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2022-09-23Drivers: hv: vmbus: Optimize vmbus_on_eventSaurabh Sengar1-19/+14
In the vmbus_on_event loop, 2 jiffies timer will not serve the purpose if callback_fn takes longer. For effective use move this check inside of callback functions where needed. Out of all the VMbus drivers using vmbus_on_event, only storvsc has a high packet volume, thus add this limit only in storvsc callback for now. There is no apparent benefit of loop itself because this tasklet will be scheduled anyway again if there are packets left in ring buffer. This patch removes this unnecessary loop as well. Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1658741848-4210-1-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2022-07-11Drivers: hv: vm_bus: Handle vmbus rescind calls after vmbus is suspendedShradha Gupta1-0/+11
Add a flag to indicate that the vmbus is suspended so we should ignore any offer message. Add a new work_queue for rescind msg, so we could drain it along with other offer work_queues upon suspension. It was observed that in some hibernation related scenario testing, after vmbus_bus_suspend() we get rescind offer message for the vmbus. This would lead to processing of a rescind message for a channel that has already been suspended. Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20220711041147.GA5569@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net Signed-off-by: Wei Liu <wei.liu@kernel.org>
2022-05-11Drivers: hv: vmbus: Remove support for Hyper-V 2008 and Hyper-V 2008R2/Win7Michael Kelley1-3/+3
The VMbus driver has special case code for running on the first released versions of Hyper-V: 2008 and 2008 R2/Windows 7. These versions are now out of support (except for extended security updates) and lack the performance features needed for effective production usage of Linux guests. Simplify the code by removing the negotiation of the VMbus protocol versions required for these releases of Hyper-V, and by removing the special case code for handling these VMbus protocol versions. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/1651509391-2058-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-10-28Drivers: hv: vmbus: Add SNP support for VMbus channel initiate messageTianyu Lan1-6/+89
The monitor pages in the CHANNELMSG_INITIATE_CONTACT msg are shared with host in Isolation VM and so it's necessary to use hvcall to set them visible to host. In Isolation VM with AMD SEV SNP, the access address should be in the extra space which is above shared gpa boundary. So remap these pages into the extra address(pa + shared_gpa_boundary). Introduce monitor_pages_original[] in the struct vmbus_connection to store monitor page virtual address returned by hv_alloc_hyperv_ zeroed_page() and free monitor page via monitor_pages_original in the vmbus_disconnect(). The monitor_pages[] is to used to access monitor page and it is initialized to be equal with monitor_pages_ original. The monitor_pages[] will be overridden in the isolation VM with va of extra address. Introduce monitor_pages_pa[] to store monitor pages' physical address and use it to populate pa in the initiate msg. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-9-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-10-28x86/hyperv: Add ghcb hvcall support for SNP VMTianyu Lan1-1/+5
hyperv provides ghcb hvcall to handle VMBus HVCALL_SIGNAL_EVENT and HVCALL_POST_MESSAGE msg in SNP Isolation VM. Add such support. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-8-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-06-02drivers: hv: Fix missing error code in vmbus_connect()Jiapeng Chong1-1/+3
Eliminate the follow smatch warning: drivers/hv/connection.c:236 vmbus_connect() warn: missing error code 'ret'. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1621940321-72353-1-git-send-email-jiapeng.chong@linux.alibaba.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-20Drivers: hv: vmbus: Initialize unload_event staticallyAndrea Parri (Microsoft)1-0/+2
If a malicious or compromised Hyper-V sends a spurious message of type CHANNELMSG_UNLOAD_RESPONSE, the function vmbus_unload_response() will call complete() on an uninitialized event, and cause an oops. Reported-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210420014350.2002-1-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-18Drivers: hv: vmbus: Introduce and negotiate VMBus protocol version 5.3Andrea Parri (Microsoft)1-1/+2
Hyper-V has added VMBus protocol version 5.3. Allow Linux guests to negotiate the new version on version of Hyper-V that support it. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210416143449.16185-2-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08drivers: hv: Fix whitespace errorsVasanth1-1/+1
Fixed checkpatch warning and errors on hv driver. Signed-off-by: Vasanth Mathivanan <vasanth3g@gmail.com> Link: https://lore.kernel.org/r/20210219171311.421961-1-vasanth3g@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11Drivers: hv: vmbus: Enforce 'VMBus version >= 5.2' on isolated guestsAndrea Parri (Microsoft)1-0/+7
Restrict the protocol version(s) that will be negotiated with the host to be 5.2 or greater if the guest is running isolated. This reduces the footprint of the code that will be exercised by Confidential VMs and hence the exposure to bugs and vulnerabilities. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210201144814.2701-4-parri.andrea@gmail.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)1-27/+11
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: Always handle the VMBus messages on CPU0Andrea Parri (Microsoft)1-19/+1
A Linux guest have to pick a "connect CPU" to communicate with the Hyper-V host. This CPU can not be taken offline because Hyper-V does not provide a way to change that CPU assignment. Current code sets the connect CPU to whatever CPU ends up running the function vmbus_negotiate_version(), and this will generate problems if that CPU is taken offine. Establish CPU0 as the connect CPU, and add logics to prevents the connect CPU from being taken offline. We could pick some other CPU, and we could pick that "other CPU" dynamically if there was a reason to do so at some point in the future. But for now, #defining the connect CPU to 0 is the most straightforward and least complex solution. While on this, add inline comments explaining "why" offer and rescind messages should not be handled by a same serialized work queue. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/20200406001514.19876-2-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2019-11-21Drivers: hv: vmbus: Remove dependencies on guest page sizeHimadri Pandya1-7/+7
Hyper-V assumes page size to be 4K. This might not be the case for ARM64 architecture. Hence use hyper-v page size and page allocation function to avoid conflicts between different host and guest page size on ARM64. Signed-off-by: Himadri Pandya <himadri18.07@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21drivers: hv: vmbus: Introduce latency testingBranden Bonaby1-0/+1
Introduce user specified latency in the packet reception path By exposing the test parameters as part of the debugfs channel attributes. We will control the testing state via these attributes. Signed-off-by: Branden Bonaby <brandonbonaby94@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21Drivers: hv: vmbus: Add module parameter to cap the VMBus versionAndrea Parri1-0/+13
Currently, Linux guests negotiate the VMBus version with Hyper-V and use the highest available VMBus version they can connect to. This has some drawbacks: by using the highest available version, certain code paths are never executed and can not be tested when the guest runs on the newest host. Add the module parameter "max_version", to upper-bound the VMBus versions guests can negotiate. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2Andrea Parri1-5/+8
Hyper-V has added VMBus protocol versions 5.1 and 5.2 in recent release versions. Allow Linux guests to negotiate these new protocol versions on versions of Hyper-V that support them. While on this, also allow guests to negotiate the VMBus protocol version 4.1 (which was missing). Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21Drivers: hv: vmbus: Introduce table of VMBus protocol versionsAndrea Parri1-32/+18
The technique used to get the next VMBus version seems increasisly clumsy as the number of VMBus versions increases. Performance is not a concern since this is only done once during system boot; it's just that we'll end up with more lines of code than is really needed. As an alternative, introduce a table with the version numbers listed in order (from the most recent to the oldest). vmbus_connect() loops through the versions listed in the table until it gets an accepted connection or gets to the end of the table (invalid version). Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> 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 Cui1-0/+2
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 Cui1-0/+3
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: Suspend/resume the vmbus itself for hibernationDexuan Cui1-2/+1
Before Linux enters hibernation, it sends the CHANNELMSG_UNLOAD message to the host so all the offers are gone. After hibernation, Linux needs to re-negotiate with the host using the same vmbus protocol version (which was in use before hibernation), and ask the host to re-offer the vmbus devices. 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 Gleixner1-14/+1
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>
2018-12-03Drivers: hv: vmbus: Offload the handling of channels to two workqueuesDexuan Cui1-3/+21
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>
2018-09-30Drivers: hv: vmbus: Use get/put_cpu() in vmbus_connect()Dexuan Cui1-3/+5
With CONFIG_DEBUG_PREEMPT=y, I always see this warning: BUG: using smp_processor_id() in preemptible [00000000] Fix the false warning by using get/put_cpu(). Here vmbus_connect() sends a message to the host and waits for the host's response. The host will deliver the response message and an interrupt on CPU msg->target_vcpu, and later the interrupt handler will wake up vmbus_connect(). vmbus_connect() doesn't really have to run on the same cpu as CPU msg->target_vcpu, so it's safe to call put_cpu() just here. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: stable@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>
2018-05-15Drivers: hv: vmbus: Removed an unnecessary cast from void *Dexuan Cui1-1/+1
In C, we don't need such a cast. Fixes: ae20b254306a ("Drivers: hv: vmbus: enable VMBus protocol version 5.0") Reported-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14Drivers: hv: vmbus: enable VMBus protocol version 5.0Dexuan Cui1-2/+42
With VMBus protocol 5.0, we're able to better support new features, e.g. running two or more VMBus drivers simultaneously in a single VM -- note: we can't simply load the current VMBus driver twice, instead, a secondary VMBus driver must be implemented. This patch adds the support for the new VMBus protocol, which is available on new Windows hosts, by: 1) We still use SINT2 for compatibility; 2) We must use Connection ID 4 for the Initiate Contact Message, and for subsequent messages, we must use the Message Connection ID field in the host-returned VersionResponse Message. Notes for developers of the secondary VMBus driver: 1) Must use VMBus protocol 5.0 as well; 2) Must use a different SINT number that is not in use. 3) Must use Connection ID 4 for the Initiate Contact Message, and for subsequent messages, must use the Message Connection ID field in the host-returned VersionResponse Message. 4) It's possible that the primary VMBus driver using protocol version 4.0 can work with a secondary VMBus driver using protocol version 5.0, but it's recommended that both should use 5.0 for new Hyper-V features in the future. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: K. Y. Srinivasan <kys@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>
2018-03-28x86/hyper-v: move hyperv.h out of uapiVitaly Kuznetsov1-1/+0
hyperv.h is not part of uapi, there are no (known) users outside of kernel. We are making changes to this file to match current Hyper-V Hypervisor Top-Level Functional Specification (TLFS, see: https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs) and we don't want to maintain backwards compatibility. Move the file renaming to hyperv-tlfs.h to avoid confusing it with mshyperv.h. In future, all definitions from TLFS should go to it and all kernel objects should go to mshyperv.h or include/linux/hyperv.h. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-11-04hyper-v: trace channel eventsVitaly Kuznetsov1-0/+2
Added an additional set of trace points for when channel gets notified or signals host. Suggested-by: Stephen Hemminger <sthemmin@microsoft.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>
2017-11-04hyper-v: trace vmbus_negotiate_version()Vitaly Kuznetsov1-0/+3
Add tracepoint to CHANNELMSG_INITIATE_CONTACT 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>
2017-10-31Drivers: hv: vmbus: Expose per-channel interrupts and events countersStephen Hemminger1-0/+2
When investigating performance, it is useful to be able to look at the number of host and guest events per-channel. This is equivalent to per-device interrupt statistics. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-10hyper-v: Globalize vp_indexVitaly Kuznetsov1-1/+2
To support implementing remote TLB flushing on Hyper-V with a hypercall we need to make vp_index available outside of vmbus module. Rename and globalize. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Simon Xiao <sixiao@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20170802160921.21791-7-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-10hyper-v: Use fast hypercall for HVCALL_SIGNAL_EVENTVitaly Kuznetsov1-1/+1
We need to pass only 8 bytes of input for HvSignalEvent which makes it a perfect fit for fast hypercall. hv_input_signal_event_buffer is not needed any more and hv_input_signal_event is converted to union for convenience. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Simon Xiao <sixiao@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20170802160921.21791-5-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-10x86/hyper-v: Make hv_do_hypercall() inlineVitaly Kuznetsov1-0/+2
We have only three call sites for hv_do_hypercall() and we're going to change HVCALL_SIGNAL_EVENT to doing fast hypercall so we can inline this function for optimization. Hyper-V top level functional specification states that r9-r11 registers and flags may be clobbered by the hypervisor during hypercall and with inlining this is somewhat important, add the clobbers. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Simon Xiao <sixiao@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20170802160921.21791-3-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-25drivers: hv: vmbus: Increase the time between retries in vmbus_post_msg()K. Y. Srinivasan1-1/+1
Commit c0bb03924f1a ("Drivers: hv: vmbus: Raise retry/wait limits in vmbus_post_msg()") increased the retry/wait limits of vmbus_post_msg() to address the new DoS protection policies in WS2016. Increase the time between retries to make the code more robust. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18Drivers: hv: vmbus: Fix rescind handlingK. Y. Srinivasan1-2/+5
Fix the rescind handling. This patch addresses the following rescind scenario that is currently not handled correctly: If a rescind were to be received while the offer is still being peocessed, we will be blocked indefinitely since the rescind message is handled on the same work element as the offer message. Fix this issue. I would like to thank Dexuan Cui <decui@microsoft.com> and Long Li <longli@microsoft.com> for working with me on this patch. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18Drivers: hv: vmbus: Fix error code returned by vmbus_post_msg()K. Y. Srinivasan1-1/+1
ENOBUFS is a more approrpiate error code to be returned when the hypervisor cannot post the message because of insufficient buffers. Make the adjustment. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17vmbus: only reschedule tasklet if time limit exceededStephen Hemminger1-31/+34
The change to reschedule tasklet if more data arrives in ring buffer can cause performance regression if host timing is such that the next response happens in small window. Go back to a modified version of the original looping behavior. If the race occurs in a small time, then loop. But if the tasklet has been running for a long interval due to flood, then reschedule the tasklet to allow migration to ksoftirqd. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-14vmbus: add direct isr callback modeStephen Hemminger1-15/+12
Change the simple boolean batched_reading into a tri-value. For future NAPI support in netvsc driver, the callback needs to occur directly in interrupt handler. Batched mode is also changed to disable host interrupts immediately in interrupt routine (to avoid unnecessary host signals), and the tasklet is rescheduled if more data is detected. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-14vmbus: change to per channel taskletStephen Hemminger1-75/+3
Make the event handling tasklet per channel rather than per-cpu. This allows for better fairness when getting lots of data on the same cpu. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-14vmbus: put related per-cpu variable togetherStephen Hemminger1-11/+9
The hv_context structure had several arrays which were per-cpu and was allocating small structures (tasklet_struct). Instead use a single per-cpu array. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10vmbus: use kernel bitops for traversing interrupt maskStephen Hemminger1-38/+17
Use standard kernel operations for find first set bit to traverse the channel bit array. This has added benefit of speeding up lookup on 64 bit and because it uses find first set instruction. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20Drivers: hv: vmbus: Move the extracting of Hypervisor version informationK. Y. Srinivasan1-5/+2
As part of the effort to separate out architecture specific code, extract hypervisor version information in an architecture specific file. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10Drivers: hv: vmbus: Raise retry/wait limits in vmbus_post_msg()Vitaly Kuznetsov1-5/+12
DoS protection conditions were altered in WS2016 and now it's easy to get -EAGAIN returned from vmbus_post_msg() (e.g. when we try changing MTU on a netvsc device in a loop). All vmbus_post_msg() callers don't retry the operation and we usually end up with a non-functional device or crash. While host's DoS protection conditions are unknown to me my tests show that it can take up to 10 seconds before the message is sent so doing udelay() is not an option, we really need to sleep. Almost all vmbus_post_msg() callers are ready to sleep but there is one special case: vmbus_initiate_unload() which can be called from interrupt/NMI context and we can't sleep there. I'm also not sure about the lonely vmbus_send_tl_connect_request() which has no in-tree users but its external users are most likely waiting for the host to reply so sleeping there is also appropriate. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-06uio-hv-generic: new userspace i/o driver for VMBusStephen Hemminger1-0/+1
This is a new driver to enable userspace networking on VMBus. It is based largely on the similar driver that already exists for PCI, and earlier work done by Brocade to support DPDK. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31Drivers: hv: vmbus: Reduce the delay between retries in vmbus_post_msg()K. Y. Srinivasan1-4/+4
The current delay between retries is unnecessarily high and is negatively affecting the time it takes to boot the system. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30Drivers: hv: vmbus: Export the vmbus_set_event() APIK. Y. Srinivasan1-0/+1
In preparation for moving some ring buffer functionality out of the vmbus driver, export the API for signaling the host. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01Drivers: hv: vmbus: Support kexec on ws2012 r2 and aboveAlex Ng1-1/+9
WS2012 R2 and above hosts can support kexec in that thay can support reconnecting to the host (as would be needed in the kexec path) on any CPU. Enable this. Pre ws2012 r2 hosts don't have this ability and consequently cannot support kexec. Signed-off-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01Drivers: hv: vmbus: avoid wait_for_completion() on crashVitaly Kuznetsov1-1/+1
wait_for_completion() may sleep, it enables interrupts and this is something we really want to avoid on crashes because interrupt handlers can cause other crashes. Switch to the recently introduced vmbus_wait_for_unload() doing busy wait instead. Reported-by: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Radim Kr.má<rkrcmar@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()Dexuan Cui1-2/+2
The hvsock driver needs this API to release all the resources related to the channel. 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>
2016-02-07Drivers: hv: vmbus: Cleanup vmbus_set_event()K. Y. Srinivasan1-2/+2
Cleanup vmbus_set_event() by inlining the hypercall to post the event and since the return value of vmbus_set_event() is not checked, make it void. As part of this cleanup, get rid of the function hv_signal_event() as it is only callled from vmbus_set_event(). Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14Drivers: hv: vmbus: Force all channel messages to be delivered on CPU 0K. Y. Srinivasan1-4/+7
Force all channel messages to be delivered on CPU0. These messages are not performance critical and are used during the setup and teardown of the channel. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>