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Re: [Xen-devel] [PATCH 2/5] xen: Add privcmd device driver



On Sun, Nov 27, 2011 at 11:07:05PM +0100, Bastian Blank wrote:
> Access to arbitrary hypercalls is currently provided via xenfs. This
> adds a standard character device to handle this. The support in xenfs

Ok, what is the benefit of that? You mentioned in the prologue "about a
year ago I started", but you didn't provide any links to the
conversation. Could you include the details please?

> remains for backward compatibility and uses the device driver code.
> 
> Signed-off-by: Bastian Blank <waldi@xxxxxxxxxx>
> ---
>  drivers/xen/Kconfig         |    7 +
>  drivers/xen/Makefile        |    2 +
>  drivers/xen/privcmd.c       |  437 
> +++++++++++++++++++++++++++++++++++++++++++
>  drivers/xen/privcmd.h       |    3 +
>  drivers/xen/xenfs/Makefile  |    2 +-
>  drivers/xen/xenfs/privcmd.c |  400 ---------------------------------------

It looks like you are doing a move of the file. Can you use 'git mv'
instead please.

If it breaks compile build, you can modify the Kconfig to inhibit the
build (say make it dependent on a symbol that won't be turned on).

And then in a later patch, reenable the Kconfig. The idea here is to
keep 'git bisection working properly'.

Another way to make this work is to provide some scaffolding code in the
existing code so that it can build in another directory. And then
in another patch remove it.

>  drivers/xen/xenfs/super.c   |    3 +-
>  drivers/xen/xenfs/xenfs.h   |    1 -
>  8 files changed, 452 insertions(+), 403 deletions(-)
>  create mode 100644 drivers/xen/privcmd.c
>  create mode 100644 drivers/xen/privcmd.h
>  delete mode 100644 drivers/xen/xenfs/privcmd.c
> 
> diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
> index 5f7ff8e..eb7574c 100644
> --- a/drivers/xen/Kconfig
> +++ b/drivers/xen/Kconfig
> @@ -86,6 +86,7 @@ config XEN_BACKEND
>  
>  config XENFS
>       tristate "Xen filesystem"
> +     select XEN_PRIVCMD
>       default y
>       help
>         The xen filesystem provides a way for domains to share
> @@ -181,4 +182,10 @@ config XEN_PCIDEV_BACKEND
>         xen-pciback.hide=(03:00.0)(04:00.0)
>  
>         If in doubt, say m.
> +
> +config XEN_PRIVCMD
> +     tristate
> +     depends on XEN_DOM0

Would it be possible for HVM domains that have the backend drivers in
them (so blkback for example) to use these hypercalls? If so should this
XEN_DOM0 be perhaps changed to something else?

> +     default m
> +
>  endmenu
> diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
> index 72bbb27..c35f65d 100644
> --- a/drivers/xen/Makefile
> +++ b/drivers/xen/Makefile
> @@ -19,9 +19,11 @@ obj-$(CONFIG_XEN_TMEM)                     += tmem.o
>  obj-$(CONFIG_SWIOTLB_XEN)            += swiotlb-xen.o
>  obj-$(CONFIG_XEN_DOM0)                       += pci.o
>  obj-$(CONFIG_XEN_PCIDEV_BACKEND)     += xen-pciback/
> +obj-$(CONFIG_XEN_PRIVCMD)            += xen-privcmd.o
>  
>  xen-evtchn-y                         := evtchn.o
>  xen-gntdev-y                         := gntdev.o
>  xen-gntalloc-y                               := gntalloc.o
> +xen-privcmd-y                                := privcmd.o
>  
>  xen-platform-pci-y                   := platform-pci.o
> diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> new file mode 100644
> index 0000000..863fbd0
> --- /dev/null
> +++ b/drivers/xen/privcmd.c
> @@ -0,0 +1,437 @@
> +/******************************************************************************
> + * privcmd.c
> + *
> + * Interface to privileged domain-0 commands.
> + *
> + * Copyright (c) 2002-2004, K A Fraser, B Dragovic
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.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/highmem.h>
> +#include <linux/pagemap.h>
> +#include <linux/seq_file.h>
> +#include <linux/miscdevice.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>
> +#include <xen/xen-ops.h>
> +
> +#include "privcmd.h"
> +
> +MODULE_LICENSE("GPL");
> +
> +#ifndef HAVE_ARCH_PRIVCMD_MMAP
> +static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
> +#endif
> +
> +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 = 0;
> +
> +     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 = xen_remap_domain_mfn_range(vma,
> +                                     msg->va & PAGE_MASK,
> +                                     msg->mfn, msg->npages,
> +                                     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 (xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
> +                                    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;
> +
> +     return put_user(*mfnp, st->user++);
> +}
> +
> +static struct vm_operations_struct privcmd_vm_ops;
> +
> +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 ||
> +         vma->vm_ops != &privcmd_vm_ops ||
> +         (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) {
> +             state.user = m.arr;
> +             ret = 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)
> +{
> +     printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
> +            vma, vma->vm_start, vma->vm_end,
> +            vmf->pgoff, vmf->virtual_address);
> +
> +     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 because copy_page_range doesn't know
> +      * how to recreate these mappings */
> +     vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
> +     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 xen_privcmd_fops = {
> +     .owner = THIS_MODULE,
> +     .unlocked_ioctl = privcmd_ioctl,
> +     .mmap = privcmd_mmap,
> +};
> +EXPORT_SYMBOL_GPL(xen_privcmd_fops);
> +
> +static struct miscdevice privcmd_dev = {
> +     .minor = MISC_DYNAMIC_MINOR,
> +     .name = "xen/privcmd",
> +     .fops = &xen_privcmd_fops,
> +};
> +
> +static int __init privcmd_init(void)
> +{
> +     int err;
> +
> +     if (!xen_domain())
> +             return -ENODEV;
> +
> +     err = misc_register(&privcmd_dev);
> +     if (err != 0) {
> +             printk(KERN_ERR "Could not register privcmd device\n");
> +             return err;
> +     }
> +     return 0;
> +}
> +
> +static void __exit privcmd_exit(void)
> +{
> +     misc_deregister(&privcmd_dev);
> +}
> +
> +module_init(privcmd_init);
> +module_exit(privcmd_exit);
> diff --git a/drivers/xen/privcmd.h b/drivers/xen/privcmd.h
> new file mode 100644
> index 0000000..14facae
> --- /dev/null
> +++ b/drivers/xen/privcmd.h
> @@ -0,0 +1,3 @@
> +#include <linux/fs.h>
> +
> +extern const struct file_operations xen_privcmd_fops;
> diff --git a/drivers/xen/xenfs/Makefile b/drivers/xen/xenfs/Makefile
> index 4fde944..5d45ff1 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 privcmd.o
> +xenfs-y                        = super.o xenbus.o
>  xenfs-$(CONFIG_XEN_DOM0) += xenstored.o
> diff --git a/drivers/xen/xenfs/privcmd.c b/drivers/xen/xenfs/privcmd.c
> deleted file mode 100644
> index dbd3b16..0000000
> --- a/drivers/xen/xenfs/privcmd.c
> +++ /dev/null
> @@ -1,400 +0,0 @@
> -/******************************************************************************
> - * 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/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>
> -#include <xen/xen-ops.h>
> -
> -#ifndef HAVE_ARCH_PRIVCMD_MMAP
> -static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
> -#endif
> -
> -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 = 0;
> -
> -     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 = xen_remap_domain_mfn_range(vma,
> -                                     msg->va & PAGE_MASK,
> -                                     msg->mfn, msg->npages,
> -                                     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 (xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
> -                                    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;
> -
> -     return put_user(*mfnp, st->user++);
> -}
> -
> -static struct vm_operations_struct privcmd_vm_ops;
> -
> -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 ||
> -         vma->vm_ops != &privcmd_vm_ops ||
> -         (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) {
> -             state.user = m.arr;
> -             ret = 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)
> -{
> -     printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
> -            vma, vma->vm_start, vma->vm_end,
> -            vmf->pgoff, vmf->virtual_address);
> -
> -     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 because copy_page_range doesn't know
> -      * how to recreate these mappings */
> -     vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
> -     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 1aa3897..a55fbf9 100644
> --- a/drivers/xen/xenfs/super.c
> +++ b/drivers/xen/xenfs/super.c
> @@ -16,6 +16,7 @@
>  #include <xen/xen.h>
>  
>  #include "xenfs.h"
> +#include "../privcmd.h"
>  
>  #include <asm/xen/hypervisor.h>
>  
> @@ -84,7 +85,7 @@ static int xenfs_fill_super(struct super_block *sb, void 
> *data, int silent)
>               [1] = {},
>               { "xenbus", &xenbus_file_ops, S_IRUSR|S_IWUSR },
>               { "capabilities", &capabilities_file_ops, S_IRUGO },
> -             { "privcmd", &privcmd_file_ops, S_IRUSR|S_IWUSR },
> +             { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
>               {""},
>       };
>       int rc;
> diff --git a/drivers/xen/xenfs/xenfs.h b/drivers/xen/xenfs/xenfs.h
> index b68aa62..5056306 100644
> --- a/drivers/xen/xenfs/xenfs.h
> +++ b/drivers/xen/xenfs/xenfs.h
> @@ -2,7 +2,6 @@
>  #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;
>  
> -- 
> 1.7.7.3
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel

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