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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 03/18] xen: introduce 'xen-qdisk'
This patch adds a new XenDevice: 'xen-qdisk' [1]. This will eventually
replace the 'xen_disk' legacy PV backend but it is illustrative to build
up the implementation incrementally, along with the XenBus/XenDevice
framework. Subsequent patches will therefore add to this device's
implementation as new features are added to the framework.
After this patch has been applied it is possible to instantiate a new
'xen-qdisk' device with a single 'vdev' parameter, which accepts values
adhering to the Xen VBD naming scheme [2]. For example, a command-line
instantiation of a xen-qdisk can be done with an argument similar to the
following:
-device xen-qdisk,vdev=hda
The implementation of the vdev parameter formulates the appropriate VBD
number for use in the PV protocol.
[1] The name 'qdisk' as always been the name given to the QEMU
implementation of the Xen PV block protocol backend implementation
[2]
http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/man/xen-vbd-interface.markdown.7
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
---
Cc: Kevin Wolf <kwolf@xxxxxxxxxx>
Cc: Max Reitz <mreitz@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Anthony Perard <anthony.perard@xxxxxxxxxx>
---
MAINTAINERS | 2 +-
hw/block/Makefile.objs | 1 +
hw/block/trace-events | 4 +
hw/block/xen-qdisk.c | 256 +++++++++++++++++++++++++++++++++++++++++++++
include/hw/xen/xen-qdisk.h | 38 +++++++
5 files changed, 300 insertions(+), 1 deletion(-)
create mode 100644 hw/block/xen-qdisk.c
create mode 100644 include/hw/xen/xen-qdisk.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 1032406c56..10f048a503 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -389,7 +389,7 @@ 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 53ce5751ae..bcdd36d318 100644
--- a/hw/block/Makefile.objs
+++ b/hw/block/Makefile.objs
@@ -5,6 +5,7 @@ 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_disk.o
+common-obj-$(CONFIG_XEN) += xen-qdisk.o
common-obj-$(CONFIG_ECC) += ecc.o
common-obj-$(CONFIG_ONENAND) += onenand.o
common-obj-$(CONFIG_NVME_PCI) += nvme.o
diff --git a/hw/block/trace-events b/hw/block/trace-events
index 335c092450..fd3c126ac1 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -127,3 +127,7 @@ 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-qdisk.c
+xen_qdisk_realize(uint32_t disk, uint32_t partition) "d%up%u"
+xen_qdisk_unrealize(uint32_t disk, uint32_t partition) "d%up%u"
diff --git a/hw/block/xen-qdisk.c b/hw/block/xen-qdisk.c
new file mode 100644
index 0000000000..72122073f7
--- /dev/null
+++ b/hw/block/xen-qdisk.c
@@ -0,0 +1,256 @@
+/*
+ * Copyright (c) Citrix Systems Inc.
+ * All rights reserved.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/cutils.h"
+#include "qapi/error.h"
+#include "qapi/visitor.h"
+#include "hw/hw.h"
+#include "hw/xen/xen-qdisk.h"
+#include "trace.h"
+
+static void xen_qdisk_realize(XenDevice *xendev, Error **errp)
+{
+ XenQdiskDevice *qdiskdev = XEN_QDISK_DEVICE(xendev);
+ XenQdiskVdev *vdev = &qdiskdev->vdev;
+
+ if (!vdev->valid) {
+ error_setg(errp, "vdev property not set");
+ return;
+ }
+
+ trace_xen_qdisk_realize(vdev->disk, vdev->partition);
+}
+
+static void xen_qdisk_unrealize(XenDevice *xendev, Error **errp)
+{
+ XenQdiskDevice *qdiskdev = XEN_QDISK_DEVICE(xendev);
+ XenQdiskVdev *vdev = &qdiskdev->vdev;
+
+ trace_xen_qdisk_unrealize(vdev->disk, vdev->partition);
+}
+
+static char *disk_to_vbd_name(unsigned int disk)
+{
+ unsigned int len = DIV_ROUND_UP(disk, 26);
+ char *name = g_malloc0(len + 1);
+
+ do {
+ name[len--] = 'a' + (disk % 26);
+ disk /= 26;
+ } while (disk != 0);
+ assert(len == 0);
+
+ return name;
+}
+
+static void xen_qdisk_get_vdev(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ DeviceState *dev = DEVICE(obj);
+ Property *prop = opaque;
+ XenQdiskVdev *vdev = qdev_get_prop_ptr(dev, prop);
+ char *str;
+
+ switch (vdev->type) {
+ case XEN_QDISK_VDEV_TYPE_DP:
+ str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition);
+ break;
+
+ case XEN_QDISK_VDEV_TYPE_XVD:
+ case XEN_QDISK_VDEV_TYPE_HD:
+ case XEN_QDISK_VDEV_TYPE_SD: {
+ char *name = disk_to_vbd_name(vdev->disk);
+
+ str = g_strdup_printf("%s%s%lu",
+ (vdev->type == XEN_QDISK_VDEV_TYPE_XVD) ?
+ "xvd" :
+ (vdev->type == XEN_QDISK_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_qdisk_set_vdev(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ DeviceState *dev = DEVICE(obj);
+ Property *prop = opaque;
+ XenQdiskVdev *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_QDISK_VDEV_TYPE_DP;
+ } else if (strcmp(str, "xv") == 0) {
+ vdev->type = XEN_QDISK_VDEV_TYPE_XVD;
+ } else if (strcmp(str, "h") == 0) {
+ vdev->type = XEN_QDISK_VDEV_TYPE_HD;
+ } else if (strcmp(str, "s") == 0) {
+ vdev->type = XEN_QDISK_VDEV_TYPE_SD;
+ } else {
+ goto invalid;
+ }
+
+ if (vdev->type == XEN_QDISK_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_QDISK_VDEV_TYPE_DP:
+ case XEN_QDISK_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_QDISK_VDEV_TYPE_HD:
+ if ((vdev->disk == 0 || vdev->disk == 1) &&
+ vdev->partition < (1 << 4)) {
+ vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition;
+ } else if ((vdev->disk == 2 || vdev->disk == 3) &&
+ vdev->partition < (1 << 4)) {
+ vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) |
+ vdev->partition;
+ } else {
+ goto invalid;
+ }
+ break;
+
+ case XEN_QDISK_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);
+ vdev->valid = true;
+ return;
+
+invalid:
+ error_setg(errp, "invalid virtual disk specifier");
+ g_free(str);
+}
+
+const PropertyInfo xen_qdisk_prop_vdev = {
+ .name = "str",
+ .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*",
+ .get = xen_qdisk_get_vdev,
+ .set = xen_qdisk_set_vdev,
+};
+
+static Property xen_qdisk_props[] = {
+ DEFINE_PROP("vdev", XenQdiskDevice, vdev,
+ xen_qdisk_prop_vdev, XenQdiskVdev),
+ DEFINE_PROP_END_OF_LIST()
+};
+
+static void xen_qdisk_class_init(ObjectClass *class, void *data)
+{
+ DeviceClass *dev_class = DEVICE_CLASS(class);
+ XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
+
+ xendev_class->realize = xen_qdisk_realize;
+ xendev_class->unrealize = xen_qdisk_unrealize;
+
+ dev_class->desc = "Xen Qdisk Device";
+ dev_class->props = xen_qdisk_props;
+}
+
+static const TypeInfo xen_qdisk_type_info = {
+ .name = TYPE_XEN_QDISK_DEVICE,
+ .parent = TYPE_XEN_DEVICE,
+ .instance_size = sizeof(XenQdiskDevice),
+ .class_init = xen_qdisk_class_init,
+};
+
+static void xen_qdisk_register_types(void)
+{
+ type_register_static(&xen_qdisk_type_info);
+}
+
+type_init(xen_qdisk_register_types)
diff --git a/include/hw/xen/xen-qdisk.h b/include/hw/xen/xen-qdisk.h
new file mode 100644
index 0000000000..ade0866037
--- /dev/null
+++ b/include/hw/xen/xen-qdisk.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) Citrix Systems Inc.
+ * All rights reserved.
+ */
+
+#ifndef HW_XEN_QDISK_H
+#define HW_XEN_QDISK_H
+
+#include "hw/xen/xen-bus.h"
+
+typedef enum XenQdiskVdevType {
+ XEN_QDISK_VDEV_TYPE_DP,
+ XEN_QDISK_VDEV_TYPE_XVD,
+ XEN_QDISK_VDEV_TYPE_HD,
+ XEN_QDISK_VDEV_TYPE_SD,
+ XEN_QDISK_VDEV_TYPE__MAX
+} XenQdiskVdevType;
+
+typedef struct XenQdiskVdev {
+ XenQdiskVdevType type;
+ unsigned long disk;
+ unsigned long partition;
+ unsigned long number;
+ bool valid;
+} XenQdiskVdev;
+
+#define TYPE_XEN_QDISK_DEVICE "xen-qdisk"
+#define XEN_QDISK_DEVICE(obj) \
+ OBJECT_CHECK(XenQdiskDevice, (obj), TYPE_XEN_QDISK_DEVICE)
+
+typedef struct XenQdiskDevice XenQdiskDevice;
+
+struct XenQdiskDevice {
+ XenDevice xendev;
+ XenQdiskVdev vdev;
+};
+
+#endif /* HW_XEN_QDISK_H */
--
2.11.0
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