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| author | Eric Farman <farman@linux.ibm.com> | 2019-06-18 22:23:49 +0200 |
|---|---|---|
| committer | Cornelia Huck <cohuck@redhat.com> | 2019-06-21 14:12:29 +0200 |
| commit | 6246590230e9c1225d2ce8d0160376b4d5511281 (patch) | |
| tree | fcdd550725a592df9273e0ebfa43e7e095a785ef | |
| parent | 1d897e478da3db91593d86227854802102e2fcd3 (diff) | |
| download | linux-6246590230e9c1225d2ce8d0160376b4d5511281.tar.gz linux-6246590230e9c1225d2ce8d0160376b4d5511281.tar.bz2 linux-6246590230e9c1225d2ce8d0160376b4d5511281.zip | |
vfio-ccw: Skip second copy of guest cp to host
We already pinned/copied/unpinned 2K (256 CCWs) of guest memory
to the host space anchored off vfio_ccw_private. There's no need
to do that again once we have the length calculated, when we could
just copy the section we need to the "permanent" space for the I/O.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20190618202352.39702-3-farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_cp.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index f358502376be..37d513e86530 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -444,7 +444,7 @@ static int ccwchain_loop_tic(struct ccwchain *chain, static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) { struct ccwchain *chain; - int len, ret; + int len; /* Copy the chain from cda to cp, and count the CCWs in it */ len = ccwchain_calc_length(cda, cp); @@ -457,12 +457,8 @@ static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) return -ENOMEM; chain->ch_iova = cda; - /* Copy the new chain from user. */ - ret = copy_ccw_from_iova(cp, chain->ch_ccw, cda, len); - if (ret) { - ccwchain_free(chain); - return ret; - } + /* Copy the actual CCWs into the new chain */ + memcpy(chain->ch_ccw, cp->guest_cp, len * sizeof(struct ccw1)); /* Loop for tics on this new chain. */ return ccwchain_loop_tic(chain, cp); |