[v2,03/18] xen: introduce 'xen-block', 'xen-disk' and 'xen-cdrom'

diff --git a/MAINTAINERS b/MAINTAINERS
index 63effdc..dd728c3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -403,7 +403,7 @@  F: hw/9pfs/xen-9p-backend.c
 F: hw/char/xen_console.c
 F: hw/display/xenfb.c
 F: hw/net/xen_nic.c
-F: hw/block/xen_*
+F: hw/block/xen*
 F: hw/xen/
 F: hw/xenpv/
 F: hw/i386/xen/
diff --git a/hw/block/Makefile.objs b/hw/block/Makefile.objs
index 53ce575..f34813a 100644
--- a/hw/block/Makefile.objs
+++ b/hw/block/Makefile.objs
@@ -4,6 +4,7 @@  common-obj-$(CONFIG_SSI_M25P80) += m25p80.o
 common-obj-$(CONFIG_NAND) += nand.o
 common-obj-$(CONFIG_PFLASH_CFI01) += pflash_cfi01.o
 common-obj-$(CONFIG_PFLASH_CFI02) += pflash_cfi02.o
+common-obj-$(CONFIG_XEN) += xen-block.o
 common-obj-$(CONFIG_XEN) += xen_disk.o
 common-obj-$(CONFIG_ECC) += ecc.o
 common-obj-$(CONFIG_ONENAND) += onenand.o
diff --git a/hw/block/trace-events b/hw/block/trace-events
index 335c092..4afbd62 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -127,3 +127,11 @@  xen_disk_init(char *name) "%s"
 xen_disk_connect(char *name) "%s"
 xen_disk_disconnect(char *name) "%s"
 xen_disk_free(char *name) "%s"
+
+# hw/block/xen-block.c
+xen_block_realize(const char *type, uint32_t disk, uint32_t partition) "%s d%up%u"
+xen_block_unrealize(const char *type, uint32_t disk, uint32_t partition) "%s d%up%u"
+xen_disk_realize(void) ""
+xen_disk_unrealize(void) ""
+xen_cdrom_realize(void) ""
+xen_cdrom_unrealize(void) ""
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
new file mode 100644
index 0000000..78f4218
--- /dev/null
+++ b/hw/block/xen-block.c
@@ -0,0 +1,347 @@ 
+/*
+ * Copyright (c) 2018  Citrix Systems Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/cutils.h"
+#include "qapi/error.h"
+#include "qapi/visitor.h"
+#include "hw/hw.h"
+#include "hw/xen/xen-block.h"
+#include "trace.h"
+
+static void xen_block_unrealize(XenDevice *xendev, Error **errp)
+{
+    XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
+    XenBlockDeviceClass *blockdev_class =
+        XEN_BLOCK_DEVICE_GET_CLASS(xendev);
+    const char *type = object_get_typename(OBJECT(blockdev));
+    XenBlockVdev *vdev = &blockdev->vdev;
+    Error *local_err = NULL;
+
+    if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
+        return;
+    }
+
+    trace_xen_block_unrealize(type, vdev->disk, vdev->partition);
+
+    if (blockdev_class->unrealize) {
+        blockdev_class->unrealize(blockdev, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+        }
+    }
+}
+
+static void xen_block_realize(XenDevice *xendev, Error **errp)
+{
+    XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
+    XenBlockDeviceClass *blockdev_class =
+        XEN_BLOCK_DEVICE_GET_CLASS(xendev);
+    const char *type = object_get_typename(OBJECT(blockdev));
+    XenBlockVdev *vdev = &blockdev->vdev;
+    Error *local_err = NULL;
+
+    if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
+        error_setg(errp, "vdev property not set");
+        return;
+    }
+
+    trace_xen_block_realize(type, vdev->disk, vdev->partition);
+
+    if (blockdev_class->realize) {
+        blockdev_class->realize(blockdev, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+        }
+    }
+}
+
+static char *disk_to_vbd_name(unsigned int disk)
+{
+    char *name, *prefix = (disk >= 26) ?
+        disk_to_vbd_name((disk / 26) - 1) : g_strdup("");
+
+    name = g_strdup_printf("%s%c", prefix, 'a' + disk);
+    g_free(prefix);
+
+    return name;
+}
+
+static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name,
+                               void *opaque, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    Property *prop = opaque;
+    XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
+    char *str;
+
+    switch (vdev->type) {
+    case XEN_BLOCK_VDEV_TYPE_DP:
+        str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition);
+        break;
+
+    case XEN_BLOCK_VDEV_TYPE_XVD:
+    case XEN_BLOCK_VDEV_TYPE_HD:
+    case XEN_BLOCK_VDEV_TYPE_SD: {
+        char *name = disk_to_vbd_name(vdev->disk);
+
+        str = g_strdup_printf("%s%s%lu",
+                              (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ?
+                              "xvd" :
+                              (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ?
+                              "hd" :
+                              "sd",
+                              name, vdev->partition);
+        g_free(name);
+        break;
+    }
+    default:
+        error_setg(errp, "invalid vdev type");
+        return;
+    }
+
+    visit_type_str(v, name, &str, errp);
+    g_free(str);
+}
+
+static unsigned int vbd_name_to_disk(const char *name, const char **endp)
+{
+    unsigned int disk = 0;
+
+    while (*name != '\0') {
+        if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) {
+            break;
+        }
+
+        disk *= 26;
+        disk += *name++ - 'a';
+    }
+    *endp = name;
+
+    return disk;
+}
+
+static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
+                               void *opaque, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    Property *prop = opaque;
+    XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
+    Error *local_err = NULL;
+    char *str, *p;
+    const char *end;
+
+    if (dev->realized) {
+        qdev_prop_set_after_realize(dev, name, errp);
+        return;
+    }
+
+    visit_type_str(v, name, &str, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    p = strchr(str, 'd');
+    if (!p) {
+        goto invalid;
+    }
+
+    *p++ = '\0';
+    if (*str == '\0') {
+        vdev->type = XEN_BLOCK_VDEV_TYPE_DP;
+    } else if (strcmp(str, "xv") == 0) {
+        vdev->type = XEN_BLOCK_VDEV_TYPE_XVD;
+    } else if (strcmp(str, "h") == 0) {
+        vdev->type = XEN_BLOCK_VDEV_TYPE_HD;
+    } else if (strcmp(str, "s") == 0) {
+        vdev->type = XEN_BLOCK_VDEV_TYPE_SD;
+    } else {
+        goto invalid;
+    }
+
+    if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) {
+        if (qemu_strtoul(p, &end, 10, &vdev->disk)) {
+            goto invalid;
+        }
+
+        if (*end == 'p') {
+            p = (char *) ++end;
+            if (*end == '\0') {
+                goto invalid;
+            }
+        }
+    } else {
+        vdev->disk = vbd_name_to_disk(p, &end);
+    }
+
+    if (*end != '\0') {
+        p = (char *)end;
+
+        if (qemu_strtoul(p, &end, 10, &vdev->partition)) {
+            goto invalid;
+        }
+
+        if (*end != '\0') {
+            goto invalid;
+        }
+    } else {
+        vdev->partition = 0;
+    }
+
+    switch (vdev->type) {
+    case XEN_BLOCK_VDEV_TYPE_DP:
+    case XEN_BLOCK_VDEV_TYPE_XVD:
+        if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
+            vdev->number = (202 << 8) | (vdev->disk << 4) |
+                vdev->partition;
+        } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) {
+            vdev->number = (1 << 28) | (vdev->disk << 8) |
+                vdev->partition;
+        } else {
+            goto invalid;
+        }
+        break;
+
+    case XEN_BLOCK_VDEV_TYPE_HD:
+        if ((vdev->disk == 0 || vdev->disk == 1) &&
+            vdev->partition < (1 << 6)) {
+            vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition;
+        } else if ((vdev->disk == 2 || vdev->disk == 3) &&
+                   vdev->partition < (1 << 6)) {
+            vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) |
+                vdev->partition;
+        } else {
+            goto invalid;
+        }
+        break;
+
+    case XEN_BLOCK_VDEV_TYPE_SD:
+        if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
+            vdev->number = (8 << 8) | (vdev->disk << 4) | vdev->partition;
+        } else {
+            goto invalid;
+        }
+        break;
+
+    default:
+        goto invalid;
+    }
+
+    g_free(str);
+    return;
+
+invalid:
+    error_setg(errp, "invalid virtual disk specifier");
+
+    vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID;
+    g_free(str);
+}
+
+/*
+ * This property deals with 'vdev' names adhering to the Xen VBD naming
+ * scheme described in:
+ *
+ * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html
+ */
+const PropertyInfo xen_block_prop_vdev = {
+    .name  = "str",
+    .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*",
+    .get = xen_block_get_vdev,
+    .set = xen_block_set_vdev,
+};
+
+static Property xen_block_props[] = {
+    DEFINE_PROP("vdev", XenBlockDevice, vdev,
+                xen_block_prop_vdev, XenBlockVdev),
+    DEFINE_PROP_END_OF_LIST()
+};
+
+static void xen_block_class_init(ObjectClass *class, void *data)
+{
+    DeviceClass *dev_class = DEVICE_CLASS(class);
+    XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
+
+    xendev_class->realize = xen_block_realize;
+    xendev_class->unrealize = xen_block_unrealize;
+
+    dev_class->props = xen_block_props;
+}
+
+static const TypeInfo xen_block_type_info = {
+    .name = TYPE_XEN_BLOCK_DEVICE,
+    .parent = TYPE_XEN_DEVICE,
+    .instance_size = sizeof(XenBlockDevice),
+    .abstract = true,
+    .class_size = sizeof(XenBlockDeviceClass),
+    .class_init = xen_block_class_init,
+};
+
+static void xen_disk_unrealize(XenBlockDevice *blockdev, Error **errp)
+{
+    trace_xen_disk_unrealize();
+}
+
+static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp)
+{
+    trace_xen_disk_realize();
+}
+
+static void xen_disk_class_init(ObjectClass *class, void *data)
+{
+    DeviceClass *dev_class = DEVICE_CLASS(class);
+    XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
+
+    blockdev_class->realize = xen_disk_realize;
+    blockdev_class->unrealize = xen_disk_unrealize;
+
+    dev_class->desc = "Xen Disk Device";
+}
+
+static const TypeInfo xen_disk_type_info = {
+    .name = TYPE_XEN_DISK_DEVICE,
+    .parent = TYPE_XEN_BLOCK_DEVICE,
+    .instance_size = sizeof(XenDiskDevice),
+    .class_init = xen_disk_class_init,
+};
+
+static void xen_cdrom_unrealize(XenBlockDevice *blockdev, Error **errp)
+{
+    trace_xen_cdrom_unrealize();
+}
+
+static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp)
+{
+    trace_xen_cdrom_realize();
+}
+
+static void xen_cdrom_class_init(ObjectClass *class, void *data)
+{
+    DeviceClass *dev_class = DEVICE_CLASS(class);
+    XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
+
+    blockdev_class->realize = xen_cdrom_realize;
+    blockdev_class->unrealize = xen_cdrom_unrealize;
+
+    dev_class->desc = "Xen CD-ROM Device";
+}
+
+static const TypeInfo xen_cdrom_type_info = {
+    .name = TYPE_XEN_CDROM_DEVICE,
+    .parent = TYPE_XEN_BLOCK_DEVICE,
+    .instance_size = sizeof(XenCDRomDevice),
+    .class_init = xen_cdrom_class_init,
+};
+
+static void xen_block_register_types(void)
+{
+    type_register_static(&xen_block_type_info);
+    type_register_static(&xen_disk_type_info);
+    type_register_static(&xen_cdrom_type_info);
+}
+
+type_init(xen_block_register_types)
diff --git a/include/hw/xen/xen-block.h b/include/hw/xen/xen-block.h
new file mode 100644
index 0000000..067932a
--- /dev/null
+++ b/include/hw/xen/xen-block.h
@@ -0,0 +1,69 @@ 
+/*
+ * Copyright (c) 2018  Citrix Systems Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_XEN_BLOCK_H
+#define HW_XEN_BLOCK_H
+
+#include "hw/xen/xen-bus.h"
+
+typedef enum XenBlockVdevType {
+    XEN_BLOCK_VDEV_TYPE_INVALID,
+    XEN_BLOCK_VDEV_TYPE_DP,
+    XEN_BLOCK_VDEV_TYPE_XVD,
+    XEN_BLOCK_VDEV_TYPE_HD,
+    XEN_BLOCK_VDEV_TYPE_SD,
+    XEN_BLOCK_VDEV_TYPE__MAX
+} XenBlockVdevType;
+
+typedef struct XenBlockVdev {
+    XenBlockVdevType type;
+    unsigned long disk;
+    unsigned long partition;
+    unsigned long number;
+} XenBlockVdev;
+
+typedef struct XenBlockDevice {
+    XenDevice xendev;
+    XenBlockVdev vdev;
+} XenBlockDevice;
+
+typedef void (*XenBlockDeviceRealize)(XenBlockDevice *blockdev, Error **errp);
+typedef void (*XenBlockDeviceUnrealize)(XenBlockDevice *blockdev, Error **errp);
+
+typedef struct XenBlockDeviceClass {
+    /*< private >*/
+    XenDeviceClass parent_class;
+    /*< public >*/
+    XenBlockDeviceRealize realize;
+    XenBlockDeviceUnrealize unrealize;
+} XenBlockDeviceClass;
+
+#define TYPE_XEN_BLOCK_DEVICE  "xen-block"
+#define XEN_BLOCK_DEVICE(obj) \
+     OBJECT_CHECK(XenBlockDevice, (obj), TYPE_XEN_BLOCK_DEVICE)
+#define XEN_BLOCK_DEVICE_CLASS(class) \
+     OBJECT_CLASS_CHECK(XenBlockDeviceClass, (class), TYPE_XEN_BLOCK_DEVICE)
+#define XEN_BLOCK_DEVICE_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(XenBlockDeviceClass, (obj), TYPE_XEN_BLOCK_DEVICE)
+
+typedef struct XenDiskDevice {
+    XenBlockDevice blockdev;
+} XenDiskDevice;
+
+#define TYPE_XEN_DISK_DEVICE  "xen-disk"
+#define XEN_DISK_DEVICE(obj) \
+     OBJECT_CHECK(XenDiskDevice, (obj), TYPE_XEN_DISK_DEVICE)
+
+typedef struct XenCDRomDevice {
+    XenBlockDevice blockdev;
+} XenCDRomDevice;
+
+#define TYPE_XEN_CDROM_DEVICE  "xen-cdrom"
+#define XEN_CDROM_DEVICE(obj) \
+     OBJECT_CHECK(XenCDRomDevice, (obj), TYPE_XEN_CDROM_DEVICE)
+
+#endif /* HW_XEN_BLOCK_H */