| Message ID | 20190618202352.39702-3-farman@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390: more vfio-ccw code rework | expand |
On Tue, 18 Jun 2019 22:23:49 +0200 Eric Farman <farman@linux.ibm.com> wrote: > 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> > --- > drivers/s390/cio/vfio_ccw_cp.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) Reviewed-by: Cornelia Huck <cohuck@redhat.com>
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);
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> --- drivers/s390/cio/vfio_ccw_cp.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)