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@xxxxxxxxxxxxx> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx> Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> --- Changes since v1[1]: - add Reviewed-by: tags - rebase on hyperv-next [1] https://lkml.kernel.org/r/20210415105926.3688-1-parri.andrea@xxxxxxxxx drivers/hv/channel.c | 14 ++--- drivers/hv/ring_buffer.c | 14 +++-- drivers/net/hyperv/netvsc.c | 8 ++- drivers/net/hyperv/rndis_filter.c | 2 + drivers/scsi/storvsc_drv.c | 94 +++++++++++++++++++++---------- include/linux/hyperv.h | 13 ++++- 6 files changed, 95 insertions(+), 50 deletions(-) diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c index 9aa789e5f22bb..2058fe969b04b 100644 --- a/drivers/hv/channel.c +++ b/drivers/hv/channel.c @@ -1124,15 +1124,14 @@ EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw); * vmbus_next_request_id - Returns a new request id. It is also * the index at which the guest memory address is stored. * Uses a spin lock to avoid race conditions. - * @rqstor: Pointer to the requestor struct + * @channel: Pointer to the VMbus channel struct * @rqst_add: Guest memory address to be stored in the array */ -u64 vmbus_next_request_id(struct vmbus_requestor *rqstor, u64 rqst_addr) +u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr) { + struct vmbus_requestor *rqstor = &channel->requestor; unsigned long flags; u64 current_id; - const struct vmbus_channel *channel = - container_of(rqstor, const struct vmbus_channel, requestor); /* Check rqstor has been initialized */ if (!channel->rqstor_size) @@ -1166,16 +1165,15 @@ EXPORT_SYMBOL_GPL(vmbus_next_request_id); /* * vmbus_request_addr - Returns the memory address stored at @trans_id * in @rqstor. Uses a spin lock to avoid race conditions. - * @rqstor: Pointer to the requestor struct + * @channel: Pointer to the VMbus channel struct * @trans_id: Request id sent back from Hyper-V. Becomes the requestor's * next request id. */ -u64 vmbus_request_addr(struct vmbus_requestor *rqstor, u64 trans_id) +u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id) { + struct vmbus_requestor *rqstor = &channel->requestor; unsigned long flags; u64 req_addr; - const struct vmbus_channel *channel = - container_of(rqstor, const struct vmbus_channel, requestor); /* Check rqstor has been initialized */ if (!channel->rqstor_size) diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 29e90477363a8..7a10048c63548 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -321,11 +321,12 @@ int hv_ringbuffer_write(struct vmbus_channel *channel, */ if (desc->flags == VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED) { - rqst_id = vmbus_next_request_id(&channel->requestor, requestid); - if (rqst_id == VMBUS_RQST_ERROR) { - spin_unlock_irqrestore(&outring_info->ring_lock, flags); - pr_err("No request id available\n"); - return -EAGAIN; + if (channel->next_request_id_callback != NULL) { + rqst_id = channel->next_request_id_callback(channel, requestid); + if (rqst_id == VMBUS_RQST_ERROR) { + spin_unlock_irqrestore(&outring_info->ring_lock, flags); + return -EAGAIN; + } } } desc = hv_get_ring_buffer(outring_info) + old_write; @@ -353,7 +354,8 @@ int hv_ringbuffer_write(struct vmbus_channel *channel, if (channel->rescind) { if (rqst_id != VMBUS_NO_RQSTOR) { /* Reclaim request ID to avoid leak of IDs */ - vmbus_request_addr(&channel->requestor, rqst_id); + if (channel->request_addr_callback != NULL) + channel->request_addr_callback(channel, rqst_id); } return -ENODEV; } diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index d17ff04986f52..553ec12cac875 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -730,7 +730,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev, int queue_sends; u64 cmd_rqst; - cmd_rqst = vmbus_request_addr(&channel->requestor, (u64)desc->trans_id); + cmd_rqst = channel->request_addr_callback(channel, (u64)desc->trans_id); if (cmd_rqst == VMBUS_RQST_ERROR) { netdev_err(ndev, "Incorrect transaction id\n"); return; @@ -790,8 +790,8 @@ static void netvsc_send_completion(struct net_device *ndev, /* First check if this is a VMBUS completion without data payload */ if (!msglen) { - cmd_rqst = vmbus_request_addr(&incoming_channel->requestor, - (u64)desc->trans_id); + cmd_rqst = incoming_channel->request_addr_callback(incoming_channel, + (u64)desc->trans_id); if (cmd_rqst == VMBUS_RQST_ERROR) { netdev_err(ndev, "Invalid transaction id\n"); return; @@ -1602,6 +1602,8 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device, netvsc_poll, NAPI_POLL_WEIGHT); /* Open the channel */ + device->channel->next_request_id_callback = vmbus_next_request_id; + device->channel->request_addr_callback = vmbus_request_addr; device->channel->rqstor_size = netvsc_rqstor_size(netvsc_ring_bytes); device->channel->max_pkt_size = NETVSC_MAX_PKT_SIZE; diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c index d7ff9ddcbae28..983bf362466ad 100644 --- a/drivers/net/hyperv/rndis_filter.c +++ b/drivers/net/hyperv/rndis_filter.c @@ -1259,6 +1259,8 @@ static void netvsc_sc_open(struct vmbus_channel *new_sc) /* Set the channel before opening.*/ nvchan->channel = new_sc; + new_sc->next_request_id_callback = vmbus_next_request_id; + new_sc->request_addr_callback = vmbus_request_addr; new_sc->rqstor_size = netvsc_rqstor_size(netvsc_ring_bytes); new_sc->max_pkt_size = NETVSC_MAX_PKT_SIZE; diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index bfbaebded8025..439bb294e7eb0 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -692,6 +692,23 @@ static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old, 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; @@ -707,11 +724,7 @@ 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, @@ -778,7 +791,7 @@ 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); @@ -847,7 +860,7 @@ 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) @@ -1249,6 +1262,7 @@ 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; @@ -1259,20 +1273,12 @@ 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) { @@ -1280,14 +1286,44 @@ 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); } } @@ -1300,11 +1336,7 @@ 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, @@ -1630,7 +1662,7 @@ 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) diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 9dd22af1b7f61..6c77b4c782851 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -783,7 +783,11 @@ struct vmbus_requestor { #define VMBUS_NO_RQSTOR U64_MAX #define VMBUS_RQST_ERROR (U64_MAX - 1) +/* NetVSC-specific */ #define VMBUS_RQST_ID_NO_RESPONSE (U64_MAX - 2) +/* StorVSC-specific */ +#define VMBUS_RQST_INIT (U64_MAX - 2) +#define VMBUS_RQST_RESET (U64_MAX - 3) struct vmbus_device { u16 dev_type; @@ -1013,6 +1017,11 @@ struct vmbus_channel { u32 fuzz_testing_interrupt_delay; u32 fuzz_testing_message_delay; + /* callback to generate a request ID from a request address */ + u64 (*next_request_id_callback)(struct vmbus_channel *channel, u64 rqst_addr); + /* callback to retrieve a request address from a request ID */ + u64 (*request_addr_callback)(struct vmbus_channel *channel, u64 rqst_id); + /* request/transaction ids for VMBus */ struct vmbus_requestor requestor; u32 rqstor_size; @@ -1021,8 +1030,8 @@ struct vmbus_channel { u32 max_pkt_size; }; -u64 vmbus_next_request_id(struct vmbus_requestor *rqstor, u64 rqst_addr); -u64 vmbus_request_addr(struct vmbus_requestor *rqstor, u64 trans_id); +u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr); +u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id); static inline bool is_hvsock_channel(const struct vmbus_channel *c) { -- 2.25.1
