diff options
Diffstat (limited to 'drivers/xen/xenfs')
-rw-r--r-- | drivers/xen/xenfs/Makefile | 6 | ||||
-rw-r--r-- | drivers/xen/xenfs/super.c | 111 | ||||
-rw-r--r-- | drivers/xen/xenfs/xenfs.h | 9 | ||||
-rw-r--r-- | drivers/xen/xenfs/xenstored.c | 69 | ||||
-rw-r--r-- | drivers/xen/xenfs/xensyms.c | 152 |
5 files changed, 347 insertions, 0 deletions
diff --git a/drivers/xen/xenfs/Makefile b/drivers/xen/xenfs/Makefile new file mode 100644 index 000000000..8490644df --- /dev/null +++ b/drivers/xen/xenfs/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_XENFS) += xenfs.o + +xenfs-y = super.o +xenfs-$(CONFIG_XEN_DOM0) += xenstored.o +xenfs-$(CONFIG_XEN_SYMS) += xensyms.o diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c new file mode 100644 index 000000000..d7d642350 --- /dev/null +++ b/drivers/xen/xenfs/super.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * xenfs.c - a filesystem for passing info between the a domain and + * the hypervisor. + * + * 2008-10-07 Alex Zeffertt Replaced /proc/xen/xenbus with xenfs filesystem + * and /proc/xen compatibility mount point. + * Turned xenfs into a loadable module. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/fs_context.h> +#include <linux/magic.h> + +#include <xen/xen.h> +#include <xen/xenbus.h> + +#include "xenfs.h" +#include "../privcmd.h" + +#include <asm/xen/hypervisor.h> + +MODULE_DESCRIPTION("Xen filesystem"); +MODULE_LICENSE("GPL"); + +static ssize_t capabilities_read(struct file *file, char __user *buf, + size_t size, loff_t *off) +{ + char *tmp = ""; + + if (xen_initial_domain()) + tmp = "control_d\n"; + + return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp)); +} + +static const struct file_operations capabilities_file_ops = { + .read = capabilities_read, + .llseek = default_llseek, +}; + +static int xenfs_fill_super(struct super_block *sb, struct fs_context *fc) +{ + static const struct tree_descr xenfs_files[] = { + [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR }, + { "capabilities", &capabilities_file_ops, S_IRUGO }, + { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR }, + {""}, + }; + + static const struct tree_descr xenfs_init_files[] = { + [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR }, + { "capabilities", &capabilities_file_ops, S_IRUGO }, + { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR }, + { "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR}, + { "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR}, +#ifdef CONFIG_XEN_SYMS + { "xensyms", &xensyms_ops, S_IRUSR}, +#endif + {""}, + }; + + return simple_fill_super(sb, XENFS_SUPER_MAGIC, + xen_initial_domain() ? xenfs_init_files : xenfs_files); +} + +static int xenfs_get_tree(struct fs_context *fc) +{ + return get_tree_single(fc, xenfs_fill_super); +} + +static const struct fs_context_operations xenfs_context_ops = { + .get_tree = xenfs_get_tree, +}; + +static int xenfs_init_fs_context(struct fs_context *fc) +{ + fc->ops = &xenfs_context_ops; + return 0; +} + +static struct file_system_type xenfs_type = { + .owner = THIS_MODULE, + .name = "xenfs", + .init_fs_context = xenfs_init_fs_context, + .kill_sb = kill_litter_super, +}; +MODULE_ALIAS_FS("xenfs"); + +static int __init xenfs_init(void) +{ + if (xen_domain()) + return register_filesystem(&xenfs_type); + + return 0; +} + +static void __exit xenfs_exit(void) +{ + if (xen_domain()) + unregister_filesystem(&xenfs_type); +} + +module_init(xenfs_init); +module_exit(xenfs_exit); + diff --git a/drivers/xen/xenfs/xenfs.h b/drivers/xen/xenfs/xenfs.h new file mode 100644 index 000000000..cfe4874b8 --- /dev/null +++ b/drivers/xen/xenfs/xenfs.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _XENFS_XENBUS_H +#define _XENFS_XENBUS_H + +extern const struct file_operations xsd_kva_file_ops; +extern const struct file_operations xsd_port_file_ops; +extern const struct file_operations xensyms_ops; + +#endif /* _XENFS_XENBUS_H */ diff --git a/drivers/xen/xenfs/xenstored.c b/drivers/xen/xenfs/xenstored.c new file mode 100644 index 000000000..f59235f9f --- /dev/null +++ b/drivers/xen/xenfs/xenstored.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/fs.h> + +#include <xen/page.h> +#include <xen/xenbus.h> + +#include "xenfs.h" + +static ssize_t xsd_read(struct file *file, char __user *buf, + size_t size, loff_t *off) +{ + const char *str = (const char *)file->private_data; + return simple_read_from_buffer(buf, size, off, str, strlen(str)); +} + +static int xsd_release(struct inode *inode, struct file *file) +{ + kfree(file->private_data); + return 0; +} + +static int xsd_kva_open(struct inode *inode, struct file *file) +{ + file->private_data = (void *)kasprintf(GFP_KERNEL, "0x%p", + xen_store_interface); + if (!file->private_data) + return -ENOMEM; + return 0; +} + +static int xsd_kva_mmap(struct file *file, struct vm_area_struct *vma) +{ + size_t size = vma->vm_end - vma->vm_start; + + if ((size > PAGE_SIZE) || (vma->vm_pgoff != 0)) + return -EINVAL; + + if (remap_pfn_range(vma, vma->vm_start, + virt_to_pfn(xen_store_interface), + size, vma->vm_page_prot)) + return -EAGAIN; + + return 0; +} + +const struct file_operations xsd_kva_file_ops = { + .open = xsd_kva_open, + .mmap = xsd_kva_mmap, + .read = xsd_read, + .release = xsd_release, +}; + +static int xsd_port_open(struct inode *inode, struct file *file) +{ + file->private_data = (void *)kasprintf(GFP_KERNEL, "%d", + xen_store_evtchn); + if (!file->private_data) + return -ENOMEM; + return 0; +} + +const struct file_operations xsd_port_file_ops = { + .open = xsd_port_open, + .read = xsd_read, + .release = xsd_release, +}; diff --git a/drivers/xen/xenfs/xensyms.c b/drivers/xen/xenfs/xensyms.c new file mode 100644 index 000000000..c6c73a33c --- /dev/null +++ b/drivers/xen/xenfs/xensyms.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/init.h> +#include <linux/seq_file.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/proc_fs.h> +#include <linux/slab.h> +#include <xen/interface/platform.h> +#include <asm/xen/hypercall.h> +#include <xen/xen-ops.h> +#include "xenfs.h" + + +#define XEN_KSYM_NAME_LEN 127 /* Hypervisor may have different name length */ + +struct xensyms { + struct xen_platform_op op; + char *name; + uint32_t namelen; +}; + +/* Grab next output page from the hypervisor */ +static int xensyms_next_sym(struct xensyms *xs) +{ + int ret; + struct xenpf_symdata *symdata = &xs->op.u.symdata; + uint64_t symnum; + + memset(xs->name, 0, xs->namelen); + symdata->namelen = xs->namelen; + + symnum = symdata->symnum; + + ret = HYPERVISOR_platform_op(&xs->op); + if (ret < 0) + return ret; + + /* + * If hypervisor's symbol didn't fit into the buffer then allocate + * a larger buffer and try again. + */ + if (unlikely(symdata->namelen > xs->namelen)) { + kfree(xs->name); + + xs->namelen = symdata->namelen; + xs->name = kzalloc(xs->namelen, GFP_KERNEL); + if (!xs->name) + return -ENOMEM; + + set_xen_guest_handle(symdata->name, xs->name); + symdata->symnum--; /* Rewind */ + + ret = HYPERVISOR_platform_op(&xs->op); + if (ret < 0) + return ret; + } + + if (symdata->symnum == symnum) + /* End of symbols */ + return 1; + + return 0; +} + +static void *xensyms_start(struct seq_file *m, loff_t *pos) +{ + struct xensyms *xs = (struct xensyms *)m->private; + + xs->op.u.symdata.symnum = *pos; + + if (xensyms_next_sym(xs)) + return NULL; + + return m->private; +} + +static void *xensyms_next(struct seq_file *m, void *p, loff_t *pos) +{ + struct xensyms *xs = (struct xensyms *)m->private; + + xs->op.u.symdata.symnum = ++(*pos); + + if (xensyms_next_sym(xs)) + return NULL; + + return p; +} + +static int xensyms_show(struct seq_file *m, void *p) +{ + struct xensyms *xs = (struct xensyms *)m->private; + struct xenpf_symdata *symdata = &xs->op.u.symdata; + + seq_printf(m, "%016llx %c %s\n", symdata->address, + symdata->type, xs->name); + + return 0; +} + +static void xensyms_stop(struct seq_file *m, void *p) +{ +} + +static const struct seq_operations xensyms_seq_ops = { + .start = xensyms_start, + .next = xensyms_next, + .show = xensyms_show, + .stop = xensyms_stop, +}; + +static int xensyms_open(struct inode *inode, struct file *file) +{ + struct seq_file *m; + struct xensyms *xs; + int ret; + + ret = seq_open_private(file, &xensyms_seq_ops, + sizeof(struct xensyms)); + if (ret) + return ret; + + m = file->private_data; + xs = (struct xensyms *)m->private; + + xs->namelen = XEN_KSYM_NAME_LEN + 1; + xs->name = kzalloc(xs->namelen, GFP_KERNEL); + if (!xs->name) { + seq_release_private(inode, file); + return -ENOMEM; + } + set_xen_guest_handle(xs->op.u.symdata.name, xs->name); + xs->op.cmd = XENPF_get_symbol; + xs->op.u.symdata.namelen = xs->namelen; + + return 0; +} + +static int xensyms_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = file->private_data; + struct xensyms *xs = (struct xensyms *)m->private; + + kfree(xs->name); + return seq_release_private(inode, file); +} + +const struct file_operations xensyms_ops = { + .open = xensyms_open, + .read = seq_read, + .llseek = seq_lseek, + .release = xensyms_release +}; |