在 2021/8/3 下午5:31, Yongji Xie 写道:
On Tue, Aug 3, 2021 at 3:58 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
在 2021/7/29 下午3:34, Xie Yongji 写道:
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 <xieyongji@xxxxxxxxxxxxx>
---
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)?
Yes, since the how it's expected to behave depends on the specific hardware.
Even for the spec, the behavior is transport specific:
PCI: requires reread until 0
MMIO: doesn't require but it might not work for the hardware so we
decide to change
CCW: the succeed of the ccw command means the success of the reset
Thanks
Actually I didn't find any other place where I can do
set_status() and get_status().
Thanks,
Yongji
