diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index af632f9d5453..6275794751cb 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -523,6 +523,7 @@ static dma64_t *get_guest_idal(struct ccw1 *ccw, struct channel_program *cp, int &container_of(cp, struct vfio_ccw_private, cp)->vdev; dma64_t *idaws; dma32_t *idaws_f1; + u64 first_idaw; int idal_len = idaw_nr * sizeof(*idaws); int idaw_size = idal_is_2k(cp) ? PAGE_SIZE / 2 : PAGE_SIZE; int idaw_mask = ~(idaw_size - 1); @@ -539,6 +540,18 @@ static dma64_t *get_guest_idal(struct ccw1 *ccw, struct channel_program *cp, int kfree(idaws); return ERR_PTR(ret); } + + idaws_f1 = (dma32_t *)idaws; + if (cp->orb.cmd.c64) + first_idaw = dma64_to_u64(idaws[0]); + else + first_idaw = dma32_to_u32(idaws_f1[0]); + + /* Unexpected mismatch from earlier read */ + if (first_idaw != cp->guest_iova) { + kfree(idaws); + return ERR_PTR(-EINVAL); + } } else { /* Fabricate an IDAL based off CCW data address */ if (cp->orb.cmd.c64) { @@ -604,6 +617,9 @@ static int ccw_count_idaws(struct ccw1 *ccw, iova = dma32_to_u32(ccw->cda); } + /* Save the read address for later */ + cp->guest_iova = iova; + /* Format-1 IDAWs operate on 2K each */ if (!cp->orb.cmd.c64) return idal_2k_nr_words((void *)iova, bytes); diff --git a/drivers/s390/cio/vfio_ccw_cp.h b/drivers/s390/cio/vfio_ccw_cp.h index a9b1d8dbc6f6..9af98ff12d67 100644 --- a/drivers/s390/cio/vfio_ccw_cp.h +++ b/drivers/s390/cio/vfio_ccw_cp.h @@ -35,6 +35,7 @@ * @initialized: whether this instance is actually initialized * @guest_cp: copy of guest channel program * @ccwchain_count: number of channel program segments (linked by TIC) + * @guest_iova: first data address of a guest channel program * * @ccwchain_list is the head of a ccwchain list, that contents the * translated result of the guest channel program that pointed out by @@ -46,6 +47,7 @@ struct channel_program { bool initialized; struct ccw1 *guest_cp; unsigned int ccwchain_count; + u64 guest_iova; }; int cp_init(struct channel_program *cp, union orb *orb);