From 3f02cb2fd9d2d9e8762102886e3e4b51285797ee Mon Sep 17 00:00:00 2001 From: Farhan Ali Date: Tue, 5 May 2020 14:27:44 +0200 Subject: vfio-ccw: Wire up the CRW irq and CRW region Use the IRQ to notify userspace that there is a CRW pending in the region, related to path-availability changes on the passthrough subchannel. Signed-off-by: Farhan Ali Signed-off-by: Eric Farman Reviewed-by: Cornelia Huck Message-Id: <20200505122745.53208-8-farman@linux.ibm.com> Signed-off-by: Cornelia Huck --- drivers/s390/cio/vfio_ccw_chp.c | 17 +++++++++++++ drivers/s390/cio/vfio_ccw_drv.c | 49 +++++++++++++++++++++++++++++++++++++ drivers/s390/cio/vfio_ccw_private.h | 8 ++++++ 3 files changed, 74 insertions(+) (limited to 'drivers/s390') diff --git a/drivers/s390/cio/vfio_ccw_chp.c b/drivers/s390/cio/vfio_ccw_chp.c index 37ea344a4d72..876f6ade51cc 100644 --- a/drivers/s390/cio/vfio_ccw_chp.c +++ b/drivers/s390/cio/vfio_ccw_chp.c @@ -82,14 +82,24 @@ static ssize_t vfio_ccw_crw_region_read(struct vfio_ccw_private *private, unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS; loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK; struct ccw_crw_region *region; + struct vfio_ccw_crw *crw; int ret; if (pos + count > sizeof(*region)) return -EINVAL; + crw = list_first_entry_or_null(&private->crw, + struct vfio_ccw_crw, next); + + if (crw) + list_del(&crw->next); + mutex_lock(&private->io_mutex); region = private->region[i].data; + if (crw) + memcpy(®ion->crw, &crw->crw, sizeof(region->crw)); + if (copy_to_user(buf, (void *)region + pos, count)) ret = -EFAULT; else @@ -98,6 +108,13 @@ static ssize_t vfio_ccw_crw_region_read(struct vfio_ccw_private *private, region->crw = 0; mutex_unlock(&private->io_mutex); + + kfree(crw); + + /* Notify the guest if more CRWs are on our queue */ + if (!list_empty(&private->crw) && private->crw_trigger) + eventfd_signal(private->crw_trigger, 1); + return ret; } diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index e4deae6fd525..9144360851ed 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -108,6 +108,16 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work) eventfd_signal(private->io_trigger, 1); } +static void vfio_ccw_crw_todo(struct work_struct *work) +{ + struct vfio_ccw_private *private; + + private = container_of(work, struct vfio_ccw_private, crw_work); + + if (!list_empty(&private->crw) && private->crw_trigger) + eventfd_signal(private->crw_trigger, 1); +} + /* * Css driver callbacks */ @@ -186,7 +196,9 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) if (ret) goto out_free; + INIT_LIST_HEAD(&private->crw); INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo); + INIT_WORK(&private->crw_work, vfio_ccw_crw_todo); atomic_set(&private->avail, 1); private->state = VFIO_CCW_STATE_STANDBY; @@ -217,9 +229,15 @@ out_free: static int vfio_ccw_sch_remove(struct subchannel *sch) { struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); + struct vfio_ccw_crw *crw, *temp; vfio_ccw_sch_quiesce(sch); + list_for_each_entry_safe(crw, temp, &private->crw, next) { + list_del(&crw->next); + kfree(crw); + } + vfio_ccw_mdev_unreg(sch); dev_set_drvdata(&sch->dev, NULL); @@ -281,6 +299,33 @@ out_unlock: return rc; } +static void vfio_ccw_queue_crw(struct vfio_ccw_private *private, + unsigned int rsc, + unsigned int erc, + unsigned int rsid) +{ + struct vfio_ccw_crw *crw; + + /* + * If unable to allocate a CRW, just drop the event and + * carry on. The guest will either see a later one or + * learn when it issues its own store subchannel. + */ + crw = kzalloc(sizeof(*crw), GFP_ATOMIC); + if (!crw) + return; + + /* + * Build the CRW based on the inputs given to us. + */ + crw->crw.rsc = rsc; + crw->crw.erc = erc; + crw->crw.rsid = rsid; + + list_add_tail(&crw->next, &private->crw); + queue_work(vfio_ccw_work_q, &private->crw_work); +} + static int vfio_ccw_chp_event(struct subchannel *sch, struct chp_link *link, int event) { @@ -311,6 +356,8 @@ static int vfio_ccw_chp_event(struct subchannel *sch, /* Path is gone */ if (sch->schib.pmcw.lpum & mask) cio_cancel_halt_clear(sch, &retry); + vfio_ccw_queue_crw(private, CRW_RSC_CPATH, CRW_ERC_PERRN, + link->chpid.id); break; case CHP_VARY_ON: /* Path logically turned on */ @@ -320,6 +367,8 @@ static int vfio_ccw_chp_event(struct subchannel *sch, case CHP_ONLINE: /* Path became available */ sch->lpm |= mask & sch->opm; + vfio_ccw_queue_crw(private, CRW_RSC_CPATH, CRW_ERC_INIT, + link->chpid.id); break; } diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index 97131b4df0b9..8723156b29ea 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -17,6 +17,7 @@ #include #include #include +#include #include #include "css.h" @@ -59,6 +60,11 @@ int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private); int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private); int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private); +struct vfio_ccw_crw { + struct list_head next; + struct crw crw; +}; + /** * struct vfio_ccw_private * @sch: pointer to the subchannel @@ -98,10 +104,12 @@ struct vfio_ccw_private { struct channel_program cp; struct irb irb; union scsw scsw; + struct list_head crw; struct eventfd_ctx *io_trigger; struct eventfd_ctx *crw_trigger; struct work_struct io_work; + struct work_struct crw_work; } __aligned(8); extern int vfio_ccw_mdev_reg(struct subchannel *sch); -- cgit v1.2.3-59-g8ed1b