Re: [PATCH V2 1/2] vdpa: Support config interrupt in vhost_vdpa

Jason Wang
2020-04-26T06:59:05Z

On 2020/4/26 下午2:09, Zhu Lingshan wrote:
> This commit implements config interrupt support in
> vhost_vdpa layer.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
> ---
> drivers/vhost/vdpa.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++
> drivers/vhost/vhost.c | 2 +-
> drivers/vhost/vhost.h | 2 ++
> include/uapi/linux/vhost.h | 2 ++
> 4 files changed, 52 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 421f02a..b94e349 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -21,6 +21,7 @@
> #include <linux/nospec.h>
> #include <linux/vhost.h>
> #include <linux/virtio_net.h>
> +#include <linux/kernel.h>
>
> #include "vhost.h"
>
> @@ -70,6 +71,7 @@ struct vhost_vdpa {
> int nvqs;
> int virtio_id;
> int minor;
> + struct eventfd_ctx *config_ctx;
> };
>
> static DEFINE_IDA(vhost_vdpa_ida);
> @@ -101,6 +103,17 @@ static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t vhost_vdpa_config_cb(void *private)
> +{
> + struct vhost_vdpa *v = private;
> + struct eventfd_ctx *config_ctx = v->config_ctx;
> +
> + if (config_ctx)
> + eventfd_signal(config_ctx, 1);
> +
> + return IRQ_HANDLED;
> +}
> +
> static void vhost_vdpa_reset(struct vhost_vdpa *v)
> {
> struct vdpa_device *vdpa = v->vdpa;
> @@ -288,6 +301,36 @@ static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
> return 0;
> }
>
> +static void vhost_vdpa_config_put(struct vhost_vdpa *v)
> +{
> + if (v->config_ctx)
> + eventfd_ctx_put(v->config_ctx);
> +}
> +
> +static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
> +{
> + struct vdpa_callback cb;
> + u32 fd;
> + struct eventfd_ctx *ctx;
> +
> + cb.callback = vhost_vdpa_config_cb;
> + cb.private = v->vdpa;
> + if (copy_from_user(&fd, argp, sizeof(fd)))
> + return -EFAULT;
> +
> + ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
> + swap(ctx, v->config_ctx);
> +
> + if (!IS_ERR_OR_NULL(ctx))
> + eventfd_ctx_put(ctx);
> +
> + if (IS_ERR(v->config_ctx))
> + return PTR_ERR(v->config_ctx);
> +
> + v->vdpa->config->set_config_cb(v->vdpa, &cb);
> +
> + return 0;
> +}
> static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
> void __user *argp)
> {
> @@ -398,6 +441,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
> case VHOST_SET_LOG_FD:
> r = -ENOIOCTLCMD;
> break;
> + case VHOST_VDPA_SET_CONFIG_CALL:
> + r = vhost_vdpa_set_config_call(v, argp);
> + break;
> default:
> r = vhost_dev_ioctl(&v->vdev, cmd, argp);
> if (r == -ENOIOCTLCMD)
> @@ -734,6 +780,7 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
> vhost_dev_stop(&v->vdev);
> vhost_vdpa_iotlb_free(v);
> vhost_vdpa_free_domain(v);
> + vhost_vdpa_config_put(v);
> vhost_dev_cleanup(&v->vdev);
> kfree(v->vdev.vqs);
> mutex_unlock(&d->mutex);
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index d450e16..e8f5b20 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -1590,7 +1590,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
> r = -EFAULT;
> break;
> }
> - ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd);
> + ctx = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(f.fd);
> if (IS_ERR(ctx)) {
> r = PTR_ERR(ctx);
> break;
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index 1813821..8663139 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -18,6 +18,8 @@
> typedef void (*vhost_work_fn_t)(struct vhost_work *work);
>
> #define VHOST_WORK_QUEUED 1
> +#define VHOST_FILE_UNBIND -1

I think it's better to document this in uapi.

> +
> struct vhost_work {
> struct llist_node node;
> vhost_work_fn_t fn;
> diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> index 9fe72e4..345acb3 100644
> --- a/include/uapi/linux/vhost.h
> +++ b/include/uapi/linux/vhost.h
> @@ -140,4 +140,6 @@
> /* Get the max ring size. */
> #define VHOST_VDPA_GET_VRING_NUM _IOR(VHOST_VIRTIO, 0x76, __u16)
>
> +/* Set event fd for config interrupt*/
> +#define VHOST_VDPA_SET_CONFIG_CALL _IOW(VHOST_VIRTIO, 0x77, u32)
> #endif

Should be "int" instead of "u32".

Thanks