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

Dong Jia Shi
2017-05-05T02:03:49Z

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>
---
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);
--
2.10.2