[Qemu-devel] [PATCH/RFC] s390x/kvm: implement and use QEMU config device for s390

[Christian Borntraeger]

From: Ekaterina Tumanova <address@hidden>

The following patch adds Qemu CONFIG device,
which interacts with kvm CONFIG device by calling KVM_CREATE_DEVICE
(to create the device in kernel), KVM_GET_DEVICE_ATTR and
KVM_SET_DEVICE_ATTR (to get and set the particular attributes of
KVM CONFIG device respectively).
This patch uses the Qemu CONFIG device to copy the
qemu_name (if specified) into the kvm CONFIG device.

Signed-off-by: Ekaterina Tumanova <address@hidden>
Signed-off-by: Christian Borntraeger <address@hidden>
Signed-off-by: Michael Mueller <address@hidden>
Signed-off-by: Jens Freimann <address@hidden>
---
 default-configs/s390x-softmmu.mak |   1 +
 hw/s390x/Makefile.objs            |   1 +
 hw/s390x/config.c                 | 113 ++++++++++++++++++++++++++++++++++++++
 hw/s390x/s390-virtio-ccw.c        |   6 ++
 hw/s390x/s390-virtio.c            |  24 ++++++++
 hw/s390x/s390-virtio.h            |   1 +
 include/hw/s390x/config.h         |  51 +++++++++++++++++
 linux-headers/asm-s390/kvm.h      |  11 ++++
 linux-headers/linux/kvm.h         |   1 +
 trace-events                      |   4 ++
 10 files changed, 213 insertions(+)
 create mode 100644 hw/s390x/config.c
 create mode 100644 include/hw/s390x/config.h

diff --git a/default-configs/s390x-softmmu.mak 
b/default-configs/s390x-softmmu.mak
index d843dc0..a07697d 100644
--- a/default-configs/s390x-softmmu.mak
+++ b/default-configs/s390x-softmmu.mak
@@ -1,3 +1,4 @@
 CONFIG_VIRTIO=y
 CONFIG_SCLPCONSOLE=y
 CONFIG_S390_FLIC=$(CONFIG_KVM)
+CONFIG_S390_CONFIG=$(CONFIG_KVM)
diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
index 1ba6c3a..dc03e1d 100644
--- a/hw/s390x/Makefile.objs
+++ b/hw/s390x/Makefile.objs
@@ -8,3 +8,4 @@ obj-y += ipl.o
 obj-y += css.o
 obj-y += s390-virtio-ccw.o
 obj-y += virtio-ccw.o
+obj-$(CONFIG_S390_CONFIG) += config.o
diff --git a/hw/s390x/config.c b/hw/s390x/config.c
new file mode 100644
index 0000000..f70e880
--- /dev/null
+++ b/hw/s390x/config.c
@@ -0,0 +1,113 @@
+/*
+ * S390 configuration and control device
+ *
+ * Copyright 2014 IBM Corp.
+ * Author(s): Ekaterina Tumanova <address@hidden>
+ *
+ * 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 <sys/ioctl.h>
+#include "hw/s390x/config.h"
+#include "trace.h"
+
+S390ConfigState *get_config_state(void)
+{
+    return S390_CONFIG(object_resolve_path("/machine/s390-config", NULL));
+}
+
+static int config_set(S390ConfigState *config, struct kvm_device_attr *attr)
+{
+    int rc;
+
+    rc = ioctl(config->fd, KVM_SET_DEVICE_ATTR, attr);
+    return rc < 0 ? -errno : rc;
+}
+
+/*
+static int config_get(S390ConfigState *config, struct kvm_device_attr *attr)
+{
+    int rc;
+
+    rc = ioctl(config->fd, KVM_GET_DEVICE_ATTR, attr);
+    return rc < 0 ? -errno : rc;
+}
+*/
+
+static int config_set_name(S390ConfigState *config, char *name)
+{
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_CONFIG_GROUP,
+        .attr  = KVM_DEV_CONFIG_NAME,
+        .addr  = (uint64_t)name,
+    };
+
+    if (!name ||
+        (qemu_strnlen(name, S390_MACHINE_NAME_SIZE)
+         >= S390_MACHINE_NAME_SIZE)) {
+        return -EINVAL;
+    }
+
+    return config_set(config, &attr);
+}
+
+static void s390_config_realize(DeviceState *dev, Error **errp)
+{
+    S390ConfigState *cfg = S390_CONFIG(dev);
+    struct kvm_create_device cd = {0};
+    int ret;
+
+    if (!kvm_check_extension(kvm_state, KVM_CAP_DEVICE_CTRL)) {
+        trace_config_no_device_api(errno);
+        return;
+    }
+
+    cd.type = KVM_DEV_TYPE_S390_CONFIG;
+    ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd);
+    if (ret < 0) {
+        trace_config_create_device(errno);
+        return;
+    }
+    cfg->fd = cd.fd;
+}
+
+void s390_config_dev_init(void)
+{
+    DeviceState *dev;
+
+    if (kvm_enabled()) {
+        dev  = qdev_create(NULL, TYPE_S390_CONFIG);
+
+        object_property_add_child(qdev_get_machine(),
+                                  TYPE_S390_CONFIG,
+                                  OBJECT(dev), NULL);
+        qdev_init_nofail(dev);
+    }
+}
+
+static void s390_config_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    S390ConfigClass *scc = S390_CONFIG_CLASS(oc);
+
+    dc->realize = s390_config_realize;
+    scc->set_name = config_set_name;
+}
+
+static const TypeInfo s390_config_info = {
+    .name          = TYPE_S390_CONFIG,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(S390ConfigState),
+    .class_init    = s390_config_class_init,
+    .class_size    = sizeof(S390ConfigClass),
+};
+
+
+static void s390_config_register_types(void)
+{
+    type_register_static(&s390_config_info);
+}
+
+type_init(s390_config_register_types)
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 0d4f6ae..1e4b9ad 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -14,9 +14,11 @@
 #include "s390-virtio.h"
 #include "hw/s390x/sclp.h"
 #include "hw/s390x/s390_flic.h"
+#include "hw/s390x/config.h"
 #include "ioinst.h"
 #include "css.h"
 #include "virtio-ccw.h"
+#include "qemu/error-report.h"
 
 void io_subsystem_reset(void)
 {
@@ -106,6 +108,10 @@ static void ccw_init(QEMUMachineInitArgs *args)
                       args->initrd_filename, "s390-ccw.img");
     s390_flic_init();
 
+    s390_config_dev_init();
+
+    s390_set_vm_name();
+
     /* register hypercalls */
     virtio_ccw_register_hcalls();
 
diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
index aef2003..7a296fd 100644
--- a/hw/s390x/s390-virtio.c
+++ b/hw/s390x/s390-virtio.c
@@ -39,6 +39,8 @@
 #include "hw/s390x/s390_flic.h"
 #include "hw/s390x/s390-virtio.h"
 
+#include "hw/s390x/config.h"
+
 //#define DEBUG_S390
 
 #ifdef DEBUG_S390
@@ -223,6 +225,24 @@ void s390_create_virtio_net(BusState *bus, const char 
*name)
     }
 }
 
+void s390_set_vm_name(void)
+{
+    S390ConfigState *config = get_config_state();
+    char machine_name[S390_MACHINE_NAME_SIZE];
+    S390ConfigClass *scc;
+
+    if (!config || !qemu_name) {
+        return;
+    }
+    strncpy(machine_name, qemu_name, sizeof(machine_name));
+
+    scc = S390_CONFIG_GET_CLASS(config);
+
+    if (scc->set_name(config, machine_name)) {
+        error_report("Setting machine name failed: %m");
+    }
+}
+
 /* PC hardware initialisation */
 static void s390_init(QEMUMachineInitArgs *args)
 {
@@ -252,6 +272,10 @@ static void s390_init(QEMUMachineInitArgs *args)
                       args->initrd_filename, ZIPL_FILENAME);
     s390_flic_init();
 
+    s390_config_dev_init();
+
+    s390_set_vm_name();
+
     /* register hypercalls */
     s390_virtio_register_hcalls();
 
diff --git a/hw/s390x/s390-virtio.h b/hw/s390x/s390-virtio.h
index 5c405e7..deca18e 100644
--- a/hw/s390x/s390-virtio.h
+++ b/hw/s390x/s390-virtio.h
@@ -26,4 +26,5 @@ void s390_init_ipl_dev(const char *kernel_filename,
                        const char *initrd_filename,
                        const char *firmware);
 void s390_create_virtio_net(BusState *bus, const char *name);
+void s390_set_vm_name(void);
 #endif
diff --git a/include/hw/s390x/config.h b/include/hw/s390x/config.h
new file mode 100644
index 0000000..14d9b02
--- /dev/null
+++ b/include/hw/s390x/config.h
@@ -0,0 +1,51 @@
+/*
+ * S390 configuration and control device
+ *
+ * Copyright 2014 IBM Corp.
+ * Author(s): Ekaterina Tumanova <address@hidden>
+ *
+ * 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 __KVM_S390_CONFIG_H
+#define __KVM_S390_CONFIG_H
+
+#include "hw/sysbus.h"
+#include "migration/qemu-file.h"
+
+#define TYPE_S390_CONFIG "s390-config"
+#define S390_CONFIG(obj) \
+    OBJECT_CHECK(S390ConfigState, (obj), TYPE_S390_CONFIG)
+#define S390_CONFIG_CLASS(class) \
+     OBJECT_CLASS_CHECK(S390ConfigClass, (class), TYPE_S390_CONFIG)
+#define S390_CONFIG_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(S390ConfigClass, (obj), TYPE_S390_CONFIG)
+
+typedef struct S390ConfigState {
+    SysBusDevice parent_obj;
+    uint32_t fd;
+} S390ConfigState;
+
+typedef struct S390ConfigClass {
+    /*< private >*/
+    SysBusDeviceClass parent_class;
+    /*< public >*/
+    int (*set_name)(S390ConfigState *config, char *name);
+} S390ConfigClass;
+
+#ifdef CONFIG_KVM
+void s390_config_dev_init(void);
+S390ConfigState *get_config_state(void);
+#define S390_MACHINE_NAME_SIZE sizeof(struct kvm_s390_attr_name)
+#else
+static inline void s390_config_dev_init(void) { }
+static inline S390ConfigState *get_config_state(void)
+{
+    return NULL;
+}
+#define S390_MACHINE_NAME_SIZE 128
+#endif
+
+#endif /* __KVM_S390_CONFIG_H */
diff --git a/linux-headers/asm-s390/kvm.h b/linux-headers/asm-s390/kvm.h
index cb4c1eb..432ffa5 100644
--- a/linux-headers/asm-s390/kvm.h
+++ b/linux-headers/asm-s390/kvm.h
@@ -57,6 +57,17 @@ struct kvm_debug_exit_arch {
 struct kvm_guest_debug_arch {
 };
 
+
+
+/* config device specific GROUPS */
+
+#define KVM_DEV_CONFIG_GROUP           0
+#define KVM_DEV_CONFIG_NAME            0
+
+struct kvm_s390_attr_name {
+       char name[128];
+};
+
 #define KVM_SYNC_PREFIX (1UL << 0)
 #define KVM_SYNC_GPRS   (1UL << 1)
 #define KVM_SYNC_ACRS   (1UL << 2)
diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index e27a4b3..59d1ec3 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -921,6 +921,7 @@ struct kvm_device_attr {
 #define   KVM_DEV_VFIO_GROUP_DEL                       2
 #define KVM_DEV_TYPE_ARM_VGIC_V2       5
 #define KVM_DEV_TYPE_FLIC              6
+#define KVM_DEV_TYPE_S390_CONFIG       7
 
 /*
  * ioctls for VM fds
diff --git a/trace-events b/trace-events
index 3df3f32..6ccd619 100644
--- a/trace-events
+++ b/trace-events
@@ -1185,6 +1185,10 @@ css_adapter_interrupt(uint8_t isc) "CSS: adapter I/O 
interrupt (isc %x)"
 virtio_ccw_interpret_ccw(int cssid, int ssid, int schid, int cmd_code) 
"VIRTIO-CCW: %x.%x.%04x: interpret command %x"
 virtio_ccw_new_device(int cssid, int ssid, int schid, int devno, const char 
*devno_mode) "VIRTIO-CCW: add subchannel %x.%x.%04x, devno %04x (%s)"
 
+# hw/s390x/config.c
+config_no_device_api(int err) "config_dev: no Device Control API support %d"
+config_create_device(int err) "config_dev: create device failed %d"
+
 # hw/intc/s390_flic.c
 flic_create_device(int err) "flic: create device failed %d"
 flic_no_device_api(int err) "flic: no Device Contral API support %d"
-- 
1.8.4.2