Today, we allocate memory for a list of IDAWs, and if the CCW being processed contains an IDAL we read that data from the guest into that space. We then copy each IDAW into the pa_iova array, or fabricate that pa_iova array with a list of addresses based on a direct-addressed CCW. Combine the reading of the guest IDAL with the creation of a pseudo-IDAL for direct-addressed CCWs, so that both CCW types have a "guest" IDAL that can be populated straight into the pa_iova array. Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx> --- drivers/s390/cio/vfio_ccw_cp.c | 72 +++++++++++++++++++++++----------- 1 file changed, 50 insertions(+), 22 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 6839e7195182..90685cee85db 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -192,11 +192,12 @@ static inline void page_array_idal_create_words(struct page_array *pa, * idaw. */ - for (i = 0; i < pa->pa_nr; i++) + for (i = 0; i < pa->pa_nr; i++) { idaws[i] = page_to_phys(pa->pa_page[i]); - /* Adjust the first IDAW, since it may not start on a page boundary */ - idaws[0] += pa->pa_iova[0] & (PAGE_SIZE - 1); + /* Incorporate any offset from each starting address */ + idaws[i] += pa->pa_iova[i] & (PAGE_SIZE - 1); + } } static void convert_ccw0_to_ccw1(struct ccw1 *source, unsigned long len) @@ -496,6 +497,44 @@ static int ccwchain_fetch_tic(struct ccw1 *ccw, return -EFAULT; } +static unsigned long *get_guest_idal(struct ccw1 *ccw, + struct channel_program *cp, + int idaw_nr) +{ + struct vfio_device *vdev = + &container_of(cp, struct vfio_ccw_private, cp)->vdev; + unsigned long *idaws; + int idal_len = idaw_nr * sizeof(*idaws); + int idaw_size = PAGE_SIZE; + int idaw_mask = ~(idaw_size - 1); + int i, ret; + + idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL); + if (!idaws) + return NULL; + + if (ccw_is_idal(ccw)) { + /* Copy IDAL from guest */ + ret = vfio_dma_rw(vdev, ccw->cda, idaws, idal_len, false); + if (ret) { + kfree(idaws); + return NULL; + } + } else { + /* Fabricate an IDAL based off CCW data address */ + if (cp->orb.cmd.c64) { + idaws[0] = ccw->cda; + for (i = 1; i < idaw_nr; i++) + idaws[i] = (idaws[i - 1] + idaw_size) & idaw_mask; + } else { + kfree(idaws); + return NULL; + } + } + + return idaws; +} + /* * ccw_count_idaws() - Calculate the number of IDAWs needed to transfer * a specified amount of data @@ -555,7 +594,7 @@ static int ccwchain_fetch_ccw(struct ccw1 *ccw, &container_of(cp, struct vfio_ccw_private, cp)->vdev; unsigned long *idaws; int ret; - int idaw_nr, idal_len; + int idaw_nr; int i; /* Calculate size of IDAL */ @@ -563,10 +602,8 @@ static int ccwchain_fetch_ccw(struct ccw1 *ccw, if (idaw_nr < 0) return idaw_nr; - idal_len = idaw_nr * sizeof(*idaws); - /* Allocate an IDAL from host storage */ - idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL); + idaws = get_guest_idal(ccw, cp, idaw_nr); if (!idaws) { ret = -ENOMEM; goto out_init; @@ -582,22 +619,13 @@ static int ccwchain_fetch_ccw(struct ccw1 *ccw, if (ret < 0) goto out_free_idaws; - if (ccw_is_idal(ccw)) { - /* Copy guest IDAL into host IDAL */ - ret = vfio_dma_rw(vdev, ccw->cda, idaws, idal_len, false); - if (ret) - goto out_unpin; - - /* - * Copy guest IDAWs into page_array, in case the memory they - * occupy is not contiguous. - */ - for (i = 0; i < idaw_nr; i++) + /* + * Copy guest IDAWs into page_array, in case the memory they + * occupy is not contiguous. + */ + for (i = 0; i < idaw_nr; i++) { + if (cp->orb.cmd.c64) pa->pa_iova[i] = idaws[i]; - } else { - pa->pa_iova[0] = ccw->cda; - for (i = 1; i < pa->pa_nr; i++) - pa->pa_iova[i] = pa->pa_iova[i - 1] + PAGE_SIZE; } if (ccw_does_data_transfer(ccw)) { -- 2.34.1