Re: [PATCH v7 10/13] s390x/css: introduce and realize ccw-request callback

Alex Williamson
2017-05-11T21:49:10Z

On Fri, 5 May 2017 04:03:49 +0200
Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> wrote:

> From: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
>
> Introduce a new callback on subchannel to handle ccw-request.
> Realize the callback in vfio-ccw device. Besides, resort to
> the event notifier handler to handling the ccw-request results.
> 1. Pread the I/O results via MMIO region.
> 2. Update the scsw info to guest.
> 3. Inject an I/O interrupt to notify guest the I/O result.
>
> Signed-off-by: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
> Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
> ---

Acked-by: Alex Williamson <alex.williamson@redhat.com>

> hw/s390x/css.c | 4 +--
> hw/s390x/s390-ccw.h | 1 +
> hw/vfio/ccw.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++
> include/hw/s390x/css.h | 2 ++
> 4 files changed, 90 insertions(+), 2 deletions(-)
>
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index 1052eea..507c60f 100644
> --- a/hw/s390x/css.c
> +++ b/hw/s390x/css.c
> @@ -259,7 +259,7 @@ uint16_t css_build_subchannel_id(SubchDev *sch)
> return css_do_build_subchannel_id(sch->cssid, sch->ssid);
> }
>
> -static void css_inject_io_interrupt(SubchDev *sch)
> +void css_inject_io_interrupt(SubchDev *sch)
> {
> uint8_t isc = (sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ISC) >> 11;
>
> @@ -668,7 +668,7 @@ static void copy_pmcw_to_guest(PMCW *dest, const PMCW *src)
> dest->chars = cpu_to_be32(src->chars);
> }
>
> -static void copy_scsw_to_guest(SCSW *dest, const SCSW *src)
> +void copy_scsw_to_guest(SCSW *dest, const SCSW *src)
> {
> dest->flags = cpu_to_be16(src->flags);
> dest->ctrl = cpu_to_be16(src->ctrl);
> diff --git a/hw/s390x/s390-ccw.h b/hw/s390x/s390-ccw.h
> index b58d8e9..9f45cf1 100644
> --- a/hw/s390x/s390-ccw.h
> +++ b/hw/s390x/s390-ccw.h
> @@ -33,6 +33,7 @@ typedef struct S390CCWDeviceClass {
> CCWDeviceClass parent_class;
> void (*realize)(S390CCWDevice *dev, char *sysfsdev, Error **errp);
> void (*unrealize)(S390CCWDevice *dev, Error **errp);
> + int (*handle_request) (ORB *, SCSW *, void *);
> } S390CCWDeviceClass;
>
> #endif
> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
> index 6760cee..3c8b518 100644
> --- a/hw/vfio/ccw.c
> +++ b/hw/vfio/ccw.c
> @@ -47,6 +47,36 @@ struct VFIODeviceOps vfio_ccw_ops = {
> .vfio_compute_needs_reset = vfio_ccw_compute_needs_reset,
> };
>
> +static int vfio_ccw_handle_request(ORB *orb, SCSW *scsw, void *data)
> +{
> + S390CCWDevice *cdev = data;
> + VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
> + struct ccw_io_region *region = vcdev->io_region;
> + int ret;
> +
> + QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB));
> + QEMU_BUILD_BUG_ON(sizeof(region->scsw_area) != sizeof(SCSW));
> + QEMU_BUILD_BUG_ON(sizeof(region->irb_area) != sizeof(IRB));
> +
> + memset(region, 0, sizeof(*region));
> +
> + memcpy(region->orb_area, orb, sizeof(ORB));
> + memcpy(region->scsw_area, scsw, sizeof(SCSW));
> +
> +again:
> + ret = pwrite(vcdev->vdev.fd, region,
> + vcdev->io_region_size, vcdev->io_region_offset);
> + if (ret != vcdev->io_region_size) {
> + if (errno == EAGAIN) {
> + goto again;
> + }
> + error_report("vfio-ccw: wirte I/O region failed with errno=%d", errno);
> + return -errno;
> + }
> +
> + return region->ret_code;
> +}
> +
> static void vfio_ccw_reset(DeviceState *dev)
> {
> CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
> @@ -59,10 +89,62 @@ static void vfio_ccw_reset(DeviceState *dev)
> static void vfio_ccw_io_notifier_handler(void *opaque)
> {
> VFIOCCWDevice *vcdev = opaque;
> + struct ccw_io_region *region = vcdev->io_region;
> + S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev);
> + CcwDevice *ccw_dev = CCW_DEVICE(cdev);
> + SubchDev *sch = ccw_dev->sch;
> + SCSW *s = &sch->curr_status.scsw;
> + IRB irb;
> + int size;
>
> if (!event_notifier_test_and_clear(&vcdev->io_notifier)) {
> return;
> }
> +
> + size = pread(vcdev->vdev.fd, region, vcdev->io_region_size,
> + vcdev->io_region_offset);
> + if (size == -1) {
> + switch (errno) {
> + case ENODEV:
> + /* Generate a deferred cc 3 condition. */
> + s->flags |= SCSW_FLAGS_MASK_CC;
> + s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
> + s->ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND);
> + goto read_err;
> + case EFAULT:
> + /* Memory problem, generate channel data check. */
> + s->ctrl &= ~SCSW_ACTL_START_PEND;
> + s->cstat = SCSW_CSTAT_DATA_CHECK;
> + s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
> + s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
> + SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
> + goto read_err;
> + default:
> + /* Error, generate channel program check. */
> + s->ctrl &= ~SCSW_ACTL_START_PEND;
> + s->cstat = SCSW_CSTAT_PROG_CHECK;
> + s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
> + s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
> + SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
> + goto read_err;
> + }
> + } else if (size != vcdev->io_region_size) {
> + /* Information transfer error, generate channel-control check. */
> + s->ctrl &= ~SCSW_ACTL_START_PEND;
> + s->cstat = SCSW_CSTAT_CHN_CTRL_CHK;
> + s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
> + s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
> + SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
> + goto read_err;
> + }
> +
> + memcpy(&irb, region->irb_area, sizeof(IRB));
> +
> + /* Update control block via irb. */
> + copy_scsw_to_guest(s, &irb.scsw);
> +
> +read_err:
> + css_inject_io_interrupt(sch);
> }
>
> static void vfio_ccw_register_io_notifier(VFIOCCWDevice *vcdev, Error **errp)
> @@ -320,6 +402,7 @@ static const VMStateDescription vfio_ccw_vmstate = {
> static void vfio_ccw_class_init(ObjectClass *klass, void *data)
> {
> DeviceClass *dc = DEVICE_CLASS(klass);
> + S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass);
>
> dc->props = vfio_ccw_properties;
> dc->vmsd = &vfio_ccw_vmstate;
> @@ -327,6 +410,8 @@ static void vfio_ccw_class_init(ObjectClass *klass, void *data)
> dc->realize = vfio_ccw_realize;
> dc->unrealize = vfio_ccw_unrealize;
> dc->reset = vfio_ccw_reset;
> +
> + cdc->handle_request = vfio_ccw_handle_request;
> }
>
> static const TypeInfo vfio_ccw_info = {
> diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
> index a8bf1db..c8c283a 100644
> --- a/include/hw/s390x/css.h
> +++ b/include/hw/s390x/css.h
> @@ -135,6 +135,8 @@ void css_subch_assign(uint8_t cssid, uint8_t ssid, uint16_t schid,
> void css_sch_build_virtual_schib(SubchDev *sch, uint8_t chpid, uint8_t type);
> int css_sch_build_schib(SubchDev *sch, CssDevId *dev_id);
> uint16_t css_build_subchannel_id(SubchDev *sch);
> +void copy_scsw_to_guest(SCSW *dest, const SCSW *src);
> +void css_inject_io_interrupt(SubchDev *sch);
> void css_reset(void);
> void css_reset_sch(SubchDev *sch);
> void css_queue_crw(uint8_t rsc, uint8_t erc, int chain, uint16_t rsid);