On Mon, Dec 5, 2022 at 5:03 PM Xie Yongji <xieyongji@xxxxxxxxxxxxx> wrote: > > As discussed in [1], this adds sysfs interface to support > specifying bounce buffer size in virtio-vdpa case. It would > be a performance tuning parameter for high throughput workloads. > > [1] https://www.spinics.net/lists/netdev/msg754288.html > > Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Thanks > --- > drivers/vdpa/vdpa_user/vduse_dev.c | 45 +++++++++++++++++++++++++++++- > 1 file changed, 44 insertions(+), 1 deletion(-) > > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c > index bd1ba6c33e09..0458d61cee1f 100644 > --- a/drivers/vdpa/vdpa_user/vduse_dev.c > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c > @@ -38,8 +38,11 @@ > #define DRV_LICENSE "GPL v2" > > #define VDUSE_DEV_MAX (1U << MINORBITS) > +#define VDUSE_MAX_BOUNCE_SIZE (1024 * 1024 * 1024) > +#define VDUSE_MIN_BOUNCE_SIZE (1024 * 1024) > #define VDUSE_BOUNCE_SIZE (64 * 1024 * 1024) > -#define VDUSE_IOVA_SIZE (128 * 1024 * 1024) > +/* 128 MB reserved for virtqueue creation */ > +#define VDUSE_IOVA_SIZE (VDUSE_MAX_BOUNCE_SIZE + 128 * 1024 * 1024) > #define VDUSE_MSG_DEFAULT_TIMEOUT 30 > > struct vduse_virtqueue { > @@ -1795,8 +1798,48 @@ static ssize_t msg_timeout_store(struct device *device, > > static DEVICE_ATTR_RW(msg_timeout); > > +static ssize_t bounce_size_show(struct device *device, > + struct device_attribute *attr, char *buf) > +{ > + struct vduse_dev *dev = dev_get_drvdata(device); > + > + return sysfs_emit(buf, "%u\n", dev->bounce_size); > +} > + > +static ssize_t bounce_size_store(struct device *device, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct vduse_dev *dev = dev_get_drvdata(device); > + unsigned int bounce_size; > + int ret; > + > + ret = -EPERM; > + mutex_lock(&dev->domain_lock); > + if (dev->domain) > + goto unlock; > + > + ret = kstrtouint(buf, 10, &bounce_size); > + if (ret < 0) > + goto unlock; > + > + ret = -EINVAL; > + if (bounce_size > VDUSE_MAX_BOUNCE_SIZE || > + bounce_size < VDUSE_MIN_BOUNCE_SIZE) > + goto unlock; > + > + dev->bounce_size = bounce_size & PAGE_MASK; > + ret = count; > +unlock: > + mutex_unlock(&dev->domain_lock); > + return ret; > +} > + > +static DEVICE_ATTR_RW(bounce_size); > + > static struct attribute *vduse_dev_attrs[] = { > &dev_attr_msg_timeout.attr, > + &dev_attr_bounce_size.attr, > NULL > }; > > -- > 2.20.1 > _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
