diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2013-02-28 12:33:16 +0100 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2013-03-05 19:12:09 -0300 |
| commit | 07e169335ff0570c6e67b5ccf74d793f00ab0834 (patch) | |
| tree | f96290e4e141305498fe5cb97a9efffc958c0d7a /drivers/s390/kvm/virtio_ccw.c | |
| parent | 503cd0c50ac7161eb5c3891b48b620cb0a5521cd (diff) | |
virtio_ccw: pass a cookie value to kvm hypercall
Lookups by channel/vq pair on host during virtio notifications might be
expensive. Interpret hypercall return value as a cookie which host can
use to do device lookups for the next notification more efficiently.
[CH: Fix line > 80 chars]
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'drivers/s390/kvm/virtio_ccw.c')
| -rw-r--r-- | drivers/s390/kvm/virtio_ccw.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c index 2029b6caa595..3d657522b3e2 100644 --- a/drivers/s390/kvm/virtio_ccw.c +++ b/drivers/s390/kvm/virtio_ccw.c @@ -77,6 +77,7 @@ struct virtio_ccw_vq_info { void *queue; struct vq_info_block *info_block; struct list_head node; + long cookie; }; #define KVM_VIRTIO_CCW_RING_ALIGN 4096 @@ -145,15 +146,18 @@ static int ccw_io_helper(struct virtio_ccw_device *vcdev, } static inline long do_kvm_notify(struct subchannel_id schid, - unsigned long queue_index) + unsigned long queue_index, + long cookie) { register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY; register struct subchannel_id __schid asm("2") = schid; register unsigned long __index asm("3") = queue_index; register long __rc asm("2"); + register long __cookie asm("4") = cookie; asm volatile ("diag 2,4,0x500\n" - : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index) + : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index), + "d"(__cookie) : "memory", "cc"); return __rc; } @@ -166,7 +170,8 @@ static void virtio_ccw_kvm_notify(struct virtqueue *vq) vcdev = to_vc_device(info->vq->vdev); ccw_device_get_schid(vcdev->cdev, &schid); - do_kvm_notify(schid, virtqueue_get_queue_index(vq)); + info->cookie = do_kvm_notify(schid, virtqueue_get_queue_index(vq), + info->cookie); } static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev, |