| Message ID | 20190301093902.27799-7-cohuck@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio-ccw: support hsch/csch (kernel part) | expand |
On 3/1/19 4:39 AM, Cornelia Huck wrote: > Add a region to the vfio-ccw device that can be used to submit > asynchronous I/O instructions. ssch continues to be handled by the > existing I/O region; the new region handles hsch and csch. > > Interrupt status continues to be reported through the same channels > as for ssch. > > Signed-off-by: Cornelia Huck <cohuck@redhat.com> This all looks pretty sensible to me. Sorry my interminable delays! Acked-by: Eric Farman <farman@linux.ibm.com> > --- > drivers/s390/cio/Makefile | 3 +- > drivers/s390/cio/vfio_ccw_async.c | 88 ++++++++++++++++++++ > drivers/s390/cio/vfio_ccw_drv.c | 46 ++++++++--- > drivers/s390/cio/vfio_ccw_fsm.c | 119 +++++++++++++++++++++++++++- > drivers/s390/cio/vfio_ccw_ops.c | 13 ++- > drivers/s390/cio/vfio_ccw_private.h | 5 ++ > include/uapi/linux/vfio.h | 2 + > include/uapi/linux/vfio_ccw.h | 12 +++ > 8 files changed, 270 insertions(+), 18 deletions(-) > create mode 100644 drivers/s390/cio/vfio_ccw_async.c > > diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile > index f230516abb96..f6a8db04177c 100644 > --- a/drivers/s390/cio/Makefile > +++ b/drivers/s390/cio/Makefile > @@ -20,5 +20,6 @@ obj-$(CONFIG_CCWGROUP) += ccwgroup.o > qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o > obj-$(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-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o vfio_ccw_fsm.o \ > + vfio_ccw_async.o > obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o > diff --git a/drivers/s390/cio/vfio_ccw_async.c b/drivers/s390/cio/vfio_ccw_async.c > new file mode 100644 > index 000000000000..8c1d2357ef5b > --- /dev/null > +++ b/drivers/s390/cio/vfio_ccw_async.c > @@ -0,0 +1,88 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Async I/O region for vfio_ccw > + * > + * Copyright Red Hat, Inc. 2019 > + * > + * Author(s): Cornelia Huck <cohuck@redhat.com> > + */ > + > +#include <linux/vfio.h> > +#include <linux/mdev.h> > + > +#include "vfio_ccw_private.h" > + > +static ssize_t vfio_ccw_async_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_cmd_region *region; > + int ret; > + > + if (pos + count > sizeof(*region)) > + return -EINVAL; > + > + mutex_lock(&private->io_mutex); > + region = private->region[i].data; > + if (copy_to_user(buf, (void *)region + pos, count)) > + ret = -EFAULT; > + else > + ret = count; > + mutex_unlock(&private->io_mutex); > + return ret; > +} > + > +static ssize_t vfio_ccw_async_region_write(struct vfio_ccw_private *private, > + const 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_cmd_region *region; > + int ret; > + > + if (pos + count > sizeof(*region)) > + return -EINVAL; > + > + if (!mutex_trylock(&private->io_mutex)) > + return -EAGAIN; > + > + region = private->region[i].data; > + if (copy_from_user((void *)region + pos, buf, count)) { > + ret = -EFAULT; > + goto out_unlock; > + } > + > + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_ASYNC_REQ); > + > + ret = region->ret_code ? region->ret_code : count; > + > +out_unlock: > + mutex_unlock(&private->io_mutex); > + return ret; > +} > + > +static void vfio_ccw_async_region_release(struct vfio_ccw_private *private, > + struct vfio_ccw_region *region) > +{ > + > +} > + > +const struct vfio_ccw_regops vfio_ccw_async_region_ops = { > + .read = vfio_ccw_async_region_read, > + .write = vfio_ccw_async_region_write, > + .release = vfio_ccw_async_region_release, > +}; > + > +int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private) > +{ > + return vfio_ccw_register_dev_region(private, > + VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD, > + &vfio_ccw_async_region_ops, > + sizeof(struct ccw_cmd_region), > + VFIO_REGION_INFO_FLAG_READ | > + VFIO_REGION_INFO_FLAG_WRITE, > + private->cmd_region); > +} > diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c > index 5ea0da1dd954..c39d01943a6a 100644 > --- a/drivers/s390/cio/vfio_ccw_drv.c > +++ b/drivers/s390/cio/vfio_ccw_drv.c > @@ -3,9 +3,11 @@ > * VFIO based Physical Subchannel device driver > * > * Copyright IBM Corp. 2017 > + * Copyright Red Hat, Inc. 2019 > * > * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> > * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> > + * Cornelia Huck <cohuck@redhat.com> > */ > > #include <linux/module.h> > @@ -23,6 +25,7 @@ > > struct workqueue_struct *vfio_ccw_work_q; > static struct kmem_cache *vfio_ccw_io_region; > +static struct kmem_cache *vfio_ccw_cmd_region; > > /* > * Helpers > @@ -110,7 +113,7 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) > { > struct pmcw *pmcw = &sch->schib.pmcw; > struct vfio_ccw_private *private; > - int ret; > + int ret = -ENOMEM; > > if (pmcw->qf) { > dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n", > @@ -124,10 +127,13 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) > > private->io_region = kmem_cache_zalloc(vfio_ccw_io_region, > GFP_KERNEL | GFP_DMA); > - if (!private->io_region) { > - kfree(private); > - return -ENOMEM; > - } > + if (!private->io_region) > + goto out_free; > + > + private->cmd_region = kmem_cache_zalloc(vfio_ccw_cmd_region, > + GFP_KERNEL | GFP_DMA); > + if (!private->cmd_region) > + goto out_free; > > private->sch = sch; > dev_set_drvdata(&sch->dev, private); > @@ -155,7 +161,10 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) > cio_disable_subchannel(sch); > out_free: > dev_set_drvdata(&sch->dev, NULL); > - kmem_cache_free(vfio_ccw_io_region, private->io_region); > + if (private->cmd_region) > + kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); > + if (private->io_region) > + kmem_cache_free(vfio_ccw_io_region, private->io_region); > kfree(private); > return ret; > } > @@ -170,6 +179,7 @@ static int vfio_ccw_sch_remove(struct subchannel *sch) > > dev_set_drvdata(&sch->dev, NULL); > > + kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); > kmem_cache_free(vfio_ccw_io_region, private->io_region); > kfree(private); > > @@ -244,7 +254,7 @@ static struct css_driver vfio_ccw_sch_driver = { > > static int __init vfio_ccw_sch_init(void) > { > - int ret; > + int ret = -ENOMEM; > > vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw"); > if (!vfio_ccw_work_q) > @@ -254,20 +264,30 @@ static int __init vfio_ccw_sch_init(void) > sizeof(struct ccw_io_region), 0, > SLAB_ACCOUNT, 0, > sizeof(struct ccw_io_region), NULL); > - if (!vfio_ccw_io_region) { > - destroy_workqueue(vfio_ccw_work_q); > - return -ENOMEM; > - } > + if (!vfio_ccw_io_region) > + goto out_err; > + > + vfio_ccw_cmd_region = kmem_cache_create_usercopy("vfio_ccw_cmd_region", > + sizeof(struct ccw_cmd_region), 0, > + SLAB_ACCOUNT, 0, > + sizeof(struct ccw_cmd_region), NULL); > + if (!vfio_ccw_cmd_region) > + goto out_err; > > isc_register(VFIO_CCW_ISC); > ret = css_driver_register(&vfio_ccw_sch_driver); > if (ret) { > isc_unregister(VFIO_CCW_ISC); > - kmem_cache_destroy(vfio_ccw_io_region); > - destroy_workqueue(vfio_ccw_work_q); > + goto out_err; > } > > return ret; > + > +out_err: > + kmem_cache_destroy(vfio_ccw_cmd_region); > + kmem_cache_destroy(vfio_ccw_io_region); > + destroy_workqueue(vfio_ccw_work_q); > + return ret; > } > > static void __exit vfio_ccw_sch_exit(void) > diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c > index b4a141fbd1a8..49d9d3da0282 100644 > --- a/drivers/s390/cio/vfio_ccw_fsm.c > +++ b/drivers/s390/cio/vfio_ccw_fsm.c > @@ -3,8 +3,10 @@ > * Finite state machine for vfio-ccw device handling > * > * Copyright IBM Corp. 2017 > + * Copyright Red Hat, Inc. 2019 > * > * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> > + * Cornelia Huck <cohuck@redhat.com> > */ > > #include <linux/vfio.h> > @@ -73,6 +75,75 @@ static int fsm_io_helper(struct vfio_ccw_private *private) > return ret; > } > > +static int fsm_do_halt(struct vfio_ccw_private *private) > +{ > + struct subchannel *sch; > + unsigned long flags; > + int ccode; > + int ret; > + > + sch = private->sch; > + > + spin_lock_irqsave(sch->lock, flags); > + > + /* Issue "Halt Subchannel" */ > + ccode = hsch(sch->schid); > + > + switch (ccode) { > + case 0: > + /* > + * Initialize device status information > + */ > + sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND; > + ret = 0; > + break; > + case 1: /* Status pending */ > + case 2: /* Busy */ > + ret = -EBUSY; > + break; > + case 3: /* Device not operational */ > + ret = -ENODEV; > + break; > + default: > + ret = ccode; > + } > + spin_unlock_irqrestore(sch->lock, flags); > + return ret; > +} > + > +static int fsm_do_clear(struct vfio_ccw_private *private) > +{ > + struct subchannel *sch; > + unsigned long flags; > + int ccode; > + int ret; > + > + sch = private->sch; > + > + spin_lock_irqsave(sch->lock, flags); > + > + /* Issue "Clear Subchannel" */ > + ccode = csch(sch->schid); > + > + switch (ccode) { > + case 0: > + /* > + * Initialize device status information > + */ > + sch->schib.scsw.cmd.actl = SCSW_ACTL_CLEAR_PEND; > + /* TODO: check what else we might need to clear */ > + ret = 0; > + break; > + case 3: /* Device not operational */ > + ret = -ENODEV; > + break; > + default: > + ret = ccode; > + } > + spin_unlock_irqrestore(sch->lock, flags); > + return ret; > +} > + > static void fsm_notoper(struct vfio_ccw_private *private, > enum vfio_ccw_event event) > { > @@ -113,6 +184,24 @@ static void fsm_io_retry(struct vfio_ccw_private *private, > private->io_region->ret_code = -EAGAIN; > } > > +static void fsm_async_error(struct vfio_ccw_private *private, > + enum vfio_ccw_event event) > +{ > + struct ccw_cmd_region *cmd_region = private->cmd_region; > + > + pr_err("vfio-ccw: FSM: %s request from state:%d\n", > + cmd_region->command == VFIO_CCW_ASYNC_CMD_HSCH ? "halt" : > + cmd_region->command == VFIO_CCW_ASYNC_CMD_CSCH ? "clear" : > + "<unknown>", private->state); > + cmd_region->ret_code = -EIO; > +} > + > +static void fsm_async_retry(struct vfio_ccw_private *private, > + enum vfio_ccw_event event) > +{ > + private->cmd_region->ret_code = -EAGAIN; > +} > + > static void fsm_disabled_irq(struct vfio_ccw_private *private, > enum vfio_ccw_event event) > { > @@ -176,11 +265,11 @@ static void fsm_io_request(struct vfio_ccw_private *private, > } > return; > } else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) { > - /* XXX: Handle halt. */ > + /* halt is handled via the async cmd region */ > io_region->ret_code = -EOPNOTSUPP; > goto err_out; > } else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) { > - /* XXX: Handle clear. */ > + /* clear is handled via the async cmd region */ > io_region->ret_code = -EOPNOTSUPP; > goto err_out; > } > @@ -190,6 +279,27 @@ static void fsm_io_request(struct vfio_ccw_private *private, > io_region->ret_code, errstr); > } > > +/* > + * Deal with an async request from userspace. > + */ > +static void fsm_async_request(struct vfio_ccw_private *private, > + enum vfio_ccw_event event) > +{ > + struct ccw_cmd_region *cmd_region = private->cmd_region; > + > + switch (cmd_region->command) { > + case VFIO_CCW_ASYNC_CMD_HSCH: > + cmd_region->ret_code = fsm_do_halt(private); > + break; > + case VFIO_CCW_ASYNC_CMD_CSCH: > + cmd_region->ret_code = fsm_do_clear(private); > + break; > + default: > + /* should not happen? */ > + cmd_region->ret_code = -EINVAL; > + } > +} > + > /* > * Got an interrupt for a normal io (state busy). > */ > @@ -213,26 +323,31 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { > [VFIO_CCW_STATE_NOT_OPER] = { > [VFIO_CCW_EVENT_NOT_OPER] = fsm_nop, > [VFIO_CCW_EVENT_IO_REQ] = fsm_io_error, > + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_error, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq, > }, > [VFIO_CCW_STATE_STANDBY] = { > [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, > [VFIO_CCW_EVENT_IO_REQ] = fsm_io_error, > + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_error, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, > }, > [VFIO_CCW_STATE_IDLE] = { > [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, > [VFIO_CCW_EVENT_IO_REQ] = fsm_io_request, > + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_request, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, > }, > [VFIO_CCW_STATE_CP_PROCESSING] = { > [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, > [VFIO_CCW_EVENT_IO_REQ] = fsm_io_retry, > + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_retry, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, > }, > [VFIO_CCW_STATE_CP_PENDING] = { > [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, > [VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy, > + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_request, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, > }, > }; > diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c > index 3fd663320bbf..ec2f796c70fe 100644 > --- a/drivers/s390/cio/vfio_ccw_ops.c > +++ b/drivers/s390/cio/vfio_ccw_ops.c > @@ -149,11 +149,20 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev) > struct vfio_ccw_private *private = > dev_get_drvdata(mdev_parent_dev(mdev)); > unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; > + int ret; > > private->nb.notifier_call = vfio_ccw_mdev_notifier; > > - return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > - &events, &private->nb); > + ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > + &events, &private->nb); > + if (ret) > + return ret; > + > + ret = vfio_ccw_register_async_dev_regions(private); > + if (ret) > + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > + &private->nb); > + return ret; > } > > static void vfio_ccw_mdev_release(struct mdev_device *mdev) > diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h > index d888a2573470..f1092c3dc1b1 100644 > --- a/drivers/s390/cio/vfio_ccw_private.h > +++ b/drivers/s390/cio/vfio_ccw_private.h > @@ -53,6 +53,8 @@ int vfio_ccw_register_dev_region(struct vfio_ccw_private *private, > const struct vfio_ccw_regops *ops, > size_t size, u32 flags, void *data); > > +int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private); > + > /** > * struct vfio_ccw_private > * @sch: pointer to the subchannel > @@ -64,6 +66,7 @@ int vfio_ccw_register_dev_region(struct vfio_ccw_private *private, > * @io_region: MMIO region to input/output I/O arguments/results > * @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 > * @num_regions: number of additional regions > * @cp: channel program for the current I/O operation > * @irb: irb info received from interrupt > @@ -81,6 +84,7 @@ struct vfio_ccw_private { > struct ccw_io_region *io_region; > struct mutex io_mutex; > struct vfio_ccw_region *region; > + struct ccw_cmd_region *cmd_region; > int num_regions; > > struct channel_program cp; > @@ -116,6 +120,7 @@ enum vfio_ccw_event { > VFIO_CCW_EVENT_NOT_OPER, > VFIO_CCW_EVENT_IO_REQ, > VFIO_CCW_EVENT_INTERRUPT, > + VFIO_CCW_EVENT_ASYNC_REQ, > /* last element! */ > NR_VFIO_CCW_EVENTS > }; > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index 56e2413d3e00..8f10748dac79 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -354,6 +354,8 @@ struct vfio_region_gfx_edid { > }; > > #define VFIO_REGION_TYPE_CCW (2) > +/* ccw sub-types */ > +#define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1) > > /* > * 10de vendor sub-type > diff --git a/include/uapi/linux/vfio_ccw.h b/include/uapi/linux/vfio_ccw.h > index 2ec5f367ff78..cbecbf0cd54f 100644 > --- a/include/uapi/linux/vfio_ccw.h > +++ b/include/uapi/linux/vfio_ccw.h > @@ -12,6 +12,7 @@ > > #include <linux/types.h> > > +/* used for START SUBCHANNEL, always present */ > struct ccw_io_region { > #define ORB_AREA_SIZE 12 > __u8 orb_area[ORB_AREA_SIZE]; > @@ -22,4 +23,15 @@ struct ccw_io_region { > __u32 ret_code; > } __packed; > > +/* > + * used for processing commands that trigger asynchronous actions > + * Note: this is controlled by a capability > + */ > +#define VFIO_CCW_ASYNC_CMD_HSCH (1 << 0) > +#define VFIO_CCW_ASYNC_CMD_CSCH (1 << 1) > +struct ccw_cmd_region { > + __u32 command; > + __u32 ret_code; > +} __packed; > + > #endif >
On 03/01/2019 04:39 AM, Cornelia Huck wrote: > Add a region to the vfio-ccw device that can be used to submit > asynchronous I/O instructions. ssch continues to be handled by the > existing I/O region; the new region handles hsch and csch. > > Interrupt status continues to be reported through the same channels > as for ssch. > > Signed-off-by: Cornelia Huck<cohuck@redhat.com> Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile index f230516abb96..f6a8db04177c 100644 --- a/drivers/s390/cio/Makefile +++ b/drivers/s390/cio/Makefile @@ -20,5 +20,6 @@ obj-$(CONFIG_CCWGROUP) += ccwgroup.o qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o obj-$(CONFIG_QDIO) += qdio.o -vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o vfio_ccw_fsm.o +vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o vfio_ccw_fsm.o \ + vfio_ccw_async.o obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o diff --git a/drivers/s390/cio/vfio_ccw_async.c b/drivers/s390/cio/vfio_ccw_async.c new file mode 100644 index 000000000000..8c1d2357ef5b --- /dev/null +++ b/drivers/s390/cio/vfio_ccw_async.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Async I/O region for vfio_ccw + * + * Copyright Red Hat, Inc. 2019 + * + * Author(s): Cornelia Huck <cohuck@redhat.com> + */ + +#include <linux/vfio.h> +#include <linux/mdev.h> + +#include "vfio_ccw_private.h" + +static ssize_t vfio_ccw_async_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_cmd_region *region; + int ret; + + if (pos + count > sizeof(*region)) + return -EINVAL; + + mutex_lock(&private->io_mutex); + region = private->region[i].data; + if (copy_to_user(buf, (void *)region + pos, count)) + ret = -EFAULT; + else + ret = count; + mutex_unlock(&private->io_mutex); + return ret; +} + +static ssize_t vfio_ccw_async_region_write(struct vfio_ccw_private *private, + const 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_cmd_region *region; + int ret; + + if (pos + count > sizeof(*region)) + return -EINVAL; + + if (!mutex_trylock(&private->io_mutex)) + return -EAGAIN; + + region = private->region[i].data; + if (copy_from_user((void *)region + pos, buf, count)) { + ret = -EFAULT; + goto out_unlock; + } + + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_ASYNC_REQ); + + ret = region->ret_code ? region->ret_code : count; + +out_unlock: + mutex_unlock(&private->io_mutex); + return ret; +} + +static void vfio_ccw_async_region_release(struct vfio_ccw_private *private, + struct vfio_ccw_region *region) +{ + +} + +const struct vfio_ccw_regops vfio_ccw_async_region_ops = { + .read = vfio_ccw_async_region_read, + .write = vfio_ccw_async_region_write, + .release = vfio_ccw_async_region_release, +}; + +int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private) +{ + return vfio_ccw_register_dev_region(private, + VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD, + &vfio_ccw_async_region_ops, + sizeof(struct ccw_cmd_region), + VFIO_REGION_INFO_FLAG_READ | + VFIO_REGION_INFO_FLAG_WRITE, + private->cmd_region); +} diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 5ea0da1dd954..c39d01943a6a 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -3,9 +3,11 @@ * VFIO based Physical Subchannel device driver * * Copyright IBM Corp. 2017 + * Copyright Red Hat, Inc. 2019 * * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> + * Cornelia Huck <cohuck@redhat.com> */ #include <linux/module.h> @@ -23,6 +25,7 @@ struct workqueue_struct *vfio_ccw_work_q; static struct kmem_cache *vfio_ccw_io_region; +static struct kmem_cache *vfio_ccw_cmd_region; /* * Helpers @@ -110,7 +113,7 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) { struct pmcw *pmcw = &sch->schib.pmcw; struct vfio_ccw_private *private; - int ret; + int ret = -ENOMEM; if (pmcw->qf) { dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n", @@ -124,10 +127,13 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) private->io_region = kmem_cache_zalloc(vfio_ccw_io_region, GFP_KERNEL | GFP_DMA); - if (!private->io_region) { - kfree(private); - return -ENOMEM; - } + if (!private->io_region) + goto out_free; + + private->cmd_region = kmem_cache_zalloc(vfio_ccw_cmd_region, + GFP_KERNEL | GFP_DMA); + if (!private->cmd_region) + goto out_free; private->sch = sch; dev_set_drvdata(&sch->dev, private); @@ -155,7 +161,10 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) cio_disable_subchannel(sch); out_free: dev_set_drvdata(&sch->dev, NULL); - kmem_cache_free(vfio_ccw_io_region, private->io_region); + if (private->cmd_region) + kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); + if (private->io_region) + kmem_cache_free(vfio_ccw_io_region, private->io_region); kfree(private); return ret; } @@ -170,6 +179,7 @@ static int vfio_ccw_sch_remove(struct subchannel *sch) dev_set_drvdata(&sch->dev, NULL); + kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); kmem_cache_free(vfio_ccw_io_region, private->io_region); kfree(private); @@ -244,7 +254,7 @@ static struct css_driver vfio_ccw_sch_driver = { static int __init vfio_ccw_sch_init(void) { - int ret; + int ret = -ENOMEM; vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw"); if (!vfio_ccw_work_q) @@ -254,20 +264,30 @@ static int __init vfio_ccw_sch_init(void) sizeof(struct ccw_io_region), 0, SLAB_ACCOUNT, 0, sizeof(struct ccw_io_region), NULL); - if (!vfio_ccw_io_region) { - destroy_workqueue(vfio_ccw_work_q); - return -ENOMEM; - } + if (!vfio_ccw_io_region) + goto out_err; + + vfio_ccw_cmd_region = kmem_cache_create_usercopy("vfio_ccw_cmd_region", + sizeof(struct ccw_cmd_region), 0, + SLAB_ACCOUNT, 0, + sizeof(struct ccw_cmd_region), NULL); + if (!vfio_ccw_cmd_region) + goto out_err; isc_register(VFIO_CCW_ISC); ret = css_driver_register(&vfio_ccw_sch_driver); if (ret) { isc_unregister(VFIO_CCW_ISC); - kmem_cache_destroy(vfio_ccw_io_region); - destroy_workqueue(vfio_ccw_work_q); + goto out_err; } return ret; + +out_err: + kmem_cache_destroy(vfio_ccw_cmd_region); + kmem_cache_destroy(vfio_ccw_io_region); + destroy_workqueue(vfio_ccw_work_q); + return ret; } static void __exit vfio_ccw_sch_exit(void) diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c index b4a141fbd1a8..49d9d3da0282 100644 --- a/drivers/s390/cio/vfio_ccw_fsm.c +++ b/drivers/s390/cio/vfio_ccw_fsm.c @@ -3,8 +3,10 @@ * Finite state machine for vfio-ccw device handling * * Copyright IBM Corp. 2017 + * Copyright Red Hat, Inc. 2019 * * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> + * Cornelia Huck <cohuck@redhat.com> */ #include <linux/vfio.h> @@ -73,6 +75,75 @@ static int fsm_io_helper(struct vfio_ccw_private *private) return ret; } +static int fsm_do_halt(struct vfio_ccw_private *private) +{ + struct subchannel *sch; + unsigned long flags; + int ccode; + int ret; + + sch = private->sch; + + spin_lock_irqsave(sch->lock, flags); + + /* Issue "Halt Subchannel" */ + ccode = hsch(sch->schid); + + switch (ccode) { + case 0: + /* + * Initialize device status information + */ + sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND; + ret = 0; + break; + case 1: /* Status pending */ + case 2: /* Busy */ + ret = -EBUSY; + break; + case 3: /* Device not operational */ + ret = -ENODEV; + break; + default: + ret = ccode; + } + spin_unlock_irqrestore(sch->lock, flags); + return ret; +} + +static int fsm_do_clear(struct vfio_ccw_private *private) +{ + struct subchannel *sch; + unsigned long flags; + int ccode; + int ret; + + sch = private->sch; + + spin_lock_irqsave(sch->lock, flags); + + /* Issue "Clear Subchannel" */ + ccode = csch(sch->schid); + + switch (ccode) { + case 0: + /* + * Initialize device status information + */ + sch->schib.scsw.cmd.actl = SCSW_ACTL_CLEAR_PEND; + /* TODO: check what else we might need to clear */ + ret = 0; + break; + case 3: /* Device not operational */ + ret = -ENODEV; + break; + default: + ret = ccode; + } + spin_unlock_irqrestore(sch->lock, flags); + return ret; +} + static void fsm_notoper(struct vfio_ccw_private *private, enum vfio_ccw_event event) { @@ -113,6 +184,24 @@ static void fsm_io_retry(struct vfio_ccw_private *private, private->io_region->ret_code = -EAGAIN; } +static void fsm_async_error(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + struct ccw_cmd_region *cmd_region = private->cmd_region; + + pr_err("vfio-ccw: FSM: %s request from state:%d\n", + cmd_region->command == VFIO_CCW_ASYNC_CMD_HSCH ? "halt" : + cmd_region->command == VFIO_CCW_ASYNC_CMD_CSCH ? "clear" : + "<unknown>", private->state); + cmd_region->ret_code = -EIO; +} + +static void fsm_async_retry(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + private->cmd_region->ret_code = -EAGAIN; +} + static void fsm_disabled_irq(struct vfio_ccw_private *private, enum vfio_ccw_event event) { @@ -176,11 +265,11 @@ static void fsm_io_request(struct vfio_ccw_private *private, } return; } else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) { - /* XXX: Handle halt. */ + /* halt is handled via the async cmd region */ io_region->ret_code = -EOPNOTSUPP; goto err_out; } else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) { - /* XXX: Handle clear. */ + /* clear is handled via the async cmd region */ io_region->ret_code = -EOPNOTSUPP; goto err_out; } @@ -190,6 +279,27 @@ static void fsm_io_request(struct vfio_ccw_private *private, io_region->ret_code, errstr); } +/* + * Deal with an async request from userspace. + */ +static void fsm_async_request(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + struct ccw_cmd_region *cmd_region = private->cmd_region; + + switch (cmd_region->command) { + case VFIO_CCW_ASYNC_CMD_HSCH: + cmd_region->ret_code = fsm_do_halt(private); + break; + case VFIO_CCW_ASYNC_CMD_CSCH: + cmd_region->ret_code = fsm_do_clear(private); + break; + default: + /* should not happen? */ + cmd_region->ret_code = -EINVAL; + } +} + /* * Got an interrupt for a normal io (state busy). */ @@ -213,26 +323,31 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { [VFIO_CCW_STATE_NOT_OPER] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_nop, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_error, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_error, [VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq, }, [VFIO_CCW_STATE_STANDBY] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_error, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_error, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, }, [VFIO_CCW_STATE_IDLE] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_request, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_request, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, }, [VFIO_CCW_STATE_CP_PROCESSING] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_retry, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_retry, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, }, [VFIO_CCW_STATE_CP_PENDING] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_request, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, }, }; diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index 3fd663320bbf..ec2f796c70fe 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -149,11 +149,20 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev) struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; + int ret; private->nb.notifier_call = vfio_ccw_mdev_notifier; - return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, - &events, &private->nb); + ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, + &events, &private->nb); + if (ret) + return ret; + + ret = vfio_ccw_register_async_dev_regions(private); + if (ret) + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, + &private->nb); + return ret; } static void vfio_ccw_mdev_release(struct mdev_device *mdev) diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index d888a2573470..f1092c3dc1b1 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -53,6 +53,8 @@ int vfio_ccw_register_dev_region(struct vfio_ccw_private *private, const struct vfio_ccw_regops *ops, size_t size, u32 flags, void *data); +int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private); + /** * struct vfio_ccw_private * @sch: pointer to the subchannel @@ -64,6 +66,7 @@ int vfio_ccw_register_dev_region(struct vfio_ccw_private *private, * @io_region: MMIO region to input/output I/O arguments/results * @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 * @num_regions: number of additional regions * @cp: channel program for the current I/O operation * @irb: irb info received from interrupt @@ -81,6 +84,7 @@ struct vfio_ccw_private { struct ccw_io_region *io_region; struct mutex io_mutex; struct vfio_ccw_region *region; + struct ccw_cmd_region *cmd_region; int num_regions; struct channel_program cp; @@ -116,6 +120,7 @@ enum vfio_ccw_event { VFIO_CCW_EVENT_NOT_OPER, VFIO_CCW_EVENT_IO_REQ, VFIO_CCW_EVENT_INTERRUPT, + VFIO_CCW_EVENT_ASYNC_REQ, /* last element! */ NR_VFIO_CCW_EVENTS }; diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 56e2413d3e00..8f10748dac79 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -354,6 +354,8 @@ struct vfio_region_gfx_edid { }; #define VFIO_REGION_TYPE_CCW (2) +/* ccw sub-types */ +#define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1) /* * 10de vendor sub-type diff --git a/include/uapi/linux/vfio_ccw.h b/include/uapi/linux/vfio_ccw.h index 2ec5f367ff78..cbecbf0cd54f 100644 --- a/include/uapi/linux/vfio_ccw.h +++ b/include/uapi/linux/vfio_ccw.h @@ -12,6 +12,7 @@ #include <linux/types.h> +/* used for START SUBCHANNEL, always present */ struct ccw_io_region { #define ORB_AREA_SIZE 12 __u8 orb_area[ORB_AREA_SIZE]; @@ -22,4 +23,15 @@ struct ccw_io_region { __u32 ret_code; } __packed; +/* + * used for processing commands that trigger asynchronous actions + * Note: this is controlled by a capability + */ +#define VFIO_CCW_ASYNC_CMD_HSCH (1 << 0) +#define VFIO_CCW_ASYNC_CMD_CSCH (1 << 1) +struct ccw_cmd_region { + __u32 command; + __u32 ret_code; +} __packed; + #endif
Add a region to the vfio-ccw device that can be used to submit asynchronous I/O instructions. ssch continues to be handled by the existing I/O region; the new region handles hsch and csch. Interrupt status continues to be reported through the same channels as for ssch. Signed-off-by: Cornelia Huck <cohuck@redhat.com> --- drivers/s390/cio/Makefile | 3 +- drivers/s390/cio/vfio_ccw_async.c | 88 ++++++++++++++++++++ drivers/s390/cio/vfio_ccw_drv.c | 46 ++++++++--- drivers/s390/cio/vfio_ccw_fsm.c | 119 +++++++++++++++++++++++++++- drivers/s390/cio/vfio_ccw_ops.c | 13 ++- drivers/s390/cio/vfio_ccw_private.h | 5 ++ include/uapi/linux/vfio.h | 2 + include/uapi/linux/vfio_ccw.h | 12 +++ 8 files changed, 270 insertions(+), 18 deletions(-) create mode 100644 drivers/s390/cio/vfio_ccw_async.c