diff options
Diffstat (limited to 'sys/xen/gnttab.c')
| -rw-r--r-- | sys/xen/gnttab.c | 720 |
1 files changed, 0 insertions, 720 deletions
diff --git a/sys/xen/gnttab.c b/sys/xen/gnttab.c deleted file mode 100644 index 9ab3145b4fee..000000000000 --- a/sys/xen/gnttab.c +++ /dev/null @@ -1,720 +0,0 @@ -/****************************************************************************** - * gnttab.c - * - * Two sets of functionality: - * 1. Granting foreign access to our memory reservation. - * 2. Accessing others' memory reservations via grant references. - * (i.e., mechanisms for both sender and recipient of grant references) - * - * Copyright (c) 2005, Christopher Clark - * Copyright (c) 2004, K A Fraser - */ - -#include <sys/cdefs.h> -__FBSDID("$FreeBSD$"); - -#include "opt_pmap.h" - -#include <sys/param.h> -#include <sys/systm.h> -#include <sys/bus.h> -#include <sys/conf.h> -#include <sys/module.h> -#include <sys/kernel.h> -#include <sys/lock.h> -#include <sys/malloc.h> -#include <sys/mman.h> -#include <sys/limits.h> -#include <sys/rman.h> -#include <machine/resource.h> - -#include <xen/xen-os.h> -#include <xen/hypervisor.h> -#include <machine/xen/synch_bitops.h> - -#include <xen/hypervisor.h> -#include <xen/gnttab.h> - -#include <vm/vm.h> -#include <vm/vm_kern.h> -#include <vm/vm_extern.h> -#include <vm/pmap.h> - -#define cmpxchg(a, b, c) atomic_cmpset_int((volatile u_int *)(a),(b),(c)) - -/* External tools reserve first few grant table entries. */ -#define NR_RESERVED_ENTRIES 8 -#define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(grant_entry_t)) - -static grant_ref_t **gnttab_list; -static unsigned int nr_grant_frames; -static unsigned int boot_max_nr_grant_frames; -static int gnttab_free_count; -static grant_ref_t gnttab_free_head; -static struct mtx gnttab_list_lock; - -#ifdef XENHVM -/* - * Resource representing allocated physical address space - * for the grant table metainfo - */ -static struct resource *gnttab_pseudo_phys_res; - -/* Resource id for allocated physical address space. */ -static int gnttab_pseudo_phys_res_id; -#endif - -static grant_entry_t *shared; - -static struct gnttab_free_callback *gnttab_free_callback_list = NULL; - -static int gnttab_expand(unsigned int req_entries); - -#define RPP (PAGE_SIZE / sizeof(grant_ref_t)) -#define gnttab_entry(entry) (gnttab_list[(entry) / RPP][(entry) % RPP]) - -static int -get_free_entries(int count, int *entries) -{ - int ref, error; - grant_ref_t head; - - mtx_lock(&gnttab_list_lock); - if ((gnttab_free_count < count) && - ((error = gnttab_expand(count - gnttab_free_count)) != 0)) { - mtx_unlock(&gnttab_list_lock); - return (error); - } - 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; - mtx_unlock(&gnttab_list_lock); - - *entries = ref; - return (0); -} - -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 (__predict_false(gnttab_free_callback_list != NULL)) - do_free_callbacks(); -} - -static void -put_free_entry(grant_ref_t ref) -{ - - mtx_lock(&gnttab_list_lock); - gnttab_entry(ref) = gnttab_free_head; - gnttab_free_head = ref; - gnttab_free_count++; - check_free_callbacks(); - mtx_unlock(&gnttab_list_lock); -} - -/* - * Public grant-issuing interface functions - */ - -int -gnttab_grant_foreign_access(domid_t domid, unsigned long frame, int readonly, - grant_ref_t *result) -{ - int error, ref; - - error = get_free_entries(1, &ref); - - if (__predict_false(error)) - return (error); - - shared[ref].frame = frame; - shared[ref].domid = domid; - wmb(); - shared[ref].flags = GTF_permit_access | (readonly ? GTF_readonly : 0); - - if (result) - *result = ref; - - return (0); -} - -void -gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, - unsigned long frame, int readonly) -{ - - shared[ref].frame = frame; - shared[ref].domid = domid; - wmb(); - shared[ref].flags = GTF_permit_access | (readonly ? GTF_readonly : 0); -} - -int -gnttab_query_foreign_access(grant_ref_t ref) -{ - uint16_t nflags; - - nflags = shared[ref].flags; - - return (nflags & (GTF_reading|GTF_writing)); -} - -int -gnttab_end_foreign_access_ref(grant_ref_t ref) -{ - uint16_t flags, nflags; - - nflags = shared[ref].flags; - do { - if ( (flags = nflags) & (GTF_reading|GTF_writing) ) { - printf("%s: WARNING: g.e. still in use!\n", __func__); - return (0); - } - } while ((nflags = synch_cmpxchg(&shared[ref].flags, flags, 0)) != - flags); - - return (1); -} - -void -gnttab_end_foreign_access(grant_ref_t ref, void *page) -{ - if (gnttab_end_foreign_access_ref(ref)) { - put_free_entry(ref); - if (page != NULL) { - free(page, M_DEVBUF); - } - } - else { - /* XXX This needs to be fixed so that the ref and page are - placed on a list to be freed up later. */ - printf("%s: WARNING: leaking g.e. and page still in use!\n", - __func__); - } -} - -void -gnttab_end_foreign_access_references(u_int count, grant_ref_t *refs) -{ - grant_ref_t *last_ref; - grant_ref_t head; - grant_ref_t tail; - - head = GNTTAB_LIST_END; - tail = *refs; - last_ref = refs + count; - while (refs != last_ref) { - - if (gnttab_end_foreign_access_ref(*refs)) { - gnttab_entry(*refs) = head; - head = *refs; - } else { - /* - * XXX This needs to be fixed so that the ref - * is placed on a list to be freed up later. - */ - printf("%s: WARNING: leaking g.e. still in use!\n", - __func__); - count--; - } - refs++; - } - - if (count != 0) { - mtx_lock(&gnttab_list_lock); - gnttab_free_count += count; - gnttab_entry(tail) = gnttab_free_head; - gnttab_free_head = head; - mtx_unlock(&gnttab_list_lock); - } -} - -int -gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn, - grant_ref_t *result) -{ - int error, ref; - - error = get_free_entries(1, &ref); - if (__predict_false(error)) - return (error); - - gnttab_grant_foreign_transfer_ref(ref, domid, pfn); - - *result = ref; - return (0); -} - -void -gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, - unsigned long pfn) -{ - shared[ref].frame = pfn; - shared[ref].domid = domid; - wmb(); - shared[ref].flags = GTF_accept_transfer; -} - -unsigned long -gnttab_end_foreign_transfer_ref(grant_ref_t ref) -{ - unsigned long frame; - uint16_t flags; - - /* - * If a transfer is not even yet started, try to reclaim the grant - * reference and return failure (== 0). - */ - while (!((flags = shared[ref].flags) & GTF_transfer_committed)) { - if ( synch_cmpxchg(&shared[ref].flags, 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 = shared[ref].flags; - cpu_relax(); - } - - /* Read the frame number /after/ reading completion status. */ - rmb(); - frame = shared[ref].frame; - KASSERT(frame != 0, ("grant table inconsistent")); - - return (frame); -} - -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); -} - -void -gnttab_free_grant_reference(grant_ref_t ref) -{ - - put_free_entry(ref); -} - -void -gnttab_free_grant_references(grant_ref_t head) -{ - grant_ref_t ref; - int count = 1; - - if (head == GNTTAB_LIST_END) - return; - - ref = head; - while (gnttab_entry(ref) != GNTTAB_LIST_END) { - ref = gnttab_entry(ref); - count++; - } - mtx_lock(&gnttab_list_lock); - gnttab_entry(ref) = gnttab_free_head; - gnttab_free_head = head; - gnttab_free_count += count; - check_free_callbacks(); - mtx_unlock(&gnttab_list_lock); -} - -int -gnttab_alloc_grant_references(uint16_t count, grant_ref_t *head) -{ - int ref, error; - - error = get_free_entries(count, &ref); - if (__predict_false(error)) - return (error); - - *head = ref; - return (0); -} - -int -gnttab_empty_grant_references(const grant_ref_t *private_head) -{ - - return (*private_head == GNTTAB_LIST_END); -} - -int -gnttab_claim_grant_reference(grant_ref_t *private_head) -{ - grant_ref_t g = *private_head; - - if (__predict_false(g == GNTTAB_LIST_END)) - return (g); - *private_head = gnttab_entry(g); - return (g); -} - -void -gnttab_release_grant_reference(grant_ref_t *private_head, grant_ref_t release) -{ - - gnttab_entry(release) = *private_head; - *private_head = release; -} - -void -gnttab_request_free_callback(struct gnttab_free_callback *callback, - void (*fn)(void *), void *arg, uint16_t count) -{ - - mtx_lock(&gnttab_list_lock); - if (callback->next) - goto out; - callback->fn = fn; - callback->arg = arg; - callback->count = count; - callback->next = gnttab_free_callback_list; - gnttab_free_callback_list = callback; - check_free_callbacks(); - out: - mtx_unlock(&gnttab_list_lock); - -} - -void -gnttab_cancel_free_callback(struct gnttab_free_callback *callback) -{ - struct gnttab_free_callback **pcb; - - mtx_lock(&gnttab_list_lock); - for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { - if (*pcb == callback) { - *pcb = callback->next; - break; - } - } - mtx_unlock(&gnttab_list_lock); -} - - -static int -grow_gnttab_list(unsigned int more_frames) -{ - unsigned int new_nr_grant_frames, extra_entries, i; - - new_nr_grant_frames = nr_grant_frames + more_frames; - extra_entries = more_frames * GREFS_PER_GRANT_FRAME; - - for (i = nr_grant_frames; i < new_nr_grant_frames; i++) - { - gnttab_list[i] = (grant_ref_t *) - malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT); - - 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: - for ( ; i >= nr_grant_frames; i--) - free(gnttab_list[i], M_DEVBUF); - 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); -} - -static inline -unsigned int max_nr_grant_frames(void) -{ - unsigned int xen_max = __max_nr_grant_frames(); - - if (xen_max > boot_max_nr_grant_frames) - return (boot_max_nr_grant_frames); - return (xen_max); -} - -#ifdef notyet -/* - * XXX needed for backend support - * - */ -static int -map_pte_fn(pte_t *pte, struct page *pmd_page, - unsigned long addr, void *data) -{ - unsigned long **frames = (unsigned long **)data; - - set_pte_at(&init_mm, addr, pte, pfn_pte_ma((*frames)[0], PAGE_KERNEL)); - (*frames)++; - return 0; -} - -static int -unmap_pte_fn(pte_t *pte, struct page *pmd_page, - unsigned long addr, void *data) -{ - - set_pte_at(&init_mm, addr, pte, __pte(0)); - return 0; -} -#endif - -#ifndef XENHVM - -static int -gnttab_map(unsigned int start_idx, unsigned int end_idx) -{ - struct gnttab_setup_table setup; - u_long *frames; - - unsigned int nr_gframes = end_idx + 1; - int i, rc; - - frames = malloc(nr_gframes * sizeof(unsigned long), M_DEVBUF, M_NOWAIT); - 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) { - free(frames, M_DEVBUF); - return (ENOSYS); - } - KASSERT(!(rc || setup.status), - ("unexpected result from grant_table_op")); - - if (shared == NULL) { - vm_offset_t area; - - area = kva_alloc(PAGE_SIZE * max_nr_grant_frames()); - KASSERT(area, ("can't allocate VM space for grant table")); - shared = (grant_entry_t *)area; - } - - for (i = 0; i < nr_gframes; i++) - PT_SET_MA(((caddr_t)shared) + i*PAGE_SIZE, - ((vm_paddr_t)frames[i]) << PAGE_SHIFT | PG_RW | PG_V); - - free(frames, M_DEVBUF); - - return (0); -} - -int -gnttab_resume(device_t dev) -{ - - if (max_nr_grant_frames() < nr_grant_frames) - return (ENOSYS); - return (gnttab_map(0, nr_grant_frames - 1)); -} - -int -gnttab_suspend(void) -{ - int i; - - for (i = 0; i < nr_grant_frames; i++) - pmap_kremove((vm_offset_t) shared + i * PAGE_SIZE); - - return (0); -} - -#else /* XENHVM */ - -static vm_paddr_t resume_frames; - -static int -gnttab_map(unsigned int start_idx, unsigned int end_idx) -{ - struct xen_add_to_physmap xatp; - unsigned int i = end_idx; - - /* - * 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 = (resume_frames >> PAGE_SHIFT) + i; - if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) - panic("HYPERVISOR_memory_op failed to map gnttab"); - } while (i-- > start_idx); - - if (shared == NULL) { - vm_offset_t area; - - area = kva_alloc(PAGE_SIZE * max_nr_grant_frames()); - KASSERT(area, ("can't allocate VM space for grant table")); - shared = (grant_entry_t *)area; - } - - for (i = start_idx; i <= end_idx; i++) { - pmap_kenter((vm_offset_t) shared + i * PAGE_SIZE, - resume_frames + i * PAGE_SIZE); - } - - return (0); -} - -int -gnttab_resume(device_t dev) -{ - unsigned int max_nr_gframes, nr_gframes; - - nr_gframes = nr_grant_frames; - max_nr_gframes = max_nr_grant_frames(); - if (max_nr_gframes < nr_gframes) - return (ENOSYS); - - if (!resume_frames) { - KASSERT(dev != NULL, - ("No resume frames and no device provided")); - - gnttab_pseudo_phys_res = bus_alloc_resource(dev, - SYS_RES_MEMORY, &gnttab_pseudo_phys_res_id, 0, ~0, - PAGE_SIZE * max_nr_gframes, RF_ACTIVE); - if (gnttab_pseudo_phys_res == NULL) - panic("Unable to reserve physical memory for gnttab"); - resume_frames = rman_get_start(gnttab_pseudo_phys_res); - } - - return (gnttab_map(0, nr_gframes - 1)); -} - -#endif - -static int -gnttab_expand(unsigned int req_entries) -{ - int error; - unsigned int cur, extra; - - cur = nr_grant_frames; - extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) / - GREFS_PER_GRANT_FRAME); - if (cur + extra > max_nr_grant_frames()) - return (ENOSPC); - - error = gnttab_map(cur, cur + extra - 1); - if (!error) - error = grow_gnttab_list(extra); - - return (error); -} - -int -gnttab_init(device_t dev) -{ - int i; - unsigned int max_nr_glist_frames; - unsigned int nr_init_grefs; - - if (!is_running_on_xen()) - return (ENODEV); - - nr_grant_frames = 1; - boot_max_nr_grant_frames = __max_nr_grant_frames(); - - /* Determine the maximum number of frames required for the - * grant reference free list on the current hypervisor. - */ - max_nr_glist_frames = (boot_max_nr_grant_frames * - GREFS_PER_GRANT_FRAME / - (PAGE_SIZE / sizeof(grant_ref_t))); - - gnttab_list = malloc(max_nr_glist_frames * sizeof(grant_ref_t *), - M_DEVBUF, M_NOWAIT); - - if (gnttab_list == NULL) - return (ENOMEM); - - for (i = 0; i < nr_grant_frames; i++) { - gnttab_list[i] = (grant_ref_t *) - malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT); - if (gnttab_list[i] == NULL) - goto ini_nomem; - } - - if (gnttab_resume(dev)) - return (ENODEV); - - 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; - - if (bootverbose) - printf("Grant table initialized\n"); - - return (0); - -ini_nomem: - for (i--; i >= 0; i--) - free(gnttab_list[i], M_DEVBUF); - free(gnttab_list, M_DEVBUF); - return (ENOMEM); - -} - -MTX_SYSINIT(gnttab, &gnttab_list_lock, "GNTTAB LOCK", MTX_DEF); |