From b3fe0304abc76572896991947b0a823c696c954f Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Mon, 23 Jul 2018 16:03:27 +0200 Subject: [PATCH] vfio-ccw: add handling for async channel instructions 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. Acked-by: Eric Farman Reviewed-by: Farhan Ali Signed-off-by: Cornelia Huck --- 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 f230516abb96d..f6a8db04177c6 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 0000000000000..8c1d2357ef5b8 --- /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 + */ + +#include +#include + +#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 5ea0da1dd9546..c39d01943a6a5 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 * Xiao Feng Ren + * Cornelia Huck */ #include @@ -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 @@ out_disable: 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 b4a141fbd1a89..49d9d3da02829 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 + * Cornelia Huck */ #include @@ -73,6 +75,75 @@ out: 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" : + "", 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 @@ err_out: 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 5b989faa011f9..3e2802a4a43db 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -150,11 +150,20 @@ 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 d888a25734708..f1092c3dc1b11 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 56e2413d3e009..8f10748dac79a 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 2ec5f367ff78f..cbecbf0cd54f4 100644 --- a/include/uapi/linux/vfio_ccw.h +++ b/include/uapi/linux/vfio_ccw.h @@ -12,6 +12,7 @@ #include +/* 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 -- 2.39.5