| Message ID | 20200206213825.11444-5-farman@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390x/vfio-ccw: Channel Path Handling | expand |
On Thu, 6 Feb 2020 22:38:20 +0100 Eric Farman <farman@linux.ibm.com> wrote: > From: Farhan Ali <alifm@linux.ibm.com> > > The schib region can be used by userspace to get the subchannel- > information block (SCHIB) for the passthrough subchannel. > This can be useful to get information such as channel path > information via the SCHIB.PMCW fields. > > Signed-off-by: Farhan Ali <alifm@linux.ibm.com> > Signed-off-by: Eric Farman <farman@linux.ibm.com> > --- > > Notes: > v1->v2: > - Add new region info to Documentation/s390/vfio-ccw.rst [CH] > - Add a block comment to struct ccw_schib_region [CH] > > v0->v1: [EF] > - Clean up checkpatch (#include, whitespace) errors > - Remove unnecessary includes from vfio_ccw_chp.c > - Add ret=-ENOMEM in error path for new region > - Add call to vfio_ccw_unregister_dev_regions() during error exit > path of vfio_ccw_mdev_open() > - New info on the module prologue > - Reorder cleanup of regions > > Documentation/s390/vfio-ccw.rst | 16 +++++- > drivers/s390/cio/Makefile | 2 +- > drivers/s390/cio/vfio_ccw_chp.c | 75 +++++++++++++++++++++++++++++ > drivers/s390/cio/vfio_ccw_drv.c | 20 ++++++++ > drivers/s390/cio/vfio_ccw_ops.c | 14 +++++- > drivers/s390/cio/vfio_ccw_private.h | 3 ++ > include/uapi/linux/vfio.h | 1 + > include/uapi/linux/vfio_ccw.h | 10 ++++ > 8 files changed, 137 insertions(+), 4 deletions(-) > create mode 100644 drivers/s390/cio/vfio_ccw_chp.c > > diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst > index fca9c4f5bd9c..b805dc995fc8 100644 > --- a/Documentation/s390/vfio-ccw.rst > +++ b/Documentation/s390/vfio-ccw.rst > @@ -231,6 +231,19 @@ This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD. > > Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region. > > +vfio-ccw schib region > +--------------------- > + > +The vfio-ccw schib region is used to return Subchannel-Information > +Block (SCHIB) data to userspace:: > + > + struct ccw_schib_region { > + #define SCHIB_AREA_SIZE 52 > + __u8 schib_area[SCHIB_AREA_SIZE]; > + } __packed; > + > +This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_SCHIB. Also mention that reading this triggers a stsch() updating the schib? > + > vfio-ccw operation details > -------------------------- > (...) > diff --git a/drivers/s390/cio/vfio_ccw_chp.c b/drivers/s390/cio/vfio_ccw_chp.c > new file mode 100644 > index 000000000000..826d08379fe3 > --- /dev/null > +++ b/drivers/s390/cio/vfio_ccw_chp.c > @@ -0,0 +1,75 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Channel path related status regions for vfio_ccw > + * > + * Copyright IBM Corp. 2019 Should the year be updated? > + * > + * Author(s): Farhan Ali <alifm@linux.ibm.com> > + */ (...)
On 2/14/20 7:32 AM, Cornelia Huck wrote: > On Thu, 6 Feb 2020 22:38:20 +0100 > Eric Farman <farman@linux.ibm.com> wrote: > >> From: Farhan Ali <alifm@linux.ibm.com> >> >> The schib region can be used by userspace to get the subchannel- >> information block (SCHIB) for the passthrough subchannel. >> This can be useful to get information such as channel path >> information via the SCHIB.PMCW fields. >> >> Signed-off-by: Farhan Ali <alifm@linux.ibm.com> >> Signed-off-by: Eric Farman <farman@linux.ibm.com> >> --- >> >> Notes: >> v1->v2: >> - Add new region info to Documentation/s390/vfio-ccw.rst [CH] >> - Add a block comment to struct ccw_schib_region [CH] >> >> v0->v1: [EF] >> - Clean up checkpatch (#include, whitespace) errors >> - Remove unnecessary includes from vfio_ccw_chp.c >> - Add ret=-ENOMEM in error path for new region >> - Add call to vfio_ccw_unregister_dev_regions() during error exit >> path of vfio_ccw_mdev_open() >> - New info on the module prologue >> - Reorder cleanup of regions >> >> Documentation/s390/vfio-ccw.rst | 16 +++++- >> drivers/s390/cio/Makefile | 2 +- >> drivers/s390/cio/vfio_ccw_chp.c | 75 +++++++++++++++++++++++++++++ >> drivers/s390/cio/vfio_ccw_drv.c | 20 ++++++++ >> drivers/s390/cio/vfio_ccw_ops.c | 14 +++++- >> drivers/s390/cio/vfio_ccw_private.h | 3 ++ >> include/uapi/linux/vfio.h | 1 + >> include/uapi/linux/vfio_ccw.h | 10 ++++ >> 8 files changed, 137 insertions(+), 4 deletions(-) >> create mode 100644 drivers/s390/cio/vfio_ccw_chp.c >> >> diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst >> index fca9c4f5bd9c..b805dc995fc8 100644 >> --- a/Documentation/s390/vfio-ccw.rst >> +++ b/Documentation/s390/vfio-ccw.rst >> @@ -231,6 +231,19 @@ This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD. >> >> Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region. >> >> +vfio-ccw schib region >> +--------------------- >> + >> +The vfio-ccw schib region is used to return Subchannel-Information >> +Block (SCHIB) data to userspace:: >> + >> + struct ccw_schib_region { >> + #define SCHIB_AREA_SIZE 52 >> + __u8 schib_area[SCHIB_AREA_SIZE]; >> + } __packed; >> + >> +This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_SCHIB. > > Also mention that reading this triggers a stsch() updating the schib? Yeah, I tucked that in the uapi header, but it should be mentioned here too. > >> + >> vfio-ccw operation details >> -------------------------- >> > > (...) > >> diff --git a/drivers/s390/cio/vfio_ccw_chp.c b/drivers/s390/cio/vfio_ccw_chp.c >> new file mode 100644 >> index 000000000000..826d08379fe3 >> --- /dev/null >> +++ b/drivers/s390/cio/vfio_ccw_chp.c >> @@ -0,0 +1,75 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Channel path related status regions for vfio_ccw >> + * >> + * Copyright IBM Corp. 2019 > > Should the year be updated? Probably. :) > >> + * >> + * Author(s): Farhan Ali <alifm@linux.ibm.com> >> + */ > > (...) >
diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst index fca9c4f5bd9c..b805dc995fc8 100644 --- a/Documentation/s390/vfio-ccw.rst +++ b/Documentation/s390/vfio-ccw.rst @@ -231,6 +231,19 @@ This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD. Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region. +vfio-ccw schib region +--------------------- + +The vfio-ccw schib region is used to return Subchannel-Information +Block (SCHIB) data to userspace:: + + struct ccw_schib_region { + #define SCHIB_AREA_SIZE 52 + __u8 schib_area[SCHIB_AREA_SIZE]; + } __packed; + +This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_SCHIB. + vfio-ccw operation details -------------------------- @@ -333,7 +346,8 @@ through DASD/ECKD device online in a guest now and use it as a block device. The current code allows the guest to start channel programs via -START SUBCHANNEL, and to issue HALT SUBCHANNEL and CLEAR SUBCHANNEL. +START SUBCHANNEL, and to issue HALT SUBCHANNEL, CLEAR SUBCHANNEL, +and STORE SUBCHANNEL. vfio-ccw supports classic (command mode) channel I/O only. Transport mode (HPF) is not supported. diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile index 23eae4188876..a9235f111e79 100644 --- a/drivers/s390/cio/Makefile +++ b/drivers/s390/cio/Makefile @@ -21,5 +21,5 @@ qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o obj-$(CONFIG_QDIO) += qdio.o vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o vfio_ccw_fsm.o \ - vfio_ccw_async.o vfio_ccw_trace.o + vfio_ccw_async.o vfio_ccw_trace.o vfio_ccw_chp.o obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o diff --git a/drivers/s390/cio/vfio_ccw_chp.c b/drivers/s390/cio/vfio_ccw_chp.c new file mode 100644 index 000000000000..826d08379fe3 --- /dev/null +++ b/drivers/s390/cio/vfio_ccw_chp.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Channel path related status regions for vfio_ccw + * + * Copyright IBM Corp. 2019 + * + * Author(s): Farhan Ali <alifm@linux.ibm.com> + */ + +#include <linux/vfio.h> +#include "vfio_ccw_private.h" + +static ssize_t vfio_ccw_schib_region_read(struct vfio_ccw_private *private, + char __user *buf, size_t count, + loff_t *ppos) +{ + unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS; + loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK; + struct ccw_schib_region *region; + int ret; + + if (pos + count > sizeof(*region)) + return -EINVAL; + + mutex_lock(&private->io_mutex); + region = private->region[i].data; + + if (cio_update_schib(private->sch)) { + ret = -ENODEV; + goto out; + } + + memcpy(region, &private->sch->schib, sizeof(*region)); + + if (copy_to_user(buf, (void *)region + pos, count)) { + ret = -EFAULT; + goto out; + } + + ret = count; + +out: + mutex_unlock(&private->io_mutex); + return ret; +} + +static ssize_t vfio_ccw_schib_region_write(struct vfio_ccw_private *private, + const char __user *buf, size_t count, + loff_t *ppos) +{ + return -EINVAL; +} + + +static void vfio_ccw_schib_region_release(struct vfio_ccw_private *private, + struct vfio_ccw_region *region) +{ + +} + +const struct vfio_ccw_regops vfio_ccw_schib_region_ops = { + .read = vfio_ccw_schib_region_read, + .write = vfio_ccw_schib_region_write, + .release = vfio_ccw_schib_region_release, +}; + +int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private) +{ + return vfio_ccw_register_dev_region(private, + VFIO_REGION_SUBTYPE_CCW_SCHIB, + &vfio_ccw_schib_region_ops, + sizeof(struct ccw_schib_region), + VFIO_REGION_INFO_FLAG_READ, + private->schib_region); +} diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index a99705e2fd73..3023a366ad47 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -27,6 +27,7 @@ struct workqueue_struct *vfio_ccw_work_q; static struct kmem_cache *vfio_ccw_io_region; static struct kmem_cache *vfio_ccw_cmd_region; +static struct kmem_cache *vfio_ccw_schib_region; debug_info_t *vfio_ccw_debug_msg_id; debug_info_t *vfio_ccw_debug_trace_id; @@ -119,6 +120,8 @@ static void vfio_ccw_sch_irq(struct subchannel *sch) static void vfio_ccw_free_regions(struct vfio_ccw_private *private) { + if (private->schib_region) + kmem_cache_free(vfio_ccw_schib_region, private->schib_region); if (private->cmd_region) kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); if (private->io_region) @@ -156,6 +159,12 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) if (!private->cmd_region) goto out_free; + private->schib_region = kmem_cache_zalloc(vfio_ccw_schib_region, + GFP_KERNEL | GFP_DMA); + + if (!private->schib_region) + goto out_free; + private->sch = sch; dev_set_drvdata(&sch->dev, private); mutex_init(&private->io_mutex); @@ -349,6 +358,7 @@ static void vfio_ccw_debug_exit(void) static void vfio_ccw_destroy_regions(void) { + kmem_cache_destroy(vfio_ccw_schib_region); kmem_cache_destroy(vfio_ccw_cmd_region); kmem_cache_destroy(vfio_ccw_io_region); } @@ -385,6 +395,16 @@ static int __init vfio_ccw_sch_init(void) goto out_err; } + vfio_ccw_schib_region = kmem_cache_create_usercopy("vfio_ccw_schib_region", + sizeof(struct ccw_schib_region), 0, + SLAB_ACCOUNT, 0, + sizeof(struct ccw_schib_region), NULL); + + if (!vfio_ccw_schib_region) { + ret = -ENOMEM; + goto out_err; + } + isc_register(VFIO_CCW_ISC); ret = css_driver_register(&vfio_ccw_sch_driver); if (ret) { diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index d4fc84b8867f..22988d67b6bb 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -172,8 +172,18 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev) ret = vfio_ccw_register_async_dev_regions(private); if (ret) - vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, - &private->nb); + goto out_unregister; + + ret = vfio_ccw_register_schib_dev_regions(private); + if (ret) + goto out_unregister; + + return ret; + +out_unregister: + vfio_ccw_unregister_dev_regions(private); + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, + &private->nb); return ret; } diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index ce3834159d98..d6601a8adf13 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -56,6 +56,7 @@ int vfio_ccw_register_dev_region(struct vfio_ccw_private *private, void vfio_ccw_unregister_dev_regions(struct vfio_ccw_private *private); int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private); +int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private); /** * struct vfio_ccw_private @@ -69,6 +70,7 @@ int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private); * @io_mutex: protect against concurrent update of I/O regions * @region: additional regions for other subchannel operations * @cmd_region: MMIO region for asynchronous I/O commands other than START + * @schib_region: MMIO region for SCHIB information * @num_regions: number of additional regions * @cp: channel program for the current I/O operation * @irb: irb info received from interrupt @@ -87,6 +89,7 @@ struct vfio_ccw_private { struct mutex io_mutex; struct vfio_ccw_region *region; struct ccw_cmd_region *cmd_region; + struct ccw_schib_region *schib_region; int num_regions; struct channel_program cp; diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 9e843a147ead..b108e2795ea3 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -378,6 +378,7 @@ struct vfio_region_gfx_edid { /* sub-types for VFIO_REGION_TYPE_CCW */ #define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1) +#define VFIO_REGION_SUBTYPE_CCW_SCHIB (2) /* * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped diff --git a/include/uapi/linux/vfio_ccw.h b/include/uapi/linux/vfio_ccw.h index cbecbf0cd54f..758bf214898d 100644 --- a/include/uapi/linux/vfio_ccw.h +++ b/include/uapi/linux/vfio_ccw.h @@ -34,4 +34,14 @@ struct ccw_cmd_region { __u32 ret_code; } __packed; +/* + * Used for processing commands that read the subchannel-information block + * Reading this region triggers a stsch() to hardware + * Note: this is controlled by a capability + */ +struct ccw_schib_region { +#define SCHIB_AREA_SIZE 52 + __u8 schib_area[SCHIB_AREA_SIZE]; +} __packed; + #endif