diff options
Diffstat (limited to 'kernel/drivers/xen/grant-table.c')
| -rw-r--r-- | kernel/drivers/xen/grant-table.c | 1114 |
1 files changed, 1114 insertions, 0 deletions
diff --git a/kernel/drivers/xen/grant-table.c b/kernel/drivers/xen/grant-table.c new file mode 100644 index 000000000..b1c7170e5 --- /dev/null +++ b/kernel/drivers/xen/grant-table.c @@ -0,0 +1,1114 @@ +/****************************************************************************** + * grant_table.c + * + * Granting foreign access to our memory reservation. + * + * Copyright (c) 2005-2006, Christopher Clark + * Copyright (c) 2004-2005, 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. + */ + +#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/delay.h> +#include <linux/hardirq.h> +#include <linux/workqueue.h> + +#include <xen/xen.h> +#include <xen/interface/xen.h> +#include <xen/page.h> +#include <xen/grant_table.h> +#include <xen/interface/memory.h> +#include <xen/hvc-console.h> +#include <xen/swiotlb-xen.h> +#include <xen/balloon.h> +#include <asm/xen/hypercall.h> +#include <asm/xen/interface.h> + +#include <asm/pgtable.h> +#include <asm/sync_bitops.h> + +/* External tools reserve first few grant table entries. */ +#define NR_RESERVED_ENTRIES 8 +#define GNTTAB_LIST_END 0xffffffff + +static grant_ref_t **gnttab_list; +static unsigned int nr_grant_frames; +static int gnttab_free_count; +static grant_ref_t gnttab_free_head; +static DEFINE_SPINLOCK(gnttab_list_lock); +struct grant_frames xen_auto_xlat_grant_frames; + +static union { + struct grant_entry_v1 *v1; + void *addr; +} gnttab_shared; + +/*This is a structure of function pointers for grant table*/ +struct gnttab_ops { + /* + * Mapping a list of frames for storing grant entries. Frames parameter + * is used to store grant table address when grant table being setup, + * nr_gframes is the number of frames to map grant table. Returning + * GNTST_okay means success and negative value means failure. + */ + int (*map_frames)(xen_pfn_t *frames, unsigned int nr_gframes); + /* + * Release a list of frames which are mapped in map_frames for grant + * entry status. + */ + void (*unmap_frames)(void); + /* + * Introducing a valid entry into the grant table, granting the frame of + * this grant entry to domain for accessing or transfering. Ref + * parameter is reference of this introduced grant entry, domid is id of + * granted domain, frame is the page frame to be granted, and flags is + * status of the grant entry to be updated. + */ + void (*update_entry)(grant_ref_t ref, domid_t domid, + unsigned long frame, unsigned flags); + /* + * Stop granting a grant entry to domain for accessing. Ref parameter is + * reference of a grant entry whose grant access will be stopped, + * readonly is not in use in this function. If the grant entry is + * currently mapped for reading or writing, just return failure(==0) + * directly and don't tear down the grant access. Otherwise, stop grant + * access for this entry and return success(==1). + */ + int (*end_foreign_access_ref)(grant_ref_t ref, int readonly); + /* + * Stop granting a grant entry to domain for transfer. Ref parameter is + * reference of a grant entry whose grant transfer will be stopped. If + * tranfer has not started, just reclaim the grant entry and return + * failure(==0). Otherwise, wait for the transfer to complete and then + * return the frame. + */ + unsigned long (*end_foreign_transfer_ref)(grant_ref_t ref); + /* + * Query the status of a grant entry. Ref parameter is reference of + * queried grant entry, return value is the status of queried entry. + * Detailed status(writing/reading) can be gotten from the return value + * by bit operations. + */ + int (*query_foreign_access)(grant_ref_t ref); +}; + +struct unmap_refs_callback_data { + struct completion completion; + int result; +}; + +static struct gnttab_ops *gnttab_interface; + +static int grant_table_version; +static int grefs_per_grant_frame; + +static struct gnttab_free_callback *gnttab_free_callback_list; + +static int gnttab_expand(unsigned int req_entries); + +#define RPP (PAGE_SIZE / sizeof(grant_ref_t)) +#define SPP (PAGE_SIZE / sizeof(grant_status_t)) + +static inline grant_ref_t *__gnttab_entry(grant_ref_t entry) +{ + return &gnttab_list[(entry) / RPP][(entry) % RPP]; +} +/* This can be used as an l-value */ +#define gnttab_entry(entry) (*__gnttab_entry(entry)) + +static int get_free_entries(unsigned count) +{ + unsigned long flags; + int ref, rc = 0; + grant_ref_t head; + + spin_lock_irqsave(&gnttab_list_lock, flags); + + if ((gnttab_free_count < count) && + ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) { + spin_unlock_irqrestore(&gnttab_list_lock, flags); + return rc; + } + + ref = head = gnttab_free_head; + gnttab_free_count -= count; + while (count-- > 1) + head = gnttab_entry(head); + gnttab_free_head = gnttab_entry(head); + gnttab_entry(head) = GNTTAB_LIST_END; + + spin_unlock_irqrestore(&gnttab_list_lock, flags); + + return ref; +} + +static void do_free_callbacks(void) +{ + struct gnttab_free_callback *callback, *next; + + callback = gnttab_free_callback_list; + gnttab_free_callback_list = NULL; + + while (callback != NULL) { + next = callback->next; + if (gnttab_free_count >= callback->count) { + callback->next = NULL; + callback->fn(callback->arg); + } else { + callback->next = gnttab_free_callback_list; + gnttab_free_callback_list = callback; + } + callback = next; + } +} + +static inline void check_free_callbacks(void) +{ + if (unlikely(gnttab_free_callback_list)) + do_free_callbacks(); +} + +static void put_free_entry(grant_ref_t ref) +{ + unsigned long flags; + spin_lock_irqsave(&gnttab_list_lock, flags); + gnttab_entry(ref) = gnttab_free_head; + gnttab_free_head = ref; + gnttab_free_count++; + check_free_callbacks(); + spin_unlock_irqrestore(&gnttab_list_lock, flags); +} + +/* + * Following applies to gnttab_update_entry_v1. + * Introducing a valid entry into the grant table: + * 1. Write ent->domid. + * 2. Write ent->frame: + * GTF_permit_access: Frame to which access is permitted. + * GTF_accept_transfer: Pseudo-phys frame slot being filled by new + * frame, or zero if none. + * 3. Write memory barrier (WMB). + * 4. Write ent->flags, inc. valid type. + */ +static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid, + unsigned long frame, unsigned flags) +{ + gnttab_shared.v1[ref].domid = domid; + gnttab_shared.v1[ref].frame = frame; + wmb(); + gnttab_shared.v1[ref].flags = flags; +} + +/* + * Public grant-issuing interface functions + */ +void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, + unsigned long frame, int readonly) +{ + gnttab_interface->update_entry(ref, domid, frame, + GTF_permit_access | (readonly ? GTF_readonly : 0)); +} +EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref); + +int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, + int readonly) +{ + int ref; + + ref = get_free_entries(1); + if (unlikely(ref < 0)) + return -ENOSPC; + + gnttab_grant_foreign_access_ref(ref, domid, frame, readonly); + + return ref; +} +EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); + +static int gnttab_query_foreign_access_v1(grant_ref_t ref) +{ + return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); +} + +int gnttab_query_foreign_access(grant_ref_t ref) +{ + return gnttab_interface->query_foreign_access(ref); +} +EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); + +static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) +{ + u16 flags, nflags; + u16 *pflags; + + pflags = &gnttab_shared.v1[ref].flags; + nflags = *pflags; + do { + flags = nflags; + if (flags & (GTF_reading|GTF_writing)) + return 0; + } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); + + return 1; +} + +static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) +{ + return gnttab_interface->end_foreign_access_ref(ref, readonly); +} + +int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) +{ + if (_gnttab_end_foreign_access_ref(ref, readonly)) + return 1; + pr_warn("WARNING: g.e. %#x still in use!\n", ref); + return 0; +} +EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); + +struct deferred_entry { + struct list_head list; + grant_ref_t ref; + bool ro; + uint16_t warn_delay; + struct page *page; +}; +static LIST_HEAD(deferred_list); +static void gnttab_handle_deferred(unsigned long); +static DEFINE_TIMER(deferred_timer, gnttab_handle_deferred, 0, 0); + +static void gnttab_handle_deferred(unsigned long unused) +{ + unsigned int nr = 10; + struct deferred_entry *first = NULL; + unsigned long flags; + + spin_lock_irqsave(&gnttab_list_lock, flags); + while (nr--) { + struct deferred_entry *entry + = list_first_entry(&deferred_list, + struct deferred_entry, list); + + if (entry == first) + break; + list_del(&entry->list); + spin_unlock_irqrestore(&gnttab_list_lock, flags); + if (_gnttab_end_foreign_access_ref(entry->ref, entry->ro)) { + put_free_entry(entry->ref); + if (entry->page) { + pr_debug("freeing g.e. %#x (pfn %#lx)\n", + entry->ref, page_to_pfn(entry->page)); + __free_page(entry->page); + } else + pr_info("freeing g.e. %#x\n", entry->ref); + kfree(entry); + entry = NULL; + } else { + if (!--entry->warn_delay) + pr_info("g.e. %#x still pending\n", entry->ref); + if (!first) + first = entry; + } + spin_lock_irqsave(&gnttab_list_lock, flags); + if (entry) + list_add_tail(&entry->list, &deferred_list); + else if (list_empty(&deferred_list)) + break; + } + if (!list_empty(&deferred_list) && !timer_pending(&deferred_timer)) { + deferred_timer.expires = jiffies + HZ; + add_timer(&deferred_timer); + } + spin_unlock_irqrestore(&gnttab_list_lock, flags); +} + +static void gnttab_add_deferred(grant_ref_t ref, bool readonly, + struct page *page) +{ + struct deferred_entry *entry = kmalloc(sizeof(*entry), GFP_ATOMIC); + const char *what = KERN_WARNING "leaking"; + + if (entry) { + unsigned long flags; + + entry->ref = ref; + entry->ro = readonly; + entry->page = page; + entry->warn_delay = 60; + spin_lock_irqsave(&gnttab_list_lock, flags); + list_add_tail(&entry->list, &deferred_list); + if (!timer_pending(&deferred_timer)) { + deferred_timer.expires = jiffies + HZ; + add_timer(&deferred_timer); + } + spin_unlock_irqrestore(&gnttab_list_lock, flags); + what = KERN_DEBUG "deferring"; + } + printk("%s g.e. %#x (pfn %#lx)\n", + what, ref, page ? page_to_pfn(page) : -1); +} + +void gnttab_end_foreign_access(grant_ref_t ref, int readonly, + unsigned long page) +{ + if (gnttab_end_foreign_access_ref(ref, readonly)) { + put_free_entry(ref); + if (page != 0) + free_page(page); + } else + gnttab_add_deferred(ref, readonly, + page ? virt_to_page(page) : NULL); +} +EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); + +int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) +{ + int ref; + + ref = get_free_entries(1); + if (unlikely(ref < 0)) + return -ENOSPC; + gnttab_grant_foreign_transfer_ref(ref, domid, pfn); + + return ref; +} +EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); + +void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, + unsigned long pfn) +{ + gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); +} +EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); + +static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) +{ + unsigned long frame; + u16 flags; + u16 *pflags; + + pflags = &gnttab_shared.v1[ref].flags; + + /* + * If a transfer is not even yet started, try to reclaim the grant + * reference and return failure (== 0). + */ + while (!((flags = *pflags) & GTF_transfer_committed)) { + if (sync_cmpxchg(pflags, flags, 0) == flags) + return 0; + cpu_relax(); + } + + /* If a transfer is in progress then wait until it is completed. */ + while (!(flags & GTF_transfer_completed)) { + flags = *pflags; + cpu_relax(); + } + + rmb(); /* Read the frame number /after/ reading completion status. */ + frame = gnttab_shared.v1[ref].frame; + BUG_ON(frame == 0); + + return frame; +} + +unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) +{ + return gnttab_interface->end_foreign_transfer_ref(ref); +} +EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); + +unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) +{ + unsigned long frame = gnttab_end_foreign_transfer_ref(ref); + put_free_entry(ref); + return frame; +} +EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); + +void gnttab_free_grant_reference(grant_ref_t ref) +{ + put_free_entry(ref); +} +EXPORT_SYMBOL_GPL(gnttab_free_grant_reference); + +void gnttab_free_grant_references(grant_ref_t head) +{ + grant_ref_t ref; + unsigned long flags; + int count = 1; + if (head == GNTTAB_LIST_END) + return; + spin_lock_irqsave(&gnttab_list_lock, flags); + ref = head; + while (gnttab_entry(ref) != GNTTAB_LIST_END) { + ref = gnttab_entry(ref); + count++; + } + gnttab_entry(ref) = gnttab_free_head; + gnttab_free_head = head; + gnttab_free_count += count; + check_free_callbacks(); + spin_unlock_irqrestore(&gnttab_list_lock, flags); +} +EXPORT_SYMBOL_GPL(gnttab_free_grant_references); + +int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) +{ + int h = get_free_entries(count); + + if (h < 0) + return -ENOSPC; + + *head = h; + + return 0; +} +EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); + +int gnttab_empty_grant_references(const grant_ref_t *private_head) +{ + return (*private_head == GNTTAB_LIST_END); +} +EXPORT_SYMBOL_GPL(gnttab_empty_grant_references); + +int gnttab_claim_grant_reference(grant_ref_t *private_head) +{ + grant_ref_t g = *private_head; + if (unlikely(g == GNTTAB_LIST_END)) + return -ENOSPC; + *private_head = gnttab_entry(g); + return g; +} +EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference); + +void gnttab_release_grant_reference(grant_ref_t *private_head, + grant_ref_t release) +{ + gnttab_entry(release) = *private_head; + *private_head = release; +} +EXPORT_SYMBOL_GPL(gnttab_release_grant_reference); + +void gnttab_request_free_callback(struct gnttab_free_callback *callback, + void (*fn)(void *), void *arg, u16 count) +{ + unsigned long flags; + struct gnttab_free_callback *cb; + + spin_lock_irqsave(&gnttab_list_lock, flags); + + /* Check if the callback is already on the list */ + cb = gnttab_free_callback_list; + while (cb) { + if (cb == callback) + goto out; + cb = cb->next; + } + + callback->fn = fn; + callback->arg = arg; + callback->count = count; + callback->next = gnttab_free_callback_list; + gnttab_free_callback_list = callback; + check_free_callbacks(); +out: + spin_unlock_irqrestore(&gnttab_list_lock, flags); +} +EXPORT_SYMBOL_GPL(gnttab_request_free_callback); + +void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) +{ + struct gnttab_free_callback **pcb; + unsigned long flags; + + spin_lock_irqsave(&gnttab_list_lock, flags); + for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { + if (*pcb == callback) { + *pcb = callback->next; + break; + } + } + spin_unlock_irqrestore(&gnttab_list_lock, flags); +} +EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); + +static int grow_gnttab_list(unsigned int more_frames) +{ + unsigned int new_nr_grant_frames, extra_entries, i; + unsigned int nr_glist_frames, new_nr_glist_frames; + + BUG_ON(grefs_per_grant_frame == 0); + + new_nr_grant_frames = nr_grant_frames + more_frames; + extra_entries = more_frames * grefs_per_grant_frame; + + nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; + new_nr_glist_frames = + (new_nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; + for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { + gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); + if (!gnttab_list[i]) + goto grow_nomem; + } + + + for (i = grefs_per_grant_frame * nr_grant_frames; + i < grefs_per_grant_frame * new_nr_grant_frames - 1; i++) + gnttab_entry(i) = i + 1; + + gnttab_entry(i) = gnttab_free_head; + gnttab_free_head = grefs_per_grant_frame * nr_grant_frames; + gnttab_free_count += extra_entries; + + nr_grant_frames = new_nr_grant_frames; + + check_free_callbacks(); + + return 0; + +grow_nomem: + while (i-- > nr_glist_frames) + free_page((unsigned long) gnttab_list[i]); + return -ENOMEM; +} + +static unsigned int __max_nr_grant_frames(void) +{ + struct gnttab_query_size query; + int rc; + + query.dom = DOMID_SELF; + + rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1); + if ((rc < 0) || (query.status != GNTST_okay)) + return 4; /* Legacy max supported number of frames */ + + return query.max_nr_frames; +} + +unsigned int gnttab_max_grant_frames(void) +{ + unsigned int xen_max = __max_nr_grant_frames(); + static unsigned int boot_max_nr_grant_frames; + + /* First time, initialize it properly. */ + if (!boot_max_nr_grant_frames) + boot_max_nr_grant_frames = __max_nr_grant_frames(); + + if (xen_max > boot_max_nr_grant_frames) + return boot_max_nr_grant_frames; + return xen_max; +} +EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); + +int gnttab_setup_auto_xlat_frames(phys_addr_t addr) +{ + xen_pfn_t *pfn; + unsigned int max_nr_gframes = __max_nr_grant_frames(); + unsigned int i; + void *vaddr; + + if (xen_auto_xlat_grant_frames.count) + return -EINVAL; + + vaddr = xen_remap(addr, PAGE_SIZE * max_nr_gframes); + if (vaddr == NULL) { + pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n", + &addr); + return -ENOMEM; + } + pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL); + if (!pfn) { + xen_unmap(vaddr); + return -ENOMEM; + } + for (i = 0; i < max_nr_gframes; i++) + pfn[i] = PFN_DOWN(addr) + i; + + xen_auto_xlat_grant_frames.vaddr = vaddr; + xen_auto_xlat_grant_frames.pfn = pfn; + xen_auto_xlat_grant_frames.count = max_nr_gframes; + + return 0; +} +EXPORT_SYMBOL_GPL(gnttab_setup_auto_xlat_frames); + +void gnttab_free_auto_xlat_frames(void) +{ + if (!xen_auto_xlat_grant_frames.count) + return; + kfree(xen_auto_xlat_grant_frames.pfn); + xen_unmap(xen_auto_xlat_grant_frames.vaddr); + + xen_auto_xlat_grant_frames.pfn = NULL; + xen_auto_xlat_grant_frames.count = 0; + xen_auto_xlat_grant_frames.vaddr = NULL; +} +EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames); + +/** + * gnttab_alloc_pages - alloc pages suitable for grant mapping into + * @nr_pages: number of pages to alloc + * @pages: returns the pages + */ +int gnttab_alloc_pages(int nr_pages, struct page **pages) +{ + int i; + int ret; + + ret = alloc_xenballooned_pages(nr_pages, pages, false); + if (ret < 0) + return ret; + + for (i = 0; i < nr_pages; i++) { +#if BITS_PER_LONG < 64 + struct xen_page_foreign *foreign; + + foreign = kzalloc(sizeof(*foreign), GFP_KERNEL); + if (!foreign) { + gnttab_free_pages(nr_pages, pages); + return -ENOMEM; + } + set_page_private(pages[i], (unsigned long)foreign); +#endif + SetPagePrivate(pages[i]); + } + + return 0; +} +EXPORT_SYMBOL(gnttab_alloc_pages); + +/** + * gnttab_free_pages - free pages allocated by gnttab_alloc_pages() + * @nr_pages; number of pages to free + * @pages: the pages + */ +void gnttab_free_pages(int nr_pages, struct page **pages) +{ + int i; + + for (i = 0; i < nr_pages; i++) { + if (PagePrivate(pages[i])) { +#if BITS_PER_LONG < 64 + kfree((void *)page_private(pages[i])); +#endif + ClearPagePrivate(pages[i]); + } + } + free_xenballooned_pages(nr_pages, pages); +} +EXPORT_SYMBOL(gnttab_free_pages); + +/* Handling of paged out grant targets (GNTST_eagain) */ +#define MAX_DELAY 256 +static inline void +gnttab_retry_eagain_gop(unsigned int cmd, void *gop, int16_t *status, + const char *func) +{ + unsigned delay = 1; + + do { + BUG_ON(HYPERVISOR_grant_table_op(cmd, gop, 1)); + if (*status == GNTST_eagain) + msleep(delay++); + } while ((*status == GNTST_eagain) && (delay < MAX_DELAY)); + + if (delay >= MAX_DELAY) { + pr_err("%s: %s eagain grant\n", func, current->comm); + *status = GNTST_bad_page; + } +} + +void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count) +{ + struct gnttab_map_grant_ref *op; + + if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, batch, count)) + BUG(); + for (op = batch; op < batch + count; op++) + if (op->status == GNTST_eagain) + gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, op, + &op->status, __func__); +} +EXPORT_SYMBOL_GPL(gnttab_batch_map); + +void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count) +{ + struct gnttab_copy *op; + + if (HYPERVISOR_grant_table_op(GNTTABOP_copy, batch, count)) + BUG(); + for (op = batch; op < batch + count; op++) + if (op->status == GNTST_eagain) + gnttab_retry_eagain_gop(GNTTABOP_copy, op, + &op->status, __func__); +} +EXPORT_SYMBOL_GPL(gnttab_batch_copy); + +int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count) +{ + int i, ret; + + ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); + if (ret) + return ret; + + for (i = 0; i < count; i++) { + /* Retry eagain maps */ + if (map_ops[i].status == GNTST_eagain) + gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, + &map_ops[i].status, __func__); + + if (map_ops[i].status == GNTST_okay) { + struct xen_page_foreign *foreign; + + SetPageForeign(pages[i]); + foreign = xen_page_foreign(pages[i]); + foreign->domid = map_ops[i].dom; + foreign->gref = map_ops[i].ref; + } + } + + return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count); +} +EXPORT_SYMBOL_GPL(gnttab_map_refs); + +int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_unmap_grant_ref *kunmap_ops, + struct page **pages, unsigned int count) +{ + unsigned int i; + int ret; + + ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); + if (ret) + return ret; + + for (i = 0; i < count; i++) + ClearPageForeign(pages[i]); + + return clear_foreign_p2m_mapping(unmap_ops, kunmap_ops, pages, count); +} +EXPORT_SYMBOL_GPL(gnttab_unmap_refs); + +#define GNTTAB_UNMAP_REFS_DELAY 5 + +static void __gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item); + +static void gnttab_unmap_work(struct work_struct *work) +{ + struct gntab_unmap_queue_data + *unmap_data = container_of(work, + struct gntab_unmap_queue_data, + gnttab_work.work); + if (unmap_data->age != UINT_MAX) + unmap_data->age++; + __gnttab_unmap_refs_async(unmap_data); +} + +static void __gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item) +{ + int ret; + int pc; + + for (pc = 0; pc < item->count; pc++) { + if (page_count(item->pages[pc]) > 1) { + unsigned long delay = GNTTAB_UNMAP_REFS_DELAY * (item->age + 1); + schedule_delayed_work(&item->gnttab_work, + msecs_to_jiffies(delay)); + return; + } + } + + ret = gnttab_unmap_refs(item->unmap_ops, item->kunmap_ops, + item->pages, item->count); + item->done(ret, item); +} + +void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item) +{ + INIT_DELAYED_WORK(&item->gnttab_work, gnttab_unmap_work); + item->age = 0; + + __gnttab_unmap_refs_async(item); +} +EXPORT_SYMBOL_GPL(gnttab_unmap_refs_async); + +static void unmap_refs_callback(int result, + struct gntab_unmap_queue_data *data) +{ + struct unmap_refs_callback_data *d = data->data; + + d->result = result; + complete(&d->completion); +} + +int gnttab_unmap_refs_sync(struct gntab_unmap_queue_data *item) +{ + struct unmap_refs_callback_data data; + + init_completion(&data.completion); + item->data = &data; + item->done = &unmap_refs_callback; + gnttab_unmap_refs_async(item); + wait_for_completion(&data.completion); + + return data.result; +} +EXPORT_SYMBOL_GPL(gnttab_unmap_refs_sync); + +static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes) +{ + int rc; + + rc = arch_gnttab_map_shared(frames, nr_gframes, + gnttab_max_grant_frames(), + &gnttab_shared.addr); + BUG_ON(rc); + + return 0; +} + +static void gnttab_unmap_frames_v1(void) +{ + arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); +} + +static int gnttab_map(unsigned int start_idx, unsigned int end_idx) +{ + struct gnttab_setup_table setup; + xen_pfn_t *frames; + unsigned int nr_gframes = end_idx + 1; + int rc; + + if (xen_feature(XENFEAT_auto_translated_physmap)) { + struct xen_add_to_physmap xatp; + unsigned int i = end_idx; + rc = 0; + BUG_ON(xen_auto_xlat_grant_frames.count < nr_gframes); + /* + * Loop backwards, so that the first hypercall has the largest + * index, ensuring that the table will grow only once. + */ + do { + xatp.domid = DOMID_SELF; + xatp.idx = i; + xatp.space = XENMAPSPACE_grant_table; + xatp.gpfn = xen_auto_xlat_grant_frames.pfn[i]; + rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); + if (rc != 0) { + pr_warn("grant table add_to_physmap failed, err=%d\n", + rc); + break; + } + } while (i-- > start_idx); + + return rc; + } + + /* No need for kzalloc as it is initialized in following hypercall + * GNTTABOP_setup_table. + */ + frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC); + if (!frames) + return -ENOMEM; + + setup.dom = DOMID_SELF; + setup.nr_frames = nr_gframes; + set_xen_guest_handle(setup.frame_list, frames); + + rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1); + if (rc == -ENOSYS) { + kfree(frames); + return -ENOSYS; + } + + BUG_ON(rc || setup.status); + + rc = gnttab_interface->map_frames(frames, nr_gframes); + + kfree(frames); + + return rc; +} + +static struct gnttab_ops gnttab_v1_ops = { + .map_frames = gnttab_map_frames_v1, + .unmap_frames = gnttab_unmap_frames_v1, + .update_entry = gnttab_update_entry_v1, + .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1, + .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1, + .query_foreign_access = gnttab_query_foreign_access_v1, +}; + +static void gnttab_request_version(void) +{ + /* Only version 1 is used, which will always be available. */ + grant_table_version = 1; + grefs_per_grant_frame = PAGE_SIZE / sizeof(struct grant_entry_v1); + gnttab_interface = &gnttab_v1_ops; + + pr_info("Grant tables using version %d layout\n", grant_table_version); +} + +static int gnttab_setup(void) +{ + unsigned int max_nr_gframes; + + max_nr_gframes = gnttab_max_grant_frames(); + if (max_nr_gframes < nr_grant_frames) + return -ENOSYS; + + if (xen_feature(XENFEAT_auto_translated_physmap) && gnttab_shared.addr == NULL) { + gnttab_shared.addr = xen_auto_xlat_grant_frames.vaddr; + if (gnttab_shared.addr == NULL) { + pr_warn("gnttab share frames (addr=0x%08lx) is not mapped!\n", + (unsigned long)xen_auto_xlat_grant_frames.vaddr); + return -ENOMEM; + } + } + return gnttab_map(0, nr_grant_frames - 1); +} + +int gnttab_resume(void) +{ + gnttab_request_version(); + return gnttab_setup(); +} + +int gnttab_suspend(void) +{ + if (!xen_feature(XENFEAT_auto_translated_physmap)) + gnttab_interface->unmap_frames(); + return 0; +} + +static int gnttab_expand(unsigned int req_entries) +{ + int rc; + unsigned int cur, extra; + + BUG_ON(grefs_per_grant_frame == 0); + cur = nr_grant_frames; + extra = ((req_entries + (grefs_per_grant_frame-1)) / + grefs_per_grant_frame); + if (cur + extra > gnttab_max_grant_frames()) + return -ENOSPC; + + rc = gnttab_map(cur, cur + extra - 1); + if (rc == 0) + rc = grow_gnttab_list(extra); + + return rc; +} + +int gnttab_init(void) +{ + int i; + unsigned long max_nr_grant_frames; + unsigned int max_nr_glist_frames, nr_glist_frames; + unsigned int nr_init_grefs; + int ret; + + gnttab_request_version(); + max_nr_grant_frames = gnttab_max_grant_frames(); + nr_grant_frames = 1; + + /* Determine the maximum number of frames required for the + * grant reference free list on the current hypervisor. + */ + BUG_ON(grefs_per_grant_frame == 0); + max_nr_glist_frames = (max_nr_grant_frames * + grefs_per_grant_frame / RPP); + + gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), + GFP_KERNEL); + if (gnttab_list == NULL) + return -ENOMEM; + + nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; + for (i = 0; i < nr_glist_frames; i++) { + gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); + if (gnttab_list[i] == NULL) { + ret = -ENOMEM; + goto ini_nomem; + } + } + + ret = arch_gnttab_init(max_nr_grant_frames); + if (ret < 0) + goto ini_nomem; + + if (gnttab_setup() < 0) { + ret = -ENODEV; + goto ini_nomem; + } + + nr_init_grefs = nr_grant_frames * grefs_per_grant_frame; + + for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) + gnttab_entry(i) = i + 1; + + gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; + gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; + gnttab_free_head = NR_RESERVED_ENTRIES; + + printk("Grant table initialized\n"); + return 0; + + ini_nomem: + for (i--; i >= 0; i--) + free_page((unsigned long)gnttab_list[i]); + kfree(gnttab_list); + return ret; +} +EXPORT_SYMBOL_GPL(gnttab_init); + +static int __gnttab_init(void) +{ + /* Delay grant-table initialization in the PV on HVM case */ + if (xen_hvm_domain()) + return 0; + + if (!xen_pv_domain()) + return -ENODEV; + + return gnttab_init(); +} +/* Starts after core_initcall so that xen_pvh_gnttab_setup can be called + * beforehand to initialize xen_auto_xlat_grant_frames. */ +core_initcall_sync(__gnttab_init); |