-dev-pci.c
>index 9eb590ce8c..31bd17353a 100644
>--- a/hw/virtio/vdpa-dev-pci.c
>+++ b/hw/virtio/vdpa-dev-pci.c
>@@ -51,10 +51,26 @@ static Property vhost_vdpa_device_pci_properties[] = {
>     DEFINE_PROP_END_OF_LIST(),
> };
>
>+static int vhost_vdpa_device_pci_post_init(VhostVdpaDevice *v, Error **errp)
>+{
>+    VhostVdpaDevicePCI *dev = container_of(v, VhostVdpaDevicePCI, vdev);
>+    VirtIOPCIProxy *vpci_dev = &dev->parent_obj;
>+
>+    vpci_dev->class_code = virtio_pci_get_class_id(v->vdev_id);
>+    vpci_dev->trans_devid = virtio_pci_get_trans_devid(v->vdev_id);
>+    /* one for config vector */
>+    vpci_dev->nvectors = v->num_queues + 1;
>+
>+    return 0;
>+}
>+
> static void
> vhost_vdpa_device_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
> {
>-    return;
>+    VhostVdpaDevicePCI *dev = VHOST_VDPA_DEVICE_PCI(vpci_dev);
>+
>+    dev->vdev.post_init = vhost_vdpa_device_pci_post_init;
>+    qdev_realize(DEVICE(&dev->vdev), BUS(&vpci_dev->bus), errp);
> }
>
> static void vhost_vdpa_device_pci_class_init(ObjectClass *klass, void *data)
>diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
>index 993cbc7d11..4defe6c33d 100644
>--- a/hw/virtio/vdpa-dev.c
>+++ b/hw/virtio/vdpa-dev.c
>@@ -29,9 +29,140 @@
> #include "sysemu/sysemu.h"
> #include "sysemu/runstate.h"
>
>+static void
>+vhost_vdpa_device_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
>+{
>+    /* Nothing to do */
>+}
>+
>+static uint32_t
>+vhost_vdpa_device_get_u32(int fd, unsigned long int cmd, Error **errp)
>+{
>+    uint32_t val = (uint32_t)-1;
>+
>+    if (ioctl(fd, cmd, &val) < 0) {
>+        error_setg(errp, "vhost-vdpa-device: cmd 0x%lx failed: %s",
>+                   cmd, strerror(errno));
>+    }
>+
>+    return val;
>+}
>+
> static void vhost_vdpa_device_realize(DeviceState *dev, Error **errp)
> {
>+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
>+    VhostVdpaDevice *v = VHOST_VDPA_DEVICE(vdev);
>+    uint32_t max_queue_size;
>+    struct vhost_virtqueue *vqs;
>+    int i, ret;
>+
>+    if (!v->vdpa_dev || v->vdpa_dev_fd == -1) {
                        ^
Should we use && operator here?

I can't start QEMU, how did you test this series?

$ ./qemu-system-x86_64 -m 512M -smp 2 -M q35,accel=kvm \
   ...
   -device vhost-vdpa-device-pci,vdpa-dev=/dev/vhost-vdpa-0
qemu-system-x86_64: -device
vhost-vdpa-device-pci,vdpa-dev=/dev/vhost-vdpa-0: both vpda-dev and
vpda-dev-fd are missing

>+        error_setg(errp, "both vpda-dev and vpda-dev-fd are missing");

Typo s/vpda/vdpa

>+        return;
>+    }
>+
>+    if (v->vdpa_dev && v->vdpa_dev_fd != -1) {
>+        error_setg(errp, "both vpda-dev and vpda-dev-fd are set");

Ditto

>+        return;
>+    }
>+
>+    if (v->vdpa_dev_fd == -1) {
>+        v->vdpa_dev_fd = qemu_open(v->vdpa_dev, O_RDWR, errp);
>+        if (*errp) {
>+            return;
>+        }
>+    }
>+    v->vdpa.device_fd = v->vdpa_dev_fd;
>+
>+    v->vdev_id = vhost_vdpa_device_get_u32(v->vdpa_dev_fd,
>+                                           VHOST_VDPA_GET_DEVICE_ID, errp);
>+    if (*errp) {
>+        goto out;
>+    }
>+
>+    max_queue_size = vhost_vdpa_device_get_u32(v->vdpa_dev_fd,
>+                                               VHOST_VDPA_GET_VRING_NUM, 
>errp);
>+    if (*errp) {
>+        goto out;
>+    }
>+
>+    if (v->queue_size > max_queue_size) {
>+        error_setg(errp, "vhost-vdpa-device: invalid queue_size: %u (max:%u)",
>+                   v->queue_size, max_queue_size);
>+        goto out;
>+    } else if (!v->queue_size) {
>+        v->queue_size = max_queue_size;
>+    }
>+
>+    v->num_queues = vhost_vdpa_device_get_u32(v->vdpa_dev_fd,
>+                                              VHOST_VDPA_GET_VQS_COUNT, errp);
>+    if (*errp) {
>+        goto out;
>+    }
>+
>+    if (!v->num_queues || v->num_queues > VIRTIO_QUEUE_MAX) {
>+        error_setg(errp, "invalid number of virtqueues: %u (max:%u)",
>+                   v->num_queues, VIRTIO_QUEUE_MAX);
>+        goto out;
>+    }
>+
>+    v->dev.nvqs = v->num_queues;
>+    vqs = g_new0(struct vhost_virtqueue, v->dev.nvqs);
>+    v->dev.vqs = vqs;
>+    v->dev.vq_index = 0;
>+    v->dev.vq_index_end = v->dev.nvqs;
>+    v->dev.backend_features = 0;
>+    v->started = false;
>+
>+    ret = vhost_dev_init(&v->dev, &v->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;
>+    }
>+
>+    v->config_size = vhost_vdpa_device_get_u32(v->vdpa_dev_fd,
>+                                               VHOST_VDPA_GET_CONFIG_SIZE, 
>errp);
>+    if (*errp) {
>+        goto vhost_cleanup;
>+    }
>+    v->config = g_malloc0(v->config_size);
>+
>+    ret = vhost_dev_get_config(&v->dev, v->config, v->config_size, NULL);
>+    if (ret < 0) {
>+        error_setg(errp, "vhost-vdpa-device: get config failed");
>+        goto free_config;
>+    }
>+
>+    virtio_init(vdev, "vhost-vdpa", v->vdev_id, v->config_size);
>+
>+    v->virtqs = g_new0(VirtQueue *, v->dev.nvqs);
>+    for (i = 0; i < v->dev.nvqs; i++) {
>+        v->virtqs[i] = virtio_add_queue(vdev, v->queue_size,
>+                                        
>vhost_vdpa_device_dummy_handle_output);
>+    }
>+
>+    if (v->post_init && v->post_init(v, errp) < 0) {
>+        goto free_virtio;
>+    }
>+
>     return;
>+
>+free_virtio:
>+    for (i = 0; i < v->num_queues; i++) {
>+        virtio_delete_queue(v->virtqs[i]);
>+    }
>+    g_free(v->virtqs);
>+    virtio_cleanup(vdev);
>+free_config:
>+    g_free(v->config);
>+vhost_cleanup:
>+    vhost_dev_cleanup(&v->dev);
>+free_vqs:
>+    g_free(vqs);
>+out:
>+    qemu_close(v->vdpa_dev_fd);
>+    v->vdpa_dev_fd = -1;
> }
>
> static void vhost_vdpa_device_unrealize(DeviceState *dev)
>@@ -66,6 +197,7 @@ 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),

Other vhost devices use the `vhostfd` property, maybe we should use the
same name.

If we go for this change, then maybe we also need to change `vdpa-dev`
to `vhostpath` or something like that

Thanks,
Stefano

>+    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 476bda0873..cf11abd0f7 100644
>--- a/include/hw/virtio/vdpa-dev.h
>+++ b/include/hw/virtio/vdpa-dev.h
>@@ -28,6 +28,16 @@ struct VhostVdpaDevice {
>     char *vdpa_dev;
>     int vdpa_dev_fd;
>     int32_t bootindex;
>+    uint32_t vdev_id;
>+    uint32_t num_queues;
>+    struct vhost_dev dev;
>+    struct vhost_vdpa vdpa;
>+    VirtQueue **virtqs;
>+    uint8_t *config;
>+    int config_size;
>+    uint16_t queue_size;
>+    bool started;
>+    int (*post_init)(VhostVdpaDevice *v, Error **errp);
> };
>
> #endif
>--
>2.23.0
>