From 61783394f4eb3a8a0944005ea2761c011788a9c3 Mon Sep 17 00:00:00 2001 From: Eric Farman Date: Fri, 21 Oct 2022 17:02:48 +0200 Subject: [PATCH] vfio/ccw: populate page_array struct inline There are two possible ways the list of addresses that get passed to vfio are calculated. One is from a guest IDAL, which would be an array of (probably) non-contiguous addresses. The other is built from contiguous pages that follow the starting address provided by ccw->cda. page_array_alloc() attempts to simplify things by pre-populating this array from the starting address, but that's not needed for a CCW with an IDAL anyway so doesn't need to be in the allocator. Move it to the caller in the non-IDAL case, since it will be overwritten when reading the guest IDAL. Remove the initialization of the pa_page output pointers, since it won't be explicitly needed for either case. Signed-off-by: Eric Farman Reviewed-by: Matthew Rosato Signed-off-by: Heiko Carstens --- drivers/s390/cio/vfio_ccw_cp.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index b1436736b7b6..f448aa93007f 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -42,7 +42,6 @@ struct ccwchain { /* * page_array_alloc() - alloc memory for page array * @pa: page_array on which to perform the operation - * @iova: target guest physical address * @len: number of pages that should be pinned from @iova * * Attempt to allocate memory for page array. @@ -56,10 +55,8 @@ struct ccwchain { * -EINVAL if pa->pa_nr is not initially zero, or pa->pa_iova is not NULL * -ENOMEM if alloc failed */ -static int page_array_alloc(struct page_array *pa, u64 iova, unsigned int len) +static int page_array_alloc(struct page_array *pa, unsigned int len) { - int i; - if (pa->pa_nr || pa->pa_iova) return -EINVAL; @@ -78,13 +75,6 @@ static int page_array_alloc(struct page_array *pa, u64 iova, unsigned int len) return -ENOMEM; } - pa->pa_iova[0] = iova; - pa->pa_page[0] = NULL; - for (i = 1; i < pa->pa_nr; i++) { - pa->pa_iova[i] = pa->pa_iova[i - 1] + PAGE_SIZE; - pa->pa_page[i] = NULL; - } - return 0; } @@ -548,7 +538,7 @@ static int ccwchain_fetch_ccw(struct ccw1 *ccw, * required for the data transfer, since we only only support * 4K IDAWs today. */ - ret = page_array_alloc(pa, iova, idaw_nr); + ret = page_array_alloc(pa, idaw_nr); if (ret < 0) goto out_free_idaws; @@ -565,11 +555,9 @@ static int ccwchain_fetch_ccw(struct ccw1 *ccw, for (i = 0; i < idaw_nr; i++) pa->pa_iova[i] = idaws[i]; } else { - /* - * No action is required here; the iova addresses in page_array - * were initialized sequentially in page_array_alloc() beginning - * with the contents of ccw->cda. - */ + pa->pa_iova[0] = iova; + 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)) { -- 2.25.1