s390x: Create QOM device for s390 storage keys

A new QOM style device is provided to back guest storage keys. A special
version for KVM is created, which handles the storage key access via
KVM_S390_GET_SKEYS and KVM_S390_SET_SKEYS ioctl.

Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

MAINTAINERS

@@ -569,6 +569,7 @@ F: hw/s390x/css.[hc]
 F: hw/s390x/sclp*.[hc]
 F: hw/s390x/ipl*.[hc]
 F: hw/s390x/*pci*.[hc]
+F: hw/s390x/s390-skeys*.c
 F: include/hw/s390x/
 F: pc-bios/s390-ccw/
 T: git git://github.com/cohuck/qemu virtio-ccw-upstr

hw/s390x/Makefile.objs

@@ -9,3 +9,5 @@ obj-y += css.o
 obj-y += s390-virtio-ccw.o
 obj-y += virtio-ccw.o
 obj-y += s390-pci-bus.o s390-pci-inst.o
+obj-y += s390-skeys.o
+obj-$(CONFIG_KVM) += s390-skeys-kvm.o

hw/s390x/s390-skeys-kvm.c

@@ -0,0 +1,75 @@
+/*
+ * s390 storage key device
+ *
+ * Copyright 2015 IBM Corp.
+ * Author(s): Jason J. Herne <jjherne@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 "hw/s390x/storage-keys.h"
+#include "sysemu/kvm.h"
+#include "qemu/error-report.h"
+
+static int kvm_s390_skeys_enabled(S390SKeysState *ss)
+{
+    S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
+    uint8_t single_key;
+    int r;
+
+    r = skeyclass->get_skeys(ss, 0, 1, &single_key);
+    if (r != 0 && r != KVM_S390_GET_SKEYS_NONE) {
+        error_report("S390_GET_KEYS error %d\n", r);
+    }
+    return (r == 0);
+}
+
+static int kvm_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
+                              uint64_t count, uint8_t *keys)
+{
+    struct kvm_s390_skeys args = {
+        .start_gfn = start_gfn,
+        .count = count,
+        .skeydata_addr = (__u64)keys
+    };
+
+    return kvm_vm_ioctl(kvm_state, KVM_S390_GET_SKEYS, &args);
+}
+
+static int kvm_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
+                              uint64_t count, uint8_t *keys)
+{
+    struct kvm_s390_skeys args = {
+        .start_gfn = start_gfn,
+        .count = count,
+        .skeydata_addr = (__u64)keys
+    };
+
+    return kvm_vm_ioctl(kvm_state, KVM_S390_SET_SKEYS, &args);
+}
+
+static void kvm_s390_skeys_class_init(ObjectClass *oc, void *data)
+{
+    S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
+
+    skeyclass->skeys_enabled = kvm_s390_skeys_enabled;
+    skeyclass->get_skeys = kvm_s390_skeys_get;
+    skeyclass->set_skeys = kvm_s390_skeys_set;
+}
+
+static const TypeInfo kvm_s390_skeys_info = {
+    .name          = TYPE_KVM_S390_SKEYS,
+    .parent        = TYPE_S390_SKEYS,
+    .instance_size = sizeof(S390SKeysState),
+    .class_init    = kvm_s390_skeys_class_init,
+    .class_size    = sizeof(S390SKeysClass),
+};
+
+static void kvm_s390_skeys_register_types(void)
+{
+    type_register_static(&kvm_s390_skeys_info);
+}
+
+type_init(kvm_s390_skeys_register_types)

hw/s390x/s390-skeys.c

@@ -0,0 +1,141 @@
+/*
+ * s390 storage key device
+ *
+ * Copyright 2015 IBM Corp.
+ * Author(s): Jason J. Herne <jjherne@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 "hw/boards.h"
+#include "hw/s390x/storage-keys.h"
+#include "qemu/error-report.h"
+
+S390SKeysState *s390_get_skeys_device(void)
+{
+    S390SKeysState *ss;
+
+    ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
+    assert(ss);
+    return ss;
+}
+
+void s390_skeys_init(void)
+{
+    Object *obj;
+
+    if (kvm_enabled()) {
+        obj = object_new(TYPE_KVM_S390_SKEYS);
+    } else {
+        obj = object_new(TYPE_QEMU_S390_SKEYS);
+    }
+    object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
+                              obj, NULL);
+    object_unref(obj);
+
+    qdev_init_nofail(DEVICE(obj));
+}
+
+static void qemu_s390_skeys_init(Object *obj)
+{
+    QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
+    MachineState *machine = MACHINE(qdev_get_machine());
+
+    skeys->key_count = machine->maxram_size / TARGET_PAGE_SIZE;
+    skeys->keydata = g_malloc0(skeys->key_count);
+}
+
+static int qemu_s390_skeys_enabled(S390SKeysState *ss)
+{
+    return 1;
+}
+
+/*
+ * TODO: for memory hotplug support qemu_s390_skeys_set and qemu_s390_skeys_get
+ * will have to make sure that the given gfn belongs to a memory region and not
+ * a memory hole.
+ */
+static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
+                              uint64_t count, uint8_t *keys)
+{
+    QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
+    int i;
+
+    /* Check for uint64 overflow and access beyond end of key data */
+    if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
+        error_report("Error: Setting storage keys for page beyond the end "
+                "of memory. gfn=%" PRIx64 " count=%" PRId64 "\n", start_gfn,
+                count);
+        return -EINVAL;
+    }
+
+    for (i = 0; i < count; i++) {
+        skeydev->keydata[start_gfn + i] = keys[i];
+    }
+    return 0;
+}
+
+static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
+                               uint64_t count, uint8_t *keys)
+{
+    QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
+    int i;
+
+    /* Check for uint64 overflow and access beyond end of key data */
+    if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
+        error_report("Error: Getting storage keys for page beyond the end "
+                "of memory. gfn=%" PRIx64 " count=%" PRId64 "\n", start_gfn,
+                count);
+        return -EINVAL;
+    }
+
+    for (i = 0; i < count; i++) {
+        keys[i] = skeydev->keydata[start_gfn + i];
+    }
+    return 0;
+}
+
+static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
+{
+    S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
+
+    skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
+    skeyclass->get_skeys = qemu_s390_skeys_get;
+    skeyclass->set_skeys = qemu_s390_skeys_set;
+}
+
+static const TypeInfo qemu_s390_skeys_info = {
+    .name          = TYPE_QEMU_S390_SKEYS,
+    .parent        = TYPE_S390_SKEYS,
+    .instance_init = qemu_s390_skeys_init,
+    .instance_size = sizeof(QEMUS390SKeysState),
+    .class_init    = qemu_s390_skeys_class_init,
+    .instance_size = sizeof(S390SKeysClass),
+};
+
+static void s390_skeys_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->hotpluggable = false;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+}
+
+static const TypeInfo s390_skeys_info = {
+    .name          = TYPE_S390_SKEYS,
+    .parent        = TYPE_DEVICE,
+    .instance_size = sizeof(S390SKeysState),
+    .class_init    = s390_skeys_class_init,
+    .class_size    = sizeof(S390SKeysClass),
+    .abstract = true,
+};
+
+static void qemu_s390_skeys_register_types(void)
+{
+    type_register_static(&s390_skeys_info);
+    type_register_static(&qemu_s390_skeys_info);
+}
+
+type_init(qemu_s390_skeys_register_types)

include/hw/s390x/storage-keys.h

@@ -0,0 +1,55 @@
+/*
+ * s390 storage key device
+ *
+ * Copyright 2015 IBM Corp.
+ * Author(s): Jason J. Herne <jjherne@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.
+ */
+
+#ifndef __S390_STORAGE_KEYS_H
+#define __S390_STORAGE_KEYS_H
+
+#include <hw/qdev.h>
+
+#define TYPE_S390_SKEYS "s390-skeys"
+#define S390_SKEYS(obj) \
+    OBJECT_CHECK(S390SKeysState, (obj), TYPE_S390_SKEYS)
+
+typedef struct S390SKeysState {
+    DeviceState parent_obj;
+
+} S390SKeysState;
+
+#define S390_SKEYS_CLASS(klass) \
+    OBJECT_CLASS_CHECK(S390SKeysClass, (klass), TYPE_S390_SKEYS)
+#define S390_SKEYS_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(S390SKeysClass, (obj), TYPE_S390_SKEYS)
+
+typedef struct S390SKeysClass {
+    DeviceClass parent_class;
+    int (*skeys_enabled)(S390SKeysState *ks);
+    int (*get_skeys)(S390SKeysState *ks, uint64_t start_gfn, uint64_t count,
+                     uint8_t *keys);
+    int (*set_skeys)(S390SKeysState *ks, uint64_t start_gfn, uint64_t count,
+                     uint8_t *keys);
+} S390SKeysClass;
+
+#define TYPE_KVM_S390_SKEYS "s390-skeys-kvm"
+#define TYPE_QEMU_S390_SKEYS "s390-skeys-qemu"
+#define QEMU_S390_SKEYS(obj) \
+    OBJECT_CHECK(QEMUS390SKeysState, (obj), TYPE_QEMU_S390_SKEYS)
+
+typedef struct QEMUS390SKeysState {
+    S390SKeysState parent_obj;
+    uint8_t *keydata;
+    uint32_t key_count;
+} QEMUS390SKeysState;
+
+void s390_skeys_init(void);
+
+S390SKeysState *s390_get_skeys_device(void);
+
+#endif /* __S390_STORAGE_KEYS_H */