s390: sclp base support

This adds a more generic infrastructure for handling Service-Call
requests on s390. Currently we only support a small subset of Read
SCP Info directly in target-s390x. This patch provides the base
infrastructure for supporting more commands and moves Read SCP
Info.
In the future we could add additional commands for hotplug, call
home and event handling.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 118 insertions, 0 deletions

diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
new file mode 100644
index 0000000000..d902a66261
--- /dev/null
+++ b/hw/s390x/sclp.c
@@ -0,0 +1,118 @@
+/*
+ * SCLP Support
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Christian Borntraeger <borntraeger@de.ibm.com>
+ *  Heinz Graalfs <graalfs@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at your
+ * option) any later version.  See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "cpu.h"
+#include "kvm.h"
+#include "memory.h"
+
+#include "sclp.h"
+
+/* Provide information about the configuration, CPUs and storage */
+static void read_SCP_info(SCCB *sccb)
+{
+    ReadInfo *read_info = (ReadInfo *) sccb;
+    int shift = 0;
+
+    while ((ram_size >> (20 + shift)) > 65535) {
+        shift++;
+    }
+    read_info->rnmax = cpu_to_be16(ram_size >> (20 + shift));
+    read_info->rnsize = 1 << shift;
+    sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_READ_COMPLETION);
+}
+
+static void sclp_execute(SCCB *sccb, uint64_t code)
+{
+    switch (code) {
+    case SCLP_CMDW_READ_SCP_INFO:
+    case SCLP_CMDW_READ_SCP_INFO_FORCED:
+        read_SCP_info(sccb);
+        break;
+    default:
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
+        break;
+    }
+}
+
+int sclp_service_call(uint32_t sccb, uint64_t code)
+{
+    int r = 0;
+    SCCB work_sccb;
+
+    hwaddr sccb_len = sizeof(SCCB);
+
+    /* first some basic checks on program checks */
+    if (cpu_physical_memory_is_io(sccb)) {
+        r = -PGM_ADDRESSING;
+        goto out;
+    }
+    if (sccb & ~0x7ffffff8ul) {
+        r = -PGM_SPECIFICATION;
+        goto out;
+    }
+
+    /*
+     * we want to work on a private copy of the sccb, to prevent guests
+     * from playing dirty tricks by modifying the memory content after
+     * the host has checked the values
+     */
+    cpu_physical_memory_read(sccb, &work_sccb, sccb_len);
+
+    /* Valid sccb sizes */
+    if (be16_to_cpu(work_sccb.h.length) < sizeof(SCCBHeader) ||
+        be16_to_cpu(work_sccb.h.length) > SCCB_SIZE) {
+        r = -PGM_SPECIFICATION;
+        goto out;
+    }
+
+    sclp_execute((SCCB *)&work_sccb, code);
+
+    cpu_physical_memory_write(sccb, &work_sccb,
+                              be16_to_cpu(work_sccb.h.length));
+
+    sclp_service_interrupt(sccb);
+
+out:
+    return r;
+}
+
+void sclp_service_interrupt(uint32_t sccb)
+{
+    s390_sclp_extint(sccb & ~3);
+}
+
+/* qemu object creation and initialization functions */
+
+static void s390_sclp_device_class_init(ObjectClass *klass, void *data)
+{
+    SysBusDeviceClass *dc = SYS_BUS_DEVICE_CLASS(klass);
+
+    dc->init = s390_sclp_dev_init;
+}
+
+static TypeInfo s390_sclp_device_info = {
+    .name = TYPE_DEVICE_S390_SCLP,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(S390SCLPDevice),
+    .class_init = s390_sclp_device_class_init,
+    .class_size = sizeof(S390SCLPDeviceClass),
+    .abstract = true,
+};
+
+static void s390_sclp_register_types(void)
+{
+    type_register_static(&s390_sclp_device_info);
+}
+
+type_init(s390_sclp_register_types)