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From:   Xie Yongji <xieyongji@bytedance.com>
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Cc:     songmuchun@bytedance.com,
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Subject: [PATCH v9 05/17] vhost-vdpa: Fail the vhost_vdpa_set_status() on reset failure
Date:   Tue, 13 Jul 2021 16:46:44 +0800
Message-Id: <20210713084656.232-6-xieyongji@bytedance.com>
In-Reply-To: <20210713084656.232-1-xieyongji@bytedance.com>
References: <20210713084656.232-1-xieyongji@bytedance.com>
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Re-read the device status to ensure it's set to zero during
resetting. Otherwise, fail the vhost_vdpa_set_status() after timeout.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
---
 drivers/vhost/vdpa.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index bb374a801bda..62b6d911c57d 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -157,7 +157,7 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 	struct vdpa_device *vdpa = v->vdpa;
 	const struct vdpa_config_ops *ops = vdpa->config;
 	u8 status, status_old;
-	int nvqs = v->nvqs;
+	int timeout = 0, nvqs = v->nvqs;
 	u16 i;
 
 	if (copy_from_user(&status, statusp, sizeof(status)))
@@ -173,6 +173,15 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 		return -EINVAL;
 
 	ops->set_status(vdpa, status);
+	if (status == 0) {
+		while (ops->get_status(vdpa)) {
+			timeout += 20;
+			if (timeout > VDPA_RESET_TIMEOUT_MS)
+				return -EIO;
+
+			msleep(20);
+		}
+	}
 
 	if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
 		for (i = 0; i < nvqs; i++)
-- 
2.11.0