[TPM] Fix an occasional problem when doing local migration due to the xenstore's

'instance' variable not being initialized at the time when it's driver
counterpart is accessed. That variable's content was used to initialize the
tpmif structure. Instead, now a pointer to the structure is passed whose
'instance' variable will be initialized before the domain is resumed.

Signed-off-by: Stefan Berger <stefanb@us.ibm.com>

diff --git a/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h b/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h
index fba08d1c915afbad3a33b3c8e3f5f8a9ea5c7d28..27b8fd283ad9c61dc4e11fd87e70e922cb85e354 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h
@@ -21,6 +21,8 @@
        pr_debug("(file=%s, line=%d) " _f,      \
                 __FILE__ , __LINE__ , ## _a )
 
+struct backend_info;
+
 typedef struct tpmif_st {
        struct list_head tpmif_list;
        /* Unique identifier for this interface. */
@@ -43,7 +45,7 @@ typedef struct tpmif_st {
        struct list_head list;  /* scheduling list */
        atomic_t refcnt;
 
-       long int tpm_instance;
+       struct backend_info *bi;
        unsigned long mmap_vstart;
 
        grant_handle_t shmem_handle;
@@ -54,7 +56,7 @@ typedef struct tpmif_st {
 } tpmif_t;
 
 void tpmif_disconnect_complete(tpmif_t * tpmif);
-tpmif_t *tpmif_find(domid_t domid, long int instance);
+tpmif_t *tpmif_find(domid_t domid, struct backend_info *bi);
 void tpmif_interface_init(void);
 void tpmif_interface_exit(void);
 void tpmif_schedule_work(tpmif_t * tpmif);
@@ -64,8 +66,11 @@ void tpmif_xenbus_exit(void);
 int tpmif_map(tpmif_t *tpmif, unsigned long shared_page, unsigned int evtchn);
 irqreturn_t tpmif_be_int(int irq, void *dev_id, struct pt_regs *regs);
 
+long int tpmback_get_instance(struct backend_info *bi);
+
 int vtpm_release_packets(tpmif_t * tpmif, int send_msgs);
 
+
 #define tpmif_get(_b) (atomic_inc(&(_b)->refcnt))
 #define tpmif_put(_b)                                  \
        do {                                            \

diff --git a/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c b/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
index 50fb3e5d75f67ba03f58bd51ebe1faf741b611d8..0105bd93bfb90d150b710cd7fd136cfbdb782d2c 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
@@ -20,7 +20,7 @@ int num_frontends = 0;
 
 LIST_HEAD(tpmif_list);
 
-static tpmif_t *alloc_tpmif(domid_t domid, long int instance)
+static tpmif_t *alloc_tpmif(domid_t domid, struct backend_info *bi)
 {
        tpmif_t *tpmif;
 
@@ -31,7 +31,7 @@ static tpmif_t *alloc_tpmif(domid_t domid, long int instance)
        memset(tpmif, 0, sizeof (*tpmif));
        tpmif->domid = domid;
        tpmif->status = DISCONNECTED;
-       tpmif->tpm_instance = instance;
+       tpmif->bi = bi;
        snprintf(tpmif->devname, sizeof(tpmif->devname), "tpmif%d", domid);
        atomic_set(&tpmif->refcnt, 1);
 
@@ -54,12 +54,12 @@ static void free_tpmif(tpmif_t * tpmif)
        kmem_cache_free(tpmif_cachep, tpmif);
 }
 
-tpmif_t *tpmif_find(domid_t domid, long int instance)
+tpmif_t *tpmif_find(domid_t domid, struct backend_info *bi)
 {
        tpmif_t *tpmif;
 
        list_for_each_entry(tpmif, &tpmif_list, tpmif_list) {
-               if (tpmif->tpm_instance == instance) {
+               if (tpmif->bi == bi) {
                        if (tpmif->domid == domid) {
                                tpmif_get(tpmif);
                                return tpmif;
@@ -69,7 +69,7 @@ tpmif_t *tpmif_find(domid_t domid, long int instance)
                }
        }
 
-       return alloc_tpmif(domid, instance);
+       return alloc_tpmif(domid, bi);
 }
 
 static int map_frontend_page(tpmif_t *tpmif, unsigned long shared_page)

diff --git a/linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c b/linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c
index 066bcf33aa9e6f08d1a004f05c411ffe878ea61a..3e2d5087a7790168d22c7b23812c3c0426a8b64e 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c
@@ -161,7 +161,7 @@ static struct packet *packet_alloc(tpmif_t * tpmif,
        if (NULL != pak) {
                if (tpmif) {
                        pak->tpmif = tpmif;
-                       pak->tpm_instance = tpmif->tpm_instance;
+                       pak->tpm_instance = tpmback_get_instance(tpmif->bi);
                        tpmif_get(tpmif);
                }
                pak->data_len = size;

diff --git a/linux-2.6-xen-sparse/drivers/xen/tpmback/xenbus.c b/linux-2.6-xen-sparse/drivers/xen/tpmback/xenbus.c
index e98072e29bbff2953007749201ebc0336e6fbf43..cb72a2ec364788b0bd30414ba15efa648c9f96a5 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/xenbus.c
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/xenbus.c
@@ -45,6 +45,14 @@ static void backend_changed(struct xenbus_watch *watch,
 static void frontend_changed(struct xenbus_device *dev,
                             enum xenbus_state frontend_state);
 
+long int tpmback_get_instance(struct backend_info *bi)
+{
+       long int res = -1;
+       if (bi && bi->is_instance_set)
+               res = bi->instance;
+       return res;
+}
+
 static int tpmback_remove(struct xenbus_device *dev)
 {
        struct backend_info *be = dev->dev.driver_data;
@@ -57,6 +65,7 @@ static int tpmback_remove(struct xenbus_device *dev)
                be->backend_watch.node = NULL;
        }
        if (be->tpmif) {
+               be->tpmif->bi = NULL;
                vtpm_release_packets(be->tpmif, 0);
                tpmif_put(be->tpmif);
                be->tpmif = NULL;
@@ -150,7 +159,7 @@ static void frontend_changed(struct xenbus_device *dev,
                break;
 
        case XenbusStateClosing:
-               be->tpmif->tpm_instance = -1;
+               be->instance = -1;
                break;
 
        case XenbusStateClosed:
@@ -233,8 +242,7 @@ static int connect_ring(struct backend_info *be)
        }
 
        if (!be->tpmif) {
-               be->tpmif = tpmif_find(dev->otherend_id,
-                                      be->instance);
+               be->tpmif = tpmif_find(dev->otherend_id, be);
                if (IS_ERR(be->tpmif)) {
                        err = PTR_ERR(be->tpmif);
                        be->tpmif = NULL;