diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst index 32310df525ba..8aad08a8b8a5 100644 --- a/Documentation/s390/vfio-ccw.rst +++ b/Documentation/s390/vfio-ccw.rst @@ -298,6 +298,26 @@ This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_SCHIB. Reading this region triggers a STORE SUBCHANNEL to be issued to the associated hardware. +vfio-ccw crw region +--------------------- + +The vfio-ccw crw region is used to return Channel Report Word (CRW) +data to userspace:: + + struct ccw_crw_region { + __u32 crw; + __u32 pad; + } __packed; + +This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_CRW. + +Reading this region returns a CRW if one that is relevant for this +subchannel (e.g. one reporting changes in channel path state) is +pending, or all zeroes if not. If multiple CRWs are pending (including +possibly chained CRWs), reading this region again will return the next +one, until no more CRWs are pending and zeroes are returned. This is +similar to how STORE CHANNEL REPORT WORD works. + vfio-ccw operation details -------------------------- diff --git a/drivers/s390/cio/vfio_ccw_chp.c b/drivers/s390/cio/vfio_ccw_chp.c index 18f3b3e873a9..37ea344a4d72 100644 --- a/drivers/s390/cio/vfio_ccw_chp.c +++ b/drivers/s390/cio/vfio_ccw_chp.c @@ -74,3 +74,58 @@ int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private) VFIO_REGION_INFO_FLAG_READ, private->schib_region); } + +static ssize_t vfio_ccw_crw_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_crw_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; + + region->crw = 0; + + mutex_unlock(&private->io_mutex); + return ret; +} + +static ssize_t vfio_ccw_crw_region_write(struct vfio_ccw_private *private, + const char __user *buf, size_t count, + loff_t *ppos) +{ + return -EINVAL; +} + +static void vfio_ccw_crw_region_release(struct vfio_ccw_private *private, + struct vfio_ccw_region *region) +{ + +} + +const struct vfio_ccw_regops vfio_ccw_crw_region_ops = { + .read = vfio_ccw_crw_region_read, + .write = vfio_ccw_crw_region_write, + .release = vfio_ccw_crw_region_release, +}; + +int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private) +{ + return vfio_ccw_register_dev_region(private, + VFIO_REGION_SUBTYPE_CCW_CRW, + &vfio_ccw_crw_region_ops, + sizeof(struct ccw_crw_region), + VFIO_REGION_INFO_FLAG_READ, + private->crw_region); +} diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 7aeff42f370d..e4deae6fd525 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -28,6 +28,7 @@ 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; +static struct kmem_cache *vfio_ccw_crw_region; debug_info_t *vfio_ccw_debug_msg_id; debug_info_t *vfio_ccw_debug_trace_id; @@ -120,6 +121,8 @@ static void vfio_ccw_sch_irq(struct subchannel *sch) static void vfio_ccw_free_regions(struct vfio_ccw_private *private) { + if (private->crw_region) + kmem_cache_free(vfio_ccw_crw_region, private->crw_region); if (private->schib_region) kmem_cache_free(vfio_ccw_schib_region, private->schib_region); if (private->cmd_region) @@ -165,6 +168,12 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) if (!private->schib_region) goto out_free; + private->crw_region = kmem_cache_zalloc(vfio_ccw_crw_region, + GFP_KERNEL | GFP_DMA); + + if (!private->crw_region) + goto out_free; + private->sch = sch; dev_set_drvdata(&sch->dev, private); mutex_init(&private->io_mutex); @@ -366,6 +375,7 @@ static void vfio_ccw_debug_exit(void) static void vfio_ccw_destroy_regions(void) { + kmem_cache_destroy(vfio_ccw_crw_region); kmem_cache_destroy(vfio_ccw_schib_region); kmem_cache_destroy(vfio_ccw_cmd_region); kmem_cache_destroy(vfio_ccw_io_region); @@ -413,6 +423,16 @@ static int __init vfio_ccw_sch_init(void) goto out_err; } + vfio_ccw_crw_region = kmem_cache_create_usercopy("vfio_ccw_crw_region", + sizeof(struct ccw_crw_region), 0, + SLAB_ACCOUNT, 0, + sizeof(struct ccw_crw_region), NULL); + + if (!vfio_ccw_crw_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 c3a74ab7bb86..8b3ed5b45277 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -178,6 +178,10 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev) if (ret) goto out_unregister; + ret = vfio_ccw_register_crw_dev_regions(private); + if (ret) + goto out_unregister; + return ret; out_unregister: @@ -389,6 +393,7 @@ static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info) { switch (info->index) { case VFIO_CCW_IO_IRQ_INDEX: + case VFIO_CCW_CRW_IRQ_INDEX: info->count = 1; info->flags = VFIO_IRQ_INFO_EVENTFD; break; @@ -416,6 +421,9 @@ static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev, case VFIO_CCW_IO_IRQ_INDEX: ctx = &private->io_trigger; break; + case VFIO_CCW_CRW_IRQ_INDEX: + ctx = &private->crw_trigger; + break; default: return -EINVAL; } diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index d6601a8adf13..97131b4df0b9 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -57,6 +57,7 @@ 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); +int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private); /** * struct vfio_ccw_private @@ -71,6 +72,7 @@ int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private); * @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 + * @crw_region: MMIO region for getting channel report words * @num_regions: number of additional regions * @cp: channel program for the current I/O operation * @irb: irb info received from interrupt @@ -90,6 +92,7 @@ struct vfio_ccw_private { struct vfio_ccw_region *region; struct ccw_cmd_region *cmd_region; struct ccw_schib_region *schib_region; + struct ccw_crw_region *crw_region; int num_regions; struct channel_program cp; @@ -97,6 +100,7 @@ struct vfio_ccw_private { union scsw scsw; struct eventfd_ctx *io_trigger; + struct eventfd_ctx *crw_trigger; struct work_struct io_work; } __aligned(8); diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 7a1abbd889bd..907758cf6d60 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -379,6 +379,7 @@ 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) +#define VFIO_REGION_SUBTYPE_CCW_CRW (3) /* * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped @@ -578,6 +579,7 @@ enum { enum { VFIO_CCW_IO_IRQ_INDEX, + VFIO_CCW_CRW_IRQ_INDEX, VFIO_CCW_NUM_IRQS }; diff --git a/include/uapi/linux/vfio_ccw.h b/include/uapi/linux/vfio_ccw.h index 758bf214898d..aa04f3aa6db0 100644 --- a/include/uapi/linux/vfio_ccw.h +++ b/include/uapi/linux/vfio_ccw.h @@ -44,4 +44,13 @@ struct ccw_schib_region { __u8 schib_area[SCHIB_AREA_SIZE]; } __packed; +/* + * Used for returning a Channel Report Word to userspace. + * Note: this is controlled by a capability + */ +struct ccw_crw_region { + __u32 crw; + __u32 pad; +} __packed; + #endif