The current timeout is set to only three seconds - and considering that vring_wait_reply() or rather get_second() is not doing any rounding, the real timeout is likely rather 2 seconds in most cases. When the host is really badly loaded and we run the guest in TCG mode instead of KVM, it's possible that we hit this timeout by mistake. So let's increase the timeout to 30 seconds instead to ease this situation (30 seconds is also the timeout that is used by the Linux SCSI subsystem for example, so this seems to be a sane value for block IO timeout).
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1549079 Signed-off-by: Thomas Huth <th...@redhat.com> --- pc-bios/s390-ccw/virtio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c index 817e7f5..cdb66f4 100644 --- a/pc-bios/s390-ccw/virtio.c +++ b/pc-bios/s390-ccw/virtio.c @@ -14,7 +14,7 @@ #include "virtio-scsi.h" #include "bswap.h" -#define VRING_WAIT_REPLY_TIMEOUT 3 +#define VRING_WAIT_REPLY_TIMEOUT 30 static VRing block[VIRTIO_MAX_VQS]; static char ring_area[VIRTIO_RING_SIZE * VIRTIO_MAX_VQS] -- 1.8.3.1
