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vfio/ccw: allocate/populate the guest idal

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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@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Eric Farman 2022-10-21 20:53:51 +02:00 committed by Heiko Carstens
parent 6a6dc14ac8
commit 61f3a16b9d
1 changed files with 52 additions and 24 deletions
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76
drivers/s390/cio/vfio_ccw_cp.c
View file

@ -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++)
/*
* 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)) {