virtio: timeout after 5sec

Remove adhoc timer and put 5sec timeout. On a busy host, code hits this.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>

3 files changed, 20 insertions, 12 deletions

diff --git a/lib/libvirtio/virtio-blk.c b/lib/libvirtio/virtio-blk.c
index 6f21404..544068f 100644
--- a/lib/libvirtio/virtio-blk.c
+++ b/lib/libvirtio/virtio-blk.c
@@ -12,6 +12,7 @@
 
 #include <stdio.h>
 #include <cpu.h>
+#include <helpers.h>
 #include "virtio.h"
 #include "virtio-blk.h"
 
@@ -78,11 +79,11 @@ int
 virtioblk_read(struct virtio_device *dev, char *buf, long blocknum, long cnt)
 {
 	struct vring_desc *desc;
-	int id, i;
+	int id;
 	static struct virtio_blk_req blkhdr;
 	//struct virtio_blk_config *blkconf;
 	uint64_t capacity;
-	uint32_t vq_size;
+	uint32_t vq_size, time;
 	struct vring_desc *vq_desc;		/* Descriptor vring */
 	struct vring_avail *vq_avail;		/* "Available" vring */
 	struct vring_used *vq_used;		/* "Used" vring */
@@ -145,10 +146,12 @@ virtioblk_read(struct virtio_device *dev, char *buf, long blocknum, long cnt)
 	virtio_queue_notify(dev, 0);
 
 	/* Wait for host to consume the descriptor */
-	i = 10000000;
-	while (*current_used_idx == last_used_idx && i-- > 0) {
+	time = SLOF_GetTimer() + VIRTIO_TIMEOUT;
+	while (*current_used_idx == last_used_idx) {
 		// do something better
 		mb();
+		if (time < SLOF_GetTimer())
+			break;
 	}
 
 	if (status == 0)
diff --git a/lib/libvirtio/virtio-scsi.c b/lib/libvirtio/virtio-scsi.c
index 53e869a..4828928 100644
--- a/lib/libvirtio/virtio-scsi.c
+++ b/lib/libvirtio/virtio-scsi.c
@@ -13,6 +13,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <cpu.h>
+#include <helpers.h>
 #include "virtio.h"
 #include "virtio-scsi.h"
 
@@ -28,8 +29,8 @@ int virtioscsi_send(struct virtio_device *dev,
 
         volatile uint16_t *current_used_idx;
         uint16_t last_used_idx;
-        int id, i;
-        uint32_t vq_size;
+        int id;
+        uint32_t vq_size, time;
 
         int vq = VIRTIO_SCSI_REQUEST_VQ;
 
@@ -74,12 +75,14 @@ int virtioscsi_send(struct virtio_device *dev,
         /* Tell HV that the vq is ready */
         virtio_queue_notify(dev, vq);
 
-        /* Wait for host to consume the descriptor */
-        i = 10000000;
-        while (*current_used_idx == last_used_idx && i-- > 0) {
-                // do something better
-                mb();
-        }
+	/* Wait for host to consume the descriptor */
+	time = SLOF_GetTimer() + VIRTIO_TIMEOUT;
+	while (*current_used_idx == last_used_idx) {
+		// do something better
+		mb();
+		if (time < SLOF_GetTimer())
+			break;
+	}
 
         return 0;
 }
diff --git a/lib/libvirtio/virtio.h b/lib/libvirtio/virtio.h
index bb86d8d..b351930 100644
--- a/lib/libvirtio/virtio.h
+++ b/lib/libvirtio/virtio.h
@@ -21,6 +21,8 @@
 #define VIRTIO_STAT_DRIVER_OK		4
 #define VIRTIO_STAT_FAILED		128
 
+#define VIRTIO_TIMEOUT		        5000 /* 5 sec timeout */
+
 /* Definitions for vring_desc.flags */
 #define VRING_DESC_F_NEXT	1	/* buffer continues via the next field */
 #define VRING_DESC_F_WRITE	2	/* buffer is write-only (otherwise read-only) */