From: Eric Farman Date: Tue, 18 Jun 2019 20:23:50 +0000 (+0200) Subject: vfio-ccw: Copy CCW data outside length calculation X-Git-Tag: v5.15~6067^2~17^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ded563f31d0eb4de0bcb101b755cdf6f4ed805e4;p=platform%2Fkernel%2Flinux-starfive.git vfio-ccw: Copy CCW data outside length calculation It doesn't make much sense to "hide" the copy to the channel_program struct inside a routine that calculates the length of the chain. Let's move it to the calling routine, which will later copy from channel_program to the memory it allocated itself. Signed-off-by: Eric Farman Message-Id: <20190618202352.39702-4-farman@linux.ibm.com> Reviewed-by: Cornelia Huck Reviewed-by: Farhan Ali Signed-off-by: Cornelia Huck --- diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 37d513e..a55f8d1 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -381,18 +381,8 @@ static void ccwchain_cda_free(struct ccwchain *chain, int idx) static int ccwchain_calc_length(u64 iova, struct channel_program *cp) { struct ccw1 *ccw = cp->guest_cp; - int cnt; + int cnt = 0; - /* - * Copy current chain from guest to host kernel. - * Currently the chain length is limited to CCWCHAIN_LEN_MAX (256). - * So copying 2K is enough (safe). - */ - cnt = copy_ccw_from_iova(cp, ccw, iova, CCWCHAIN_LEN_MAX); - if (cnt) - return cnt; - - cnt = 0; do { cnt++; @@ -446,7 +436,12 @@ static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) struct ccwchain *chain; int len; - /* Copy the chain from cda to cp, and count the CCWs in it */ + /* Copy 2K (the most we support today) of possible CCWs */ + len = copy_ccw_from_iova(cp, cp->guest_cp, cda, CCWCHAIN_LEN_MAX); + if (len) + return len; + + /* Count the CCWs in the current chain */ len = ccwchain_calc_length(cda, cp); if (len < 0) return len;