diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/xen/grant-table.c | 309 |
1 files changed, 6 insertions, 303 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index eeba7544f0cd..c254ae036f18 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -69,7 +69,6 @@ struct grant_frames xen_auto_xlat_grant_frames; static union { struct grant_entry_v1 *v1; - union grant_entry_v2 *v2; void *addr; } gnttab_shared; @@ -120,36 +119,10 @@ struct gnttab_ops { * by bit operations. */ int (*query_foreign_access)(grant_ref_t ref); - /* - * Grant a domain to access a range of bytes within the page referred by - * an available grant entry. Ref parameter is reference of a grant entry - * which will be sub-page accessed, domid is id of grantee domain, frame - * is frame address of subpage grant, flags is grant type and flag - * information, page_off is offset of the range of bytes, and length is - * length of bytes to be accessed. - */ - void (*update_subpage_entry)(grant_ref_t ref, domid_t domid, - unsigned long frame, int flags, - unsigned page_off, unsigned length); - /* - * Redirect an available grant entry on domain A to another grant - * reference of domain B, then allow domain C to use grant reference - * of domain B transitively. Ref parameter is an available grant entry - * reference on domain A, domid is id of domain C which accesses grant - * entry transitively, flags is grant type and flag information, - * trans_domid is id of domain B whose grant entry is finally accessed - * transitively, trans_gref is grant entry transitive reference of - * domain B. - */ - void (*update_trans_entry)(grant_ref_t ref, domid_t domid, int flags, - domid_t trans_domid, grant_ref_t trans_gref); }; static struct gnttab_ops *gnttab_interface; -/*This reflects status of grant entries, so act as a global value*/ -static grant_status_t *grstatus; - static int grant_table_version; static int grefs_per_grant_frame; @@ -231,7 +204,7 @@ static void put_free_entry(grant_ref_t ref) } /* - * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2. + * Following applies to gnttab_update_entry_v1. * Introducing a valid entry into the grant table: * 1. Write ent->domid. * 2. Write ent->frame: @@ -250,15 +223,6 @@ static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid, gnttab_shared.v1[ref].flags = flags; } -static void gnttab_update_entry_v2(grant_ref_t ref, domid_t domid, - unsigned long frame, unsigned flags) -{ - gnttab_shared.v2[ref].hdr.domid = domid; - gnttab_shared.v2[ref].full_page.frame = frame; - wmb(); - gnttab_shared.v2[ref].hdr.flags = GTF_permit_access | flags; -} - /* * Public grant-issuing interface functions */ @@ -285,132 +249,11 @@ int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, } EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); -static void gnttab_update_subpage_entry_v2(grant_ref_t ref, domid_t domid, - unsigned long frame, int flags, - unsigned page_off, unsigned length) -{ - gnttab_shared.v2[ref].sub_page.frame = frame; - gnttab_shared.v2[ref].sub_page.page_off = page_off; - gnttab_shared.v2[ref].sub_page.length = length; - gnttab_shared.v2[ref].hdr.domid = domid; - wmb(); - gnttab_shared.v2[ref].hdr.flags = - GTF_permit_access | GTF_sub_page | flags; -} - -int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid, - unsigned long frame, int flags, - unsigned page_off, - unsigned length) -{ - if (flags & (GTF_accept_transfer | GTF_reading | - GTF_writing | GTF_transitive)) - return -EPERM; - - if (gnttab_interface->update_subpage_entry == NULL) - return -ENOSYS; - - gnttab_interface->update_subpage_entry(ref, domid, frame, flags, - page_off, length); - - return 0; -} -EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage_ref); - -int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, - int flags, unsigned page_off, - unsigned length) -{ - int ref, rc; - - ref = get_free_entries(1); - if (unlikely(ref < 0)) - return -ENOSPC; - - rc = gnttab_grant_foreign_access_subpage_ref(ref, domid, frame, flags, - page_off, length); - if (rc < 0) { - put_free_entry(ref); - return rc; - } - - return ref; -} -EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage); - -bool gnttab_subpage_grants_available(void) -{ - return gnttab_interface->update_subpage_entry != NULL; -} -EXPORT_SYMBOL_GPL(gnttab_subpage_grants_available); - -static void gnttab_update_trans_entry_v2(grant_ref_t ref, domid_t domid, - int flags, domid_t trans_domid, - grant_ref_t trans_gref) -{ - gnttab_shared.v2[ref].transitive.trans_domid = trans_domid; - gnttab_shared.v2[ref].transitive.gref = trans_gref; - gnttab_shared.v2[ref].hdr.domid = domid; - wmb(); - gnttab_shared.v2[ref].hdr.flags = - GTF_permit_access | GTF_transitive | flags; -} - -int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid, - int flags, domid_t trans_domid, - grant_ref_t trans_gref) -{ - if (flags & (GTF_accept_transfer | GTF_reading | - GTF_writing | GTF_sub_page)) - return -EPERM; - - if (gnttab_interface->update_trans_entry == NULL) - return -ENOSYS; - - gnttab_interface->update_trans_entry(ref, domid, flags, trans_domid, - trans_gref); - - return 0; -} -EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans_ref); - -int gnttab_grant_foreign_access_trans(domid_t domid, int flags, - domid_t trans_domid, - grant_ref_t trans_gref) -{ - int ref, rc; - - ref = get_free_entries(1); - if (unlikely(ref < 0)) - return -ENOSPC; - - rc = gnttab_grant_foreign_access_trans_ref(ref, domid, flags, - trans_domid, trans_gref); - if (rc < 0) { - put_free_entry(ref); - return rc; - } - - return ref; -} -EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans); - -bool gnttab_trans_grants_available(void) -{ - return gnttab_interface->update_trans_entry != NULL; -} -EXPORT_SYMBOL_GPL(gnttab_trans_grants_available); - static int gnttab_query_foreign_access_v1(grant_ref_t ref) { return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); } -static int gnttab_query_foreign_access_v2(grant_ref_t ref) -{ - return grstatus[ref] & (GTF_reading|GTF_writing); -} - int gnttab_query_foreign_access(grant_ref_t ref) { return gnttab_interface->query_foreign_access(ref); @@ -433,29 +276,6 @@ static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) return 1; } -static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly) -{ - gnttab_shared.v2[ref].hdr.flags = 0; - mb(); - if (grstatus[ref] & (GTF_reading|GTF_writing)) { - return 0; - } else { - /* The read of grstatus needs to have acquire - semantics. On x86, reads already have - that, and we just need to protect against - compiler reorderings. On other - architectures we may need a full - barrier. */ -#ifdef CONFIG_X86 - barrier(); -#else - mb(); -#endif - } - - 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); @@ -616,37 +436,6 @@ static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) return frame; } -static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) -{ - unsigned long frame; - u16 flags; - u16 *pflags; - - pflags = &gnttab_shared.v2[ref].hdr.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.v2[ref].full_page.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); @@ -962,12 +751,6 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, } EXPORT_SYMBOL_GPL(gnttab_unmap_refs); -static unsigned nr_status_frames(unsigned nr_grant_frames) -{ - BUG_ON(grefs_per_grant_frame == 0); - return (nr_grant_frames * grefs_per_grant_frame + SPP - 1) / SPP; -} - static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes) { int rc; @@ -985,55 +768,6 @@ static void gnttab_unmap_frames_v1(void) arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); } -static int gnttab_map_frames_v2(xen_pfn_t *frames, unsigned int nr_gframes) -{ - uint64_t *sframes; - unsigned int nr_sframes; - struct gnttab_get_status_frames getframes; - int rc; - - nr_sframes = nr_status_frames(nr_gframes); - - /* No need for kzalloc as it is initialized in following hypercall - * GNTTABOP_get_status_frames. - */ - sframes = kmalloc(nr_sframes * sizeof(uint64_t), GFP_ATOMIC); - if (!sframes) - return -ENOMEM; - - getframes.dom = DOMID_SELF; - getframes.nr_frames = nr_sframes; - set_xen_guest_handle(getframes.frame_list, sframes); - - rc = HYPERVISOR_grant_table_op(GNTTABOP_get_status_frames, - &getframes, 1); - if (rc == -ENOSYS) { - kfree(sframes); - return -ENOSYS; - } - - BUG_ON(rc || getframes.status); - - rc = arch_gnttab_map_status(sframes, nr_sframes, - nr_status_frames(gnttab_max_grant_frames()), - &grstatus); - BUG_ON(rc); - kfree(sframes); - - 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_v2(void) -{ - arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); - arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames)); -} - static int gnttab_map(unsigned int start_idx, unsigned int end_idx) { struct gnttab_setup_table setup; @@ -1101,43 +835,13 @@ static struct gnttab_ops gnttab_v1_ops = { .query_foreign_access = gnttab_query_foreign_access_v1, }; -static struct gnttab_ops gnttab_v2_ops = { - .map_frames = gnttab_map_frames_v2, - .unmap_frames = gnttab_unmap_frames_v2, - .update_entry = gnttab_update_entry_v2, - .end_foreign_access_ref = gnttab_end_foreign_access_ref_v2, - .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, - .query_foreign_access = gnttab_query_foreign_access_v2, - .update_subpage_entry = gnttab_update_subpage_entry_v2, - .update_trans_entry = gnttab_update_trans_entry_v2, -}; - static void gnttab_request_version(void) { - int rc; - struct gnttab_set_version gsv; + /* 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; - gsv.version = 1; - - rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1); - if (rc == 0 && gsv.version == 2) { - grant_table_version = 2; - grefs_per_grant_frame = PAGE_SIZE / sizeof(union grant_entry_v2); - gnttab_interface = &gnttab_v2_ops; - } else if (grant_table_version == 2) { - /* - * If we've already used version 2 features, - * but then suddenly discover that they're not - * available (e.g. migrating to an older - * version of Xen), almost unbounded badness - * can happen. - */ - panic("we need grant tables version 2, but only version 1 is available"); - } else { - 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); } @@ -1225,8 +929,7 @@ int gnttab_init(void) } } - ret = arch_gnttab_init(max_nr_grant_frames, - nr_status_frames(max_nr_grant_frames)); + ret = arch_gnttab_init(max_nr_grant_frames); if (ret < 0) goto ini_nomem; |