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authorAndrea Parri (Microsoft) <parri.andrea@gmail.com>2021-05-10 23:08:41 +0200
committerWei Liu <wei.liu@kernel.org>2021-05-14 17:39:32 +0000
commitbf5fd8cae3c8f0d1e6f71a076e0ce2bd17645d0b (patch)
tree821a2794528229affecf651b860e9b7011d502c3 /drivers/scsi/storvsc_drv.c
parentadae1e931acd8b430d31141a283ea06d4b705417 (diff)
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scsi: storvsc: Use blk_mq_unique_tag() to generate requestIDs
Use blk_mq_unique_tag() to generate requestIDs for StorVSC, avoiding all issues with allocating enough entries in the VMbus requestor. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20210510210841.370472-1-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'drivers/scsi/storvsc_drv.c')
-rw-r--r--drivers/scsi/storvsc_drv.c94
1 files changed, 63 insertions, 31 deletions
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 07149fa72b68..403753929320 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -696,6 +696,23 @@ old_is_alloced:
spin_unlock_irqrestore(&stor_device->lock, flags);
}
+static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
+{
+ struct storvsc_cmd_request *request =
+ (struct storvsc_cmd_request *)(unsigned long)rqst_addr;
+
+ if (rqst_addr == VMBUS_RQST_INIT)
+ return VMBUS_RQST_INIT;
+ if (rqst_addr == VMBUS_RQST_RESET)
+ return VMBUS_RQST_RESET;
+
+ /*
+ * Cannot return an ID of 0, which is reserved for an unsolicited
+ * message from Hyper-V.
+ */
+ return (u64)blk_mq_unique_tag(request->cmd->request) + 1;
+}
+
static void handle_sc_creation(struct vmbus_channel *new_sc)
{
struct hv_device *device = new_sc->primary_channel->device_obj;
@@ -711,11 +728,7 @@ static void handle_sc_creation(struct vmbus_channel *new_sc)
memset(&props, 0, sizeof(struct vmstorage_channel_properties));
new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
- /*
- * The size of vmbus_requestor is an upper bound on the number of requests
- * that can be in-progress at any one time across all channels.
- */
- new_sc->rqstor_size = scsi_driver.can_queue;
+ new_sc->next_request_id_callback = storvsc_next_request_id;
ret = vmbus_open(new_sc,
storvsc_ringbuffer_size,
@@ -782,7 +795,7 @@ static void handle_multichannel_storage(struct hv_device *device, int max_chns)
ret = vmbus_sendpacket(device->channel, vstor_packet,
(sizeof(struct vstor_packet) -
stor_device->vmscsi_size_delta),
- (unsigned long)request,
+ VMBUS_RQST_INIT,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
@@ -851,7 +864,7 @@ static int storvsc_execute_vstor_op(struct hv_device *device,
ret = vmbus_sendpacket(device->channel, vstor_packet,
(sizeof(struct vstor_packet) -
stor_device->vmscsi_size_delta),
- (unsigned long)request,
+ VMBUS_RQST_INIT,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret != 0)
@@ -1253,6 +1266,7 @@ static void storvsc_on_channel_callback(void *context)
const struct vmpacket_descriptor *desc;
struct hv_device *device;
struct storvsc_device *stor_device;
+ struct Scsi_Host *shost;
if (channel->primary_channel != NULL)
device = channel->primary_channel->device_obj;
@@ -1263,20 +1277,12 @@ static void storvsc_on_channel_callback(void *context)
if (!stor_device)
return;
- foreach_vmbus_pkt(desc, channel) {
- void *packet = hv_pkt_data(desc);
- struct storvsc_cmd_request *request;
- u64 cmd_rqst;
-
- cmd_rqst = vmbus_request_addr(&channel->requestor,
- desc->trans_id);
- if (cmd_rqst == VMBUS_RQST_ERROR) {
- dev_err(&device->device,
- "Incorrect transaction id\n");
- continue;
- }
+ shost = stor_device->host;
- request = (struct storvsc_cmd_request *)(unsigned long)cmd_rqst;
+ foreach_vmbus_pkt(desc, channel) {
+ struct vstor_packet *packet = hv_pkt_data(desc);
+ struct storvsc_cmd_request *request = NULL;
+ u64 rqst_id = desc->trans_id;
if (hv_pkt_datalen(desc) < sizeof(struct vstor_packet) -
stor_device->vmscsi_size_delta) {
@@ -1284,14 +1290,44 @@ static void storvsc_on_channel_callback(void *context)
continue;
}
- if (request == &stor_device->init_request ||
- request == &stor_device->reset_request) {
- memcpy(&request->vstor_packet, packet,
- (sizeof(struct vstor_packet) - stor_device->vmscsi_size_delta));
- complete(&request->wait_event);
+ if (rqst_id == VMBUS_RQST_INIT) {
+ request = &stor_device->init_request;
+ } else if (rqst_id == VMBUS_RQST_RESET) {
+ request = &stor_device->reset_request;
} else {
+ /* Hyper-V can send an unsolicited message with ID of 0 */
+ if (rqst_id == 0) {
+ /*
+ * storvsc_on_receive() looks at the vstor_packet in the message
+ * from the ring buffer. If the operation in the vstor_packet is
+ * COMPLETE_IO, then we call storvsc_on_io_completion(), and
+ * dereference the guest memory address. Make sure we don't call
+ * storvsc_on_io_completion() with a guest memory address that is
+ * zero if Hyper-V were to construct and send such a bogus packet.
+ */
+ if (packet->operation == VSTOR_OPERATION_COMPLETE_IO) {
+ dev_err(&device->device, "Invalid packet with ID of 0\n");
+ continue;
+ }
+ } else {
+ struct scsi_cmnd *scmnd;
+
+ /* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
+ scmnd = scsi_host_find_tag(shost, rqst_id - 1);
+ if (scmnd == NULL) {
+ dev_err(&device->device, "Incorrect transaction ID\n");
+ continue;
+ }
+ request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
+ }
+
storvsc_on_receive(stor_device, packet, request);
+ continue;
}
+
+ memcpy(&request->vstor_packet, packet,
+ (sizeof(struct vstor_packet) - stor_device->vmscsi_size_delta));
+ complete(&request->wait_event);
}
}
@@ -1304,11 +1340,7 @@ static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
memset(&props, 0, sizeof(struct vmstorage_channel_properties));
device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
- /*
- * The size of vmbus_requestor is an upper bound on the number of requests
- * that can be in-progress at any one time across all channels.
- */
- device->channel->rqstor_size = scsi_driver.can_queue;
+ device->channel->next_request_id_callback = storvsc_next_request_id;
ret = vmbus_open(device->channel,
ring_size,
@@ -1634,7 +1666,7 @@ static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
ret = vmbus_sendpacket(device->channel, vstor_packet,
(sizeof(struct vstor_packet) -
stor_device->vmscsi_size_delta),
- (unsigned long)&stor_device->reset_request,
+ VMBUS_RQST_RESET,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret != 0)