Re: [PATCH 3/3] vfio-ccw: add handling for asnyc channel instructions

Eric Farman
2018-12-17T21:54:31Z

On 11/22/2018 11:54 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>
> ---
> drivers/s390/cio/Makefile | 3 +-
> drivers/s390/cio/vfio_ccw_async.c | 88 ++++++++++++++++
> drivers/s390/cio/vfio_ccw_drv.c | 48 ++++++---
> drivers/s390/cio/vfio_ccw_fsm.c | 158 +++++++++++++++++++++++++++-
> drivers/s390/cio/vfio_ccw_ops.c | 13 ++-
> drivers/s390/cio/vfio_ccw_private.h | 6 ++
> include/uapi/linux/vfio.h | 4 +
> include/uapi/linux/vfio_ccw.h | 12 +++
> 8 files changed, 313 insertions(+), 19 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..8c7f51d17d70
> --- /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. 2018
> + *
> + * Author(s): Cornelia Huck <cohuck@redhat.com>
> + */
> +
> +#include <linux/vfio.h>
> +#include <linux/mdev.h>
> +
> +#include "vfio_ccw_private.h"
> +
> +static size_t vfio_ccw_async_region_read(struct vfio_ccw_private *private,

I think this should return ssize_t ? (same for _write, below)

> + 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;
> +
> + if (pos + count > sizeof(*region))
> + return -EINVAL;
> +
> + region = private->region[i].data;
> + if (copy_to_user(buf, (void *)region + pos, count))
> + return -EFAULT;
> +
> + return count;
> +
> +}
> +
> +static size_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;
> +
> + if (pos + count > sizeof(*region))
> + return -EINVAL;
> +
> + if (private->state == VFIO_CCW_STATE_NOT_OPER ||
> + private->state == VFIO_CCW_STATE_STANDBY)
> + return -EACCES;
> +
> + region = private->region[i].data;
> + if (copy_from_user((void *)region + pos, buf, count))
> + return -EFAULT;
> +
> + switch (region->command) {
> + case VFIO_CCW_ASYNC_CMD_HSCH:
> + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_HALT_REQ);
> + break;
> + case VFIO_CCW_ASYNC_CMD_CSCH:
> + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLEAR_REQ);
> + break;

I find myself wondering why we add separate VFIO_CCW_EVENT_x_REQ entries
for HALT and CLEAR, rather than a single VFIO_CCW_EVENT_ASYNC_REQ and a
switch on cmd_region->command within it to go to fsm_do_halt,
fsm_do_clear, or whatever.

> + default:
> + return -EINVAL;
> + }
> +
> + return region->ret_code ? region->ret_code : count;
> +}
> +
> +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 a10cec0e86eb..890c588a3a61 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. 2018
> *
> * 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
> @@ -76,7 +79,8 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work)
> private = container_of(work, struct vfio_ccw_private, io_work);
> irb = &private->irb;
>
> - if (scsw_is_solicited(&irb->scsw)) {
> + if (scsw_is_solicited(&irb->scsw) &&
> + (scsw_fctl(&irb->scsw) & SCSW_FCTL_START_FUNC)) {
> cp_update_scsw(&private->cp, &irb->scsw);
> cp_free(&private->cp);
> }
> @@ -104,7 +108,7 @@ 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",
> @@ -118,10 +122,13 @@ 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);
> @@ -148,7 +155,10 @@ 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;
> }
> @@ -237,7 +247,7 @@ 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)
> @@ -247,20 +257,30 @@ 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 f94aa01f9c36..0caf77e8f377 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. 2018
> *
> * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
> + * Cornelia Huck <cohuck@redhat.com>
> */
>
> #include <linux/vfio.h>
> @@ -68,6 +70,81 @@ 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);
> + private->state = VFIO_CCW_STATE_BUSY;
> +
> + /* 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);
> + private->state = VFIO_CCW_STATE_BUSY;
> +
> + /* 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)
> {
> @@ -102,6 +179,20 @@ static void fsm_io_busy(struct vfio_ccw_private *private,
> private->io_region->ret_code = -EBUSY;
> }
>
> +static void fsm_async_error(struct vfio_ccw_private *private,
> + enum vfio_ccw_event event)
> +{
> + pr_err("vfio-ccw: FSM: halt/clear request from state:%d\n",
> + private->state);

Worth stating whether it's a Halt or Clear here, rather than leaving it
ambiguous?

> + private->cmd_region->ret_code = -EIO;
> +}
> +
> +static void fsm_async_busy(struct vfio_ccw_private *private,
> + enum vfio_ccw_event event)
> +{
> + private->cmd_region->ret_code = -EBUSY;
> +}
> +
> static void fsm_disabled_irq(struct vfio_ccw_private *private,
> enum vfio_ccw_event event)
> {
> @@ -166,11 +257,11 @@ 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;
> }
> @@ -181,6 +272,59 @@ static void fsm_io_request(struct vfio_ccw_private *private,
> io_region->ret_code, errstr);
> }
>
> +/*
> + * Deal with a halt request from userspace.
> + */
> +static void fsm_halt_request(struct vfio_ccw_private *private,
> + enum vfio_ccw_event event)
> +{
> + struct ccw_cmd_region *cmd_region = private->cmd_region;
> + int state = private->state;
> +
> + private->state = VFIO_CCW_STATE_BOXED;
> +
> + if (cmd_region->command != VFIO_CCW_ASYNC_CMD_HSCH) {
> + /* should not happen? */
> + cmd_region->ret_code = -EINVAL;
> + goto err_out;
> + }
> +
> + cmd_region->ret_code = fsm_do_halt(private);
> + if (cmd_region->ret_code)
> + goto err_out;
> +
> + return;
> +
> +err_out:
> + private->state = state;
> +}
> +
> +/*
> + * Deal with a clear request from userspace.
> + */
> +static void fsm_clear_request(struct vfio_ccw_private *private,
> + enum vfio_ccw_event event)
> +{
> + struct ccw_cmd_region *cmd_region = private->cmd_region;
> + int state = private->state;
> +
> + private->state = VFIO_CCW_STATE_BOXED;
> +
> + if (cmd_region->command != VFIO_CCW_ASYNC_CMD_CSCH) {
> + /* should not happen? */
> + cmd_region->ret_code = -EINVAL;
> + goto err_out;
> + }
> +
> + cmd_region->ret_code = fsm_do_clear(private);
> + if (cmd_region->ret_code)
> + goto err_out;
> +
> + return;
> +
> +err_out:
> + private->state = state;
> +}
> /*
> * Got an interrupt for a normal io (state busy).
> */
> @@ -204,26 +348,36 @@ 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_HALT_REQ] = fsm_async_error,
> + [VFIO_CCW_EVENT_CLEAR_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_HALT_REQ] = fsm_async_error,
> + [VFIO_CCW_EVENT_CLEAR_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_HALT_REQ] = fsm_halt_request,
> + [VFIO_CCW_EVENT_CLEAR_REQ] = fsm_clear_request,
> [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
> },
> [VFIO_CCW_STATE_BOXED] = {
> [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
> [VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy,
> + [VFIO_CCW_EVENT_HALT_REQ] = fsm_async_busy,
> + [VFIO_CCW_EVENT_CLEAR_REQ] = fsm_async_busy,
> [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
> },
> [VFIO_CCW_STATE_BUSY] = {
> [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
> [VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy,
> + [VFIO_CCW_EVENT_HALT_REQ] = fsm_halt_request,
> + [VFIO_CCW_EVENT_CLEAR_REQ] = fsm_clear_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 a5d731ed2a39..0e1f7f7bf927 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -148,11 +148,20 @@ 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 a6f9f84526e2..1a41a14831ae 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
> @@ -62,6 +64,7 @@ int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
> * @mdev: pointer to the mediated device
> * @nb: notifier for vfio events
> * @io_region: MMIO region to input/output I/O arguments/results
> + * @cmd_region: MMIO region for asynchronous I/O commands other than START
> * @region: additional regions for other subchannel operations
> * @num_regions: number of additional regions
> * @cp: channel program for the current I/O operation
> @@ -79,6 +82,7 @@ struct vfio_ccw_private {
> struct notifier_block nb;
> struct ccw_io_region *io_region;
> struct vfio_ccw_region *region;
> + struct ccw_cmd_region *cmd_region;
> int num_regions;
>
> struct channel_program cp;
> @@ -114,6 +118,8 @@ enum vfio_ccw_event {
> VFIO_CCW_EVENT_NOT_OPER,
> VFIO_CCW_EVENT_IO_REQ,
> VFIO_CCW_EVENT_INTERRUPT,
> + VFIO_CCW_EVENT_HALT_REQ,
> + VFIO_CCW_EVENT_CLEAR_REQ,
> /* last element! */
> NR_VFIO_CCW_EVENTS
> };
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index 565669f95534..c01472ec77ea 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -304,6 +304,7 @@ struct vfio_region_info_cap_type {
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
>
> +
> #define VFIO_REGION_TYPE_GFX (1)
> #define VFIO_REGION_SUBTYPE_GFX_EDID (1)
>
> @@ -354,6 +355,9 @@ struct vfio_region_gfx_edid {
> #define VFIO_DEVICE_GFX_LINK_STATE_DOWN 2
> };
>
> +/* ccw sub-types */
> +#define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1)
> +
> /*
> * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped
> * which allows direct access to non-MSIX registers which happened to be within
> 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
>