On Tue, Aug 3, 2021 at 3:58 PM Jason Wang [off-list ref] wrote:

在 2021/7/29 下午3:34, Xie Yongji 写道:

quoted

Re-read the device status to ensure it's set to zero during
resetting. Otherwise, fail the vdpa_reset() after timeout.

Signed-off-by: Xie Yongji <redacted>
---
  include/linux/vdpa.h | 15 ++++++++++++++-
  1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 406d53a606ac..d1a80ef05089 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h

@@ -6,6 +6,7 @@
  #include <linux/device.h>
  #include <linux/interrupt.h>
  #include <linux/vhost_iotlb.h>
+#include <linux/delay.h>

  /**
   * struct vdpa_calllback - vDPA callback definition.

@@ -340,12 +341,24 @@ static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev)
      return vdev->dma_dev;
  }

-static inline void vdpa_reset(struct vdpa_device *vdev)
+#define VDPA_RESET_TIMEOUT_MS 1000
+
+static inline int vdpa_reset(struct vdpa_device *vdev)
  {
      const struct vdpa_config_ops *ops = vdev->config;
+     int timeout = 0;

      vdev->features_valid = false;
      ops->set_status(vdev, 0);
+     while (ops->get_status(vdev)) {
+             timeout += 20;
+             if (timeout > VDPA_RESET_TIMEOUT_MS)
+                     return -EIO;
+
+             msleep(20);
+     }

I wonder if it's better to do this in the vDPA parent?

Thanks

Sorry, I didn't get you here. Do you mean vDPA parent driver (e.g.
VDUSE)? Actually I didn't find any other place where I can do
set_status() and get_status().

Thanks,
Yongji