diff options
| -rw-r--r-- | arch/x86/xen/grant-table.c | 7 | ||||
| -rw-r--r-- | drivers/xen/grant-table.c | 181 | ||||
| -rw-r--r-- | include/xen/grant_table.h | 4 | ||||
| -rw-r--r-- | include/xen/interface/grant_table.h | 167 | ||||
| -rw-r--r-- | include/xen/interface/xen.h | 2 |
5 files changed, 310 insertions, 51 deletions
diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c index 6bbfd7a..c6ab2e7 100644 --- a/arch/x86/xen/grant-table.c +++ b/arch/x86/xen/grant-table.c @@ -64,10 +64,10 @@ static int unmap_pte_fn(pte_t *pte, struct page *pmd_page, int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes, unsigned long max_nr_gframes, - struct grant_entry **__shared) + void **__shared) { int rc; - struct grant_entry *shared = *__shared; + void *shared = *__shared; if (shared == NULL) { struct vm_struct *area = @@ -83,8 +83,7 @@ int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes, return rc; } -void arch_gnttab_unmap_shared(struct grant_entry *shared, - unsigned long nr_gframes) +void arch_gnttab_unmap_shared(void *shared, unsigned long nr_gframes) { apply_to_page_range(&init_mm, (unsigned long)shared, PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL); diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index bf1c094..18355a5 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -53,7 +53,7 @@ /* External tools reserve first few grant table entries. */ #define NR_RESERVED_ENTRIES 8 #define GNTTAB_LIST_END 0xffffffff -#define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(struct grant_entry)) +#define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(struct grant_entry_v1)) static grant_ref_t **gnttab_list; static unsigned int nr_grant_frames; @@ -64,7 +64,63 @@ static DEFINE_SPINLOCK(gnttab_list_lock); unsigned long xen_hvm_resume_frames; EXPORT_SYMBOL_GPL(xen_hvm_resume_frames); -static struct grant_entry *shared; +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. First input + * parameter is used to storing grant table address when grant table + * being setup, second parameter is the number of frames to map grant + * table. Returning GNTST_okay means success and negative value means + * failure. + */ + int (*map_frames)(unsigned long *, unsigned int); + /* + * 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, or + * transitively accessing. First input parameter is reference of this + * introduced grant entry, second one is domid of granted domain, third + * one is the frame to be granted, and the last one is status of the + * grant entry to be updated. + */ + void (*update_entry)(grant_ref_t, domid_t, unsigned long, unsigned); + /* + * Stop granting a grant entry to domain for accessing. First input + * parameter is reference of a grant entry whose grant access will be + * stopped, second one is not in use now. 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, int); + /* + * Stop granting a grant entry to domain for transfer. 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); + /* + * Query the status of a grant entry. Input 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); +}; + +static struct gnttab_ops *gnttab_interface; + +static int grant_table_version; static struct gnttab_free_callback *gnttab_free_callback_list; @@ -142,23 +198,23 @@ static void put_free_entry(grant_ref_t ref) spin_unlock_irqrestore(&gnttab_list_lock, flags); } -static void update_grant_entry(grant_ref_t ref, domid_t domid, - unsigned long frame, unsigned flags) +/* + * 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) { - /* - * 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. - */ - shared[ref].frame = frame; - shared[ref].domid = domid; + gnttab_shared.v1[ref].domid = domid; + gnttab_shared.v1[ref].frame = frame; wmb(); - shared[ref].flags = flags; + gnttab_shared.v1[ref].flags = flags; } /* @@ -167,7 +223,7 @@ static void update_grant_entry(grant_ref_t ref, domid_t domid, void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, unsigned long frame, int readonly) { - update_grant_entry(ref, domid, frame, + gnttab_interface->update_entry(ref, domid, frame, GTF_permit_access | (readonly ? GTF_readonly : 0)); } EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref); @@ -187,31 +243,37 @@ int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, } EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); -int gnttab_query_foreign_access(grant_ref_t ref) +static int gnttab_query_foreign_access_v1(grant_ref_t ref) { - u16 nflags; - - nflags = shared[ref].flags; + return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); +} - return nflags & (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); -int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) +static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) { u16 flags, nflags; - nflags = shared[ref].flags; + nflags = gnttab_shared.v1[ref].flags; do { flags = nflags; if (flags & (GTF_reading|GTF_writing)) { printk(KERN_ALERT "WARNING: g.e. still in use!\n"); return 0; } - } while ((nflags = sync_cmpxchg(&shared[ref].flags, flags, 0)) != flags); + } while ((nflags = sync_cmpxchg(&gnttab_shared.v1[ref].flags, flags, 0)) != flags); return 1; } + +int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) +{ + return gnttab_interface->end_foreign_access_ref(ref, readonly); +} EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); void gnttab_end_foreign_access(grant_ref_t ref, int readonly, @@ -246,11 +308,11 @@ EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, unsigned long pfn) { - update_grant_entry(ref, domid, pfn, GTF_accept_transfer); + gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); } EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); -unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) +static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) { unsigned long frame; u16 flags; @@ -259,24 +321,29 @@ unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) * 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 (sync_cmpxchg(&shared[ref].flags, flags, 0) == flags) + while (!((flags = gnttab_shared.v1[ref].flags) & GTF_transfer_committed)) { + if (sync_cmpxchg(&gnttab_shared.v1[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; + flags = gnttab_shared.v1[ref].flags; cpu_relax(); } rmb(); /* Read the frame number /after/ reading completion status. */ - frame = shared[ref].frame; + 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) @@ -520,6 +587,23 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, } EXPORT_SYMBOL_GPL(gnttab_unmap_refs); +static int gnttab_map_frames_v1(unsigned long *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_shared(gnttab_shared.addr, nr_grant_frames); +} + static int gnttab_map(unsigned int start_idx, unsigned int end_idx) { struct gnttab_setup_table setup; @@ -567,19 +651,35 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx) BUG_ON(rc || setup.status); - rc = arch_gnttab_map_shared(frames, nr_gframes, gnttab_max_grant_frames(), - &shared); - BUG_ON(rc); + rc = gnttab_interface->map_frames(frames, nr_gframes); kfree(frames); - return 0; + 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) +{ + grant_table_version = 1; + gnttab_interface = &gnttab_v1_ops; + printk(KERN_INFO "Grant tables using version %d layout.\n", + grant_table_version); } int gnttab_resume(void) { unsigned int max_nr_gframes; + gnttab_request_version(); max_nr_gframes = gnttab_max_grant_frames(); if (max_nr_gframes < nr_grant_frames) return -ENOSYS; @@ -587,9 +687,10 @@ int gnttab_resume(void) if (xen_pv_domain()) return gnttab_map(0, nr_grant_frames - 1); - if (!shared) { - shared = ioremap(xen_hvm_resume_frames, PAGE_SIZE * max_nr_gframes); - if (shared == NULL) { + if (gnttab_shared.addr == NULL) { + gnttab_shared.addr = ioremap(xen_hvm_resume_frames, + PAGE_SIZE * max_nr_gframes); + if (gnttab_shared.addr == NULL) { printk(KERN_WARNING "Failed to ioremap gnttab share frames!"); return -ENOMEM; @@ -603,7 +704,7 @@ int gnttab_resume(void) int gnttab_suspend(void) { - arch_gnttab_unmap_shared(shared, nr_grant_frames); + gnttab_interface->unmap_frames(); return 0; } diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index 11e2dfc..c7a40f8 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -145,8 +145,8 @@ gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes, unsigned long max_nr_gframes, - struct grant_entry **__shared); -void arch_gnttab_unmap_shared(struct grant_entry *shared, + void **__shared); +void arch_gnttab_unmap_shared(void *shared, unsigned long nr_gframes); extern unsigned long xen_hvm_resume_frames; diff --git a/include/xen/interface/grant_table.h b/include/xen/interface/grant_table.h index 39e5717..a17d844 100644 --- a/include/xen/interface/grant_table.h +++ b/include/xen/interface/grant_table.h @@ -85,12 +85,22 @@ */ /* + * Reference to a grant entry in a specified domain's grant table. + */ +typedef uint32_t grant_ref_t; + +/* * A grant table comprises a packed array of grant entries in one or more * page frames shared between Xen and a guest. * [XEN]: This field is written by Xen and read by the sharing guest. * [GST]: This field is written by the guest and read by Xen. */ -struct grant_entry { + +/* + * Version 1 of the grant table entry structure is maintained purely + * for backwards compatibility. New guests should use version 2. + */ +struct grant_entry_v1 { /* GTF_xxx: various type and flag information. [XEN,GST] */ uint16_t flags; /* The domain being granted foreign privileges. [GST] */ @@ -108,10 +118,13 @@ struct grant_entry { * GTF_permit_access: Allow @domid to map/access @frame. * GTF_accept_transfer: Allow @domid to transfer ownership of one page frame * to this guest. Xen writes the page number to @frame. + * GTF_transitive: Allow @domid to transitively access a subrange of + * @trans_grant in @trans_domid. No mappings are allowed. */ #define GTF_invalid (0U<<0) #define GTF_permit_access (1U<<0) #define GTF_accept_transfer (2U<<0) +#define GTF_transitive (3U<<0) #define GTF_type_mask (3U<<0) /* @@ -119,6 +132,9 @@ struct grant_entry { * GTF_readonly: Restrict @domid to read-only mappings and accesses. [GST] * GTF_reading: Grant entry is currently mapped for reading by @domid. [XEN] * GTF_writing: Grant entry is currently mapped for writing by @domid. [XEN] + * GTF_sub_page: Grant access to only a subrange of the page. @domid + * will only be allowed to copy from the grant, and not + * map it. [GST] */ #define _GTF_readonly (2) #define GTF_readonly (1U<<_GTF_readonly) @@ -126,6 +142,8 @@ struct grant_entry { #define GTF_reading (1U<<_GTF_reading) #define _GTF_writing (4) #define GTF_writing (1U<<_GTF_writing) +#define _GTF_sub_page (8) +#define GTF_sub_page (1U<<_GTF_sub_page) /* * Subflags for GTF_accept_transfer: @@ -142,15 +160,81 @@ struct grant_entry { #define _GTF_transfer_completed (3) #define GTF_transfer_completed (1U<<_GTF_transfer_completed) +/* + * Version 2 grant table entries. These fulfil the same role as + * version 1 entries, but can represent more complicated operations. + * Any given domain will have either a version 1 or a version 2 table, + * and every entry in the table will be the same version. + * + * The interface by which domains use grant references does not depend + * on the grant table version in use by the other domain. + */ -/*********************************** - * GRANT TABLE QUERIES AND USES +/* + * Version 1 and version 2 grant entries share a common prefix. The + * fields of the prefix are documented as part of struct + * grant_entry_v1. */ +struct grant_entry_header { + uint16_t flags; + domid_t domid; +}; /* - * Reference to a grant entry in a specified domain's grant table. + * Version 2 of the grant entry structure, here is an union because three + * different types are suppotted: full_page, sub_page and transitive. + */ +union grant_entry_v2 { + struct grant_entry_header hdr; + + /* + * This member is used for V1-style full page grants, where either: + * + * -- hdr.type is GTF_accept_transfer, or + * -- hdr.type is GTF_permit_access and GTF_sub_page is not set. + * + * In that case, the frame field has the same semantics as the + * field of the same name in the V1 entry structure. + */ + struct { + struct grant_entry_header hdr; + uint32_t pad0; + uint64_t frame; + } full_page; + + /* + * If the grant type is GTF_grant_access and GTF_sub_page is set, + * @domid is allowed to access bytes [@page_off,@page_off+@length) + * in frame @frame. + */ + struct { + struct grant_entry_header hdr; + uint16_t page_off; + uint16_t length; + uint64_t frame; + } sub_page; + + /* + * If the grant is GTF_transitive, @domid is allowed to use the + * grant @gref in domain @trans_domid, as if it was the local + * domain. Obviously, the transitive access must be compatible + * with the original grant. + */ + struct { + struct grant_entry_header hdr; + domid_t trans_domid; + uint16_t pad0; + grant_ref_t gref; + } transitive; + + uint32_t __spacer[4]; /* Pad to a power of two */ +}; + +typedef uint16_t grant_status_t; + +/*********************************** + * GRANT TABLE QUERIES AND USES */ -typedef uint32_t grant_ref_t; /* * Handle to track a mapping created via a grant reference. @@ -322,6 +406,79 @@ struct gnttab_query_size { DEFINE_GUEST_HANDLE_STRUCT(gnttab_query_size); /* + * GNTTABOP_unmap_and_replace: Destroy one or more grant-reference mappings + * tracked by <handle> but atomically replace the page table entry with one + * pointing to the machine address under <new_addr>. <new_addr> will be + * redirected to the null entry. + * NOTES: + * 1. The call may fail in an undefined manner if either mapping is not + * tracked by <handle>. + * 2. After executing a batch of unmaps, it is guaranteed that no stale + * mappings will remain in the device or host TLBs. + */ +#define GNTTABOP_unmap_and_replace 7 +struct gnttab_unmap_and_replace { + /* IN parameters. */ + uint64_t host_addr; + uint64_t new_addr; + grant_handle_t handle; + /* OUT parameters. */ + int16_t status; /* GNTST_* */ +}; +DEFINE_GUEST_HANDLE_STRUCT(gnttab_unmap_and_replace); + +/* + * GNTTABOP_set_version: Request a particular version of the grant + * table shared table structure. This operation can only be performed + * once in any given domain. It must be performed before any grants + * are activated; otherwise, the domain will be stuck with version 1. + * The only defined versions are 1 and 2. + */ +#define GNTTABOP_set_version 8 +struct gnttab_set_version { + /* IN parameters */ + uint32_t version; +}; +DEFINE_GUEST_HANDLE_STRUCT(gnttab_set_version); + +/* + * GNTTABOP_get_status_frames: Get the list of frames used to store grant + * status for <dom>. In grant format version 2, the status is separated + * from the other shared grant fields to allow more efficient synchronization + * using barriers instead of atomic cmpexch operations. + * <nr_frames> specify the size of vector <frame_list>. + * The frame addresses are returned in the <frame_list>. + * Only <nr_frames> addresses are returned, even if the table is larger. + * NOTES: + * 1. <dom> may be specified as DOMID_SELF. + * 2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF. + */ +#define GNTTABOP_get_status_frames 9 +struct gnttab_get_status_frames { + /* IN parameters. */ + uint32_t nr_frames; + domid_t dom; + /* OUT parameters. */ + int16_t status; /* GNTST_* */ + GUEST_HANDLE(uint64_t) frame_list; +}; +DEFINE_GUEST_HANDLE_STRUCT(gnttab_get_status_frames); + +/* + * GNTTABOP_get_version: Get the grant table version which is in + * effect for domain <dom>. + */ +#define GNTTABOP_get_version 10 +struct gnttab_get_version { + /* IN parameters */ + domid_t dom; + uint16_t pad; + /* OUT parameters */ + uint32_t version; +}; +DEFINE_GUEST_HANDLE_STRUCT(gnttab_get_version); + +/* * Bitfield values for update_pin_status.flags. */ /* Map the grant entry for access by I/O devices. */ diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h index 6a6e914..a890804 100644 --- a/include/xen/interface/xen.h +++ b/include/xen/interface/xen.h @@ -523,6 +523,8 @@ struct tmem_op { } u; }; +DEFINE_GUEST_HANDLE(u64); + #else /* __ASSEMBLY__ */ /* In assembly code we cannot use C numeric constant suffixes. */ |