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Various fixes and improvements in vfio-ccw, including a first stab

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at adding tracepoints.
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Merge tag 'vfio-ccw-20180529' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features

Pull vfio-ccw from Cornelia Huck with the following changes:

 - Various fixes and improvements in vfio-ccw, including a first stab
   at adding tracepoints.
This commit is contained in:
Martin Schwidefsky 2018-06-12 15:13:14 +02:00
commit d7927df833
5 changed files with 152 additions and 69 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/s390/cio/Makefile
View File

@ -5,6 +5,7 @@
# The following is required for define_trace.h to find ./trace.h
CFLAGS_trace.o := -I$(src)
CFLAGS_vfio_ccw_fsm.o := -I$(src)
obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o idset.o isc.o \
fcx.o itcw.o crw.o ccwreq.o trace.o ioasm.o

144
drivers/s390/cio/vfio_ccw_cp.c
View File

@ -23,9 +23,13 @@
#define CCWCHAIN_LEN_MAX 256
struct pfn_array {
/* Starting guest physical I/O address. */
unsigned long pa_iova;
/* Array that stores PFNs of the pages need to pin. */
unsigned long *pa_iova_pfn;
/* Array that receives PFNs of the pages pinned. */
unsigned long *pa_pfn;
/* Number of pages pinned from @pa_iova. */
int pa_nr;
};
@ -46,70 +50,33 @@ struct ccwchain {
};
/*
* pfn_array_pin() - pin user pages in memory
* pfn_array_alloc_pin() - alloc memory for PFNs, then pin user pages in memory
* @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 pin user pages in memory.
* Attempt to allocate memory for PFNs, and pin user pages in memory.
*
* Usage of pfn_array:
* @pa->pa_iova starting guest physical I/O address. Assigned by caller.
* @pa->pa_iova_pfn array that stores PFNs of the pages need to pin. Allocated
* by caller.
* @pa->pa_pfn array that receives PFNs of the pages pinned. Allocated by
* caller.
* @pa->pa_nr number of pages from @pa->pa_iova to pin. Assigned by
* caller.
* number of pages pinned. Assigned by callee.
* 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 0 or negative, returns 0.
* 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.
*/
static int pfn_array_pin(struct pfn_array *pa, struct device *mdev)
{
int i, ret;
if (pa->pa_nr <= 0) {
pa->pa_nr = 0;
return 0;
}
pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT;
for (i = 1; i < pa->pa_nr; i++)
pa->pa_iova_pfn[i] = pa->pa_iova_pfn[i - 1] + 1;
ret = vfio_pin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr,
IOMMU_READ | IOMMU_WRITE, pa->pa_pfn);
if (ret > 0 && ret != pa->pa_nr) {
vfio_unpin_pages(mdev, pa->pa_iova_pfn, ret);
pa->pa_nr = 0;
return 0;
}
return ret;
}
/* 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);
pa->pa_nr = 0;
kfree(pa->pa_iova_pfn);
}
/* Alloc memory for PFNs, then pin pages with them. */
static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev,
u64 iova, unsigned int len)
{
int ret = 0;
int i, ret = 0;
if (!len)
return 0;
if (pa->pa_nr)
if (pa->pa_nr || pa->pa_iova_pfn)
return -EINVAL;
pa->pa_iova = iova;
@ -126,16 +93,37 @@ static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev,
return -ENOMEM;
pa->pa_pfn = pa->pa_iova_pfn + pa->pa_nr;
ret = pfn_array_pin(pa, mdev);
pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT;
for (i = 1; i < pa->pa_nr; i++)
pa->pa_iova_pfn[i] = pa->pa_iova_pfn[i - 1] + 1;
if (ret > 0)
return ret;
else if (!ret)
ret = vfio_pin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr,
IOMMU_READ | IOMMU_WRITE, pa->pa_pfn);
if (ret < 0) {
goto err_out;
} else if (ret > 0 && ret != pa->pa_nr) {
vfio_unpin_pages(mdev, pa->pa_iova_pfn, ret);
ret = -EINVAL;
kfree(pa->pa_iova_pfn);
goto err_out;
}
return ret;
err_out:
pa->pa_nr = 0;
kfree(pa->pa_iova_pfn);
pa->pa_iova_pfn = NULL;
return ret;
}
/* 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);
pa->pa_nr = 0;
kfree(pa->pa_iova_pfn);
}
static int pfn_array_table_init(struct pfn_array_table *pat, int nr)
@ -365,6 +353,9 @@ static void cp_unpin_free(struct channel_program *cp)
* This is the chain length not considering any TICs.
* You need to do a new round for each TIC target.
*
* The program is also validated for absence of not yet supported
* indirect data addressing scenarios.
*
* Returns: the length of the ccw chain or -errno.
*/
static int ccwchain_calc_length(u64 iova, struct channel_program *cp)
@ -391,6 +382,14 @@ static int ccwchain_calc_length(u64 iova, struct channel_program *cp)
do {
cnt++;
/*
* As we don't want to fail direct addressing even if the
* orb specified one of the unsupported formats, we defer
* checking for IDAWs in unsupported formats to here.
*/
if ((!cp->orb.cmd.c64 || cp->orb.cmd.i2k) && ccw_is_idal(ccw))
return -EOPNOTSUPP;
if ((!ccw_is_chain(ccw)) && (!ccw_is_tic(ccw)))
break;
@ -503,7 +502,7 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
struct ccw1 *ccw;
struct pfn_array_table *pat;
unsigned long *idaws;
int idaw_nr;
int ret;
ccw = chain->ch_ccw + idx;
@ -523,18 +522,19 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
* needed when translating a direct ccw to a idal ccw.
*/
pat = chain->ch_pat + idx;
if (pfn_array_table_init(pat, 1))
return -ENOMEM;
idaw_nr = pfn_array_alloc_pin(pat->pat_pa, cp->mdev,
ccw->cda, ccw->count);
if (idaw_nr < 0)
return idaw_nr;
ret = pfn_array_table_init(pat, 1);
if (ret)
goto out_init;
ret = pfn_array_alloc_pin(pat->pat_pa, cp->mdev, ccw->cda, ccw->count);
if (ret < 0)
goto out_init;
/* Translate this direct ccw to a idal ccw. */
idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
idaws = kcalloc(ret, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
if (!idaws) {
pfn_array_table_unpin_free(pat, cp->mdev);
return -ENOMEM;
ret = -ENOMEM;
goto out_unpin;
}
ccw->cda = (__u32) virt_to_phys(idaws);
ccw->flags |= CCW_FLAG_IDA;
@ -542,6 +542,12 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
pfn_array_table_idal_create_words(pat, idaws);
return 0;
out_unpin:
pfn_array_table_unpin_free(pat, cp->mdev);
out_init:
ccw->cda = 0;
return ret;
}
static int ccwchain_fetch_idal(struct ccwchain *chain,
@ -571,7 +577,7 @@ static int ccwchain_fetch_idal(struct ccwchain *chain,
pat = chain->ch_pat + idx;
ret = pfn_array_table_init(pat, idaw_nr);
if (ret)
return ret;
goto out_init;
/* Translate idal ccw to use new allocated idaws. */
idaws = kzalloc(idaw_len, GFP_DMA | GFP_KERNEL);
@ -603,6 +609,8 @@ out_free_idaws:
kfree(idaws);
out_unpin:
pfn_array_table_unpin_free(pat, cp->mdev);
out_init:
ccw->cda = 0;
return ret;
}
@ -656,10 +664,8 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb)
/*
* XXX:
* Only support prefetch enable mode now.
* Only support 64bit addressing idal.
* Only support 4k IDAW.
*/
if (!orb->cmd.pfch || !orb->cmd.c64 || orb->cmd.i2k)
if (!orb->cmd.pfch)
return -EOPNOTSUPP;
INIT_LIST_HEAD(&cp->ccwchain_list);
@ -688,6 +694,10 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb)
ret = ccwchain_loop_tic(chain, cp);
if (ret)
cp_unpin_free(cp);
/* It is safe to force: if not set but idals used
* ccwchain_calc_length returns an error.
*/
cp->orb.cmd.c64 = 1;
return ret;
}

5
drivers/s390/cio/vfio_ccw_drv.c
View File

@ -177,6 +177,7 @@ static int vfio_ccw_sch_event(struct subchannel *sch, int process)
{
struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
unsigned long flags;
int rc = -EAGAIN;
spin_lock_irqsave(sch->lock, flags);
if (!device_is_registered(&sch->dev))
@ -187,6 +188,7 @@ static int vfio_ccw_sch_event(struct subchannel *sch, int process)
if (cio_update_schib(sch)) {
vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER);
rc = 0;
goto out_unlock;
}
@ -195,11 +197,12 @@ static int vfio_ccw_sch_event(struct subchannel *sch, int process)
private->state = private->mdev ? VFIO_CCW_STATE_IDLE :
VFIO_CCW_STATE_STANDBY;
}
rc = 0;
out_unlock:
spin_unlock_irqrestore(sch->lock, flags);
return 0;
return rc;
}
static struct css_device_id vfio_ccw_sch_ids[] = {

17
drivers/s390/cio/vfio_ccw_fsm.c
View File

@ -13,6 +13,9 @@
#include "ioasm.h"
#include "vfio_ccw_private.h"
#define CREATE_TRACE_POINTS
#include "vfio_ccw_trace.h"
static int fsm_io_helper(struct vfio_ccw_private *private)
{
struct subchannel *sch;
@ -110,6 +113,10 @@ static void fsm_disabled_irq(struct vfio_ccw_private *private,
*/
cio_disable_subchannel(sch);
}
inline struct subchannel_id get_schid(struct vfio_ccw_private *p)
{
return p->sch->schid;
}
/*
* Deal with the ccw command request from the userspace.
@ -121,6 +128,7 @@ static void fsm_io_request(struct vfio_ccw_private *private,
union scsw *scsw = &private->scsw;
struct ccw_io_region *io_region = &private->io_region;
struct mdev_device *mdev = private->mdev;
char *errstr = "request";
private->state = VFIO_CCW_STATE_BOXED;
@ -132,15 +140,19 @@ static void fsm_io_request(struct vfio_ccw_private *private,
/* Don't try to build a cp if transport mode is specified. */
if (orb->tm.b) {
io_region->ret_code = -EOPNOTSUPP;
errstr = "transport mode";
goto err_out;
}
io_region->ret_code = cp_init(&private->cp, mdev_dev(mdev),
orb);
if (io_region->ret_code)
if (io_region->ret_code) {
errstr = "cp init";
goto err_out;
}
io_region->ret_code = cp_prefetch(&private->cp);
if (io_region->ret_code) {
errstr = "cp prefetch";
cp_free(&private->cp);
goto err_out;
}
@ -148,6 +160,7 @@ static void fsm_io_request(struct vfio_ccw_private *private,
/* Start channel program and wait for I/O interrupt. */
io_region->ret_code = fsm_io_helper(private);
if (io_region->ret_code) {
errstr = "cp fsm_io_helper";
cp_free(&private->cp);
goto err_out;
}
@ -164,6 +177,8 @@ static void fsm_io_request(struct vfio_ccw_private *private,
err_out:
private->state = VFIO_CCW_STATE_IDLE;
trace_vfio_ccw_io_fctl(scsw->cmd.fctl, get_schid(private),
io_region->ret_code, errstr);
}
/*

54
drivers/s390/cio/vfio_ccw_trace.h Normal file
View File

@ -0,0 +1,54 @@
/* SPDX-License-Identifier: GPL-2.0
* Tracepoints for vfio_ccw driver
*
* Copyright IBM Corp. 2018
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Halil Pasic <pasic@linux.vnet.ibm.com>
*/
#undef TRACE_SYSTEM
#define TRACE_SYSTEM vfio_ccw
#if !defined(_VFIO_CCW_TRACE_) || defined(TRACE_HEADER_MULTI_READ)
#define _VFIO_CCW_TRACE_
#include <linux/tracepoint.h>
TRACE_EVENT(vfio_ccw_io_fctl,
TP_PROTO(int fctl, struct subchannel_id schid, int errno, char *errstr),
TP_ARGS(fctl, schid, errno, errstr),
TP_STRUCT__entry(
__field(int, fctl)
__field_struct(struct subchannel_id, schid)
__field(int, errno)
__field(char*, errstr)
),
TP_fast_assign(
__entry->fctl = fctl;
__entry->schid = schid;
__entry->errno = errno;
__entry->errstr = errstr;
),
TP_printk("schid=%x.%x.%04x fctl=%x errno=%d info=%s",
__entry->schid.cssid,
__entry->schid.ssid,
__entry->schid.sch_no,
__entry->fctl,
__entry->errno,
__entry->errstr)
);
#endif /* _VFIO_CCW_TRACE_ */
/* This part must be outside protection */
#undef TRACE_INCLUDE_PATH
#define TRACE_INCLUDE_PATH .
#undef TRACE_INCLUDE_FILE
#define TRACE_INCLUDE_FILE vfio_ccw_trace
#include <trace/define_trace.h>