diff options
| -rw-r--r-- | drivers/xen/xenfs/Makefile | 2 | ||||
| -rw-r--r-- | drivers/xen/xenfs/privcmd.c | 436 | ||||
| -rw-r--r-- | drivers/xen/xenfs/super.c | 2 | ||||
| -rw-r--r-- | drivers/xen/xenfs/xenfs.h | 1 | ||||
| -rw-r--r-- | include/xen/Kbuild | 1 | ||||
| -rw-r--r-- | include/xen/privcmd.h | 80 |
6 files changed, 521 insertions, 1 deletions
diff --git a/drivers/xen/xenfs/Makefile b/drivers/xen/xenfs/Makefile index 5d45ff13cc01..4a0be9a82af3 100644 --- a/drivers/xen/xenfs/Makefile +++ b/drivers/xen/xenfs/Makefile @@ -1,4 +1,4 @@ obj-$(CONFIG_XENFS) += xenfs.o xenfs-y = super.o xenbus.o -xenfs-$(CONFIG_XEN_DOM0) += xenstored.o +xenfs-$(CONFIG_XEN_DOM0) += xenstored.o privcmd.o diff --git a/drivers/xen/xenfs/privcmd.c b/drivers/xen/xenfs/privcmd.c new file mode 100644 index 000000000000..c7192f314f86 --- /dev/null +++ b/drivers/xen/xenfs/privcmd.c @@ -0,0 +1,436 @@ +/****************************************************************************** + * privcmd.c + * + * Interface to privileged domain-0 commands. + * + * Copyright (c) 2002-2004, K A Fraser, B Dragovic + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/uaccess.h> +#include <linux/swap.h> +#include <linux/smp_lock.h> +#include <linux/highmem.h> +#include <linux/pagemap.h> +#include <linux/seq_file.h> + +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/tlb.h> +#include <asm/xen/hypervisor.h> +#include <asm/xen/hypercall.h> + +#include <xen/xen.h> +#include <xen/privcmd.h> +#include <xen/interface/xen.h> +#include <xen/features.h> +#include <xen/page.h> + +#ifndef HAVE_ARCH_PRIVCMD_MMAP +static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma); +#endif + +struct remap_data { + unsigned long mfn; + unsigned domid; + pgprot_t prot; +}; + +static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token, + unsigned long addr, void *data) +{ + struct remap_data *rmd = data; + pte_t pte = pte_mkspecial(pfn_pte(rmd->mfn++, rmd->prot)); + + xen_set_domain_pte(ptep, pte, rmd->domid); + + return 0; +} + +int remap_domain_mfn_range(struct vm_area_struct *vma, unsigned long addr, + unsigned long mfn, unsigned long size, + pgprot_t prot, unsigned domid) +{ + struct remap_data rmd; + int err; + + prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP); + + vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; + + rmd.mfn = mfn; + rmd.prot = prot; + rmd.domid = domid; + + err = apply_to_page_range(vma->vm_mm, addr, size, + remap_area_mfn_pte_fn, &rmd); + + return err; +} + +static long privcmd_ioctl_hypercall(void __user *udata) +{ + struct privcmd_hypercall hypercall; + long ret; + + if (copy_from_user(&hypercall, udata, sizeof(hypercall))) + return -EFAULT; + + ret = privcmd_call(hypercall.op, + hypercall.arg[0], hypercall.arg[1], + hypercall.arg[2], hypercall.arg[3], + hypercall.arg[4]); + + return ret; +} + +static void free_page_list(struct list_head *pages) +{ + struct page *p, *n; + + list_for_each_entry_safe(p, n, pages, lru) + __free_page(p); + + INIT_LIST_HEAD(pages); +} + +/* + * Given an array of items in userspace, return a list of pages + * containing the data. If copying fails, either because of memory + * allocation failure or a problem reading user memory, return an + * error code; its up to the caller to dispose of any partial list. + */ +static int gather_array(struct list_head *pagelist, + unsigned nelem, size_t size, + void __user *data) +{ + unsigned pageidx; + void *pagedata; + int ret; + + if (size > PAGE_SIZE) + return 0; + + pageidx = PAGE_SIZE; + pagedata = NULL; /* quiet, gcc */ + while (nelem--) { + if (pageidx > PAGE_SIZE-size) { + struct page *page = alloc_page(GFP_KERNEL); + + ret = -ENOMEM; + if (page == NULL) + goto fail; + + pagedata = page_address(page); + + list_add_tail(&page->lru, pagelist); + pageidx = 0; + } + + ret = -EFAULT; + if (copy_from_user(pagedata + pageidx, data, size)) + goto fail; + + data += size; + pageidx += size; + } + + ret = 0; + +fail: + return ret; +} + +/* + * Call function "fn" on each element of the array fragmented + * over a list of pages. + */ +static int traverse_pages(unsigned nelem, size_t size, + struct list_head *pos, + int (*fn)(void *data, void *state), + void *state) +{ + void *pagedata; + unsigned pageidx; + int ret; + + BUG_ON(size > PAGE_SIZE); + + pageidx = PAGE_SIZE; + pagedata = NULL; /* hush, gcc */ + + while (nelem--) { + if (pageidx > PAGE_SIZE-size) { + struct page *page; + pos = pos->next; + page = list_entry(pos, struct page, lru); + pagedata = page_address(page); + pageidx = 0; + } + + ret = (*fn)(pagedata + pageidx, state); + if (ret) + break; + pageidx += size; + } + + return ret; +} + +struct mmap_mfn_state { + unsigned long va; + struct vm_area_struct *vma; + domid_t domain; +}; + +static int mmap_mfn_range(void *data, void *state) +{ + struct privcmd_mmap_entry *msg = data; + struct mmap_mfn_state *st = state; + struct vm_area_struct *vma = st->vma; + int rc; + + /* Do not allow range to wrap the address space. */ + if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) || + ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va)) + return -EINVAL; + + /* Range chunks must be contiguous in va space. */ + if ((msg->va != st->va) || + ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end)) + return -EINVAL; + + rc = remap_domain_mfn_range(vma, + msg->va & PAGE_MASK, + msg->mfn, + msg->npages << PAGE_SHIFT, + vma->vm_page_prot, + st->domain); + if (rc < 0) + return rc; + + st->va += msg->npages << PAGE_SHIFT; + + return 0; +} + +static long privcmd_ioctl_mmap(void __user *udata) +{ + struct privcmd_mmap mmapcmd; + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + int rc; + LIST_HEAD(pagelist); + struct mmap_mfn_state state; + + if (!xen_initial_domain()) + return -EPERM; + + if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd))) + return -EFAULT; + + rc = gather_array(&pagelist, + mmapcmd.num, sizeof(struct privcmd_mmap_entry), + mmapcmd.entry); + + if (rc || list_empty(&pagelist)) + goto out; + + down_write(&mm->mmap_sem); + + { + struct page *page = list_first_entry(&pagelist, + struct page, lru); + struct privcmd_mmap_entry *msg = page_address(page); + + vma = find_vma(mm, msg->va); + rc = -EINVAL; + + if (!vma || (msg->va != vma->vm_start) || + !privcmd_enforce_singleshot_mapping(vma)) + goto out_up; + } + + state.va = vma->vm_start; + state.vma = vma; + state.domain = mmapcmd.dom; + + rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry), + &pagelist, + mmap_mfn_range, &state); + + +out_up: + up_write(&mm->mmap_sem); + +out: + free_page_list(&pagelist); + + return rc; +} + +struct mmap_batch_state { + domid_t domain; + unsigned long va; + struct vm_area_struct *vma; + int err; + + xen_pfn_t __user *user; +}; + +static int mmap_batch_fn(void *data, void *state) +{ + xen_pfn_t *mfnp = data; + struct mmap_batch_state *st = state; + + if (remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, + *mfnp, PAGE_SIZE, + st->vma->vm_page_prot, st->domain) < 0) { + *mfnp |= 0xf0000000U; + st->err++; + } + st->va += PAGE_SIZE; + + return 0; +} + +static int mmap_return_errors(void *data, void *state) +{ + xen_pfn_t *mfnp = data; + struct mmap_batch_state *st = state; + + put_user(*mfnp, st->user++); + + return 0; +} + +static long privcmd_ioctl_mmap_batch(void __user *udata) +{ + int ret; + struct privcmd_mmapbatch m; + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + unsigned long nr_pages; + LIST_HEAD(pagelist); + struct mmap_batch_state state; + + if (!xen_initial_domain()) + return -EPERM; + + if (copy_from_user(&m, udata, sizeof(m))) + return -EFAULT; + + nr_pages = m.num; + if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT))) + return -EINVAL; + + ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), + m.arr); + + if (ret || list_empty(&pagelist)) + goto out; + + down_write(&mm->mmap_sem); + + vma = find_vma(mm, m.addr); + ret = -EINVAL; + if (!vma || + (m.addr != vma->vm_start) || + ((m.addr + (nr_pages << PAGE_SHIFT)) != vma->vm_end) || + !privcmd_enforce_singleshot_mapping(vma)) { + up_write(&mm->mmap_sem); + goto out; + } + + state.domain = m.dom; + state.vma = vma; + state.va = m.addr; + state.err = 0; + + ret = traverse_pages(m.num, sizeof(xen_pfn_t), + &pagelist, mmap_batch_fn, &state); + + up_write(&mm->mmap_sem); + + if (state.err > 0) { + ret = state.err; + + state.user = udata; + traverse_pages(m.num, sizeof(xen_pfn_t), + &pagelist, + mmap_return_errors, &state); + } + +out: + free_page_list(&pagelist); + + return ret; +} + +static long privcmd_ioctl(struct file *file, + unsigned int cmd, unsigned long data) +{ + int ret = -ENOSYS; + void __user *udata = (void __user *) data; + + switch (cmd) { + case IOCTL_PRIVCMD_HYPERCALL: + ret = privcmd_ioctl_hypercall(udata); + break; + + case IOCTL_PRIVCMD_MMAP: + ret = privcmd_ioctl_mmap(udata); + break; + + case IOCTL_PRIVCMD_MMAPBATCH: + ret = privcmd_ioctl_mmap_batch(udata); + break; + + default: + ret = -EINVAL; + break; + } + + return ret; +} + +#ifndef HAVE_ARCH_PRIVCMD_MMAP +static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + return VM_FAULT_SIGBUS; +} + +static struct vm_operations_struct privcmd_vm_ops = { + .fault = privcmd_fault +}; + +static int privcmd_mmap(struct file *file, struct vm_area_struct *vma) +{ + /* Unsupported for auto-translate guests. */ + if (xen_feature(XENFEAT_auto_translated_physmap)) + return -ENOSYS; + + /* DONTCOPY is essential for Xen as copy_page_range is broken. */ + vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY; + vma->vm_ops = &privcmd_vm_ops; + vma->vm_private_data = NULL; + + return 0; +} + +static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma) +{ + return (xchg(&vma->vm_private_data, (void *)1) == NULL); +} +#endif + +const struct file_operations privcmd_file_ops = { + .unlocked_ioctl = privcmd_ioctl, + .mmap = privcmd_mmap, +}; diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c index 3cf7707217f2..8c7462866e90 100644 --- a/drivers/xen/xenfs/super.c +++ b/drivers/xen/xenfs/super.c @@ -96,6 +96,8 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent) &xsd_kva_file_ops, NULL, S_IRUSR|S_IWUSR); xenfs_create_file(sb, sb->s_root, "xsd_port", &xsd_port_file_ops, NULL, S_IRUSR|S_IWUSR); + xenfs_create_file(sb, sb->s_root, "privcmd", + &privcmd_file_ops, NULL, S_IRUSR|S_IWUSR); } return rc; diff --git a/drivers/xen/xenfs/xenfs.h b/drivers/xen/xenfs/xenfs.h index 5056306e7aa8..b68aa6200003 100644 --- a/drivers/xen/xenfs/xenfs.h +++ b/drivers/xen/xenfs/xenfs.h @@ -2,6 +2,7 @@ #define _XENFS_XENBUS_H extern const struct file_operations xenbus_file_ops; +extern const struct file_operations privcmd_file_ops; extern const struct file_operations xsd_kva_file_ops; extern const struct file_operations xsd_port_file_ops; diff --git a/include/xen/Kbuild b/include/xen/Kbuild index 4e65c16a445b..84ad8f02fee5 100644 --- a/include/xen/Kbuild +++ b/include/xen/Kbuild @@ -1 +1,2 @@ header-y += evtchn.h +header-y += privcmd.h diff --git a/include/xen/privcmd.h b/include/xen/privcmd.h new file mode 100644 index 000000000000..b42cdfd92fee --- /dev/null +++ b/include/xen/privcmd.h @@ -0,0 +1,80 @@ +/****************************************************************************** + * privcmd.h + * + * Interface to /proc/xen/privcmd. + * + * Copyright (c) 2003-2005, K A Fraser + * + * 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; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#ifndef __LINUX_PUBLIC_PRIVCMD_H__ +#define __LINUX_PUBLIC_PRIVCMD_H__ + +#include <linux/types.h> + +typedef unsigned long xen_pfn_t; + +#ifndef __user +#define __user +#endif + +struct privcmd_hypercall { + __u64 op; + __u64 arg[5]; +}; + +struct privcmd_mmap_entry { + __u64 va; + __u64 mfn; + __u64 npages; +}; + +struct privcmd_mmap { + int num; + domid_t dom; /* target domain */ + struct privcmd_mmap_entry __user *entry; +}; + +struct privcmd_mmapbatch { + int num; /* number of pages to populate */ + domid_t dom; /* target domain */ + __u64 addr; /* virtual address */ + xen_pfn_t __user *arr; /* array of mfns - top nibble set on err */ +}; + +/* + * @cmd: IOCTL_PRIVCMD_HYPERCALL + * @arg: &privcmd_hypercall_t + * Return: Value returned from execution of the specified hypercall. + */ +#define IOCTL_PRIVCMD_HYPERCALL \ + _IOC(_IOC_NONE, 'P', 0, sizeof(struct privcmd_hypercall)) +#define IOCTL_PRIVCMD_MMAP \ + _IOC(_IOC_NONE, 'P', 2, sizeof(struct privcmd_mmap)) +#define IOCTL_PRIVCMD_MMAPBATCH \ + _IOC(_IOC_NONE, 'P', 3, sizeof(struct privcmd_mmapbatch)) + +#endif /* __LINUX_PUBLIC_PRIVCMD_H__ */ |