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path: root/drivers/hv/hv_fcopy.c
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2016-03-02Drivers: hv: util: Pass the channel information during the init callK. Y. Srinivasan1-1/+1
Pass the channel information to the util drivers that need to defer reading the channel while they are processing a request. This would address the following issue reported by Vitaly: Commit 3cace4a61610 ("Drivers: hv: utils: run polling callback always in interrupt context") removed direct *_transaction.state = HVUTIL_READY assignments from *_handle_handshake() functions introducing the following race: if a userspace daemon connects before we get first non-negotiation request from the server hv_poll_channel() won't set transaction state to HVUTIL_READY as (!channel) condition will fail, we set it to non-NULL on the first real request from the server. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-15Drivers: hv: utils: run polling callback always in interrupt contextOlaf Hering1-22/+12
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 <olaf@aepfle.de> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-15Drivers: hv: util: Increase the timeout for util servicesK. Y. Srinivasan1-1/+2
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 <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05Drivers: hv: fcopy: dynamically allocate smsg_out in fcopy_send_data()Vitaly Kuznetsov1-8/+13
struct hv_start_fcopy is too big to be on stack on i386, the following warning is reported: >> drivers/hv/hv_fcopy.c:159:1: warning: the frame size of 1088 bytes is larger than 1024 bytes [-Wframe-larger-than=] Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: utils: unify driver registration reportingVitaly Kuznetsov1-2/+1
Unify driver registration reporting and move it to debug level as normally daemons write to syslog themselves and these kernel messages are useless. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: fcopy: full handshake supportVitaly Kuznetsov1-1/+15
Introduce FCOPY_VERSION_1 to support kernel replying to the negotiation message with its own version. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: fcopy: convert to hv_utils_transportVitaly Kuznetsov1-148/+46
Unify the code with the recently introduced hv_utils_transport. Netlink communication is disabled for fcopy. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: fcopy: set .owner reference for file operationsVitaly Kuznetsov1-4/+2
Get an additional reference otherwise a crash is observed when hv_utils module is being unloaded while fcopy daemon is still running. .owner gives us an additional reference when someone holds a descriptor for the device. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: fcopy: switch to using the hvutil_device_state state machineVitaly Kuznetsov1-40/+30
Switch to using the hvutil_device_state state machine from using 3 different state variables: fcopy_transaction.active, opened, and in_hand_shake. State transitions are: -> HVUTIL_DEVICE_INIT when driver loads or on device release -> HVUTIL_READY if the handshake was successful -> HVUTIL_HOSTMSG_RECEIVED when there is a non-negotiation message from the host -> HVUTIL_USERSPACE_REQ after userspace daemon read the message -> HVUTIL_USERSPACE_RECV after/if userspace has replied -> HVUTIL_READY after we respond to the host -> HVUTIL_DEVICE_DYING on driver unload In hv_fcopy_onchannelcallback() process ICMSGTYPE_NEGOTIATE messages even when the userspace daemon is disconnected, otherwise we can make the host think we don't support FCOPY and disable the service completely. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: fcopy: rename fcopy_work -> fcopy_timeout_workVitaly Kuznetsov1-7/+7
'fcopy_work' (and fcopy_work_func) is a misnomer as it sounds like we expect this useful work to happen and in reality it is just an emergency escape when timeout happens. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: fcopy: process deferred messages when we complete the transactionVitaly Kuznetsov1-3/+9
In theory, the host is not supposed to issue any requests before be reply to the previous one. In KVP we, however, support the following scenarios: 1) A message was received before userspace daemon registered; 2) A message was received while the previous one is still being processed. In FCOPY we support only the former. Add support for the later, use hv_poll_channel() to do the job. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-25hv: hv_fcopy: drop the obsolete message on transfer failureDexuan Cui1-0/+27
In the case the user-space daemon crashes, hangs or is killed, we need to down the semaphore, otherwise, after the daemon starts next time, the obsolete data in fcopy_transaction.message or fcopy_transaction.fcopy_msg will be used immediately. Cc: Jason Wang <jasowang@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-18Drivers: hv: hv_fcopy: fix a race condition for SMP guestDexuan Cui1-1/+1
We should schedule the 5s "timer work" before starting the data transfer, otherwise, the data transfer code may finish so fast on another virtual cpu that when the code(fcopy_write()) trying to cancel the 5s "timer work" can occasionally fail because the "timer work" may haven't been scheduled yet and as a result the fcopy process will be aborted wrongly by fcopy_work_func() in 5s. Thank Liz Zhang <lizzha@microsoft.com> for the initial investigation on the bug. This addresses https://bugzilla.redhat.com/show_bug.cgi?id=1118123 Tested-by: Liz Zhang <lizzha@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-19Drivers: hv: fcopy_open() can be staticFengguang Wu1-2/+2
CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-18Drivers: hv: Implement the file copy serviceK. Y. Srinivasan1-0/+414
Implement the file copy service for Linux guests on Hyper-V. This permits the host to copy a file (over VMBUS) into the guest. This facility is part of "guest integration services" supported on the Windows platform. Here is a link that provides additional details on this functionality: http://technet.microsoft.com/en-us/library/dn464282.aspx In V1 version of the patch I have addressed comments from Olaf Hering <olaf@aepfle.de> and Dan Carpenter <dan.carpenter@oracle.com> In V2 version of this patch I did some minor cleanup (making some globals static). In V4 version of the patch I have addressed all of Olaf's most recent set of comments/concerns. In V5 version of the patch I had addressed Greg's most recent comments. I would like to thank Greg for suggesting that I use misc device; it has significantly simplified the code. In V6 version of the patch I have cleaned up error message based on Olaf's comments. I have also rebased the patch based on the current tip. In this version of the patch, I have addressed the latest comments from Greg. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>