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path: root/drivers/hv/channel_mgmt.c
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2020-09-15Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: "Two patches from Michael and Dexuan to fix vmbus hanging issues" * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload Drivers: hv: vmbus: hibernation: do not hang forever in vmbus_bus_resume()
2020-09-14Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unloadMichael Kelley
vmbus_wait_for_unload() looks for a CHANNELMSG_UNLOAD_RESPONSE message coming from Hyper-V. But if the message isn't found for some reason, the panic path gets hung forever. Add a timeout of 10 seconds to prevent this. Fixes: 415719160de3 ("Drivers: hv: vmbus: avoid scheduling in interrupt context in vmbus_initiate_unload()") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/1600026449-23651-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-20Drivers: hv: vmbus: Remove the lock field from the vmbus_channel structAndrea Parri (Microsoft)
The spinlock is (now) *not used to protect test-and-set accesses to attributes of the structure or sc_list operations. There is, AFAICT, a distinct lack of {WRITE,READ}_ONCE()s in the handling of channel->state, but the changes below do not seem to make things "worse". ;-) Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-9-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections ↵Andrea Parri (Microsoft)
(sc_list updaters) None of the readers/updaters of sc_list rely on channel->lock for synchronization. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-7-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Remove the numa_node field from the vmbus_channel structAndrea Parri (Microsoft)
The field is read only in numa_node_show() and it is already stored twice (after a call to cpu_to_node()) in target_cpu_store() and init_vp_index(); there is no need to "cache" its value in the channel data structure. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-3-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Remove the target_vp field from the vmbus_channel structAndrea Parri (Microsoft)
The field is read only in __vmbus_open() and it is already stored twice (after a call to hv_cpu_number_to_vp_number()) in target_cpu_store() and init_vp_index(); there is no need to "cache" its value in the channel data structure. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-2-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-23Drivers: hv: vmbus: Resolve more races involving init_vp_index()Andrea Parri (Microsoft)
init_vp_index() uses the (per-node) hv_numa_map[] masks to record the CPUs allocated for channel interrupts at a given time, and distribute the performance-critical channels across the available CPUs: in part., the mask of "candidate" target CPUs in a given NUMA node, for a newly offered channel, is determined by XOR-ing the node's CPU mask and the node's hv_numa_map. This operation/mechanism assumes that no offline CPUs is set in the hv_numa_map mask, an assumption that does not hold since such mask is currently not updated when a channel is removed or assigned to a different CPU. To address the issues described above, this adds hooks in the channel removal path (hv_process_channel_removal()) and in target_cpu_store() in order to clear, resp. to update, the hv_numa_map[] masks as needed. This also adds a (missed) update of the masks in init_vp_index() (cf., e.g., the memory-allocation failure path in this function). Like in the case of init_vp_index(), such hooks require to determine if the given channel is performance critical. init_vp_index() does this by parsing the channel's offer, it can not rely on the device data structure (device_obj) to retrieve such information because the device data structure has not been allocated/linked with the channel by the time that init_vp_index() executes. A similar situation may hold in hv_is_alloced_cpu() (defined below); the adopted approach is to "cache" the device type of the channel, as computed by parsing the channel's offer, in the channel structure itself. Fixes: 7527810573436f ("Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type") Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200522171901.204127-3-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-23Drivers: hv: vmbus: Resolve race between init_vp_index() and CPU hotplugAndrea Parri (Microsoft)
vmbus_process_offer() does two things (among others): 1) first, it sets the channel's target CPU with cpu_hotplug_lock; 2) it then adds the channel to the channel list(s) with channel_mutex. Since cpu_hotplug_lock is released before (2), the channel's target CPU (as designated in (1)) can be deemed "free" by hv_synic_cleanup() and go offline before the channel is added to the list. Fix the race condition by "extending" the cpu_hotplug_lock critical section to include (2) (and (1)), nesting the channel_mutex critical section within the cpu_hotplug_lock critical section as done elsewhere (hv_synic_cleanup(), target_cpu_store()) in the hyperv drivers code. Move even further by extending the channel_mutex critical section to include (1) (and (2)): this change allows to remove (the now redundant) bind_channel_to_cpu_lock, and generally simplifies the handling of the target CPUs (that are now always modified with channel_mutex held). Fixes: d570aec0f2154e ("Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug") Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200522171901.204127-2-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20drivers: hv: remove redundant assignment to pointer primary_channelColin Ian King
The pointer primary_channel is being assigned with a value that is never used. The assignment is redundant and can be removed. Move the definition of primary_channel to a narrower scope. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/r/20200414152343.243166-1-colin.king@canonical.com [ wei: move primary_channel and update commit message ] Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message typeAndrea Parri (Microsoft)
VMBus version 4.1 and later support the CHANNELMSG_MODIFYCHANNEL(22) message type which can be used to request Hyper-V to change the vCPU that a channel will interrupt. Introduce the CHANNELMSG_MODIFYCHANNEL message type, and define the vmbus_send_modifychannel() function to send CHANNELMSG_MODIFYCHANNEL requests to the host via a hypercall. The function is then used to define a sysfs "store" operation, which allows to change the (v)CPU the channel will interrupt by using the sysfs interface. The feature can be used for load balancing or other purposes. One interesting catch here is that Hyper-V can *not* currently ACK CHANNELMSG_MODIFYCHANNEL messages with the promise that (after the ACK is sent) the channel won't send any more interrupts to the "old" CPU. The peculiarity of the CHANNELMSG_MODIFYCHANNEL messages is problematic if the user want to take a CPU offline, since we don't want to take a CPU offline (and, potentially, "lose" channel interrupts on such CPU) if the host is still processing a CHANNELMSG_MODIFYCHANNEL message associated to that CPU. It is worth mentioning, however, that we have been unable to observe the above mentioned "race": in all our tests, CHANNELMSG_MODIFYCHANNEL requests appeared *as if* they were processed synchronously by the host. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-11-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> [ wei: fix conflict in channel_mgmt.c ] Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplugAndrea Parri (Microsoft)
init_vp_index() may access the cpu_online_mask mask via its calls of cpumask_of_node(). Make sure to protect these accesses with a cpus_read_lock() critical section. Also, remove some (hardcoded) instances of CPU(0) from init_vp_index() and replace them with VMBUS_CONNECT_CPU. The connect CPU can not go offline, since Hyper-V does not provide a way to change it. Finally, order the accesses of target_cpu from init_vp_index() and hv_synic_cleanup() by relying on the channel_mutex; this is achieved by moving the call of init_vp_index() into vmbus_process_offer(). Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-10-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity logicAndrea Parri (Microsoft)
The logic is unused since commit 509879bdb30b8 ("Drivers: hv: Introduce a policy for controlling channel affinity"). This logic assumes that a channel target_cpu doesn't change during the lifetime of a channel, but this assumption is incompatible with the new functionality that allows changing the vCPU a channel will interrupt. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-9-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. ↵Andrea Parri (Microsoft)
channel removal Since vmbus_chan_sched() dereferences the ring buffer pointer, we have to make sure that the ring buffer data structures don't get freed while such dereferencing is happening. Current code does this by sending an IPI to the CPU that is allowed to access that ring buffer from interrupt level, cf., vmbus_reset_channel_cb(). But with the new functionality to allow changing the CPU that a channel will interrupt, we can't be sure what CPU will be running the vmbus_chan_sched() function for a particular channel, so the current IPI mechanism is infeasible. Instead synchronize vmbus_chan_sched() and vmbus_reset_channel_cb() by using the (newly introduced) per-channel spin lock "sched_lock". Move the test for onchannel_callback being NULL before the "switch" control statement in vmbus_chan_sched(), in order to not access the ring buffer if the vmbus_reset_channel_cb() has been completed on the channel. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-7-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of ↵Andrea Parri (Microsoft)
channels When Hyper-V sends an interrupt to the guest, the guest has to figure out which channel the interrupt is associated with. Hyper-V sets a bit in a memory page that is shared with the guest, indicating a particular "relid" that the interrupt is associated with. The current Linux code then uses a set of per-CPU linked lists to map a given "relid" to a pointer to a channel structure. This design introduces a synchronization problem if the CPU that Hyper-V will interrupt for a certain channel is changed. If the interrupt comes on the "old CPU" and the channel was already moved to the per-CPU list of the "new CPU", then the relid -> channel mapping will fail and the interrupt is dropped. Similarly, if the interrupt comes on the new CPU but the channel was not moved to the per-CPU list of the new CPU, then the mapping will fail and the interrupt is dropped. Relids are integers ranging from 0 to 2047. The mapping from relids to channel structures can be done by setting up an array with 2048 entries, each entry being a pointer to a channel structure (hence total size ~16K bytes, which is not a problem). The array is global, so there are no per-CPU linked lists to update. The array can be searched and updated by loading from/storing to the array at the specified index. With no per-CPU data structures, the above mentioned synchronization problem is avoided and the relid2channel() function gets simpler. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-4-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Don't bind the offer&rescind works to a specific CPUAndrea Parri (Microsoft)
The offer and rescind works are currently scheduled on the so called "connect CPU". However, this is not really needed: we can synchronize the works by relying on the usage of the offer_in_progress counter and of the channel_mutex mutex. This synchronization is already in place. So, remove this unnecessary "bind to the connect CPU" constraint and update the inline comments accordingly. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-3-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: check VMBus messages lengthsVitaly Kuznetsov
VMBus message handlers (channel_message_table) receive a pointer to 'struct vmbus_channel_message_header' and cast it to a structure of their choice, which is sometimes longer than the header. We, however, don't check that the message is long enough so in case hypervisor screws up we'll be accessing memory beyond what was allocated for temporary buffer. Previously, we used to always allocate and copy 256 bytes from message page to temporary buffer but this is hardly better: in case the message is shorter than we expect we'll be trying to consume garbage as some real data and no memory guarding technique will be able to identify an issue. Introduce 'min_payload_len' to 'struct vmbus_channel_message_table_entry' and check against it in vmbus_on_msg_dpc(). Note, we can't require the exact length as new hypervisor versions may add extra fields to messages, we only check that the message is not shorter than we expect. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104326.45361-1-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: avoid passing opaque pointer to vmbus_onmessage()Vitaly Kuznetsov
vmbus_onmessage() doesn't need the header of the message, it only uses it to get to the payload, we can pass the pointer to the payload directly. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104154.45010-4-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-10x86/Hyper-V: Unload vmbus channel in hv panic callbackTianyu Lan
When kdump is not configured, a Hyper-V VM might still respond to network traffic after a kernel panic when kernel parameter panic=0. The panic CPU goes into an infinite loop with interrupts enabled, and the VMbus driver interrupt handler still works because the VMbus connection is unloaded only in the kdump path. The network responses make the other end of the connection think the VM is still functional even though it has panic'ed, which could affect any failover actions that should be taken. Fix this by unloading the VMbus connection during the panic process. vmbus_initiate_unload() could then be called twice (e.g., by hyperv_panic_event() and hv_crash_handler(), so reset the connection state in vmbus_initiate_unload() to ensure the unload is done only once. Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic") Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20200406155331.2105-2-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-01-25Drivers: hv: vmbus: Ignore CHANNELMSG_TL_CONNECT_RESULT(23)Dexuan Cui
When a Linux hv_sock app tries to connect to a Service GUID on which no host app is listening, a recent host (RS3+) sends a CHANNELMSG_TL_CONNECT_RESULT (23) message to Linux and this triggers such a warning: unknown msgtype=23 WARNING: CPU: 2 PID: 0 at drivers/hv/vmbus_drv.c:1031 vmbus_on_msg_dpc Actually Linux can safely ignore the message because the Linux app's connect() will time out in 2 seconds: see VSOCK_DEFAULT_CONNECT_TIMEOUT and vsock_stream_connect(). We don't bother to make use of the message because: 1) it's only supported on recent hosts; 2) a non-trivial effort is required to use the message in Linux, but the benefit is small. So, let's not see the warning by silently ignoring the message. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06Drivers: hv: vmbus: Resume after fixing up old primary channelsDexuan Cui
When the host re-offers the primary channels upon resume, the host only guarantees the Instance GUID doesn't change, so vmbus_bus_suspend() should invalidate channel->offermsg.child_relid and figure out the number of primary channels that need to be fixed up upon resume. Upon resume, vmbus_onoffer() finds the old channel structs, and maps the new offers to the old channels, and fixes up the old structs, and finally the resume callbacks of the VSC drivers will re-open the channels. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06Drivers: hv: vmbus: Suspend after cleaning up hv_sock and sub channelsDexuan Cui
Before suspend, Linux must make sure all the hv_sock channels have been properly cleaned up, because a hv_sock connection can not persist across hibernation, and the user-space app must be properly notified of the state change of the connection. Before suspend, Linux also must make sure all the sub-channels have been destroyed, i.e. the related channel structs of the sub-channels must be properly removed, otherwise they would cause a conflict when the sub-channels are recreated upon resume. Add a counter to track such channels, and vmbus_bus_suspend() should wait for the counter to drop to zero. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06Drivers: hv: vmbus: Ignore the offers when resuming from hibernationDexuan Cui
When the VM resumes, the host re-sends the offers. We should not add the offers to the global vmbus_connection.chn_list again. This patch assumes the RELIDs of the channels don't change across hibernation. Actually this is not always true, especially in the case of NIC SR-IOV the VF vmbus device's RELID sometimes can change. A later patch will address this issue by mapping the new offers to the old channels and fixing up the old channels, if necessary. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 320Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 33 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000435.254582722@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-10Drivers: hv: vmbus: Fix race condition with new ring_buffer_info mutexKimberly Brown
Fix a race condition that can result in a ring buffer pointer being set to null while a "_show" function is reading the ring buffer's data. This problem was discussed here: https://lkml.org/lkml/2018/10/18/779 To fix the race condition, add a new mutex lock to the "hv_ring_buffer_info" struct. Add a new function, "hv_ringbuffer_pre_init()", where a channel's inbound and outbound ring_buffer_info mutex locks are initialized. Acquire/release the locks in the "hv_ringbuffer_cleanup()" function, which is where the ring buffer pointers are set to null. Acquire/release the locks in the four channel-level "_show" functions that access ring buffer data. Remove the "const" qualifier from the "vmbus_channel" parameter and the "rbi" variable of the channel-level "_show" functions so that the locks can be acquired/released in these functions. Acquire/release the locks in hv_ringbuffer_get_debuginfo(). Remove the "const" qualifier from the "hv_ring_buffer_info" parameter so that the locks can be acquired/released in this function. Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-20Drivers: hv: vmbus: Expose monitor data only when monitor pages are usedKimberly Brown
There are two methods for signaling the host: the monitor page mechanism and hypercalls. The monitor page mechanism is used by performance critical channels (storage, networking, etc.) because it provides improved throughput. However, latency is increased. Monitor pages are allocated to these channels. Monitor pages are not allocated to channels that do not use the monitor page mechanism. Therefore, these channels do not have a valid monitor id or valid monitor page data. In these cases, some of the "_show" functions return incorrect data. They return an invalid monitor id and data that is beyond the bounds of the hv_monitor_page array fields. The "channel->offermsg.monitor_allocated" value can be used to determine whether monitor pages have been allocated to a channel. Add "is_visible()" callback functions for the device-level and channel-level attribute groups. These functions will hide the monitor sysfs files when the monitor mechanism is not used. Remove ".default_attributes" from "vmbus_chan_attrs" and create a channel-level attribute group. These changes allow the new "is_visible()" callback function to be applied to the channel-level attributes. Call "sysfs_create_group()" in "vmbus_add_channel_kobj()" to create the channel's sysfs files. Add a new function, “vmbus_remove_channel_attr_group()”, and call it in "free_channel()" to remove the channel's sysfs files when the channel is closed. Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-14vmbus: Switch to use new generic UUID APIAndy Shevchenko
There are new types and helpers that are supposed to be used in new code. As a preparation to get rid of legacy types and API functions do the conversion here. Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: devel@linuxdriverproject.org Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-10Merge 4.20-rc6 into char-misc-nextGreg Kroah-Hartman
This should resolve the hv driver merge conflict. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-03Drivers: hv: vmbus: Offload the handling of channels to two workqueuesDexuan Cui
vmbus_process_offer() mustn't call channel->sc_creation_callback() directly for sub-channels, because sc_creation_callback() -> vmbus_open() may never get the host's response to the OPEN_CHANNEL message (the host may rescind a channel at any time, e.g. in the case of hot removing a NIC), and vmbus_onoffer_rescind() may not wake up the vmbus_open() as it's blocked due to a non-zero vmbus_connection.offer_in_progress, and finally we have a deadlock. The above is also true for primary channels, if the related device drivers use sync probing mode by default. And, usually the handling of primary channels and sub-channels can depend on each other, so we should offload them to different workqueues to avoid possible deadlock, e.g. in sync-probing mode, NIC1's netvsc_subchan_work() can race with NIC2's netvsc_probe() -> rtnl_lock(), and causes deadlock: the former gets the rtnl_lock and waits for all the sub-channels to appear, but the latter can't get the rtnl_lock and this blocks the handling of sub-channels. The patch can fix the multiple-NIC deadlock described above for v3.x kernels (e.g. RHEL 7.x) which don't support async-probing of devices, and v4.4, v4.9, v4.14 and v4.18 which support async-probing but don't enable async-probing for Hyper-V drivers (yet). The patch can also fix the hang issue in sub-channel's handling described above for all versions of kernels, including v4.19 and v4.20-rc4. So actually the patch should be applied to all the existing kernels, not only the kernels that have 8195b1396ec8. Fixes: 8195b1396ec8 ("hv_netvsc: fix deadlock on hotplug") Cc: stable@vger.kernel.org Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.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>
2018-11-26Drivers: hv: vmbus: Remove the useless API vmbus_get_outgoing_channel()Dexuan Cui
Commit d86adf482b84 ("scsi: storvsc: Enable multi-queue support") removed the usage of the API in Jan 2017, and the API is not used since then. netvsc and storvsc have their own algorithms to determine the outgoing channel, so this API is useless. And the API is potentially unsafe, because it reads primary->num_sc without any lock held. This can be risky considering the RESCIND-OFFER message. Let's remove the API. Cc: Long Li <longli@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.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>
2018-10-02Drivers: hv: vmbus: Use cpumask_var_t for on-stack cpu maskDexuan Cui
A cpumask structure on the stack can cause a warning with CONFIG_NR_CPUS=8192 (e.g. Ubuntu 16.04 and 18.04 use this): drivers/hv//channel_mgmt.c: In function ‘init_vp_index’: drivers/hv//channel_mgmt.c:702:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=] Nowadays it looks most distros enable CONFIG_CPUMASK_OFFSTACK=y, and hence we can work around the warning by using cpumask_var_t. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: <Stable@vger.kernel.org> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-02Drivers: hv: vmbus: Fix the descriptions of some function parametersDexuan Cui
No functional change. Added descriptions for some parameters. Fixed some typos. Removed some out-of-date comments. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-25vmbus: pass channel to hv_process_channel_removalStephen Hemminger
Rather than passing relid and then looking up the channel. Pass the channel directly, since caller already knows it. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-02Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind()Dexuan Cui
Before setting channel->rescind in vmbus_rescind_cleanup(), we should make sure the channel callback won't run any more, otherwise a high-level driver like pci_hyperv, which may be infinitely waiting for the host VSP's response and notices the channel has been rescinded, can't safely give up: e.g., in hv_pci_protocol_negotiation() -> wait_for_response(), it's unsafe to exit from wait_for_response() and proceed with the on-stack variable "comp_pkt" popped. The issue was originally spotted by Michael Kelley <mikelley@microsoft.com>. In vmbus_close_internal(), the patch also minimizes the range protected by disabling/enabling channel->callback_event: we don't really need that for the whole function. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Michael Kelley <mikelley@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-03Drivers: hv: vmbus: Fix the offer_in_progress in vmbus_process_offer()Dexuan Cui
I didn't really hit a real bug, but just happened to spot the bug: we have decreased the counter at the beginning of vmbus_process_offer(), so we mustn't decrease it again. Fixes: 6f3d791f3006 ("Drivers: hv: vmbus: Fix rescind handling issues") Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: stable@vger.kernel.org Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Stable <stable@vger.kernel.org> # 4.14 and above Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-28Drivers: hv: vmbus: do not mark HV_PCIE as perf_deviceDexuan Cui
The pci-hyperv driver's channel callback hv_pci_onchannelcallback() is not really a hot path, so we don't need to mark it as a perf_device, meaning with this patch all HV_PCIE channels' target_cpu will be CPU0. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: stable@vger.kernel.org Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-06hv_vmbus: Correct the stale comments regarding cpu affinityHaiyang Zhang
The comments doesn't match what the current code does, also have a typo. This patch corrects them. Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28Drivers: hv: vmbus: Fix a rescind issueK. Y. Srinivasan
The current rescind processing code will not correctly handle the case where the host immediately rescinds a channel that has been offerred. In this case, we could be blocked in the open call and since the channel is rescinded, the host will not respond and we could be blocked forever in the vmbus open call.i Fix this problem. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-04hyper-v: trace vmbus_release_relid()Vitaly Kuznetsov
Add tracepoint to CHANNELMSG_RELID_RELEASED sender. 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>
2017-11-04hyper-v: trace vmbus_request_offers()Vitaly Kuznetsov
Add tracepoint to CHANNELMSG_REQUESTOFFERS sender. 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>
2017-11-04hyper-v: trace vmbus_onversion_response()Vitaly Kuznetsov
Add tracepoint to CHANNELMSG_VERSION_RESPONSE handler. 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>
2017-11-04hyper-v: trace vmbus_ongpadl_torndown()Vitaly Kuznetsov
Add tracepoint to CHANNELMSG_GPADL_TORNDOWN handler. 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>
2017-11-04hyper-v: trace vmbus_ongpadl_created()Vitaly Kuznetsov
Add tracepoint to CHANNELMSG_GPADL_CREATED handler. 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>
2017-11-04hyper-v: trace vmbus_onopen_result()Vitaly Kuznetsov
Add tracepoint to CHANNELMSG_OPENCHANNEL_RESULT handler. 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>
2017-11-04hyper-v: trace vmbus_onoffer_rescind()Vitaly Kuznetsov
Add tracepoint to CHANNELMSG_RESCIND_CHANNELOFFER handler. 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>
2017-11-04hyper-v: trace vmbus_onoffer()Vitaly Kuznetsov
Add tracepoint to CHANNELMSG_OFFERCHANNEL handler. 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>
2017-11-04hyper-v: trace vmbus_on_message()Vitaly Kuznetsov
Add tracepoint to vmbus_on_message() which is called when we start processing a blocking from work context. 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>
2017-10-23Merge 4.14-rc6 into char-misc-nextGreg Kroah-Hartman
We want the driver fixes in here and this resolves a merge issue with the binder driver. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-20vmbus: hvsock: add proper sync for vmbus_hvsock_device_unregister()Dexuan Cui
Without the patch, vmbus_hvsock_device_unregister() can destroy the device prematurely when close() is called, and can cause NULl dereferencing or potential data loss (the last portion of the data stream may be dropped prematurely). Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-16Merge 4.14-rc5 into char-misc-nextGreg Kroah-Hartman
We need the fixes in here to resolve merge issues and for testing. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-04Drivers: hv: vmbus: Fix bugs in rescind handlingK. Y. Srinivasan
This patch addresses the following bugs in the current rescind handling code: 1. Fixes a race condition where we may be invoking hv_process_channel_removal() on an already freed channel. 2. Prevents indefinite wait when rescinding sub-channels by correctly setting the probe_complete state. I would like to thank Dexuan for patiently reviewing earlier versions of this patch and identifying many of the issues fixed here. Greg, please apply this to 4.14-final. Fixes: '54a66265d675 ("Drivers: hv: vmbus: Fix rescind handling")' Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Cc: stable@vger.kernel.org # (4.13 and above) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>