Implement a basic infrastructure of handling channel I/O instruction
interception for passed through devices:
1. Branch the code path of instruction interception handling by
SubChannel type.
2. For a passed through device, issue the ORB to do ccw translation
and perform an I/O operation.
3. Inject an I/O interrupt to notify guest the I/O result.
4. Assign different condition code based on the I/O result, or
trigger a program check.
Signed-off-by: Xiao Feng Ren <renxiaof@xxxxxxxxxxxxxxxxxx>
---
hw/s390x/css.c | 130 ++++++++++++++++++++++++++++++++++++++++++++------
hw/s390x/css.h | 8 ++++
hw/s390x/s390-ccw.c | 12 +++++
hw/s390x/virtio-ccw.c | 1 +
target-s390x/ioinst.c | 9 ++++
5 files changed, 145 insertions(+), 15 deletions(-)
diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 5d02ad3..a46e63b 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -463,7 +463,7 @@ static int css_interpret_ccw(SubchDev *sch, hwaddr ccw_addr,
return ret;
}
-static void sch_handle_start_func(SubchDev *sch, ORB *orb)
+static void sch_handle_start_func_virtual(SubchDev *sch, ORB *orb)
{
PMCW *p = &sch->curr_status.pmcw;
@@ -558,13 +558,79 @@ static void sch_handle_start_func(SubchDev *sch, ORB *orb)
}
+static void copy_scsw_to_guest(SCSW *dest, const SCSW *src)
+{
+ dest->flags = cpu_to_be16(src->flags);
+ dest->ctrl = cpu_to_be16(src->ctrl);
+ dest->cpa = cpu_to_be32(src->cpa);
+ dest->dstat = src->dstat;
+ dest->cstat = src->cstat;
+ dest->count = cpu_to_be16(src->count);
+}
+
+static int sch_handle_start_func_passthrough(SubchDev *sch, ORB *orb)
+{
+
+ PMCW *p = &sch->curr_status.pmcw;
+ SCSW *s = &sch->curr_status.scsw;
+ int ret;
+
+ if (!(s->ctrl & SCSW_ACTL_SUSP)) {
+ assert(orb != NULL);
+ p->intparm = orb->intparm;
+ }
+
+ /* Prepare the irb for the guest. */
+ memset(&sch->irb, 0, sizeof(IRB));
+
+ /*
+ * TODO:
+ * Only support prefetch enable mode.
+ * Only support 64bit addressing idal.
+ */
+ if (!(orb->ctrl0 & ORB_CTRL0_MASK_PFCH) ||
+ !(orb->ctrl0 & ORB_CTRL0_MASK_C64)) {
+ return -EINVAL;
+ }
+
+ ret = s390_ccw_cmd_request(orb, &sch->irb, s, sch->driver_data);
+ switch (ret) {
+ case 0:
+ /* Update control block via irb. */
+ copy_scsw_to_guest(s, &sch->irb.scsw);
+ break;
+ case -EBUSY:
+ break;
+ case -ENODEV:
+ break;
+ case -EACCES:
+ /* Let's reflect an inaccessible host device by cc 3. */
+ ret = -ENODEV;
+ break;
+ case -ENOMEM:
+ /* No memory, generate deferred cc 1. */
+ s->flags &= ~SCSW_FLAGS_MASK_CC;
+ s->flags |= (1 << 8);
+ s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
+ s->ctrl |= SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
+ break;
+ default:
+ /* All other return codes will trigger a program check,
+ * or set cc to 1.
+ */
+ break;
+ };
+
+ return ret;
+}
+
/*
* On real machines, this would run asynchronously to the main vcpus.
* We might want to make some parts of the ssch handling (interpreting
* read/writes) asynchronous later on if we start supporting more than
* our current very simple devices.
*/
-static void do_subchannel_work(SubchDev *sch, ORB *orb)
+static void do_subchannel_work_virtual(SubchDev *sch, ORB *orb)
{
SCSW *s = &sch->curr_status.scsw;
@@ -574,7 +640,7 @@ static void do_subchannel_work(SubchDev *sch, ORB *orb)
} else if (s->ctrl & SCSW_FCTL_HALT_FUNC) {
sch_handle_halt_func(sch);
} else if (s->ctrl & SCSW_FCTL_START_FUNC) {
- sch_handle_start_func(sch, orb);
+ sch_handle_start_func_virtual(sch, orb);
} else {
/* Cannot happen. */
return;
@@ -582,6 +648,51 @@ static void do_subchannel_work(SubchDev *sch, ORB *orb)
css_inject_io_interrupt(sch);
}
+static int do_subchannel_work_passthrough(SubchDev *sch, ORB *orb)
+{
+ int ret;
+ SCSW *s = &sch->curr_status.scsw;
+
+ if (s->ctrl & SCSW_FCTL_CLEAR_FUNC) {
+ /* TODO: Clear handling */
+ sch_handle_clear_func(sch);
+ ret = 0;
+ } else if (s->ctrl & SCSW_FCTL_HALT_FUNC) {
+ /* TODO: Halt handling */
+ sch_handle_halt_func(sch);
+ ret = 0;
+ } else if (s->ctrl & SCSW_FCTL_START_FUNC) {
+ ret = sch_handle_start_func_passthrough(sch, orb);
+ } else {
+ /* Cannot happen. */
+ return -ENODEV;
+ }
+
+ css_inject_io_interrupt(sch);
+
+ return ret;
+}
+
+static int do_subchannel_work(SubchDev *sch, ORB *orb)
+{
+ int ret;
+
+ switch (sch->type) {
+ case SUBCH_TYPE_VIRTUAL:
+ do_subchannel_work_virtual(sch, orb);
+ ret = 0;
+ break;
+ case SUBCH_TYPE_PASSTHROUGH:
+ ret = do_subchannel_work_passthrough(sch, orb);
+ break;
+ default:
+ assert(false);
+ ret = -EINVAL;
+ };
+
+ return ret;
+}
+
static void copy_pmcw_to_guest(PMCW *dest, const PMCW *src)
{
int i;
@@ -602,16 +713,6 @@ 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)
-{
- dest->flags = cpu_to_be16(src->flags);
- dest->ctrl = cpu_to_be16(src->ctrl);
- dest->cpa = cpu_to_be32(src->cpa);
- dest->dstat = src->dstat;
- dest->cstat = src->cstat;
- dest->count = cpu_to_be16(src->count);
-}
-
static void copy_schib_to_guest(SCHIB *dest, const SCHIB *src)
{
int i;
@@ -898,8 +999,7 @@ int css_do_ssch(SubchDev *sch, ORB *orb)
s->ctrl |= (SCSW_FCTL_START_FUNC | SCSW_ACTL_START_PEND);
s->flags &= ~SCSW_FLAGS_MASK_PNO;
- do_subchannel_work(sch, orb);
- ret = 0;
+ ret = do_subchannel_work(sch, orb);
out:
return ret;
diff --git a/hw/s390x/css.h b/hw/s390x/css.h
index c280226..5f16edc 100644
--- a/hw/s390x/css.h
+++ b/hw/s390x/css.h
@@ -76,6 +76,8 @@ struct SubchDev {
uint8_t ssid;
uint16_t schid;
uint16_t devno;
+ uint8_t type;
+ IRB irb;
SCHIB curr_status;
uint8_t sense_data[32];
hwaddr channel_prog;
@@ -99,6 +101,11 @@ typedef struct IndAddr {
QTAILQ_ENTRY(IndAddr) sibling;
} IndAddr;
+enum {
+ SUBCH_TYPE_VIRTUAL = 0,
+ SUBCH_TYPE_PASSTHROUGH = 1,
+};
+
IndAddr *get_indicator(hwaddr ind_addr, int len);
void release_indicator(AdapterInfo *adapter, IndAddr *indicator);
int map_indicator(AdapterInfo *adapter, IndAddr *indicator);
@@ -123,6 +130,7 @@ void css_generate_css_crws(uint8_t cssid);
void css_clear_sei_pending(void);
void css_adapter_interrupt(uint8_t isc);
int css_sch_build_schib(SubchDev *sch, const char *hschid);
+int s390_ccw_cmd_request(ORB *orb, IRB *irb, SCSW *scsw, void *data);
#define CSS_IO_ADAPTER_VIRTIO 1
int css_register_io_adapter(uint8_t type, uint8_t isc, bool swap,
diff --git a/hw/s390x/s390-ccw.c b/hw/s390x/s390-ccw.c
index 7b378f9..ed6f242 100644
--- a/hw/s390x/s390-ccw.c
+++ b/hw/s390x/s390-ccw.c
@@ -18,6 +18,17 @@
#include "s390-ccw-bus.h"
#include "s390-ccw.h"
+int s390_ccw_cmd_request(ORB *orb, IRB *irb, SCSW *scsw, void *data)
+{
+ S390CCWDevice *cdev = data;
+
+ if (cdev->handle_request) {
+ return cdev->handle_request(orb, irb, scsw, data);
+ } else {
+ return -ENOSYS;
+ }
+}
+
static void s390_ccw_realize(S390CCWDevice *cdev, Error **errp)
{
unsigned int cssid, ssid, devno, schid;
@@ -89,6 +100,7 @@ static void s390_ccw_realize(S390CCWDevice *cdev, Error **errp)
sch->cssid = cssid;
sch->ssid = ssid;
sch->devno = devno;
+ sch->type = SUBCH_TYPE_PASSTHROUGH;
cdev->sch = NULL;
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index d51642d..621befb 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -758,6 +758,7 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
sch->channel_prog = 0x0;
sch->last_cmd_valid = false;
sch->thinint_active = false;
+ sch->type = SUBCH_TYPE_VIRTUAL;
/*
* Use a device number if provided. Otherwise, fall back to subchannel
* number.
diff --git a/target-s390x/ioinst.c b/target-s390x/ioinst.c
index 142ff93..59f15af 100644
--- a/target-s390x/ioinst.c
+++ b/target-s390x/ioinst.c
@@ -244,6 +244,15 @@ void ioinst_handle_ssch(S390CPU *cpu, uint64_t reg1, uint32_t ipb)
case -EBUSY:
cc = 2;
break;
+ case -EFAULT:
+ /*
+ * TODO:
+ * I'm wondering whether there is something better
+ * to do for us here (like setting some device or
+ * subchannel status).
+ */
+ program_interrupt(env, PGM_ADDRESSING, 4);
+ return;
case 0:
cc = 0;
break;
--
2.6.6
--
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