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* Drivers: hv: utils: fix a race on userspace daemons registrationVitaly Kuznetsov2016-08-311-11/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Background: userspace daemons registration protocol for Hyper-V utilities drivers has two steps: 1) daemon writes its own version to kernel 2) kernel reads it and replies with module version at this point we consider the handshake procedure being completed and we do hv_poll_channel() transitioning the utility device to HVUTIL_READY state. At this point we're ready to handle messages from kernel. When hvutil_transport is in HVUTIL_TRANSPORT_CHARDEV mode we have a single buffer for outgoing message. hvutil_transport_send() puts to this buffer and till the buffer is cleared with hvt_op_read() returns -EFAULT to all consequent calls. Host<->guest protocol guarantees there is no more than one request at a time and we will not get new requests till we reply to the previous one so this single message buffer is enough. Now to the race. When we finish negotiation procedure and send kernel module version to userspace with hvutil_transport_send() it goes into the above mentioned buffer and if the daemon is slow enough to read it from there we can get a collision when a request from the host comes, we won't be able to put anything to the buffer so the request will be lost. To solve the issue we need to know when the negotiation is really done (when the version message is read by the daemon) and transition to HVUTIL_READY state after this happens. Implement a callback on read to support this. Old style netlink communication is not affected by the change, we don't really know when these messages are delivered but we don't have a single message buffer there. Reported-by: Barry Davis <barry_davis@stormagic.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>
* Drivers: hv: kvp: fix IP FailoverVitaly Kuznetsov2016-05-011-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | Hyper-V VMs can be replicated to another hosts and there is a feature to set different IP for replicas, it is called 'Failover TCP/IP'. When such guest starts Hyper-V host sends it KVP_OP_SET_IP_INFO message as soon as we finish negotiation procedure. The problem is that it can happen (and it actually happens) before userspace daemon connects and we reply with HV_E_FAIL to the message. As there are no repetitions we fail to set the requested IP. Solve the issue by postponing our reply to the negotiation message till userspace daemon is connected. We can't wait too long as there is a host-side timeout (cca. 75 seconds) and if we fail to reply in this time frame the whole KVP service will become inactive. The solution is not ideal - if it takes userspace daemon more than 60 seconds to connect IP Failover will still fail but I don't see a solution with our current separation between kernel and userspace parts. Other two modules (VSS and FCOPY) don't require such delay, leave them untouched. 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>
* Drivers: hv: util: Pass the channel information during the init callK. Y. Srinivasan2016-03-021-1/+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>
* Drivers: hv: utils: Invoke the poll function after handshakeK. Y. Srinivasan2015-12-151-1/+1
| | | | | | | | | | When the handshake with daemon is complete, we should poll the channel since during the handshake, we will not be processing any messages. This is a potential bug if the host is waiting for a response from the guest. I would like to thank Dexuan for pointing this out. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: utils: run polling callback always in interrupt contextOlaf Hering2015-12-151-18/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Drivers: hv: util: Increase the timeout for util servicesK. Y. Srinivasan2015-12-151-1/+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>
* Drivers: hv: kvp: check kzalloc return valueVitaly Kuznetsov2015-08-051-0/+3
| | | | | | | | | | | | | | kzalloc() return value check was accidentally lost in 11bc3a5fa91f: "Drivers: hv: kvp: convert to hv_utils_transport" commit. We don't need to reset kvp_transaction.state here as we have the kvp_timeout_func() timeout function and in case we're in OOM situation it is preferable to wait. Reported-by: Dan Carpenter <dan.carpenter@oracle.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>
* Drivers: hv: utils: unify driver registration reportingVitaly Kuznetsov2015-05-241-1/+2
| | | | | | | | | | 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>
* Drivers: hv: kvp: convert to hv_utils_transportVitaly Kuznetsov2015-05-241-49/+42
| | | | | | | | | Convert to hv_utils_transport to support both netlink and /dev/vmbus/hv_kvp communication methods. 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>
* Drivers: hv: kvp: switch to using the hvutil_device_state state machineVitaly Kuznetsov2015-05-241-38/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch to using the hvutil_device_state state machine from using 2 different state variables: kvp_transaction.active 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 we sent the message to the userspace daemon -> HVUTIL_USERSPACE_RECV after/if the userspace daemon has replied -> HVUTIL_READY after we respond to the host -> HVUTIL_DEVICE_DYING on driver unload In hv_kvp_onchannelcallback() process ICMSGTYPE_NEGOTIATE messages even when the userspace daemon is disconnected, otherwise we can make the host think we don't support KVP and disable the service completely. Unfortunately there is no good way we can figure out that the userspace daemon has died (unless we start treating all timeouts as such). In case the daemon restarts we skip the negotiation procedure (so the daemon is supposed to has the same version). This behavior is unchanged from in_handshake approach. 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>
* Drivers: hv: kvp: rename kvp_work -> kvp_timeout_workVitaly Kuznetsov2015-05-241-8/+8
| | | | | | | | | | | 'kvp_work' (and kvp_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>
* Drivers: hv: kvp: move poll_channel() to hyperv_vmbus.hVitaly Kuznetsov2015-05-241-14/+3
| | | | | | | | | | Move poll_channel() to hyperv_vmbus.h and make it inline and rename it to hv_poll_channel() so it can be reused in other hv_util modules. 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>
* Drivers: hv: kvp: reset kvp_contextVitaly Kuznetsov2015-05-241-0/+1
| | | | | | | | | | | | | | | We set kvp_context when we want to postpone receiving a packet from vmbus due to the previous transaction being unfinished. We, however, never reset this state, all consequent kvp_respond_to_host() calls will result in poll_channel() calling hv_kvp_onchannelcallback(). This doesn't cause real issues as: 1) Host is supposed to serialize transactions as well 2) If no message is pending vmbus_recvpacket() will return 0 recvlen. This is just a cleanup. 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>
* Drivers: hv: util: move kvp/vss function declarations to hyperv_vmbus.hVitaly Kuznetsov2015-05-241-0/+1
| | | | | | | | | | These declarations are internal to hv_util module and hv_fcopy_* declarations already reside there. 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>
* Drivers: hv: kvp,vss: Fast propagation of userspace communication failureVitaly Kuznetsov2014-11-271-1/+8
| | | | | | | | | | | | | | | | | If we fail to send a message to userspace daemon with cn_netlink_send() there is no need to wait for userspace to reply as it is not going to happen. This happens when kvp or vss daemon is stopped after a successful handshake. Report HV_E_FAIL immediately and cancel the timeout job so host won't receive two failures. Use pr_warn() for VSS and pr_debug() for KVP deliberately as VSS request are rare and result in a failed backup. KVP requests are much more frequent after a successful handshake so avoid flooding logs. It would be nice to have an ability to de-negotiate with the host in case userspace daemon gets disconnected so we won't receive new requests. But I'm not sure it is possible. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: util: Fix a bug in the KVP codeK. Y. Srinivasan2014-07-091-3/+14
| | | | | | | | | | Add code to poll the channel since we process only one message at a time and the host may not interrupt us. Also increase the receive buffer size since some KVP messages are close to 8K bytes in size. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* connector: add portid to unicast in addition to broadcastingDavid Fries2014-02-081-2/+2
| | | | | | | | | This allows replying only to the requestor portid while still supporting broadcasting. Pass 0 to portid for the previous behavior. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: util: Correctly support ws2008R2 and earlierK. Y. Srinivasan2013-09-261-12/+26
| | | | | | | | | | | | | The current code does not correctly negotiate the version numbers for the util driver when hosted on earlier hosts. The version numbers presented by this driver were not compatible with the version numbers supported by Windows Server 2008. Fix this problem. I would like to thank Olaf Hering (ohering@suse.com) for identifying the problem. Reported-by: Olaf Hering <ohering@suse.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: remove HV_DRV_VERSIONOlaf Hering2013-08-021-0/+2
| | | | | | | | | | | | | | | | | Remove HV_DRV_VERSION, it has no meaning for upstream drivers. Initially it was supposed to show the "Linux Integration Services" version, now it is not in sync anymore with the out-of-tree drivers available from the MSFT website. The only place where a version string is still required is the KVP command "IntegrationServicesVersion" which is handled by tools/hv/hv_kvp_daemon.c. To satisfy such KVP request from the host pass the current string to the daemon during KVP userland registration. Signed-off-by: Olaf Hering <olaf@aepfle.de> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: util: Fix a bug in version negotiation code for util servicesK. Y. Srinivasan2013-07-271-1/+23
| | | | | | | | | | | The current code picked the highest version advertised by the host. WS2012 R2 has implemented a protocol version for KVP that is not compatible with prior protocol versions of KVP. Fix the bug in the current code by explicitly specifying the protocol version that the guest can support. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: kvp: Copy the address family informationK. Y. Srinivasan2012-09-051-0/+2
| | | | | | | | | | | | This is part of the IP injection protocol in that the host expects this field to reflect what addresses (address families) are currently bound to the interface. The KVP daemon is currently collecting this information and sending it to the kernel component. I had overlooked copying this and sending it back to the host. This patch addresses this issue. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: kvp: Support the new IP injection messagesK. Y. Srinivasan2012-08-171-6/+135
| | | | | | | | Implement support for the new IP injection messages in the driver code. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: kvp: Cleanup error handling in KVPK. Y. Srinivasan2012-08-161-23/+91
| | | | | | | | | | | In preparation to implementing IP injection, cleanup the way we propagate and handle errors both in the driver as well as in the user level daemon. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: Olaf Hering <olaf@aepfle.de> Reviewed-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: util: Properly handle version negotiations.K. Y. Srinivasan2012-05-141-1/+2
| | | | | | | | | | | The current version negotiation code is not "future proof". Fix this by allowing each service the flexibility to either specify the highest version it can support or it can support the highest version number the host is offering. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Tools: hv: Support enumeration from all the poolsK. Y. Srinivasan2012-03-161-3/+4
| | | | | | | | | | We have only supported enumeration only from the AUTO pool. Now support enumeration from all the available pools. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: Support the newly introduced KVP messages in the driverK. Y. Srinivasan2012-03-161-51/+167
| | | | | | | | | | | | Support the newly defined KVP message types. It turns out that the host pushes a set of standard key value pairs as soon as the guest opens the KVP channel. Since we cannot handle these tuples until the user level daemon loads up, defer reading the KVP channel until the user level daemon is launched. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: Add new message types to enhance KVPK. Y. Srinivasan2012-03-131-2/+3
| | | | | | | | | | Add additional KVP (Key Value Pair) protocol messages to enhance KVP functionality for Linux guests on Hyper-V. As part of this, patch define an explicit version negoitiation message. Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: hv: kvp: Cleanup the kernel/user protocolK. Y. Srinivasan2012-02-091-16/+25
| | | | | | | | | Now, cleanup the user/kernel KVP protocol by using the same structure definition that is used for host/guest KVP protocol. This simplifies the code. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: hv: kvp: Move the contents of hv_kvp.h to hyperv.hK. Y. Srinivasan2012-02-031-2/+0
| | | | | | | | | | In preparation for consolidating all KVP related defines into a single header file that both the kernel and user level components can use, move the contents of hv_kvp.h into hyperv.h. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* NLS: improve UTF8 -> UTF16 string conversion routineAlan Stern2011-11-181-4/+6
| | | | | | | | | | | | | | | | | | | | The utf8s_to_utf16s conversion routine needs to be improved. Unlike its utf16s_to_utf8s sibling, it doesn't accept arguments specifying the maximum length of the output buffer or the endianness of its 16-bit output. This patch (as1501) adds the two missing arguments, and adjusts the only two places in the kernel where the function is called. A follow-on patch will add a third caller that does utilize the new capabilities. The two conversion routines are still annoyingly inconsistent in the way they handle invalid byte combinations. But that's a subject for a different patch. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* hv: rename prep_negotiate_resp() to vmbus_prep_negotiate_resp()Greg Kroah-Hartman2011-10-111-1/+1
| | | | | | | | It's a global symbol, so properly prefix it and use the proper EXPORT value as well. Cc: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Staging: hv: move hyperv code out of staging directoryGreg Kroah-Hartman2011-10-111-0/+339
After many years wandering the desert, it is finally time for the Microsoft HyperV code to move out of the staging directory. Or at least the core hyperv bus code, and the utility driver, the rest still have some review to get through by the various subsystem maintainers. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>