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path: root/drivers/xen/grant-table.c
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Diffstat (limited to 'drivers/xen/grant-table.c')
-rw-r--r--drivers/xen/grant-table.c521
1 files changed, 460 insertions, 61 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index bf1c094f4eb..b4d4eac761d 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -44,16 +44,19 @@
#include <xen/page.h>
#include <xen/grant_table.h>
#include <xen/interface/memory.h>
+#include <xen/hvc-console.h>
#include <asm/xen/hypercall.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
-#define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(struct grant_entry))
+#define GREFS_PER_GRANT_FRAME \
+(grant_table_version == 1 ? \
+(PAGE_SIZE / sizeof(struct grant_entry_v1)) : \
+(PAGE_SIZE / sizeof(union grant_entry_v2)))
static grant_ref_t **gnttab_list;
static unsigned int nr_grant_frames;
@@ -64,13 +67,97 @@ 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;
+ union grant_entry_v2 *v2;
+ 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)(unsigned long *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);
+ /*
+ * 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 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)
{
@@ -142,23 +229,33 @@ 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)
+/*
+ * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2.
+ * 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;
+}
+
+static void gnttab_update_entry_v2(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.v2[ref].hdr.domid = domid;
+ gnttab_shared.v2[ref].full_page.frame = frame;
wmb();
- shared[ref].flags = flags;
+ gnttab_shared.v2[ref].hdr.flags = GTF_permit_access | flags;
}
/*
@@ -167,7 +264,7 @@ 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 +284,184 @@ 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)
+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);
+
+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)
{
- u16 nflags;
+ 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;
+ }
- nflags = shared[ref].flags;
+ return ref;
+}
+EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans);
- return nflags & (GTF_reading|GTF_writing);
+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);
}
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;
+ u16 *pflags;
- nflags = shared[ref].flags;
+ pflags = &gnttab_shared.v1[ref].flags;
+ nflags = *pflags;
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(pflags, flags, 0)) != flags);
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;
+}
+
+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,
@@ -246,37 +496,76 @@ 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;
+ 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 = shared[ref].flags) & GTF_transfer_committed)) {
- if (sync_cmpxchg(&shared[ref].flags, flags, 0) == flags)
+ 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 = shared[ref].flags;
+ flags = *pflags;
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;
+}
+
+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);
+}
EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref);
unsigned long gnttab_end_foreign_transfer(grant_ref_t ref)
@@ -448,8 +737,8 @@ unsigned int gnttab_max_grant_frames(void)
EXPORT_SYMBOL_GPL(gnttab_max_grant_frames);
int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
- struct gnttab_map_grant_ref *kmap_ops,
- struct page **pages, unsigned int count)
+ struct gnttab_map_grant_ref *kmap_ops,
+ struct page **pages, unsigned int count)
{
int i, ret;
pte_t *pte;
@@ -472,24 +761,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
(map_ops[i].host_addr & ~PAGE_MASK));
mfn = pte_mfn(*pte);
} else {
- /* If you really wanted to do this:
- * mfn = PFN_DOWN(map_ops[i].dev_bus_addr);
- *
- * The reason we do not implement it is b/c on the
- * unmap path (gnttab_unmap_refs) we have no means of
- * checking whether the page is !GNTMAP_contains_pte.
- *
- * That is without some extra data-structure to carry
- * the struct page, bool clear_pte, and list_head next
- * tuples and deal with allocation/delallocation, etc.
- *
- * The users of this API set the GNTMAP_contains_pte
- * flag so lets just return not supported until it
- * becomes neccessary to implement.
- */
- return -EOPNOTSUPP;
+ mfn = PFN_DOWN(map_ops[i].dev_bus_addr);
}
- ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]);
+ ret = m2p_add_override(mfn, pages[i], kmap_ops ?
+ &kmap_ops[i] : NULL);
if (ret)
return ret;
}
@@ -499,7 +774,7 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
EXPORT_SYMBOL_GPL(gnttab_map_refs);
int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
- struct page **pages, unsigned int count)
+ struct page **pages, unsigned int count, bool clear_pte)
{
int i, ret;
@@ -511,7 +786,7 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
return ret;
for (i = 0; i < count; i++) {
- ret = m2p_remove_override(pages[i], true /* clear the PTE */);
+ ret = m2p_remove_override(pages[i], clear_pte);
if (ret)
return ret;
}
@@ -520,6 +795,77 @@ 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)
+{
+ return (nr_grant_frames * GREFS_PER_GRANT_FRAME + SPP - 1) / SPP;
+}
+
+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(gnttab_shared.addr, nr_grant_frames);
+}
+
+static int gnttab_map_frames_v2(unsigned long *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;
@@ -551,6 +897,9 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_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;
@@ -567,19 +916,68 @@ 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 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;
+
+ if (xen_hvm_domain())
+ gsv.version = 1;
+ else
+ gsv.version = 2;
+ rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1);
+ if (rc == 0 && gsv.version == 2) {
+ grant_table_version = 2;
+ 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;
+ 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 +985,10 @@ 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 +1002,7 @@ int gnttab_resume(void)
int gnttab_suspend(void)
{
- arch_gnttab_unmap_shared(shared, nr_grant_frames);
+ gnttab_interface->unmap_frames();
return 0;
}