xen: add /sys/hypervisor support

Adds support for Xen info under /sys/hypervisor.  Taken from Novell 2.6.27
backport tree.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

3 files changed, 487 insertions, 1 deletions

diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 526187c8a12..88bca1c42db 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -41,3 +41,13 @@ config XEN_COMPAT_XENFS
          a xen platform.
          If in doubt, say yes.
 
+config XEN_SYS_HYPERVISOR
+       bool "Create xen entries under /sys/hypervisor"
+       depends on XEN && SYSFS
+       select SYS_HYPERVISOR
+       default y
+       help
+         Create entries under /sys/hypervisor describing the Xen
+         hypervisor environment.  When running native or in another
+         virtual environment, /sys/hypervisor will still be present,
+         but will have no xen contents.
\ No newline at end of file
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index ff8accc9e10..f3603a39db5 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -4,4 +4,5 @@ obj-y	+= xenbus/
 obj-$(CONFIG_HOTPLUG_CPU)       += cpu_hotplug.o
 obj-$(CONFIG_XEN_XENCOMM)       += xencomm.o
 obj-$(CONFIG_XEN_BALLOON)       += balloon.o
-obj-$(CONFIG_XENFS)             += xenfs/
\ No newline at end of file
+obj-$(CONFIG_XENFS)             += xenfs/
+obj-$(CONFIG_XEN_SYS_HYPERVISOR)        += sys-hypervisor.o
diff --git a/drivers/xen/sys-hypervisor.c b/drivers/xen/sys-hypervisor.c
new file mode 100644
index 00000000000..cb29d1ccf0d
--- /dev/null
+++ b/drivers/xen/sys-hypervisor.c
@@ -0,0 +1,475 @@
+/*
+ *  copyright (c) 2006 IBM Corporation
+ *  Authored by: Mike D. Day <ncmike@us.ibm.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+#include <xen/xenbus.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/version.h>
+
+#define HYPERVISOR_ATTR_RO(_name) \
+static struct hyp_sysfs_attr  _name##_attr = __ATTR_RO(_name)
+
+#define HYPERVISOR_ATTR_RW(_name) \
+static struct hyp_sysfs_attr _name##_attr = \
+        __ATTR(_name, 0644, _name##_show, _name##_store)
+
+struct hyp_sysfs_attr {
+        struct attribute attr;
+        ssize_t (*show)(struct hyp_sysfs_attr *, char *);
+        ssize_t (*store)(struct hyp_sysfs_attr *, const char *, size_t);
+        void *hyp_attr_data;
+};
+
+static ssize_t type_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        return sprintf(buffer, "xen\n");
+}
+
+HYPERVISOR_ATTR_RO(type);
+
+static int __init xen_sysfs_type_init(void)
+{
+        return sysfs_create_file(hypervisor_kobj, &type_attr.attr);
+}
+
+static void xen_sysfs_type_destroy(void)
+{
+        sysfs_remove_file(hypervisor_kobj, &type_attr.attr);
+}
+
+/* xen version attributes */
+static ssize_t major_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int version = HYPERVISOR_xen_version(XENVER_version, NULL);
+        if (version)
+                return sprintf(buffer, "%d\n", version >> 16);
+        return -ENODEV;
+}
+
+HYPERVISOR_ATTR_RO(major);
+
+static ssize_t minor_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int version = HYPERVISOR_xen_version(XENVER_version, NULL);
+        if (version)
+                return sprintf(buffer, "%d\n", version & 0xff);
+        return -ENODEV;
+}
+
+HYPERVISOR_ATTR_RO(minor);
+
+static ssize_t extra_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int ret = -ENOMEM;
+        char *extra;
+
+        extra = kmalloc(XEN_EXTRAVERSION_LEN, GFP_KERNEL);
+        if (extra) {
+                ret = HYPERVISOR_xen_version(XENVER_extraversion, extra);
+                if (!ret)
+                        ret = sprintf(buffer, "%s\n", extra);
+                kfree(extra);
+        }
+
+        return ret;
+}
+
+HYPERVISOR_ATTR_RO(extra);
+
+static struct attribute *version_attrs[] = {
+        &major_attr.attr,
+        &minor_attr.attr,
+        &extra_attr.attr,
+        NULL
+};
+
+static struct attribute_group version_group = {
+        .name = "version",
+        .attrs = version_attrs,
+};
+
+static int __init xen_sysfs_version_init(void)
+{
+        return sysfs_create_group(hypervisor_kobj, &version_group);
+}
+
+static void xen_sysfs_version_destroy(void)
+{
+        sysfs_remove_group(hypervisor_kobj, &version_group);
+}
+
+/* UUID */
+
+static ssize_t uuid_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        char *vm, *val;
+        int ret;
+        extern int xenstored_ready;
+
+        if (!xenstored_ready)
+                return -EBUSY;
+
+        vm = xenbus_read(XBT_NIL, "vm", "", NULL);
+        if (IS_ERR(vm))
+                return PTR_ERR(vm);
+        val = xenbus_read(XBT_NIL, vm, "uuid", NULL);
+        kfree(vm);
+        if (IS_ERR(val))
+                return PTR_ERR(val);
+        ret = sprintf(buffer, "%s\n", val);
+        kfree(val);
+        return ret;
+}
+
+HYPERVISOR_ATTR_RO(uuid);
+
+static int __init xen_sysfs_uuid_init(void)
+{
+        return sysfs_create_file(hypervisor_kobj, &uuid_attr.attr);
+}
+
+static void xen_sysfs_uuid_destroy(void)
+{
+        sysfs_remove_file(hypervisor_kobj, &uuid_attr.attr);
+}
+
+/* xen compilation attributes */
+
+static ssize_t compiler_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int ret = -ENOMEM;
+        struct xen_compile_info *info;
+
+        info = kmalloc(sizeof(struct xen_compile_info), GFP_KERNEL);
+        if (info) {
+                ret = HYPERVISOR_xen_version(XENVER_compile_info, info);
+                if (!ret)
+                        ret = sprintf(buffer, "%s\n", info->compiler);
+                kfree(info);
+        }
+
+        return ret;
+}
+
+HYPERVISOR_ATTR_RO(compiler);
+
+static ssize_t compiled_by_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int ret = -ENOMEM;
+        struct xen_compile_info *info;
+
+        info = kmalloc(sizeof(struct xen_compile_info), GFP_KERNEL);
+        if (info) {
+                ret = HYPERVISOR_xen_version(XENVER_compile_info, info);
+                if (!ret)
+                        ret = sprintf(buffer, "%s\n", info->compile_by);
+                kfree(info);
+        }
+
+        return ret;
+}
+
+HYPERVISOR_ATTR_RO(compiled_by);
+
+static ssize_t compile_date_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int ret = -ENOMEM;
+        struct xen_compile_info *info;
+
+        info = kmalloc(sizeof(struct xen_compile_info), GFP_KERNEL);
+        if (info) {
+                ret = HYPERVISOR_xen_version(XENVER_compile_info, info);
+                if (!ret)
+                        ret = sprintf(buffer, "%s\n", info->compile_date);
+                kfree(info);
+        }
+
+        return ret;
+}
+
+HYPERVISOR_ATTR_RO(compile_date);
+
+static struct attribute *xen_compile_attrs[] = {
+        &compiler_attr.attr,
+        &compiled_by_attr.attr,
+        &compile_date_attr.attr,
+        NULL
+};
+
+static struct attribute_group xen_compilation_group = {
+        .name = "compilation",
+        .attrs = xen_compile_attrs,
+};
+
+int __init static xen_compilation_init(void)
+{
+        return sysfs_create_group(hypervisor_kobj, &xen_compilation_group);
+}
+
+static void xen_compilation_destroy(void)
+{
+        sysfs_remove_group(hypervisor_kobj, &xen_compilation_group);
+}
+
+/* xen properties info */
+
+static ssize_t capabilities_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int ret = -ENOMEM;
+        char *caps;
+
+        caps = kmalloc(XEN_CAPABILITIES_INFO_LEN, GFP_KERNEL);
+        if (caps) {
+                ret = HYPERVISOR_xen_version(XENVER_capabilities, caps);
+                if (!ret)
+                        ret = sprintf(buffer, "%s\n", caps);
+                kfree(caps);
+        }
+
+        return ret;
+}
+
+HYPERVISOR_ATTR_RO(capabilities);
+
+static ssize_t changeset_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int ret = -ENOMEM;
+        char *cset;
+
+        cset = kmalloc(XEN_CHANGESET_INFO_LEN, GFP_KERNEL);
+        if (cset) {
+                ret = HYPERVISOR_xen_version(XENVER_changeset, cset);
+                if (!ret)
+                        ret = sprintf(buffer, "%s\n", cset);
+                kfree(cset);
+        }
+
+        return ret;
+}
+
+HYPERVISOR_ATTR_RO(changeset);
+
+static ssize_t virtual_start_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int ret = -ENOMEM;
+        struct xen_platform_parameters *parms;
+
+        parms = kmalloc(sizeof(struct xen_platform_parameters), GFP_KERNEL);
+        if (parms) {
+                ret = HYPERVISOR_xen_version(XENVER_platform_parameters,
+                                             parms);
+                if (!ret)
+                        ret = sprintf(buffer, "%lx\n", parms->virt_start);
+                kfree(parms);
+        }
+
+        return ret;
+}
+
+HYPERVISOR_ATTR_RO(virtual_start);
+
+static ssize_t pagesize_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        int ret;
+
+        ret = HYPERVISOR_xen_version(XENVER_pagesize, NULL);
+        if (ret > 0)
+                ret = sprintf(buffer, "%x\n", ret);
+
+        return ret;
+}
+
+HYPERVISOR_ATTR_RO(pagesize);
+
+/* eventually there will be several more features to export */
+static ssize_t xen_feature_show(int index, char *buffer)
+{
+        int ret = -ENOMEM;
+        struct xen_feature_info *info;
+
+        info = kmalloc(sizeof(struct xen_feature_info), GFP_KERNEL);
+        if (info) {
+                info->submap_idx = index;
+                ret = HYPERVISOR_xen_version(XENVER_get_features, info);
+                if (!ret)
+                        ret = sprintf(buffer, "%d\n", info->submap);
+                kfree(info);
+        }
+
+        return ret;
+}
+
+static ssize_t writable_pt_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+        return xen_feature_show(XENFEAT_writable_page_tables, buffer);
+}
+
+HYPERVISOR_ATTR_RO(writable_pt);
+
+static struct attribute *xen_properties_attrs[] = {
+        &capabilities_attr.attr,
+        &changeset_attr.attr,
+        &virtual_start_attr.attr,
+        &pagesize_attr.attr,
+        &writable_pt_attr.attr,
+        NULL
+};
+
+static struct attribute_group xen_properties_group = {
+        .name = "properties",
+        .attrs = xen_properties_attrs,
+};
+
+static int __init xen_properties_init(void)
+{
+        return sysfs_create_group(hypervisor_kobj, &xen_properties_group);
+}
+
+static void xen_properties_destroy(void)
+{
+        sysfs_remove_group(hypervisor_kobj, &xen_properties_group);
+}
+
+#ifdef CONFIG_KEXEC
+
+extern size_t vmcoreinfo_size_xen;
+extern unsigned long paddr_vmcoreinfo_xen;
+
+static ssize_t vmcoreinfo_show(struct hyp_sysfs_attr *attr, char *page)
+{
+        return sprintf(page, "%lx %zx\n",
+                paddr_vmcoreinfo_xen, vmcoreinfo_size_xen);
+}
+
+HYPERVISOR_ATTR_RO(vmcoreinfo);
+
+static int __init xen_sysfs_vmcoreinfo_init(void)
+{
+        return sysfs_create_file(hypervisor_kobj,
+                                 &vmcoreinfo_attr.attr);
+}
+
+static void xen_sysfs_vmcoreinfo_destroy(void)
+{
+        sysfs_remove_file(hypervisor_kobj, &vmcoreinfo_attr.attr);
+}
+
+#endif
+
+static int __init hyper_sysfs_init(void)
+{
+        int ret;
+
+        if (!xen_domain())
+                return -ENODEV;
+
+        ret = xen_sysfs_type_init();
+        if (ret)
+                goto out;
+        ret = xen_sysfs_version_init();
+        if (ret)
+                goto version_out;
+        ret = xen_compilation_init();
+        if (ret)
+                goto comp_out;
+        ret = xen_sysfs_uuid_init();
+        if (ret)
+                goto uuid_out;
+        ret = xen_properties_init();
+        if (ret)
+                goto prop_out;
+#ifdef CONFIG_KEXEC
+        if (vmcoreinfo_size_xen != 0) {
+                ret = xen_sysfs_vmcoreinfo_init();
+                if (ret)
+                        goto vmcoreinfo_out;
+        }
+#endif
+
+        goto out;
+
+#ifdef CONFIG_KEXEC
+vmcoreinfo_out:
+#endif
+        xen_properties_destroy();
+prop_out:
+        xen_sysfs_uuid_destroy();
+uuid_out:
+        xen_compilation_destroy();
+comp_out:
+        xen_sysfs_version_destroy();
+version_out:
+        xen_sysfs_type_destroy();
+out:
+        return ret;
+}
+
+static void __exit hyper_sysfs_exit(void)
+{
+#ifdef CONFIG_KEXEC
+        if (vmcoreinfo_size_xen != 0)
+                xen_sysfs_vmcoreinfo_destroy();
+#endif
+        xen_properties_destroy();
+        xen_compilation_destroy();
+        xen_sysfs_uuid_destroy();
+        xen_sysfs_version_destroy();
+        xen_sysfs_type_destroy();
+
+}
+module_init(hyper_sysfs_init);
+module_exit(hyper_sysfs_exit);
+
+static ssize_t hyp_sysfs_show(struct kobject *kobj,
+                              struct attribute *attr,
+                              char *buffer)
+{
+        struct hyp_sysfs_attr *hyp_attr;
+        hyp_attr = container_of(attr, struct hyp_sysfs_attr, attr);
+        if (hyp_attr->show)
+                return hyp_attr->show(hyp_attr, buffer);
+        return 0;
+}
+
+static ssize_t hyp_sysfs_store(struct kobject *kobj,
+                               struct attribute *attr,
+                               const char *buffer,
+                               size_t len)
+{
+        struct hyp_sysfs_attr *hyp_attr;
+        hyp_attr = container_of(attr, struct hyp_sysfs_attr, attr);
+        if (hyp_attr->store)
+                return hyp_attr->store(hyp_attr, buffer, len);
+        return 0;
+}
+
+static struct sysfs_ops hyp_sysfs_ops = {
+        .show = hyp_sysfs_show,
+        .store = hyp_sysfs_store,
+};
+
+static struct kobj_type hyp_sysfs_kobj_type = {
+        .sysfs_ops = &hyp_sysfs_ops,
+};
+
+static int __init hypervisor_subsys_init(void)
+{
+        if (!xen_domain())
+                return -ENODEV;
+
+        hypervisor_kobj->ktype = &hyp_sysfs_kobj_type;
+        return 0;
+}
+device_initcall(hypervisor_subsys_init);