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various vfio-ccw fixes (ccw translation, state machine)

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Merge tag 'vfio-ccw-20190603' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features

various vfio-ccw fixes (ccw translation, state machine)
This commit is contained in:
Heiko Carstens 2019-06-04 15:04:53 +02:00
commit 753469a23b
2 changed files with 119 additions and 46 deletions
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159
drivers/s390/cio/vfio_ccw_cp.c
View File

@ -50,31 +50,25 @@ struct ccwchain {
};
/*
* pfn_array_alloc_pin() - alloc memory for PFNs, then pin user pages in memory
* pfn_array_alloc() - alloc memory for PFNs
* @pa: pfn_array on which to perform the operation
* @mdev: the mediated device to perform pin/unpin operations
* @iova: target guest physical address
* @len: number of bytes that should be pinned from @iova
*
* Attempt to allocate memory for PFNs, and pin user pages in memory.
* Attempt to allocate memory for PFNs.
*
* Usage of pfn_array:
* We expect (pa_nr == 0) and (pa_iova_pfn == NULL), any field in
* this structure will be filled in by this function.
*
* Returns:
* Number of pages pinned on success.
* If @pa->pa_nr is not 0, or @pa->pa_iova_pfn is not NULL initially,
* returns -EINVAL.
* If no pages were pinned, returns -errno.
* 0 if PFNs are allocated
* -EINVAL if pa->pa_nr is not initially zero, or pa->pa_iova_pfn is not NULL
* -ENOMEM if alloc failed
*/
static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev,
u64 iova, unsigned int len)
static int pfn_array_alloc(struct pfn_array *pa, u64 iova, unsigned int len)
{
int i, ret = 0;
if (!len)
return 0;
int i;
if (pa->pa_nr || pa->pa_iova_pfn)
return -EINVAL;
@ -94,8 +88,27 @@ static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev,
pa->pa_pfn = pa->pa_iova_pfn + pa->pa_nr;
pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT;
for (i = 1; i < pa->pa_nr; i++)
pa->pa_pfn[0] = -1ULL;
for (i = 1; i < pa->pa_nr; i++) {
pa->pa_iova_pfn[i] = pa->pa_iova_pfn[i - 1] + 1;
pa->pa_pfn[i] = -1ULL;
}
return 0;
}
/*
* pfn_array_pin() - Pin user pages in memory
* @pa: pfn_array on which to perform the operation
* @mdev: the mediated device to perform pin operations
*
* Returns number of pages pinned upon success.
* If the pin request partially succeeds, or fails completely,
* all pages are left unpinned and a negative error value is returned.
*/
static int pfn_array_pin(struct pfn_array *pa, struct device *mdev)
{
int ret = 0;
ret = vfio_pin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr,
IOMMU_READ | IOMMU_WRITE, pa->pa_pfn);
@ -112,8 +125,6 @@ static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev,
err_out:
pa->pa_nr = 0;
kfree(pa->pa_iova_pfn);
pa->pa_iova_pfn = NULL;
return ret;
}
@ -121,7 +132,9 @@ err_out:
/* Unpin the pages before releasing the memory. */
static void pfn_array_unpin_free(struct pfn_array *pa, struct device *mdev)
{
vfio_unpin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr);
/* Only unpin if any pages were pinned to begin with */
if (pa->pa_nr)
vfio_unpin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr);
pa->pa_nr = 0;
kfree(pa->pa_iova_pfn);
}
@ -209,10 +222,16 @@ static long copy_from_iova(struct device *mdev,
int i, ret;
unsigned long l, m;
ret = pfn_array_alloc_pin(&pa, mdev, iova, n);
if (ret <= 0)
ret = pfn_array_alloc(&pa, iova, n);
if (ret < 0)
return ret;
ret = pfn_array_pin(&pa, mdev);
if (ret < 0) {
pfn_array_unpin_free(&pa, mdev);
return ret;
}
l = n;
for (i = 0; i < pa.pa_nr; i++) {
from = pa.pa_pfn[i] << PAGE_SHIFT;
@ -272,17 +291,56 @@ static long copy_ccw_from_iova(struct channel_program *cp,
/*
* Helpers to operate ccwchain.
*/
#define ccw_is_test(_ccw) (((_ccw)->cmd_code & 0x0F) == 0)
#define ccw_is_read(_ccw) (((_ccw)->cmd_code & 0x03) == 0x02)
#define ccw_is_read_backward(_ccw) (((_ccw)->cmd_code & 0x0F) == 0x0C)
#define ccw_is_sense(_ccw) (((_ccw)->cmd_code & 0x0F) == CCW_CMD_BASIC_SENSE)
#define ccw_is_noop(_ccw) ((_ccw)->cmd_code == CCW_CMD_NOOP)
#define ccw_is_tic(_ccw) ((_ccw)->cmd_code == CCW_CMD_TIC)
#define ccw_is_idal(_ccw) ((_ccw)->flags & CCW_FLAG_IDA)
#define ccw_is_skip(_ccw) ((_ccw)->flags & CCW_FLAG_SKIP)
#define ccw_is_chain(_ccw) ((_ccw)->flags & (CCW_FLAG_CC | CCW_FLAG_DC))
/*
* ccw_does_data_transfer()
*
* Determine whether a CCW will move any data, such that the guest pages
* would need to be pinned before performing the I/O.
*
* Returns 1 if yes, 0 if no.
*/
static inline int ccw_does_data_transfer(struct ccw1 *ccw)
{
/* If the count field is zero, then no data will be transferred */
if (ccw->count == 0)
return 0;
/* If the command is a NOP, then no data will be transferred */
if (ccw_is_noop(ccw))
return 0;
/* If the skip flag is off, then data will be transferred */
if (!ccw_is_skip(ccw))
return 1;
/*
* If the skip flag is on, it is only meaningful if the command
* code is a read, read backward, sense, or sense ID. In those
* cases, no data will be transferred.
*/
if (ccw_is_read(ccw) || ccw_is_read_backward(ccw))
return 0;
if (ccw_is_sense(ccw))
return 0;
/* The skip flag is on, but it is ignored for this command code. */
return 1;
}
/*
* is_cpa_within_range()
*
@ -348,9 +406,7 @@ static void ccwchain_cda_free(struct ccwchain *chain, int idx)
{
struct ccw1 *ccw = chain->ch_ccw + idx;
if (ccw_is_test(ccw) || ccw_is_noop(ccw) || ccw_is_tic(ccw))
return;
if (!ccw->count)
if (ccw_is_tic(ccw))
return;
kfree((void *)(u64)ccw->cda);
@ -537,17 +593,14 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
struct pfn_array_table *pat;
unsigned long *idaws;
int ret;
int bytes = 1;
int idaw_nr = 1;
ccw = chain->ch_ccw + idx;
if (!ccw->count) {
/*
* We just want the translation result of any direct ccw
* to be an IDA ccw, so let's add the IDA flag for it.
* Although the flag will be ignored by firmware.
*/
ccw->flags |= CCW_FLAG_IDA;
return 0;
if (ccw->count) {
bytes = ccw->count;
idaw_nr = idal_nr_words((void *)(u64)ccw->cda, ccw->count);
}
/*
@ -560,12 +613,20 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
if (ret)
goto out_init;
ret = pfn_array_alloc_pin(pat->pat_pa, cp->mdev, ccw->cda, ccw->count);
ret = pfn_array_alloc(pat->pat_pa, ccw->cda, bytes);
if (ret < 0)
goto out_unpin;
if (ccw_does_data_transfer(ccw)) {
ret = pfn_array_pin(pat->pat_pa, cp->mdev);
if (ret < 0)
goto out_unpin;
} else {
pat->pat_pa->pa_nr = 0;
}
/* Translate this direct ccw to a idal ccw. */
idaws = kcalloc(ret, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
if (!idaws) {
ret = -ENOMEM;
goto out_unpin;
@ -590,21 +651,23 @@ static int ccwchain_fetch_idal(struct ccwchain *chain,
{
struct ccw1 *ccw;
struct pfn_array_table *pat;
struct pfn_array *pa;
unsigned long *idaws;
u64 idaw_iova;
unsigned int idaw_nr, idaw_len;
int i, ret;
int bytes = 1;
ccw = chain->ch_ccw + idx;
if (!ccw->count)
return 0;
if (ccw->count)
bytes = ccw->count;
/* Calculate size of idaws. */
ret = copy_from_iova(cp->mdev, &idaw_iova, ccw->cda, sizeof(idaw_iova));
if (ret)
return ret;
idaw_nr = idal_nr_words((void *)(idaw_iova), ccw->count);
idaw_nr = idal_nr_words((void *)(idaw_iova), bytes);
idaw_len = idaw_nr * sizeof(*idaws);
/* Pin data page(s) in memory. */
@ -628,9 +691,18 @@ static int ccwchain_fetch_idal(struct ccwchain *chain,
for (i = 0; i < idaw_nr; i++) {
idaw_iova = *(idaws + i);
pa = pat->pat_pa + i;
ret = pfn_array_alloc_pin(pat->pat_pa + i, cp->mdev,
idaw_iova, 1);
ret = pfn_array_alloc(pa, idaw_iova, 1);
if (ret < 0)
goto out_free_idaws;
if (!ccw_does_data_transfer(ccw)) {
pa->pa_nr = 0;
continue;
}
ret = pfn_array_pin(pa, cp->mdev);
if (ret < 0)
goto out_free_idaws;
}
@ -660,9 +732,6 @@ static int ccwchain_fetch_one(struct ccwchain *chain,
{
struct ccw1 *ccw = chain->ch_ccw + idx;
if (ccw_is_test(ccw) || ccw_is_noop(ccw))
return 0;
if (ccw_is_tic(ccw))
return ccwchain_fetch_tic(chain, idx, cp);
@ -886,7 +955,11 @@ void cp_update_scsw(struct channel_program *cp, union scsw *scsw)
*/
list_for_each_entry(chain, &cp->ccwchain_list, next) {
ccw_head = (u32)(u64)chain->ch_ccw;
if (is_cpa_within_range(cpa, ccw_head, chain->ch_len)) {
/*
* On successful execution, cpa points just beyond the end
* of the chain.
*/
if (is_cpa_within_range(cpa, ccw_head, chain->ch_len + 1)) {
/*
* (cpa - ccw_head) is the offset value of the host
* physical ccw to its chain head.

6
drivers/s390/cio/vfio_ccw_drv.c
View File

@ -95,11 +95,11 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work)
memcpy(private->io_region->irb_area, irb, sizeof(*irb));
mutex_unlock(&private->io_mutex);
if (private->io_trigger)
eventfd_signal(private->io_trigger, 1);
if (private->mdev && is_final)
private->state = VFIO_CCW_STATE_IDLE;
if (private->io_trigger)
eventfd_signal(private->io_trigger, 1);
}
/*