Commit 61f3a16b authored by Eric Farman's avatar Eric Farman Committed by Heiko Carstens
Browse files

vfio/ccw: allocate/populate the guest idal 



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: default avatarEric Farman <farman@linux.ibm.com>
Reviewed-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 6a6dc14a

drivers/s390/cio/vfio_ccw_cp.c

+52 −24
Original line number Diff line number Diff line
@@ -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 ERR_PTR(-ENOMEM);



	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 ERR_PTR(ret);

		}

	} 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 ERR_PTR(-EOPNOTSUPP);

		}

	}



	return idaws;

}



/*

 * ccw_count_idaws() - Calculate the number of IDAWs needed to transfer

 * a specified amount of data
@@ -560,7 +599,7 @@ 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 */
@@ -568,12 +607,10 @@ 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);

	if (!idaws) {

		ret = -ENOMEM;

	idaws = get_guest_idal(ccw, cp, idaw_nr);

	if (IS_ERR(idaws)) {

		ret = PTR_ERR(idaws);

		goto out_init;

	}
@@ -587,22 +624,13 @@ 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++)

	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)) {