| // SPDX-License-Identifier: GPL-2.0-only |
| /****************************************************************************** |
| * privcmd.c |
| * |
| * Interface to privileged domain-0 commands. |
| * |
| * Copyright (c) 2002-2004, K A Fraser, B Dragovic |
| */ |
| |
| #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
| |
| #include <linux/eventfd.h> |
| #include <linux/file.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/poll.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/string.h> |
| #include <linux/workqueue.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 <linux/moduleparam.h> |
| #include <linux/virtio_mmio.h> |
| |
| #include <asm/xen/hypervisor.h> |
| #include <asm/xen/hypercall.h> |
| |
| #include <xen/xen.h> |
| #include <xen/events.h> |
| #include <xen/privcmd.h> |
| #include <xen/interface/xen.h> |
| #include <xen/interface/memory.h> |
| #include <xen/interface/hvm/dm_op.h> |
| #include <xen/interface/hvm/ioreq.h> |
| #include <xen/features.h> |
| #include <xen/page.h> |
| #include <xen/xen-ops.h> |
| #include <xen/balloon.h> |
| |
| #include "privcmd.h" |
| |
| MODULE_LICENSE("GPL"); |
| |
| #define PRIV_VMA_LOCKED ((void *)1) |
| |
| static unsigned int privcmd_dm_op_max_num = 16; |
| module_param_named(dm_op_max_nr_bufs, privcmd_dm_op_max_num, uint, 0644); |
| MODULE_PARM_DESC(dm_op_max_nr_bufs, |
| "Maximum number of buffers per dm_op hypercall"); |
| |
| static unsigned int privcmd_dm_op_buf_max_size = 4096; |
| module_param_named(dm_op_buf_max_size, privcmd_dm_op_buf_max_size, uint, |
| 0644); |
| MODULE_PARM_DESC(dm_op_buf_max_size, |
| "Maximum size of a dm_op hypercall buffer"); |
| |
| struct privcmd_data { |
| domid_t domid; |
| }; |
| |
| static int privcmd_vma_range_is_mapped( |
| struct vm_area_struct *vma, |
| unsigned long addr, |
| unsigned long nr_pages); |
| |
| static long privcmd_ioctl_hypercall(struct file *file, void __user *udata) |
| { |
| struct privcmd_data *data = file->private_data; |
| struct privcmd_hypercall hypercall; |
| long ret; |
| |
| /* Disallow arbitrary hypercalls if restricted */ |
| if (data->domid != DOMID_INVALID) |
| return -EPERM; |
| |
| if (copy_from_user(&hypercall, udata, sizeof(hypercall))) |
| return -EFAULT; |
| |
| xen_preemptible_hcall_begin(); |
| ret = privcmd_call(hypercall.op, |
| hypercall.arg[0], hypercall.arg[1], |
| hypercall.arg[2], hypercall.arg[3], |
| hypercall.arg[4]); |
| xen_preemptible_hcall_end(); |
| |
| 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, |
| const 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; |
| } |
| |
| /* |
| * Similar to traverse_pages, but use each page as a "block" of |
| * data to be processed as one unit. |
| */ |
| static int traverse_pages_block(unsigned nelem, size_t size, |
| struct list_head *pos, |
| int (*fn)(void *data, int nr, void *state), |
| void *state) |
| { |
| void *pagedata; |
| int ret = 0; |
| |
| BUG_ON(size > PAGE_SIZE); |
| |
| while (nelem) { |
| int nr = (PAGE_SIZE/size); |
| struct page *page; |
| if (nr > nelem) |
| nr = nelem; |
| pos = pos->next; |
| page = list_entry(pos, struct page, lru); |
| pagedata = page_address(page); |
| ret = (*fn)(pagedata, nr, state); |
| if (ret) |
| break; |
| nelem -= nr; |
| } |
| |
| return ret; |
| } |
| |
| struct mmap_gfn_state { |
| unsigned long va; |
| struct vm_area_struct *vma; |
| domid_t domain; |
| }; |
| |
| static int mmap_gfn_range(void *data, void *state) |
| { |
| struct privcmd_mmap_entry *msg = data; |
| struct mmap_gfn_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_gfn_range(vma, |
| msg->va & PAGE_MASK, |
| msg->mfn, msg->npages, |
| vma->vm_page_prot, |
| st->domain, NULL); |
| if (rc < 0) |
| return rc; |
| |
| st->va += msg->npages << PAGE_SHIFT; |
| |
| return 0; |
| } |
| |
| static long privcmd_ioctl_mmap(struct file *file, void __user *udata) |
| { |
| struct privcmd_data *data = file->private_data; |
| struct privcmd_mmap mmapcmd; |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma; |
| int rc; |
| LIST_HEAD(pagelist); |
| struct mmap_gfn_state state; |
| |
| /* We only support privcmd_ioctl_mmap_batch for non-auto-translated. */ |
| if (xen_feature(XENFEAT_auto_translated_physmap)) |
| return -ENOSYS; |
| |
| if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd))) |
| return -EFAULT; |
| |
| /* If restriction is in place, check the domid matches */ |
| if (data->domid != DOMID_INVALID && data->domid != mmapcmd.dom) |
| return -EPERM; |
| |
| rc = gather_array(&pagelist, |
| mmapcmd.num, sizeof(struct privcmd_mmap_entry), |
| mmapcmd.entry); |
| |
| if (rc || list_empty(&pagelist)) |
| goto out; |
| |
| mmap_write_lock(mm); |
| |
| { |
| struct page *page = list_first_entry(&pagelist, |
| struct page, lru); |
| struct privcmd_mmap_entry *msg = page_address(page); |
| |
| vma = vma_lookup(mm, msg->va); |
| rc = -EINVAL; |
| |
| if (!vma || (msg->va != vma->vm_start) || vma->vm_private_data) |
| goto out_up; |
| vma->vm_private_data = PRIV_VMA_LOCKED; |
| } |
| |
| state.va = vma->vm_start; |
| state.vma = vma; |
| state.domain = mmapcmd.dom; |
| |
| rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry), |
| &pagelist, |
| mmap_gfn_range, &state); |
| |
| |
| out_up: |
| mmap_write_unlock(mm); |
| |
| out: |
| free_page_list(&pagelist); |
| |
| return rc; |
| } |
| |
| struct mmap_batch_state { |
| domid_t domain; |
| unsigned long va; |
| struct vm_area_struct *vma; |
| int index; |
| /* A tristate: |
| * 0 for no errors |
| * 1 if at least one error has happened (and no |
| * -ENOENT errors have happened) |
| * -ENOENT if at least 1 -ENOENT has happened. |
| */ |
| int global_error; |
| int version; |
| |
| /* User-space gfn array to store errors in the second pass for V1. */ |
| xen_pfn_t __user *user_gfn; |
| /* User-space int array to store errors in the second pass for V2. */ |
| int __user *user_err; |
| }; |
| |
| /* auto translated dom0 note: if domU being created is PV, then gfn is |
| * mfn(addr on bus). If it's auto xlated, then gfn is pfn (input to HAP). |
| */ |
| static int mmap_batch_fn(void *data, int nr, void *state) |
| { |
| xen_pfn_t *gfnp = data; |
| struct mmap_batch_state *st = state; |
| struct vm_area_struct *vma = st->vma; |
| struct page **pages = vma->vm_private_data; |
| struct page **cur_pages = NULL; |
| int ret; |
| |
| if (xen_feature(XENFEAT_auto_translated_physmap)) |
| cur_pages = &pages[st->index]; |
| |
| BUG_ON(nr < 0); |
| ret = xen_remap_domain_gfn_array(st->vma, st->va & PAGE_MASK, gfnp, nr, |
| (int *)gfnp, st->vma->vm_page_prot, |
| st->domain, cur_pages); |
| |
| /* Adjust the global_error? */ |
| if (ret != nr) { |
| if (ret == -ENOENT) |
| st->global_error = -ENOENT; |
| else { |
| /* Record that at least one error has happened. */ |
| if (st->global_error == 0) |
| st->global_error = 1; |
| } |
| } |
| st->va += XEN_PAGE_SIZE * nr; |
| st->index += nr / XEN_PFN_PER_PAGE; |
| |
| return 0; |
| } |
| |
| static int mmap_return_error(int err, struct mmap_batch_state *st) |
| { |
| int ret; |
| |
| if (st->version == 1) { |
| if (err) { |
| xen_pfn_t gfn; |
| |
| ret = get_user(gfn, st->user_gfn); |
| if (ret < 0) |
| return ret; |
| /* |
| * V1 encodes the error codes in the 32bit top |
| * nibble of the gfn (with its known |
| * limitations vis-a-vis 64 bit callers). |
| */ |
| gfn |= (err == -ENOENT) ? |
| PRIVCMD_MMAPBATCH_PAGED_ERROR : |
| PRIVCMD_MMAPBATCH_MFN_ERROR; |
| return __put_user(gfn, st->user_gfn++); |
| } else |
| st->user_gfn++; |
| } else { /* st->version == 2 */ |
| if (err) |
| return __put_user(err, st->user_err++); |
| else |
| st->user_err++; |
| } |
| |
| return 0; |
| } |
| |
| static int mmap_return_errors(void *data, int nr, void *state) |
| { |
| struct mmap_batch_state *st = state; |
| int *errs = data; |
| int i; |
| int ret; |
| |
| for (i = 0; i < nr; i++) { |
| ret = mmap_return_error(errs[i], st); |
| if (ret < 0) |
| return ret; |
| } |
| return 0; |
| } |
| |
| /* Allocate pfns that are then mapped with gfns from foreign domid. Update |
| * the vma with the page info to use later. |
| * Returns: 0 if success, otherwise -errno |
| */ |
| static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs) |
| { |
| int rc; |
| struct page **pages; |
| |
| pages = kvcalloc(numpgs, sizeof(pages[0]), GFP_KERNEL); |
| if (pages == NULL) |
| return -ENOMEM; |
| |
| rc = xen_alloc_unpopulated_pages(numpgs, pages); |
| if (rc != 0) { |
| pr_warn("%s Could not alloc %d pfns rc:%d\n", __func__, |
| numpgs, rc); |
| kvfree(pages); |
| return -ENOMEM; |
| } |
| BUG_ON(vma->vm_private_data != NULL); |
| vma->vm_private_data = pages; |
| |
| return 0; |
| } |
| |
| static const struct vm_operations_struct privcmd_vm_ops; |
| |
| static long privcmd_ioctl_mmap_batch( |
| struct file *file, void __user *udata, int version) |
| { |
| struct privcmd_data *data = file->private_data; |
| int ret; |
| struct privcmd_mmapbatch_v2 m; |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma; |
| unsigned long nr_pages; |
| LIST_HEAD(pagelist); |
| struct mmap_batch_state state; |
| |
| switch (version) { |
| case 1: |
| if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch))) |
| return -EFAULT; |
| /* Returns per-frame error in m.arr. */ |
| m.err = NULL; |
| if (!access_ok(m.arr, m.num * sizeof(*m.arr))) |
| return -EFAULT; |
| break; |
| case 2: |
| if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2))) |
| return -EFAULT; |
| /* Returns per-frame error code in m.err. */ |
| if (!access_ok(m.err, m.num * (sizeof(*m.err)))) |
| return -EFAULT; |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| /* If restriction is in place, check the domid matches */ |
| if (data->domid != DOMID_INVALID && data->domid != m.dom) |
| return -EPERM; |
| |
| nr_pages = DIV_ROUND_UP(m.num, XEN_PFN_PER_PAGE); |
| 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) |
| goto out; |
| if (list_empty(&pagelist)) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| if (version == 2) { |
| /* Zero error array now to only copy back actual errors. */ |
| if (clear_user(m.err, sizeof(int) * m.num)) { |
| ret = -EFAULT; |
| goto out; |
| } |
| } |
| |
| mmap_write_lock(mm); |
| |
| vma = find_vma(mm, m.addr); |
| if (!vma || |
| vma->vm_ops != &privcmd_vm_ops) { |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| |
| /* |
| * Caller must either: |
| * |
| * Map the whole VMA range, which will also allocate all the |
| * pages required for the auto_translated_physmap case. |
| * |
| * Or |
| * |
| * Map unmapped holes left from a previous map attempt (e.g., |
| * because those foreign frames were previously paged out). |
| */ |
| if (vma->vm_private_data == NULL) { |
| if (m.addr != vma->vm_start || |
| m.addr + (nr_pages << PAGE_SHIFT) != vma->vm_end) { |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| if (xen_feature(XENFEAT_auto_translated_physmap)) { |
| ret = alloc_empty_pages(vma, nr_pages); |
| if (ret < 0) |
| goto out_unlock; |
| } else |
| vma->vm_private_data = PRIV_VMA_LOCKED; |
| } else { |
| if (m.addr < vma->vm_start || |
| m.addr + (nr_pages << PAGE_SHIFT) > vma->vm_end) { |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| if (privcmd_vma_range_is_mapped(vma, m.addr, nr_pages)) { |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| } |
| |
| state.domain = m.dom; |
| state.vma = vma; |
| state.va = m.addr; |
| state.index = 0; |
| state.global_error = 0; |
| state.version = version; |
| |
| BUILD_BUG_ON(((PAGE_SIZE / sizeof(xen_pfn_t)) % XEN_PFN_PER_PAGE) != 0); |
| /* mmap_batch_fn guarantees ret == 0 */ |
| BUG_ON(traverse_pages_block(m.num, sizeof(xen_pfn_t), |
| &pagelist, mmap_batch_fn, &state)); |
| |
| mmap_write_unlock(mm); |
| |
| if (state.global_error) { |
| /* Write back errors in second pass. */ |
| state.user_gfn = (xen_pfn_t *)m.arr; |
| state.user_err = m.err; |
| ret = traverse_pages_block(m.num, sizeof(xen_pfn_t), |
| &pagelist, mmap_return_errors, &state); |
| } else |
| ret = 0; |
| |
| /* If we have not had any EFAULT-like global errors then set the global |
| * error to -ENOENT if necessary. */ |
| if ((ret == 0) && (state.global_error == -ENOENT)) |
| ret = -ENOENT; |
| |
| out: |
| free_page_list(&pagelist); |
| return ret; |
| |
| out_unlock: |
| mmap_write_unlock(mm); |
| goto out; |
| } |
| |
| static int lock_pages( |
| struct privcmd_dm_op_buf kbufs[], unsigned int num, |
| struct page *pages[], unsigned int nr_pages, unsigned int *pinned) |
| { |
| unsigned int i, off = 0; |
| |
| for (i = 0; i < num; ) { |
| unsigned int requested; |
| int page_count; |
| |
| requested = DIV_ROUND_UP( |
| offset_in_page(kbufs[i].uptr) + kbufs[i].size, |
| PAGE_SIZE) - off; |
| if (requested > nr_pages) |
| return -ENOSPC; |
| |
| page_count = pin_user_pages_fast( |
| (unsigned long)kbufs[i].uptr + off * PAGE_SIZE, |
| requested, FOLL_WRITE, pages); |
| if (page_count <= 0) |
| return page_count ? : -EFAULT; |
| |
| *pinned += page_count; |
| nr_pages -= page_count; |
| pages += page_count; |
| |
| off = (requested == page_count) ? 0 : off + page_count; |
| i += !off; |
| } |
| |
| return 0; |
| } |
| |
| static void unlock_pages(struct page *pages[], unsigned int nr_pages) |
| { |
| unpin_user_pages_dirty_lock(pages, nr_pages, true); |
| } |
| |
| static long privcmd_ioctl_dm_op(struct file *file, void __user *udata) |
| { |
| struct privcmd_data *data = file->private_data; |
| struct privcmd_dm_op kdata; |
| struct privcmd_dm_op_buf *kbufs; |
| unsigned int nr_pages = 0; |
| struct page **pages = NULL; |
| struct xen_dm_op_buf *xbufs = NULL; |
| unsigned int i; |
| long rc; |
| unsigned int pinned = 0; |
| |
| if (copy_from_user(&kdata, udata, sizeof(kdata))) |
| return -EFAULT; |
| |
| /* If restriction is in place, check the domid matches */ |
| if (data->domid != DOMID_INVALID && data->domid != kdata.dom) |
| return -EPERM; |
| |
| if (kdata.num == 0) |
| return 0; |
| |
| if (kdata.num > privcmd_dm_op_max_num) |
| return -E2BIG; |
| |
| kbufs = kcalloc(kdata.num, sizeof(*kbufs), GFP_KERNEL); |
| if (!kbufs) |
| return -ENOMEM; |
| |
| if (copy_from_user(kbufs, kdata.ubufs, |
| sizeof(*kbufs) * kdata.num)) { |
| rc = -EFAULT; |
| goto out; |
| } |
| |
| for (i = 0; i < kdata.num; i++) { |
| if (kbufs[i].size > privcmd_dm_op_buf_max_size) { |
| rc = -E2BIG; |
| goto out; |
| } |
| |
| if (!access_ok(kbufs[i].uptr, |
| kbufs[i].size)) { |
| rc = -EFAULT; |
| goto out; |
| } |
| |
| nr_pages += DIV_ROUND_UP( |
| offset_in_page(kbufs[i].uptr) + kbufs[i].size, |
| PAGE_SIZE); |
| } |
| |
| pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL); |
| if (!pages) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| |
| xbufs = kcalloc(kdata.num, sizeof(*xbufs), GFP_KERNEL); |
| if (!xbufs) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| |
| rc = lock_pages(kbufs, kdata.num, pages, nr_pages, &pinned); |
| if (rc < 0) |
| goto out; |
| |
| for (i = 0; i < kdata.num; i++) { |
| set_xen_guest_handle(xbufs[i].h, kbufs[i].uptr); |
| xbufs[i].size = kbufs[i].size; |
| } |
| |
| xen_preemptible_hcall_begin(); |
| rc = HYPERVISOR_dm_op(kdata.dom, kdata.num, xbufs); |
| xen_preemptible_hcall_end(); |
| |
| out: |
| unlock_pages(pages, pinned); |
| kfree(xbufs); |
| kfree(pages); |
| kfree(kbufs); |
| |
| return rc; |
| } |
| |
| static long privcmd_ioctl_restrict(struct file *file, void __user *udata) |
| { |
| struct privcmd_data *data = file->private_data; |
| domid_t dom; |
| |
| if (copy_from_user(&dom, udata, sizeof(dom))) |
| return -EFAULT; |
| |
| /* Set restriction to the specified domain, or check it matches */ |
| if (data->domid == DOMID_INVALID) |
| data->domid = dom; |
| else if (data->domid != dom) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static long privcmd_ioctl_mmap_resource(struct file *file, |
| struct privcmd_mmap_resource __user *udata) |
| { |
| struct privcmd_data *data = file->private_data; |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma; |
| struct privcmd_mmap_resource kdata; |
| xen_pfn_t *pfns = NULL; |
| struct xen_mem_acquire_resource xdata = { }; |
| int rc; |
| |
| if (copy_from_user(&kdata, udata, sizeof(kdata))) |
| return -EFAULT; |
| |
| /* If restriction is in place, check the domid matches */ |
| if (data->domid != DOMID_INVALID && data->domid != kdata.dom) |
| return -EPERM; |
| |
| /* Both fields must be set or unset */ |
| if (!!kdata.addr != !!kdata.num) |
| return -EINVAL; |
| |
| xdata.domid = kdata.dom; |
| xdata.type = kdata.type; |
| xdata.id = kdata.id; |
| |
| if (!kdata.addr && !kdata.num) { |
| /* Query the size of the resource. */ |
| rc = HYPERVISOR_memory_op(XENMEM_acquire_resource, &xdata); |
| if (rc) |
| return rc; |
| return __put_user(xdata.nr_frames, &udata->num); |
| } |
| |
| mmap_write_lock(mm); |
| |
| vma = find_vma(mm, kdata.addr); |
| if (!vma || vma->vm_ops != &privcmd_vm_ops) { |
| rc = -EINVAL; |
| goto out; |
| } |
| |
| pfns = kcalloc(kdata.num, sizeof(*pfns), GFP_KERNEL | __GFP_NOWARN); |
| if (!pfns) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| |
| if (IS_ENABLED(CONFIG_XEN_AUTO_XLATE) && |
| xen_feature(XENFEAT_auto_translated_physmap)) { |
| unsigned int nr = DIV_ROUND_UP(kdata.num, XEN_PFN_PER_PAGE); |
| struct page **pages; |
| unsigned int i; |
| |
| rc = alloc_empty_pages(vma, nr); |
| if (rc < 0) |
| goto out; |
| |
| pages = vma->vm_private_data; |
| |
| for (i = 0; i < kdata.num; i++) { |
| xen_pfn_t pfn = |
| page_to_xen_pfn(pages[i / XEN_PFN_PER_PAGE]); |
| |
| pfns[i] = pfn + (i % XEN_PFN_PER_PAGE); |
| } |
| } else |
| vma->vm_private_data = PRIV_VMA_LOCKED; |
| |
| xdata.frame = kdata.idx; |
| xdata.nr_frames = kdata.num; |
| set_xen_guest_handle(xdata.frame_list, pfns); |
| |
| xen_preemptible_hcall_begin(); |
| rc = HYPERVISOR_memory_op(XENMEM_acquire_resource, &xdata); |
| xen_preemptible_hcall_end(); |
| |
| if (rc) |
| goto out; |
| |
| if (IS_ENABLED(CONFIG_XEN_AUTO_XLATE) && |
| xen_feature(XENFEAT_auto_translated_physmap)) { |
| rc = xen_remap_vma_range(vma, kdata.addr, kdata.num << PAGE_SHIFT); |
| } else { |
| unsigned int domid = |
| (xdata.flags & XENMEM_rsrc_acq_caller_owned) ? |
| DOMID_SELF : kdata.dom; |
| int num, *errs = (int *)pfns; |
| |
| BUILD_BUG_ON(sizeof(*errs) > sizeof(*pfns)); |
| num = xen_remap_domain_mfn_array(vma, |
| kdata.addr & PAGE_MASK, |
| pfns, kdata.num, errs, |
| vma->vm_page_prot, |
| domid); |
| if (num < 0) |
| rc = num; |
| else if (num != kdata.num) { |
| unsigned int i; |
| |
| for (i = 0; i < num; i++) { |
| rc = errs[i]; |
| if (rc < 0) |
| break; |
| } |
| } else |
| rc = 0; |
| } |
| |
| out: |
| mmap_write_unlock(mm); |
| kfree(pfns); |
| |
| return rc; |
| } |
| |
| #ifdef CONFIG_XEN_PRIVCMD_EVENTFD |
| /* Irqfd support */ |
| static struct workqueue_struct *irqfd_cleanup_wq; |
| static DEFINE_MUTEX(irqfds_lock); |
| static LIST_HEAD(irqfds_list); |
| |
| struct privcmd_kernel_irqfd { |
| struct xen_dm_op_buf xbufs; |
| domid_t dom; |
| bool error; |
| struct eventfd_ctx *eventfd; |
| struct work_struct shutdown; |
| wait_queue_entry_t wait; |
| struct list_head list; |
| poll_table pt; |
| }; |
| |
| static void irqfd_deactivate(struct privcmd_kernel_irqfd *kirqfd) |
| { |
| lockdep_assert_held(&irqfds_lock); |
| |
| list_del_init(&kirqfd->list); |
| queue_work(irqfd_cleanup_wq, &kirqfd->shutdown); |
| } |
| |
| static void irqfd_shutdown(struct work_struct *work) |
| { |
| struct privcmd_kernel_irqfd *kirqfd = |
| container_of(work, struct privcmd_kernel_irqfd, shutdown); |
| u64 cnt; |
| |
| eventfd_ctx_remove_wait_queue(kirqfd->eventfd, &kirqfd->wait, &cnt); |
| eventfd_ctx_put(kirqfd->eventfd); |
| kfree(kirqfd); |
| } |
| |
| static void irqfd_inject(struct privcmd_kernel_irqfd *kirqfd) |
| { |
| u64 cnt; |
| long rc; |
| |
| eventfd_ctx_do_read(kirqfd->eventfd, &cnt); |
| |
| xen_preemptible_hcall_begin(); |
| rc = HYPERVISOR_dm_op(kirqfd->dom, 1, &kirqfd->xbufs); |
| xen_preemptible_hcall_end(); |
| |
| /* Don't repeat the error message for consecutive failures */ |
| if (rc && !kirqfd->error) { |
| pr_err("Failed to configure irq for guest domain: %d\n", |
| kirqfd->dom); |
| } |
| |
| kirqfd->error = rc; |
| } |
| |
| static int |
| irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) |
| { |
| struct privcmd_kernel_irqfd *kirqfd = |
| container_of(wait, struct privcmd_kernel_irqfd, wait); |
| __poll_t flags = key_to_poll(key); |
| |
| if (flags & EPOLLIN) |
| irqfd_inject(kirqfd); |
| |
| if (flags & EPOLLHUP) { |
| mutex_lock(&irqfds_lock); |
| irqfd_deactivate(kirqfd); |
| mutex_unlock(&irqfds_lock); |
| } |
| |
| return 0; |
| } |
| |
| static void |
| irqfd_poll_func(struct file *file, wait_queue_head_t *wqh, poll_table *pt) |
| { |
| struct privcmd_kernel_irqfd *kirqfd = |
| container_of(pt, struct privcmd_kernel_irqfd, pt); |
| |
| add_wait_queue_priority(wqh, &kirqfd->wait); |
| } |
| |
| static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd) |
| { |
| struct privcmd_kernel_irqfd *kirqfd, *tmp; |
| __poll_t events; |
| struct fd f; |
| void *dm_op; |
| int ret; |
| |
| kirqfd = kzalloc(sizeof(*kirqfd) + irqfd->size, GFP_KERNEL); |
| if (!kirqfd) |
| return -ENOMEM; |
| dm_op = kirqfd + 1; |
| |
| if (copy_from_user(dm_op, u64_to_user_ptr(irqfd->dm_op), irqfd->size)) { |
| ret = -EFAULT; |
| goto error_kfree; |
| } |
| |
| kirqfd->xbufs.size = irqfd->size; |
| set_xen_guest_handle(kirqfd->xbufs.h, dm_op); |
| kirqfd->dom = irqfd->dom; |
| INIT_WORK(&kirqfd->shutdown, irqfd_shutdown); |
| |
| f = fdget(irqfd->fd); |
| if (!f.file) { |
| ret = -EBADF; |
| goto error_kfree; |
| } |
| |
| kirqfd->eventfd = eventfd_ctx_fileget(f.file); |
| if (IS_ERR(kirqfd->eventfd)) { |
| ret = PTR_ERR(kirqfd->eventfd); |
| goto error_fd_put; |
| } |
| |
| /* |
| * Install our own custom wake-up handling so we are notified via a |
| * callback whenever someone signals the underlying eventfd. |
| */ |
| init_waitqueue_func_entry(&kirqfd->wait, irqfd_wakeup); |
| init_poll_funcptr(&kirqfd->pt, irqfd_poll_func); |
| |
| mutex_lock(&irqfds_lock); |
| |
| list_for_each_entry(tmp, &irqfds_list, list) { |
| if (kirqfd->eventfd == tmp->eventfd) { |
| ret = -EBUSY; |
| mutex_unlock(&irqfds_lock); |
| goto error_eventfd; |
| } |
| } |
| |
| list_add_tail(&kirqfd->list, &irqfds_list); |
| mutex_unlock(&irqfds_lock); |
| |
| /* |
| * Check if there was an event already pending on the eventfd before we |
| * registered, and trigger it as if we didn't miss it. |
| */ |
| events = vfs_poll(f.file, &kirqfd->pt); |
| if (events & EPOLLIN) |
| irqfd_inject(kirqfd); |
| |
| /* |
| * Do not drop the file until the kirqfd is fully initialized, otherwise |
| * we might race against the EPOLLHUP. |
| */ |
| fdput(f); |
| return 0; |
| |
| error_eventfd: |
| eventfd_ctx_put(kirqfd->eventfd); |
| |
| error_fd_put: |
| fdput(f); |
| |
| error_kfree: |
| kfree(kirqfd); |
| return ret; |
| } |
| |
| static int privcmd_irqfd_deassign(struct privcmd_irqfd *irqfd) |
| { |
| struct privcmd_kernel_irqfd *kirqfd; |
| struct eventfd_ctx *eventfd; |
| |
| eventfd = eventfd_ctx_fdget(irqfd->fd); |
| if (IS_ERR(eventfd)) |
| return PTR_ERR(eventfd); |
| |
| mutex_lock(&irqfds_lock); |
| |
| list_for_each_entry(kirqfd, &irqfds_list, list) { |
| if (kirqfd->eventfd == eventfd) { |
| irqfd_deactivate(kirqfd); |
| break; |
| } |
| } |
| |
| mutex_unlock(&irqfds_lock); |
| |
| eventfd_ctx_put(eventfd); |
| |
| /* |
| * Block until we know all outstanding shutdown jobs have completed so |
| * that we guarantee there will not be any more interrupts once this |
| * deassign function returns. |
| */ |
| flush_workqueue(irqfd_cleanup_wq); |
| |
| return 0; |
| } |
| |
| static long privcmd_ioctl_irqfd(struct file *file, void __user *udata) |
| { |
| struct privcmd_data *data = file->private_data; |
| struct privcmd_irqfd irqfd; |
| |
| if (copy_from_user(&irqfd, udata, sizeof(irqfd))) |
| return -EFAULT; |
| |
| /* No other flags should be set */ |
| if (irqfd.flags & ~PRIVCMD_IRQFD_FLAG_DEASSIGN) |
| return -EINVAL; |
| |
| /* If restriction is in place, check the domid matches */ |
| if (data->domid != DOMID_INVALID && data->domid != irqfd.dom) |
| return -EPERM; |
| |
| if (irqfd.flags & PRIVCMD_IRQFD_FLAG_DEASSIGN) |
| return privcmd_irqfd_deassign(&irqfd); |
| |
| return privcmd_irqfd_assign(&irqfd); |
| } |
| |
| static int privcmd_irqfd_init(void) |
| { |
| irqfd_cleanup_wq = alloc_workqueue("privcmd-irqfd-cleanup", 0, 0); |
| if (!irqfd_cleanup_wq) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| static void privcmd_irqfd_exit(void) |
| { |
| struct privcmd_kernel_irqfd *kirqfd, *tmp; |
| |
| mutex_lock(&irqfds_lock); |
| |
| list_for_each_entry_safe(kirqfd, tmp, &irqfds_list, list) |
| irqfd_deactivate(kirqfd); |
| |
| mutex_unlock(&irqfds_lock); |
| |
| destroy_workqueue(irqfd_cleanup_wq); |
| } |
| |
| /* Ioeventfd Support */ |
| #define QUEUE_NOTIFY_VQ_MASK 0xFFFF |
| |
| static DEFINE_MUTEX(ioreq_lock); |
| static LIST_HEAD(ioreq_list); |
| |
| /* per-eventfd structure */ |
| struct privcmd_kernel_ioeventfd { |
| struct eventfd_ctx *eventfd; |
| struct list_head list; |
| u64 addr; |
| unsigned int addr_len; |
| unsigned int vq; |
| }; |
| |
| /* per-guest CPU / port structure */ |
| struct ioreq_port { |
| int vcpu; |
| unsigned int port; |
| struct privcmd_kernel_ioreq *kioreq; |
| }; |
| |
| /* per-guest structure */ |
| struct privcmd_kernel_ioreq { |
| domid_t dom; |
| unsigned int vcpus; |
| u64 uioreq; |
| struct ioreq *ioreq; |
| spinlock_t lock; /* Protects ioeventfds list */ |
| struct list_head ioeventfds; |
| struct list_head list; |
| struct ioreq_port ports[0]; |
| }; |
| |
| static irqreturn_t ioeventfd_interrupt(int irq, void *dev_id) |
| { |
| struct ioreq_port *port = dev_id; |
| struct privcmd_kernel_ioreq *kioreq = port->kioreq; |
| struct ioreq *ioreq = &kioreq->ioreq[port->vcpu]; |
| struct privcmd_kernel_ioeventfd *kioeventfd; |
| unsigned int state = STATE_IOREQ_READY; |
| |
| if (ioreq->state != STATE_IOREQ_READY || |
| ioreq->type != IOREQ_TYPE_COPY || ioreq->dir != IOREQ_WRITE) |
| return IRQ_NONE; |
| |
| /* |
| * We need a barrier, smp_mb(), here to ensure reads are finished before |
| * `state` is updated. Since the lock implementation ensures that |
| * appropriate barrier will be added anyway, we can avoid adding |
| * explicit barrier here. |
| * |
| * Ideally we don't need to update `state` within the locks, but we do |
| * that here to avoid adding explicit barrier. |
| */ |
| |
| spin_lock(&kioreq->lock); |
| ioreq->state = STATE_IOREQ_INPROCESS; |
| |
| list_for_each_entry(kioeventfd, &kioreq->ioeventfds, list) { |
| if (ioreq->addr == kioeventfd->addr + VIRTIO_MMIO_QUEUE_NOTIFY && |
| ioreq->size == kioeventfd->addr_len && |
| (ioreq->data & QUEUE_NOTIFY_VQ_MASK) == kioeventfd->vq) { |
| eventfd_signal(kioeventfd->eventfd, 1); |
| state = STATE_IORESP_READY; |
| break; |
| } |
| } |
| spin_unlock(&kioreq->lock); |
| |
| /* |
| * We need a barrier, smp_mb(), here to ensure writes are finished |
| * before `state` is updated. Since the lock implementation ensures that |
| * appropriate barrier will be added anyway, we can avoid adding |
| * explicit barrier here. |
| */ |
| |
| ioreq->state = state; |
| |
| if (state == STATE_IORESP_READY) { |
| notify_remote_via_evtchn(port->port); |
| return IRQ_HANDLED; |
| } |
| |
| return IRQ_NONE; |
| } |
| |
| static void ioreq_free(struct privcmd_kernel_ioreq *kioreq) |
| { |
| struct ioreq_port *ports = kioreq->ports; |
| int i; |
| |
| lockdep_assert_held(&ioreq_lock); |
| |
| list_del(&kioreq->list); |
| |
| for (i = kioreq->vcpus - 1; i >= 0; i--) |
| unbind_from_irqhandler(irq_from_evtchn(ports[i].port), &ports[i]); |
| |
| kfree(kioreq); |
| } |
| |
| static |
| struct privcmd_kernel_ioreq *alloc_ioreq(struct privcmd_ioeventfd *ioeventfd) |
| { |
| struct privcmd_kernel_ioreq *kioreq; |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma; |
| struct page **pages; |
| unsigned int *ports; |
| int ret, size, i; |
| |
| lockdep_assert_held(&ioreq_lock); |
| |
| size = struct_size(kioreq, ports, ioeventfd->vcpus); |
| kioreq = kzalloc(size, GFP_KERNEL); |
| if (!kioreq) |
| return ERR_PTR(-ENOMEM); |
| |
| kioreq->dom = ioeventfd->dom; |
| kioreq->vcpus = ioeventfd->vcpus; |
| kioreq->uioreq = ioeventfd->ioreq; |
| spin_lock_init(&kioreq->lock); |
| INIT_LIST_HEAD(&kioreq->ioeventfds); |
| |
| /* The memory for ioreq server must have been mapped earlier */ |
| mmap_write_lock(mm); |
| vma = find_vma(mm, (unsigned long)ioeventfd->ioreq); |
| if (!vma) { |
| pr_err("Failed to find vma for ioreq page!\n"); |
| mmap_write_unlock(mm); |
| ret = -EFAULT; |
| goto error_kfree; |
| } |
| |
| pages = vma->vm_private_data; |
| kioreq->ioreq = (struct ioreq *)(page_to_virt(pages[0])); |
| mmap_write_unlock(mm); |
| |
| size = sizeof(*ports) * kioreq->vcpus; |
| ports = kzalloc(size, GFP_KERNEL); |
| if (!ports) { |
| ret = -ENOMEM; |
| goto error_kfree; |
| } |
| |
| if (copy_from_user(ports, u64_to_user_ptr(ioeventfd->ports), size)) { |
| ret = -EFAULT; |
| goto error_kfree_ports; |
| } |
| |
| for (i = 0; i < kioreq->vcpus; i++) { |
| kioreq->ports[i].vcpu = i; |
| kioreq->ports[i].port = ports[i]; |
| kioreq->ports[i].kioreq = kioreq; |
| |
| ret = bind_evtchn_to_irqhandler_lateeoi(ports[i], |
| ioeventfd_interrupt, IRQF_SHARED, "ioeventfd", |
| &kioreq->ports[i]); |
| if (ret < 0) |
| goto error_unbind; |
| } |
| |
| kfree(ports); |
| |
| list_add_tail(&kioreq->list, &ioreq_list); |
| |
| return kioreq; |
| |
| error_unbind: |
| while (--i >= 0) |
| unbind_from_irqhandler(irq_from_evtchn(ports[i]), &kioreq->ports[i]); |
| error_kfree_ports: |
| kfree(ports); |
| error_kfree: |
| kfree(kioreq); |
| return ERR_PTR(ret); |
| } |
| |
| static struct privcmd_kernel_ioreq * |
| get_ioreq(struct privcmd_ioeventfd *ioeventfd, struct eventfd_ctx *eventfd) |
| { |
| struct privcmd_kernel_ioreq *kioreq; |
| unsigned long flags; |
| |
| list_for_each_entry(kioreq, &ioreq_list, list) { |
| struct privcmd_kernel_ioeventfd *kioeventfd; |
| |
| /* |
| * kioreq fields can be accessed here without a lock as they are |
| * never updated after being added to the ioreq_list. |
| */ |
| if (kioreq->uioreq != ioeventfd->ioreq) { |
| continue; |
| } else if (kioreq->dom != ioeventfd->dom || |
| kioreq->vcpus != ioeventfd->vcpus) { |
| pr_err("Invalid ioeventfd configuration mismatch, dom (%u vs %u), vcpus (%u vs %u)\n", |
| kioreq->dom, ioeventfd->dom, kioreq->vcpus, |
| ioeventfd->vcpus); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| /* Look for a duplicate eventfd for the same guest */ |
| spin_lock_irqsave(&kioreq->lock, flags); |
| list_for_each_entry(kioeventfd, &kioreq->ioeventfds, list) { |
| if (eventfd == kioeventfd->eventfd) { |
| spin_unlock_irqrestore(&kioreq->lock, flags); |
| return ERR_PTR(-EBUSY); |
| } |
| } |
| spin_unlock_irqrestore(&kioreq->lock, flags); |
| |
| return kioreq; |
| } |
| |
| /* Matching kioreq isn't found, allocate a new one */ |
| return alloc_ioreq(ioeventfd); |
| } |
| |
| static void ioeventfd_free(struct privcmd_kernel_ioeventfd *kioeventfd) |
| { |
| list_del(&kioeventfd->list); |
| eventfd_ctx_put(kioeventfd->eventfd); |
| kfree(kioeventfd); |
| } |
| |
| static int privcmd_ioeventfd_assign(struct privcmd_ioeventfd *ioeventfd) |
| { |
| struct privcmd_kernel_ioeventfd *kioeventfd; |
| struct privcmd_kernel_ioreq *kioreq; |
| unsigned long flags; |
| struct fd f; |
| int ret; |
| |
| /* Check for range overflow */ |
| if (ioeventfd->addr + ioeventfd->addr_len < ioeventfd->addr) |
| return -EINVAL; |
| |
| /* Vhost requires us to support length 1, 2, 4, and 8 */ |
| if (!(ioeventfd->addr_len == 1 || ioeventfd->addr_len == 2 || |
| ioeventfd->addr_len == 4 || ioeventfd->addr_len == 8)) |
| return -EINVAL; |
| |
| /* 4096 vcpus limit enough ? */ |
| if (!ioeventfd->vcpus || ioeventfd->vcpus > 4096) |
| return -EINVAL; |
| |
| kioeventfd = kzalloc(sizeof(*kioeventfd), GFP_KERNEL); |
| if (!kioeventfd) |
| return -ENOMEM; |
| |
| f = fdget(ioeventfd->event_fd); |
| if (!f.file) { |
| ret = -EBADF; |
| goto error_kfree; |
| } |
| |
| kioeventfd->eventfd = eventfd_ctx_fileget(f.file); |
| fdput(f); |
| |
| if (IS_ERR(kioeventfd->eventfd)) { |
| ret = PTR_ERR(kioeventfd->eventfd); |
| goto error_kfree; |
| } |
| |
| kioeventfd->addr = ioeventfd->addr; |
| kioeventfd->addr_len = ioeventfd->addr_len; |
| kioeventfd->vq = ioeventfd->vq; |
| |
| mutex_lock(&ioreq_lock); |
| kioreq = get_ioreq(ioeventfd, kioeventfd->eventfd); |
| if (IS_ERR(kioreq)) { |
| mutex_unlock(&ioreq_lock); |
| ret = PTR_ERR(kioreq); |
| goto error_eventfd; |
| } |
| |
| spin_lock_irqsave(&kioreq->lock, flags); |
| list_add_tail(&kioeventfd->list, &kioreq->ioeventfds); |
| spin_unlock_irqrestore(&kioreq->lock, flags); |
| |
| mutex_unlock(&ioreq_lock); |
| |
| return 0; |
| |
| error_eventfd: |
| eventfd_ctx_put(kioeventfd->eventfd); |
| |
| error_kfree: |
| kfree(kioeventfd); |
| return ret; |
| } |
| |
| static int privcmd_ioeventfd_deassign(struct privcmd_ioeventfd *ioeventfd) |
| { |
| struct privcmd_kernel_ioreq *kioreq, *tkioreq; |
| struct eventfd_ctx *eventfd; |
| unsigned long flags; |
| int ret = 0; |
| |
| eventfd = eventfd_ctx_fdget(ioeventfd->event_fd); |
| if (IS_ERR(eventfd)) |
| return PTR_ERR(eventfd); |
| |
| mutex_lock(&ioreq_lock); |
| list_for_each_entry_safe(kioreq, tkioreq, &ioreq_list, list) { |
| struct privcmd_kernel_ioeventfd *kioeventfd, *tmp; |
| /* |
| * kioreq fields can be accessed here without a lock as they are |
| * never updated after being added to the ioreq_list. |
| */ |
| if (kioreq->dom != ioeventfd->dom || |
| kioreq->uioreq != ioeventfd->ioreq || |
| kioreq->vcpus != ioeventfd->vcpus) |
| continue; |
| |
| spin_lock_irqsave(&kioreq->lock, flags); |
| list_for_each_entry_safe(kioeventfd, tmp, &kioreq->ioeventfds, list) { |
| if (eventfd == kioeventfd->eventfd) { |
| ioeventfd_free(kioeventfd); |
| spin_unlock_irqrestore(&kioreq->lock, flags); |
| |
| if (list_empty(&kioreq->ioeventfds)) |
| ioreq_free(kioreq); |
| goto unlock; |
| } |
| } |
| spin_unlock_irqrestore(&kioreq->lock, flags); |
| break; |
| } |
| |
| pr_err("Ioeventfd isn't already assigned, dom: %u, addr: %llu\n", |
| ioeventfd->dom, ioeventfd->addr); |
| ret = -ENODEV; |
| |
| unlock: |
| mutex_unlock(&ioreq_lock); |
| eventfd_ctx_put(eventfd); |
| |
| return ret; |
| } |
| |
| static long privcmd_ioctl_ioeventfd(struct file *file, void __user *udata) |
| { |
| struct privcmd_data *data = file->private_data; |
| struct privcmd_ioeventfd ioeventfd; |
| |
| if (copy_from_user(&ioeventfd, udata, sizeof(ioeventfd))) |
| return -EFAULT; |
| |
| /* No other flags should be set */ |
| if (ioeventfd.flags & ~PRIVCMD_IOEVENTFD_FLAG_DEASSIGN) |
| return -EINVAL; |
| |
| /* If restriction is in place, check the domid matches */ |
| if (data->domid != DOMID_INVALID && data->domid != ioeventfd.dom) |
| return -EPERM; |
| |
| if (ioeventfd.flags & PRIVCMD_IOEVENTFD_FLAG_DEASSIGN) |
| return privcmd_ioeventfd_deassign(&ioeventfd); |
| |
| return privcmd_ioeventfd_assign(&ioeventfd); |
| } |
| |
| static void privcmd_ioeventfd_exit(void) |
| { |
| struct privcmd_kernel_ioreq *kioreq, *tmp; |
| unsigned long flags; |
| |
| mutex_lock(&ioreq_lock); |
| list_for_each_entry_safe(kioreq, tmp, &ioreq_list, list) { |
| struct privcmd_kernel_ioeventfd *kioeventfd, *tmp; |
| |
| spin_lock_irqsave(&kioreq->lock, flags); |
| list_for_each_entry_safe(kioeventfd, tmp, &kioreq->ioeventfds, list) |
| ioeventfd_free(kioeventfd); |
| spin_unlock_irqrestore(&kioreq->lock, flags); |
| |
| ioreq_free(kioreq); |
| } |
| mutex_unlock(&ioreq_lock); |
| } |
| #else |
| static inline long privcmd_ioctl_irqfd(struct file *file, void __user *udata) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static inline int privcmd_irqfd_init(void) |
| { |
| return 0; |
| } |
| |
| static inline void privcmd_irqfd_exit(void) |
| { |
| } |
| |
| static inline long privcmd_ioctl_ioeventfd(struct file *file, void __user *udata) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static inline void privcmd_ioeventfd_exit(void) |
| { |
| } |
| #endif /* CONFIG_XEN_PRIVCMD_EVENTFD */ |
| |
| static long privcmd_ioctl(struct file *file, |
| unsigned int cmd, unsigned long data) |
| { |
| int ret = -ENOTTY; |
| void __user *udata = (void __user *) data; |
| |
| switch (cmd) { |
| case IOCTL_PRIVCMD_HYPERCALL: |
| ret = privcmd_ioctl_hypercall(file, udata); |
| break; |
| |
| case IOCTL_PRIVCMD_MMAP: |
| ret = privcmd_ioctl_mmap(file, udata); |
| break; |
| |
| case IOCTL_PRIVCMD_MMAPBATCH: |
| ret = privcmd_ioctl_mmap_batch(file, udata, 1); |
| break; |
| |
| case IOCTL_PRIVCMD_MMAPBATCH_V2: |
| ret = privcmd_ioctl_mmap_batch(file, udata, 2); |
| break; |
| |
| case IOCTL_PRIVCMD_DM_OP: |
| ret = privcmd_ioctl_dm_op(file, udata); |
| break; |
| |
| case IOCTL_PRIVCMD_RESTRICT: |
| ret = privcmd_ioctl_restrict(file, udata); |
| break; |
| |
| case IOCTL_PRIVCMD_MMAP_RESOURCE: |
| ret = privcmd_ioctl_mmap_resource(file, udata); |
| break; |
| |
| case IOCTL_PRIVCMD_IRQFD: |
| ret = privcmd_ioctl_irqfd(file, udata); |
| break; |
| |
| case IOCTL_PRIVCMD_IOEVENTFD: |
| ret = privcmd_ioctl_ioeventfd(file, udata); |
| break; |
| |
| default: |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static int privcmd_open(struct inode *ino, struct file *file) |
| { |
| struct privcmd_data *data = kzalloc(sizeof(*data), GFP_KERNEL); |
| |
| if (!data) |
| return -ENOMEM; |
| |
| /* DOMID_INVALID implies no restriction */ |
| data->domid = DOMID_INVALID; |
| |
| file->private_data = data; |
| return 0; |
| } |
| |
| static int privcmd_release(struct inode *ino, struct file *file) |
| { |
| struct privcmd_data *data = file->private_data; |
| |
| kfree(data); |
| return 0; |
| } |
| |
| static void privcmd_close(struct vm_area_struct *vma) |
| { |
| struct page **pages = vma->vm_private_data; |
| int numpgs = vma_pages(vma); |
| int numgfns = (vma->vm_end - vma->vm_start) >> XEN_PAGE_SHIFT; |
| int rc; |
| |
| if (!xen_feature(XENFEAT_auto_translated_physmap) || !numpgs || !pages) |
| return; |
| |
| rc = xen_unmap_domain_gfn_range(vma, numgfns, pages); |
| if (rc == 0) |
| xen_free_unpopulated_pages(numpgs, pages); |
| else |
| pr_crit("unable to unmap MFN range: leaking %d pages. rc=%d\n", |
| numpgs, rc); |
| kvfree(pages); |
| } |
| |
| static vm_fault_t privcmd_fault(struct vm_fault *vmf) |
| { |
| printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n", |
| vmf->vma, vmf->vma->vm_start, vmf->vma->vm_end, |
| vmf->pgoff, (void *)vmf->address); |
| |
| return VM_FAULT_SIGBUS; |
| } |
| |
| static const struct vm_operations_struct privcmd_vm_ops = { |
| .close = privcmd_close, |
| .fault = privcmd_fault |
| }; |
| |
| static int privcmd_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| /* DONTCOPY is essential for Xen because copy_page_range doesn't know |
| * how to recreate these mappings */ |
| vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTCOPY | |
| VM_DONTEXPAND | VM_DONTDUMP); |
| vma->vm_ops = &privcmd_vm_ops; |
| vma->vm_private_data = NULL; |
| |
| return 0; |
| } |
| |
| /* |
| * For MMAPBATCH*. This allows asserting the singleshot mapping |
| * on a per pfn/pte basis. Mapping calls that fail with ENOENT |
| * can be then retried until success. |
| */ |
| static int is_mapped_fn(pte_t *pte, unsigned long addr, void *data) |
| { |
| return pte_none(ptep_get(pte)) ? 0 : -EBUSY; |
| } |
| |
| static int privcmd_vma_range_is_mapped( |
| struct vm_area_struct *vma, |
| unsigned long addr, |
| unsigned long nr_pages) |
| { |
| return apply_to_page_range(vma->vm_mm, addr, nr_pages << PAGE_SHIFT, |
| is_mapped_fn, NULL) != 0; |
| } |
| |
| const struct file_operations xen_privcmd_fops = { |
| .owner = THIS_MODULE, |
| .unlocked_ioctl = privcmd_ioctl, |
| .open = privcmd_open, |
| .release = privcmd_release, |
| .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) { |
| pr_err("Could not register Xen privcmd device\n"); |
| return err; |
| } |
| |
| err = misc_register(&xen_privcmdbuf_dev); |
| if (err != 0) { |
| pr_err("Could not register Xen hypercall-buf device\n"); |
| goto err_privcmdbuf; |
| } |
| |
| err = privcmd_irqfd_init(); |
| if (err != 0) { |
| pr_err("irqfd init failed\n"); |
| goto err_irqfd; |
| } |
| |
| return 0; |
| |
| err_irqfd: |
| misc_deregister(&xen_privcmdbuf_dev); |
| err_privcmdbuf: |
| misc_deregister(&privcmd_dev); |
| return err; |
| } |
| |
| static void __exit privcmd_exit(void) |
| { |
| privcmd_ioeventfd_exit(); |
| privcmd_irqfd_exit(); |
| misc_deregister(&privcmd_dev); |
| misc_deregister(&xen_privcmdbuf_dev); |
| } |
| |
| module_init(privcmd_init); |
| module_exit(privcmd_exit); |