clear-pkgs-linux-iot-lts2018/0424-vbs-fix-virtio_vq_index_get-func-handling-of-multi-V.patch

From 8d1b9355d0c96eef3b3b97eb5fc7e19457fc1ba9 Mon Sep 17 00:00:00 2001
From: Ong Hock Yu <ong.hock.yu@intel.com>
Date: Fri, 31 Aug 2018 10:59:03 +0800
Subject: [PATCH 424/550] vbs: fix virtio_vq_index_get func handling of multi
 VQ concurrent request.

Under multiple VQ use case, it is possible to have concurrent requests.
Added support to return multiple vq index from all vcpu.

Signed-off-by: Ong Hock Yu <ong.hock.yu@intel.com>
---
 drivers/vbs/vbs.c       | 27 ++++++++++++++++++++++-----
 drivers/vbs/vbs_rng.c   |  2 +-
 include/linux/vbs/vbs.h | 11 ++++++++---
 3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/drivers/vbs/vbs.c b/drivers/vbs/vbs.c
index c2d8a5262a8d..0e0516ad8794 100644
--- a/drivers/vbs/vbs.c
+++ b/drivers/vbs/vbs.c
@@ -148,9 +148,12 @@ long virtio_dev_deregister(struct virtio_dev_info *dev)
 	return 0;
 }
 
-int virtio_vq_index_get(struct virtio_dev_info *dev, unsigned long *ioreqs_map)
+int virtio_vqs_index_get(struct virtio_dev_info *dev,
+						unsigned long *ioreqs_map,
+						int *vqs_index,
+						int max_vqs_index)
 {
-	int val = -1;
+	int idx = 0;
 	struct vhm_request *req;
 	int vcpu;
 
@@ -178,10 +181,24 @@ int virtio_vq_index_get(struct virtio_dev_info *dev, unsigned long *ioreqs_map)
 			} else {
 				pr_debug("%s: write request! type %d\n",
 						__func__, req->type);
+
+				if (idx == max_vqs_index) {
+					pr_warn("%s: The allocated vqs\n"
+						"size (%d) is smaller than the\n"
+						"number of vcpu (%d)! This\n"
+						"might caused the process of\n"
+						"some requests be delayed.",
+						__func__, max_vqs_index,
+						dev->_ctx.max_vcpu);
+					break;
+				}
+
 				if (dev->io_range_type == PIO_RANGE)
-					val = req->reqs.pio_request.value;
+					vqs_index[idx++] =
+						req->reqs.pio_request.value;
 				else
-					val = req->reqs.mmio_request.value;
+					vqs_index[idx++] =
+						req->reqs.mmio_request.value;
 			}
 			smp_mb();
 			atomic_set(&req->processed, REQ_STATE_COMPLETE);
@@ -189,7 +206,7 @@ int virtio_vq_index_get(struct virtio_dev_info *dev, unsigned long *ioreqs_map)
 		}
 	}
 
-	return val;
+	return idx;
 }
 
 static long virtio_vqs_info_set(struct virtio_dev_info *dev,
diff --git a/drivers/vbs/vbs_rng.c b/drivers/vbs/vbs_rng.c
index fd2bb27af66e..c5e28cc12c55 100644
--- a/drivers/vbs/vbs_rng.c
+++ b/drivers/vbs/vbs_rng.c
@@ -268,7 +268,7 @@ static int handle_kick(int client_id, unsigned long *ioreqs_map)
 		return -EINVAL;
 	}
 
-	val = virtio_vq_index_get(&rng->dev, ioreqs_map);
+	virtio_vqs_index_get(&rng->dev, ioreqs_map, &val, 1);
 
 	if (val >= 0)
 		handle_vq_kick(rng, val);
diff --git a/include/linux/vbs/vbs.h b/include/linux/vbs/vbs.h
index 30df8ebf68a0..d9d932c49e88 100644
--- a/include/linux/vbs/vbs.h
+++ b/include/linux/vbs/vbs.h
@@ -262,7 +262,7 @@ long virtio_dev_register(struct virtio_dev_info *dev);
 long virtio_dev_deregister(struct virtio_dev_info *dev);
 
 /**
- * virtio_vq_index_get - get virtqueue index that frontend kicks
+ * virtio_vqs_index_get - get virtqueue indexes that frontend kicks
  *
  * This API is normally called in the VBS-K device's callback
  * function, to get value write to the "kick" register from
@@ -270,10 +270,15 @@ long virtio_dev_deregister(struct virtio_dev_info *dev);
  *
  * @dev: Pointer to VBS-K device data struct
  * @ioreqs_map: requests bitmap need to handle, provided by VHM
+ * @vqs_index: array to store the vq indexes
+ * @max_vqs_index: size of vqs_index array
  *
- * Return: >=0 on virtqueue index, <0 on error
+ * Return: Number of vq request
  */
-int virtio_vq_index_get(struct virtio_dev_info *dev, unsigned long *ioreqs_map);
+int virtio_vqs_index_get(struct virtio_dev_info *dev,
+						unsigned long *ioreqs_map,
+						int *vqs_index,
+						int max_vqs_index);
 
 /**
  * virtio_dev_reset - reset a VBS-K device
-- 
2.19.1