From c0b200cfb0403740171c7527b3ac71d03f82947a Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Mon, 14 Dec 2015 16:01:32 -0800 Subject: Drivers: hv: util: Increase the timeout for util services Util services such as KVP and FCOPY need assistance from daemon's running in user space. Increase the timeout so we don't prematurely terminate the transaction in the kernel. Host sets up a 60 second timeout for all util driver transactions. The host will retry the transaction if it times out. Set the guest timeout at 30 seconds. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hyperv_vmbus.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/hv/hyperv_vmbus.h') diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 3782636562a1..225b96bcf7fe 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -30,6 +30,11 @@ #include #include +/* + * Timeout for services such as KVP and fcopy. + */ +#define HV_UTIL_TIMEOUT 30 + /* * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent * is set by CPUID(HVCPUID_VERSION_FEATURES). -- cgit v1.2.3 From 3cace4a616108539e2730f8dc21a636474395e0f Mon Sep 17 00:00:00 2001 From: Olaf Hering Date: Mon, 14 Dec 2015 16:01:33 -0800 Subject: Drivers: hv: utils: run polling callback always in interrupt context All channel interrupts are bound to specific VCPUs in the guest at the point channel is created. While currently, we invoke the polling function on the correct CPU (the CPU to which the channel is bound to) in some cases we may run the polling function in a non-interrupt context. This potentially can cause an issue as the polling function can be interrupted by the channel callback function. Fix the issue by running the polling function on the appropriate CPU at interrupt level. Additional details of the issue being addressed by this patch are given below: Currently hv_fcopy_onchannelcallback is called from interrupts and also via the ->write function of hv_utils. Since the used global variables to maintain state are not thread safe the state can get out of sync. This affects the variable state as well as the channel inbound buffer. As suggested by KY adjust hv_poll_channel to always run the given callback on the cpu which the channel is bound to. This avoids the need for locking because all the util services are single threaded and only one transaction is active at any given point in time. Additionally, remove the context variable, they will always be the same as recv_channel. Signed-off-by: Olaf Hering Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv_fcopy.c | 34 ++++++++++++---------------------- drivers/hv/hv_kvp.c | 28 ++++++++++------------------ drivers/hv/hv_snapshot.c | 29 +++++++++++------------------ drivers/hv/hyperv_vmbus.h | 6 +----- 4 files changed, 34 insertions(+), 63 deletions(-) (limited to 'drivers/hv/hyperv_vmbus.h') diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c index bbdec50c4a1c..c37a71e13de0 100644 --- a/drivers/hv/hv_fcopy.c +++ b/drivers/hv/hv_fcopy.c @@ -51,7 +51,6 @@ static struct { struct hv_fcopy_hdr *fcopy_msg; /* current message */ struct vmbus_channel *recv_channel; /* chn we got the request */ u64 recv_req_id; /* request ID. */ - void *fcopy_context; /* for the channel callback */ } fcopy_transaction; static void fcopy_respond_to_host(int error); @@ -67,6 +66,13 @@ static struct hvutil_transport *hvt; */ static int dm_reg_value; +static void fcopy_poll_wrapper(void *channel) +{ + /* Transaction is finished, reset the state here to avoid races. */ + fcopy_transaction.state = HVUTIL_READY; + hv_fcopy_onchannelcallback(channel); +} + static void fcopy_timeout_func(struct work_struct *dummy) { /* @@ -74,13 +80,7 @@ static void fcopy_timeout_func(struct work_struct *dummy) * process the pending transaction. */ fcopy_respond_to_host(HV_E_FAIL); - - /* Transaction is finished, reset the state. */ - if (fcopy_transaction.state > HVUTIL_READY) - fcopy_transaction.state = HVUTIL_READY; - - hv_poll_channel(fcopy_transaction.fcopy_context, - hv_fcopy_onchannelcallback); + hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper); } static int fcopy_handle_handshake(u32 version) @@ -108,9 +108,7 @@ static int fcopy_handle_handshake(u32 version) return -EINVAL; } pr_debug("FCP: userspace daemon ver. %d registered\n", version); - fcopy_transaction.state = HVUTIL_READY; - hv_poll_channel(fcopy_transaction.fcopy_context, - hv_fcopy_onchannelcallback); + hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper); return 0; } @@ -227,15 +225,8 @@ void hv_fcopy_onchannelcallback(void *context) int util_fw_version; int fcopy_srv_version; - if (fcopy_transaction.state > HVUTIL_READY) { - /* - * We will defer processing this callback once - * the current transaction is complete. - */ - fcopy_transaction.fcopy_context = context; + if (fcopy_transaction.state > HVUTIL_READY) return; - } - fcopy_transaction.fcopy_context = NULL; vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen, &requestid); @@ -305,9 +296,8 @@ static int fcopy_on_msg(void *msg, int len) if (cancel_delayed_work_sync(&fcopy_timeout_work)) { fcopy_transaction.state = HVUTIL_USERSPACE_RECV; fcopy_respond_to_host(*val); - fcopy_transaction.state = HVUTIL_READY; - hv_poll_channel(fcopy_transaction.fcopy_context, - hv_fcopy_onchannelcallback); + hv_poll_channel(fcopy_transaction.recv_channel, + fcopy_poll_wrapper); } return 0; diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c index e6aa33a89b0e..2a3420c4ca59 100644 --- a/drivers/hv/hv_kvp.c +++ b/drivers/hv/hv_kvp.c @@ -66,7 +66,6 @@ static struct { struct hv_kvp_msg *kvp_msg; /* current message */ struct vmbus_channel *recv_channel; /* chn we got the request */ u64 recv_req_id; /* request ID. */ - void *kvp_context; /* for the channel callback */ } kvp_transaction; /* @@ -94,6 +93,13 @@ static struct hvutil_transport *hvt; */ #define HV_DRV_VERSION "3.1" +static void kvp_poll_wrapper(void *channel) +{ + /* Transaction is finished, reset the state here to avoid races. */ + kvp_transaction.state = HVUTIL_READY; + hv_kvp_onchannelcallback(channel); +} + static void kvp_register(int reg_value) { @@ -121,12 +127,7 @@ static void kvp_timeout_func(struct work_struct *dummy) */ kvp_respond_to_host(NULL, HV_E_FAIL); - /* Transaction is finished, reset the state. */ - if (kvp_transaction.state > HVUTIL_READY) - kvp_transaction.state = HVUTIL_READY; - - hv_poll_channel(kvp_transaction.kvp_context, - hv_kvp_onchannelcallback); + hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper); } static int kvp_handle_handshake(struct hv_kvp_msg *msg) @@ -218,9 +219,7 @@ static int kvp_on_msg(void *msg, int len) */ if (cancel_delayed_work_sync(&kvp_timeout_work)) { kvp_respond_to_host(message, error); - kvp_transaction.state = HVUTIL_READY; - hv_poll_channel(kvp_transaction.kvp_context, - hv_kvp_onchannelcallback); + hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper); } return 0; @@ -596,15 +595,8 @@ void hv_kvp_onchannelcallback(void *context) int util_fw_version; int kvp_srv_version; - if (kvp_transaction.state > HVUTIL_READY) { - /* - * We will defer processing this callback once - * the current transaction is complete. - */ - kvp_transaction.kvp_context = context; + if (kvp_transaction.state > HVUTIL_READY) return; - } - kvp_transaction.kvp_context = NULL; vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen, &requestid); diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c index 815405f2e777..a548ae42c927 100644 --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -53,7 +53,6 @@ static struct { struct vmbus_channel *recv_channel; /* chn we got the request */ u64 recv_req_id; /* request ID. */ struct hv_vss_msg *msg; /* current message */ - void *vss_context; /* for the channel callback */ } vss_transaction; @@ -74,6 +73,13 @@ static void vss_timeout_func(struct work_struct *dummy); static DECLARE_DELAYED_WORK(vss_timeout_work, vss_timeout_func); static DECLARE_WORK(vss_send_op_work, vss_send_op); +static void vss_poll_wrapper(void *channel) +{ + /* Transaction is finished, reset the state here to avoid races. */ + vss_transaction.state = HVUTIL_READY; + hv_vss_onchannelcallback(channel); +} + /* * Callback when data is received from user mode. */ @@ -86,12 +92,7 @@ static void vss_timeout_func(struct work_struct *dummy) pr_warn("VSS: timeout waiting for daemon to reply\n"); vss_respond_to_host(HV_E_FAIL); - /* Transaction is finished, reset the state. */ - if (vss_transaction.state > HVUTIL_READY) - vss_transaction.state = HVUTIL_READY; - - hv_poll_channel(vss_transaction.vss_context, - hv_vss_onchannelcallback); + hv_poll_channel(vss_transaction.recv_channel, vss_poll_wrapper); } static int vss_handle_handshake(struct hv_vss_msg *vss_msg) @@ -138,9 +139,8 @@ static int vss_on_msg(void *msg, int len) if (cancel_delayed_work_sync(&vss_timeout_work)) { vss_respond_to_host(vss_msg->error); /* Transaction is finished, reset the state. */ - vss_transaction.state = HVUTIL_READY; - hv_poll_channel(vss_transaction.vss_context, - hv_vss_onchannelcallback); + hv_poll_channel(vss_transaction.recv_channel, + vss_poll_wrapper); } } else { /* This is a spurious call! */ @@ -238,15 +238,8 @@ void hv_vss_onchannelcallback(void *context) struct icmsg_hdr *icmsghdrp; struct icmsg_negotiate *negop = NULL; - if (vss_transaction.state > HVUTIL_READY) { - /* - * We will defer processing this callback once - * the current transaction is complete. - */ - vss_transaction.vss_context = context; + if (vss_transaction.state > HVUTIL_READY) return; - } - vss_transaction.vss_context = NULL; vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen, &requestid); diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 225b96bcf7fe..12156db2e88e 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -764,11 +764,7 @@ static inline void hv_poll_channel(struct vmbus_channel *channel, if (!channel) return; - if (channel->target_cpu != smp_processor_id()) - smp_call_function_single(channel->target_cpu, - cb, channel, true); - else - cb(channel); + smp_call_function_single(channel->target_cpu, cb, channel, true); } enum hvutil_device_state { -- cgit v1.2.3 From a108393dbf764efb2405f21ca759806c65b8bc16 Mon Sep 17 00:00:00 2001 From: Jake Oshins Date: Mon, 14 Dec 2015 16:01:40 -0800 Subject: drivers:hv: Export the API to invoke a hypercall on Hyper-V This patch exposes the function that hv_vmbus.ko uses to make hypercalls. This is necessary for retargeting an interrupt when it is given a new affinity. Since we are exporting this API, rename the API as it will be visible outside the hv.c file. Signed-off-by: Jake Oshins Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv.c | 20 ++++++++++---------- drivers/hv/hyperv_vmbus.h | 2 +- include/linux/hyperv.h | 1 + 3 files changed, 12 insertions(+), 11 deletions(-) (limited to 'drivers/hv/hyperv_vmbus.h') diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index ad7fc6d92c35..eb4e383dbc58 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -89,9 +89,9 @@ static int query_hypervisor_info(void) } /* - * do_hypercall- Invoke the specified hypercall + * hv_do_hypercall- Invoke the specified hypercall */ -static u64 do_hypercall(u64 control, void *input, void *output) +u64 hv_do_hypercall(u64 control, void *input, void *output) { u64 input_address = (input) ? virt_to_phys(input) : 0; u64 output_address = (output) ? virt_to_phys(output) : 0; @@ -132,6 +132,7 @@ static u64 do_hypercall(u64 control, void *input, void *output) return hv_status_lo | ((u64)hv_status_hi << 32); #endif /* !x86_64 */ } +EXPORT_SYMBOL_GPL(hv_do_hypercall); #ifdef CONFIG_X86_64 static cycle_t read_hv_clock_tsc(struct clocksource *arg) @@ -316,7 +317,7 @@ int hv_post_message(union hv_connection_id connection_id, { struct hv_input_post_message *aligned_msg; - u16 status; + u64 status; if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) return -EMSGSIZE; @@ -330,11 +331,10 @@ int hv_post_message(union hv_connection_id connection_id, aligned_msg->payload_size = payload_size; memcpy((void *)aligned_msg->payload, payload, payload_size); - status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL) - & 0xFFFF; + status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL); put_cpu(); - return status; + return status & 0xFFFF; } @@ -344,13 +344,13 @@ int hv_post_message(union hv_connection_id connection_id, * * This involves a hypercall. */ -u16 hv_signal_event(void *con_id) +int hv_signal_event(void *con_id) { - u16 status; + u64 status; - status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF); + status = hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL); - return status; + return status & 0xFFFF; } static int hv_ce_set_next_event(unsigned long delta, diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 12156db2e88e..9beeb148797f 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -587,7 +587,7 @@ extern int hv_post_message(union hv_connection_id connection_id, enum hv_message_type message_type, void *payload, size_t payload_size); -extern u16 hv_signal_event(void *con_id); +extern int hv_signal_event(void *con_id); extern int hv_synic_alloc(void); diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index fddb3e0e8feb..24d0b656e6e7 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -984,6 +984,7 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, bool fb_overlap_ok); int vmbus_cpu_number_to_vp_number(int cpu_number); +u64 hv_do_hypercall(u64 control, void *input, void *output); /** * VMBUS_DEVICE - macro used to describe a specific hyperv vmbus device -- cgit v1.2.3 From d6f591e339d23f434efda11917da511870891472 Mon Sep 17 00:00:00 2001 From: Dexuan Cui Date: Mon, 14 Dec 2015 16:01:51 -0800 Subject: Drivers: hv: vmbus: channge vmbus_connection.channel_lock to mutex spinlock is unnecessary here. mutex is enough. Signed-off-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/channel_mgmt.c | 12 ++++++------ drivers/hv/connection.c | 7 +++---- drivers/hv/hyperv_vmbus.h | 2 +- 3 files changed, 10 insertions(+), 11 deletions(-) (limited to 'drivers/hv/hyperv_vmbus.h') diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 9c9da3a6c03a..d0131717c1d5 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -206,9 +206,9 @@ void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid) } if (channel->primary_channel == NULL) { - spin_lock_irqsave(&vmbus_connection.channel_lock, flags); + mutex_lock(&vmbus_connection.channel_mutex); list_del(&channel->listentry); - spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); + mutex_unlock(&vmbus_connection.channel_mutex); primary_channel = channel; } else { @@ -253,7 +253,7 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) unsigned long flags; /* Make sure this is a new offer */ - spin_lock_irqsave(&vmbus_connection.channel_lock, flags); + mutex_lock(&vmbus_connection.channel_mutex); list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { if (!uuid_le_cmp(channel->offermsg.offer.if_type, @@ -269,7 +269,7 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) list_add_tail(&newchannel->listentry, &vmbus_connection.chn_list); - spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); + mutex_unlock(&vmbus_connection.channel_mutex); if (!fnew) { /* @@ -341,9 +341,9 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) err_deq_chan: vmbus_release_relid(newchannel->offermsg.child_relid); - spin_lock_irqsave(&vmbus_connection.channel_lock, flags); + mutex_lock(&vmbus_connection.channel_mutex); list_del(&newchannel->listentry); - spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); + mutex_unlock(&vmbus_connection.channel_mutex); if (newchannel->target_cpu != get_cpu()) { put_cpu(); diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index 4fc2e8836e60..521f48ed188e 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -146,7 +146,7 @@ int vmbus_connect(void) spin_lock_init(&vmbus_connection.channelmsg_lock); INIT_LIST_HEAD(&vmbus_connection.chn_list); - spin_lock_init(&vmbus_connection.channel_lock); + mutex_init(&vmbus_connection.channel_mutex); /* * Setup the vmbus event connection for channel interrupt @@ -282,11 +282,10 @@ struct vmbus_channel *relid2channel(u32 relid) { struct vmbus_channel *channel; struct vmbus_channel *found_channel = NULL; - unsigned long flags; struct list_head *cur, *tmp; struct vmbus_channel *cur_sc; - spin_lock_irqsave(&vmbus_connection.channel_lock, flags); + mutex_lock(&vmbus_connection.channel_mutex); list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { if (channel->offermsg.child_relid == relid) { found_channel = channel; @@ -305,7 +304,7 @@ struct vmbus_channel *relid2channel(u32 relid) } } } - spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); + mutex_unlock(&vmbus_connection.channel_mutex); return found_channel; } diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 9beeb148797f..4d67e984ac4f 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -683,7 +683,7 @@ struct vmbus_connection { /* List of channels */ struct list_head chn_list; - spinlock_t channel_lock; + struct mutex channel_mutex; struct workqueue_struct *work_queue; }; -- cgit v1.2.3 From 940b68e2c3e4ebf032885203c3970e9649f814af Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Mon, 14 Dec 2015 19:02:01 -0800 Subject: Drivers: hv: ring_buffer: eliminate hv_ringbuffer_peek() Currently, there is only one user for hv_ringbuffer_read()/ hv_ringbuffer_peak() functions and the usage of these functions is: - insecure as we drop ring_lock between them, someone else (in theory only) can acquire it in between; - non-optimal as we do a number of things (acquire/release the above mentioned lock, calculate available space on the ring, ...) twice and this path is performance-critical. Remove hv_ringbuffer_peek() moving the logic from __vmbus_recvpacket() to hv_ringbuffer_read(). Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/channel.c | 30 ++-------------------- drivers/hv/hyperv_vmbus.h | 11 +++----- drivers/hv/ring_buffer.c | 65 +++++++++++++++++++++++++++-------------------- 3 files changed, 42 insertions(+), 64 deletions(-) (limited to 'drivers/hv/hyperv_vmbus.h') diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c index dd6de7fc442f..1161d68a1863 100644 --- a/drivers/hv/channel.c +++ b/drivers/hv/channel.c @@ -927,37 +927,11 @@ __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, u32 bufferlen, u32 *buffer_actual_len, u64 *requestid, bool raw) { - struct vmpacket_descriptor desc; - u32 packetlen; - u32 userlen; int ret; bool signal = false; - *buffer_actual_len = 0; - *requestid = 0; - - - ret = hv_ringbuffer_peek(&channel->inbound, &desc, - sizeof(struct vmpacket_descriptor)); - if (ret != 0) - return 0; - - packetlen = desc.len8 << 3; - if (!raw) - userlen = packetlen - (desc.offset8 << 3); - else - userlen = packetlen; - - *buffer_actual_len = userlen; - - if (userlen > bufferlen) - return -ENOBUFS; - - *requestid = desc.trans_id; - - /* Copy over the packet to the user buffer */ - ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen, - raw ? 0 : desc.offset8 << 3, &signal); + ret = hv_ringbuffer_read(&channel->inbound, buffer, bufferlen, + buffer_actual_len, requestid, &signal, raw); if (signal) vmbus_setevent(channel); diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 4d67e984ac4f..0411b7bfb3c0 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -619,14 +619,9 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info, struct kvec *kv_list, u32 kv_count, bool *signal); -int hv_ringbuffer_peek(struct hv_ring_buffer_info *ring_info, void *buffer, - u32 buflen); - -int hv_ringbuffer_read(struct hv_ring_buffer_info *ring_info, - void *buffer, - u32 buflen, - u32 offset, bool *signal); - +int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, + void *buffer, u32 buflen, u32 *buffer_actual_len, + u64 *requestid, bool *signal, bool raw); void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, struct hv_ring_buffer_debug_info *debug_info); diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 07f9408fc59e..b53702ce692f 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -380,30 +380,59 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info, return 0; } -static inline int __hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, - void *buffer, u32 buflen, u32 offset, - bool *signal, bool advance) +int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, + void *buffer, u32 buflen, u32 *buffer_actual_len, + u64 *requestid, bool *signal, bool raw) { u32 bytes_avail_towrite; u32 bytes_avail_toread; u32 next_read_location = 0; u64 prev_indices = 0; unsigned long flags; + struct vmpacket_descriptor desc; + u32 offset; + u32 packetlen; + int ret = 0; if (buflen <= 0) return -EINVAL; spin_lock_irqsave(&inring_info->ring_lock, flags); + *buffer_actual_len = 0; + *requestid = 0; + hv_get_ringbuffer_availbytes(inring_info, &bytes_avail_toread, &bytes_avail_towrite); /* Make sure there is something to read */ - if (bytes_avail_toread < buflen) { - spin_unlock_irqrestore(&inring_info->ring_lock, flags); + if (bytes_avail_toread < sizeof(desc)) { + /* + * No error is set when there is even no header, drivers are + * supposed to analyze buffer_actual_len. + */ + goto out_unlock; + } - return -EAGAIN; + next_read_location = hv_get_next_read_location(inring_info); + next_read_location = hv_copyfrom_ringbuffer(inring_info, &desc, + sizeof(desc), + next_read_location); + + offset = raw ? 0 : (desc.offset8 << 3); + packetlen = (desc.len8 << 3) - offset; + *buffer_actual_len = packetlen; + *requestid = desc.trans_id; + + if (bytes_avail_toread < packetlen + offset) { + ret = -EAGAIN; + goto out_unlock; + } + + if (packetlen > buflen) { + ret = -ENOBUFS; + goto out_unlock; } next_read_location = @@ -411,12 +440,9 @@ static inline int __hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, next_read_location = hv_copyfrom_ringbuffer(inring_info, buffer, - buflen, + packetlen, next_read_location); - if (!advance) - goto out_unlock; - next_read_location = hv_copyfrom_ringbuffer(inring_info, &prev_indices, sizeof(u64), @@ -436,22 +462,5 @@ static inline int __hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, out_unlock: spin_unlock_irqrestore(&inring_info->ring_lock, flags); - return 0; -} - -/* Read from ring buffer without advancing the read index. */ -int hv_ringbuffer_peek(struct hv_ring_buffer_info *inring_info, - void *buffer, u32 buflen) -{ - return __hv_ringbuffer_read(inring_info, buffer, buflen, - 0, NULL, false); -} - -/* Read from ring buffer and advance the read index. */ -int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, - void *buffer, u32 buflen, u32 offset, - bool *signal) -{ - return __hv_ringbuffer_read(inring_info, buffer, buflen, - offset, signal, true); + return ret; } -- cgit v1.2.3