diff options
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 58 |
1 files changed, 57 insertions, 1 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index addcef50df7a..44b92fa1b7fa 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -848,18 +848,74 @@ void vmbus_initiate_unload(bool crash) } /* + * find_primary_channel_by_offer - Get the channel object given the new offer. + * This is only used in the resume path of hibernation. + */ +static struct vmbus_channel * +find_primary_channel_by_offer(const struct vmbus_channel_offer_channel *offer) +{ + struct vmbus_channel *channel = NULL, *iter; + const guid_t *inst1, *inst2; + + /* Ignore sub-channel offers. */ + if (offer->offer.sub_channel_index != 0) + return NULL; + + mutex_lock(&vmbus_connection.channel_mutex); + + list_for_each_entry(iter, &vmbus_connection.chn_list, listentry) { + inst1 = &iter->offermsg.offer.if_instance; + inst2 = &offer->offer.if_instance; + + if (guid_equal(inst1, inst2)) { + channel = iter; + break; + } + } + + mutex_unlock(&vmbus_connection.channel_mutex); + + return channel; +} + +/* * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. * */ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) { struct vmbus_channel_offer_channel *offer; - struct vmbus_channel *newchannel; + struct vmbus_channel *oldchannel, *newchannel; + size_t offer_sz; offer = (struct vmbus_channel_offer_channel *)hdr; trace_vmbus_onoffer(offer); + oldchannel = find_primary_channel_by_offer(offer); + + if (oldchannel != NULL) { + atomic_dec(&vmbus_connection.offer_in_progress); + + /* + * We're resuming from hibernation: we expect the host to send + * exactly the same offers that we had before the hibernation. + */ + offer_sz = sizeof(*offer); + if (memcmp(offer, &oldchannel->offermsg, offer_sz) == 0) + return; + + pr_debug("Mismatched offer from the host (relid=%d)\n", + offer->child_relid); + + print_hex_dump_debug("Old vmbus offer: ", DUMP_PREFIX_OFFSET, + 16, 4, &oldchannel->offermsg, offer_sz, + false); + print_hex_dump_debug("New vmbus offer: ", DUMP_PREFIX_OFFSET, + 16, 4, offer, offer_sz, false); + return; + } + /* Allocate the channel object and save this offer. */ newchannel = alloc_channel(); if (!newchannel) { |