@ -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 ;
Linus Torvalds
11 years ago