diff options
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index af1d82eb8ecf..d6c611457601 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -28,6 +28,7 @@ #include <linux/list.h> #include <linux/module.h> #include <linux/completion.h> +#include <linux/delay.h> #include <linux/hyperv.h> #include "hyperv_vmbus.h" @@ -589,6 +590,40 @@ static void init_vp_index(struct vmbus_channel *channel, u16 dev_type) channel->target_vp = hv_context.vp_index[cur_cpu]; } +static void vmbus_wait_for_unload(void) +{ + int cpu = smp_processor_id(); + void *page_addr = hv_context.synic_message_page[cpu]; + struct hv_message *msg = (struct hv_message *)page_addr + + VMBUS_MESSAGE_SINT; + struct vmbus_channel_message_header *hdr; + bool unloaded = false; + + while (1) { + if (msg->header.message_type == HVMSG_NONE) { + mdelay(10); + continue; + } + + hdr = (struct vmbus_channel_message_header *)msg->u.payload; + if (hdr->msgtype == CHANNELMSG_UNLOAD_RESPONSE) + unloaded = true; + + msg->header.message_type = HVMSG_NONE; + /* + * header.message_type needs to be written before we do + * wrmsrl() below. + */ + mb(); + + if (msg->header.message_flags.msg_pending) + wrmsrl(HV_X64_MSR_EOM, 0); + + if (unloaded) + break; + } +} + /* * vmbus_unload_response - Handler for the unload response. */ @@ -614,7 +649,14 @@ void vmbus_initiate_unload(void) hdr.msgtype = CHANNELMSG_UNLOAD; vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header)); - wait_for_completion(&vmbus_connection.unload_event); + /* + * vmbus_initiate_unload() is also called on crash and the crash can be + * happening in an interrupt context, where scheduling is impossible. + */ + if (!in_interrupt()) + wait_for_completion(&vmbus_connection.unload_event); + else + vmbus_wait_for_unload(); } /* |