diff options
Diffstat (limited to 'drivers/s390/cio/vfio_ccw_cp.c')
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_cp.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 3645d1720c4b..b9febc581b1f 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -8,6 +8,7 @@ * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> */ +#include <linux/ratelimit.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/iommu.h> @@ -625,23 +626,27 @@ static int ccwchain_fetch_one(struct ccwchain *chain, * the target channel program from @orb->cmd.iova to the new ccwchain(s). * * Limitations: - * 1. Supports only prefetch enabled mode. - * 2. Supports idal(c64) ccw chaining. - * 3. Supports 4k idaw. + * 1. Supports idal(c64) ccw chaining. + * 2. Supports 4k idaw. * * Returns: * %0 on success and a negative error value on failure. */ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb) { + /* custom ratelimit used to avoid flood during guest IPL */ + static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 1); int ret; /* - * XXX: - * Only support prefetch enable mode now. + * We only support prefetching the channel program. We assume all channel + * programs executed by supported guests likewise support prefetching. + * Executing a channel program that does not specify prefetching will + * typically not cause an error, but a warning is issued to help identify + * the problem if something does break. */ - if (!orb->cmd.pfch) - return -EOPNOTSUPP; + if (!orb->cmd.pfch && __ratelimit(&ratelimit_state)) + dev_warn(mdev, "Prefetching channel program even though prefetch not specified in ORB"); INIT_LIST_HEAD(&cp->ccwchain_list); memcpy(&cp->orb, orb, sizeof(*orb)); |