[PATCH 1/6] s390x/virtio-ccw: Adapter interrupt support.

Cornelia Huck
2014-02-25T17:25:15Z

Handle the new CCW_CMD_SET_IND_ADAPTER command enabling adapter interrupts
on guest request. When active, host->guest notifications will be handled
via global_indicator -> queue indicators instead of queue indicators +
subchannel I/O interrupt. Indicators for virtqueues may be present at an
offset.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
hw/s390x/css.c | 10 +++++
hw/s390x/css.h | 2 +
hw/s390x/virtio-ccw.c | 102 +++++++++++++++++++++++++++++++++++++++++++++----
hw/s390x/virtio-ccw.h | 4 ++
target-s390x/ioinst.h | 2 +
target-s390x/kvm.c | 8 +++-
trace-events | 1 +
7 files changed, 120 insertions(+), 9 deletions(-)

diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 75b04b4..7074d2b 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -116,6 +116,15 @@ void css_conditional_io_interrupt(SubchDev *sch)
}
}

+void css_adapter_interrupt(uint8_t isc)
+{
+ S390CPU *cpu = s390_cpu_addr2state(0);
+ uint32_t io_int_word = (isc << 27) | IO_INT_WORD_AI;
+
+ trace_css_adapter_interrupt(isc);
+ s390_io_interrupt(cpu, 0, 0, 0, io_int_word);
+}
+
static void sch_handle_clear_func(SubchDev *sch)
{
PMCW *p = &sch->curr_status.pmcw;
@@ -1259,6 +1268,7 @@ void css_reset_sch(SubchDev *sch)
sch->channel_prog = 0x0;
sch->last_cmd_valid = false;
sch->orb = NULL;
+ sch->thinint_active = false;
}

void css_reset(void)
diff --git a/hw/s390x/css.h b/hw/s390x/css.h
index b536ab5..e9b4405 100644
--- a/hw/s390x/css.h
+++ b/hw/s390x/css.h
@@ -77,6 +77,7 @@ struct SubchDev {
CCW1 last_cmd;
bool last_cmd_valid;
ORB *orb;
+ bool thinint_active;
/* transport-provided data: */
int (*ccw_cb) (SubchDev *, CCW1);
SenseId id;
@@ -97,4 +98,5 @@ void css_queue_crw(uint8_t rsc, uint8_t erc, int chain, uint16_t rsid);
void css_generate_sch_crws(uint8_t cssid, uint8_t ssid, uint16_t schid,
int hotplugged, int add);
void css_generate_chp_crws(uint8_t cssid, uint8_t chpid);
+void css_adapter_interrupt(uint8_t isc);
#endif
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index f6e0e3e..a01801e 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -1,7 +1,7 @@
/*
* virtio ccw target implementation
*
- * Copyright 2012 IBM Corp.
+ * Copyright 2012,2014 IBM Corp.
* Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at
@@ -188,6 +188,13 @@ typedef struct VirtioFeatDesc {
uint8_t index;
} QEMU_PACKED VirtioFeatDesc;

+typedef struct VirtioThinintInfo {
+ hwaddr summary_indicator;
+ hwaddr device_indicator;
+ uint64_t ind_bit;
+ uint8_t isc;
+} QEMU_PACKED VirtioThinintInfo;
+
/* Specify where the virtqueues for the subchannel are in guest memory. */
static int virtio_ccw_set_vqs(SubchDev *sch, uint64_t addr, uint32_t align,
uint16_t index, uint16_t num)
@@ -237,6 +244,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
bool check_len;
int len;
hwaddr hw_len;
+ VirtioThinintInfo *thinint;

if (!dev) {
return -EINVAL;
@@ -428,6 +436,11 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
ret = -EINVAL;
break;
}
+ if (sch->thinint_active) {
+ /* Trigger a command reject. */
+ ret = -ENOSYS;
+ break;
+ }
if (!ccw.cda) {
ret = -EFAULT;
} else {
@@ -480,6 +493,42 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
ret = 0;
}
break;
+ case CCW_CMD_SET_IND_ADAPTER:
+ if (check_len) {
+ if (ccw.count != sizeof(*thinint)) {
+ ret = -EINVAL;
+ break;
+ }
+ } else if (ccw.count < sizeof(*thinint)) {
+ /* Can't execute command. */
+ ret = -EINVAL;
+ break;
+ }
+ len = sizeof(*thinint);
+ hw_len = len;
+ if (!ccw.cda) {
+ ret = -EFAULT;
+ } else if (dev->indicators && !sch->thinint_active) {
+ /* Trigger a command reject. */
+ ret = -ENOSYS;
+ } else {
+ thinint = cpu_physical_memory_map(ccw.cda, &hw_len, 0);
+ if (!thinint) {
+ ret = -EFAULT;
+ } else {
+ len = hw_len;
+ dev->summary_indicator = thinint->summary_indicator;
+ dev->indicators = thinint->device_indicator;
+ dev->thinint_isc = thinint->isc;
+ dev->ind_bit = thinint->ind_bit;
+ cpu_physical_memory_unmap(thinint, hw_len, 0, hw_len);
+ sch->thinint_active = ((dev->indicators != 0) &&
+ (dev->summary_indicator != 0));
+ sch->curr_status.scsw.count = ccw.count - len;
+ ret = 0;
+ }
+ }
+ break;
default:
ret = -ENOSYS;
break;
@@ -511,6 +560,7 @@ static int virtio_ccw_device_init(VirtioCcwDevice *dev, VirtIODevice *vdev)
sch->channel_prog = 0x0;
sch->last_cmd_valid = false;
sch->orb = NULL;
+ sch->thinint_active = false;
/*
* Use a device number if provided. Otherwise, fall back to subchannel
* number.
@@ -858,6 +908,28 @@ static inline VirtioCcwDevice *to_virtio_ccw_dev_fast(DeviceState *d)
return container_of(d, VirtioCcwDevice, parent_obj);
}

+static uint8_t virtio_set_ind_atomic(SubchDev *sch, uint64_t ind_loc,
+ uint8_t to_be_set)
+{
+ uint8_t ind_old, ind_new;
+ hwaddr len = 1;
+ uint8_t *ind_addr;
+
+ ind_addr = cpu_physical_memory_map(ind_loc, &len, 1);
+ if (!ind_addr) {
+ error_report("%s(%x.%x.%04x): unable to access indicator",
+ __func__, sch->cssid, sch->ssid, sch->schid);
+ return -1;
+ }
+ do {
+ ind_old = *ind_addr;
+ ind_new = ind_old | to_be_set;
+ } while (atomic_cmpxchg(ind_addr, ind_old, ind_new) != ind_old);
+ cpu_physical_memory_unmap(ind_addr, len, 1, len);
+
+ return ind_old;
+}
+
static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
{
VirtioCcwDevice *dev = to_virtio_ccw_dev_fast(d);
@@ -872,9 +944,26 @@ static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
if (!dev->indicators) {
return;
}
- indicators = ldq_phys(&address_space_memory, dev->indicators);
- indicators |= 1ULL << vector;
- stq_phys(&address_space_memory, dev->indicators, indicators);
+ if (sch->thinint_active) {
+ /*
+ * In the adapter interrupt case, indicators points to a
+ * memory area that may be (way) larger than 64 bit and
+ * ind_bit indicates the start of the indicators in a big
+ * endian notation.
+ */
+ virtio_set_ind_atomic(sch, dev->indicators +
+ (dev->ind_bit + vector) / 8,
+ 0x80 >> ((dev->ind_bit + vector) % 8));
+ if (!virtio_set_ind_atomic(sch, dev->summary_indicator,
+ 0x01)) {
+ css_adapter_interrupt(dev->thinint_isc);
+ }
+ } else {
+ indicators = ldq_phys(&address_space_memory, dev->indicators);
+ indicators |= 1ULL << vector;
+ stq_phys(&address_space_memory, dev->indicators, indicators);
+ css_conditional_io_interrupt(sch);
+ }
} else {
if (!dev->indicators2) {
return;
@@ -883,10 +972,8 @@ static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
indicators = ldq_phys(&address_space_memory, dev->indicators2);
indicators |= 1ULL << vector;
stq_phys(&address_space_memory, dev->indicators2, indicators);
+ css_conditional_io_interrupt(sch);
}
-
- css_conditional_io_interrupt(sch);
-
}

static unsigned virtio_ccw_get_features(DeviceState *d)
@@ -907,6 +994,7 @@ static void virtio_ccw_reset(DeviceState *d)
css_reset_sch(dev->sch);
dev->indicators = 0;
dev->indicators2 = 0;
+ dev->summary_indicator = 0;
}

static void virtio_ccw_vmstate_change(DeviceState *d, bool running)
diff --git a/hw/s390x/virtio-ccw.h b/hw/s390x/virtio-ccw.h
index 00932c7..4393e44 100644
--- a/hw/s390x/virtio-ccw.h
+++ b/hw/s390x/virtio-ccw.h
@@ -38,6 +38,7 @@
#define CCW_CMD_SET_IND 0x43
#define CCW_CMD_SET_CONF_IND 0x53
#define CCW_CMD_READ_VQ_CONF 0x32
+#define CCW_CMD_SET_IND_ADAPTER 0x73

#define TYPE_VIRTIO_CCW_DEVICE "virtio-ccw-device"
#define VIRTIO_CCW_DEVICE(obj) \
@@ -83,9 +84,12 @@ struct VirtioCcwDevice {
bool ioeventfd_started;
bool ioeventfd_disabled;
uint32_t flags;
+ uint8_t thinint_isc;
/* Guest provided values: */
hwaddr indicators;
hwaddr indicators2;
+ hwaddr summary_indicator;
+ uint64_t ind_bit;
};

/* virtual css bus type */
diff --git a/target-s390x/ioinst.h b/target-s390x/ioinst.h
index 613da49..5bbc67d 100644
--- a/target-s390x/ioinst.h
+++ b/target-s390x/ioinst.h
@@ -212,6 +212,8 @@ typedef struct IOIntCode {
#define IO_INT_WORD_ISC(_int_word) ((_int_word & 0x38000000) >> 24)
#define ISC_TO_ISC_BITS(_isc) ((0x80 >> _isc) << 24)

+#define IO_INT_WORD_AI 0x80000000
+
int ioinst_disassemble_sch_ident(uint32_t value, int *m, int *cssid, int *ssid,
int *schid);
void ioinst_handle_xsch(S390CPU *cpu, uint64_t reg1);
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index d3f0d4a..7e8321e 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -868,8 +868,12 @@ void kvm_s390_io_interrupt(S390CPU *cpu, uint16_t subchannel_id,
{
uint32_t type;

- type = ((subchannel_id & 0xff00) << 24) |
- ((subchannel_id & 0x00060) << 22) | (subchannel_nr << 16);
+ if (io_int_word & IO_INT_WORD_AI) {
+ type = KVM_S390_INT_IO(1, 0, 0, 0);
+ } else {
+ type = ((subchannel_id & 0xff00) << 24) |
+ ((subchannel_id & 0x00060) << 22) | (subchannel_nr << 16);
+ }
kvm_s390_interrupt_internal(cpu, type,
((uint32_t)subchannel_id << 16) | subchannel_nr,
((uint64_t)io_int_parm << 32) | io_int_word, 1);
diff --git a/trace-events b/trace-events
index 8bc7cc4..372ea64 100644
--- a/trace-events
+++ b/trace-events
@@ -1157,6 +1157,7 @@ css_chpid_add(uint8_t cssid, uint8_t chpid, uint8_t type) "CSS: add chpid %x.%02
css_new_image(uint8_t cssid, const char *default_cssid) "CSS: add css image %02x %s"
css_assign_subch(const char *do_assign, uint8_t cssid, uint8_t ssid, uint16_t schid, uint16_t devno) "CSS: %s %x.%x.%04x (devno %04x)"
css_io_interrupt(int cssid, int ssid, int schid, uint32_t intparm, uint8_t isc, const char *conditional) "CSS: I/O interrupt on sch %x.%x.%04x (intparm %08x, isc %x) %s"
+css_adapter_interrupt(uint8_t isc) "CSS: adapter I/O interrupt (isc %x)"

# hw/s390x/virtio-ccw.c
virtio_ccw_interpret_ccw(int cssid, int ssid, int schid, int cmd_code) "VIRTIO-CCW: %x.%x.%04x: interpret command %x"
--
1.7.9.5