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2015-08-05Drivers: hv: vmbus: use cpu_hotplug_enable/disableVitaly Kuznetsov
Commit e513229b4c38 ("Drivers: hv: vmbus: prevent cpu offlining on newer hypervisors") was altering smp_ops.cpu_disable to prevent CPU offlining. We can bo better by using cpu_hotplug_enable/disable functions instead of such hard-coding. Reported-by: Radim Kr.má <rkrcmar@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05Drivers: hv: vmbus: add a sysfs attr to show the binding of channel/VPDexuan Cui
This is useful to analyze performance issue. 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>
2015-08-05Drivers: hv: vmbus: Implement a clocksource based on the TSC pageK. Y. Srinivasan
The current Hyper-V clock source is based on the per-partition reference counter and this counter is being accessed via s synthetic MSR - HV_X64_MSR_TIME_REF_COUNT. Hyper-V has a more efficient way of computing the per-partition reference counter value that does not involve reading a synthetic MSR. We implement a time source based on this mechanism. Tested-by: Vivek Yadav <vyadav@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05drivers/hv: Migrate to new 'set-state' interfaceViresh Kumar
Migrate hv driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED. Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: devel@linuxdriverproject.org Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05Drivers: hv_vmbus: Fix signal to host conditionChristopher Oo
Fixes a bug where previously hv_ringbuffer_read would pass in the old number of bytes available to read instead of the expected old read index when calculating when to signal to the host that the ringbuffer is empty. Since the previous write size is already saved, also changes the hv_need_to_signal_on_read to use the previously read value rather than recalculating it. Signed-off-by: Christopher Oo <t-chriso@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05Drivers: hv: vmbus: Further improve CPU affiliation logicDexuan Cui
Keep track of CPU affiliations of sub-channels within the scope of the primary channel. This will allow us to better distribute the load amongst available CPUs. 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>
2015-08-05Drivers: hv: vmbus: Improve the CPU affiliation for channelsK. Y. Srinivasan
The current code tracks the assigned CPUs within a NUMA node in the context of the primary channel. So, if we have a VM with a single NUMA node with 8 VCPUs, we may end up unevenly distributing the channel load. Fix the issue by tracking affiliations globally. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05drivers:hv: Move MMIO range picking from hyper_fb to hv_vmbusJake Oshins
This patch deletes the logic from hyperv_fb which picked a range of MMIO space for the frame buffer and adds new logic to hv_vmbus which picks ranges for child drivers. The new logic isn't quite the same as the old, as it considers more possible ranges. Signed-off-by: Jake Oshins <jakeo@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05drivers:hv: Modify hv_vmbus to search for all MMIO ranges available.Jake Oshins
This patch changes the logic in hv_vmbus to record all of the ranges in the VM's firmware (BIOS or UEFI) that offer regions of memory-mapped I/O space for use by paravirtual front-end drivers. The old logic just found one range above 4GB and called it good. This logic will find any ranges above 1MB. It would have been possible with this patch to just use existing resource allocation functions, rather than keep track of the entire set of Hyper-V related MMIO regions in VMBus. This strategy, however, is not sufficient when the resource allocator needs to be aware of the constraints of a Hyper-V virtual machine, which is what happens in the next patch in the series. So this first patch exists to show the first steps in reworking the MMIO allocation paths for Hyper-V front-end drivers. Signed-off-by: Jake Oshins <jakeo@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04Drivers: hv: vmbus: Consider ND NIC in binding channels to CPUsK. Y. Srinivasan
We cycle through all the "high performance" channels to distribute load across the available CPUs. Process the NetworkDirect as a high performance device. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04mshyperv: fix recognition of Hyper-V guest crash MSR'sDenis V. Lunev
Hypervisor Top Level Functional Specification v3.1/4.0 notes that cpuid (0x40000003) EDX's 10th bit should be used to check that Hyper-V guest crash MSR's functionality available. This patch should fix this recognition. Currently the code checks EAX register instead of EDX. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04Drivers: hv: vmbus: don't send CHANNELMSG_UNLOAD on pre-Win2012R2 hostsVitaly Kuznetsov
Pre-Win2012R2 hosts don't properly handle CHANNELMSG_UNLOAD and wait_for_completion() hangs. Avoid sending such request on old hosts. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04Drivers: hv: vmbus: fix typo in hv_port_info structNik Nyby
This fixes a typo: base_flag_bumber to base_flag_number Signed-off-by: Nik Nyby <nikolas@gnu.org> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04hv: util: checking the wrong variableDan Carpenter
We don't catch this allocation failure because there is a typo and we check the wrong variable. Fixes: 14b50f80c32d ('Drivers: hv: util: introduce hv_utils_transport abstraction') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04Drivers: hv: vmbus: Permit sending of packets without payloadK. Y. Srinivasan
The guest may have to send a completion packet back to the host. To support this usage, permit sending a packet without a payload - we would be only sending the descriptor in this case. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04Drivers: hv: balloon: Enable dynamic memory protocol negotiation with ↵Alex Ng
Windows 10 hosts Support Win10 protocol for Dynamic Memory. Thia patch allows guests on Win10 hosts to hot-add memory even when dynamic memory is not enabled on the guest. 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>
2015-08-04Drivers: hv: fcopy: dynamically allocate smsg_out in fcopy_send_data()Vitaly Kuznetsov
struct hv_start_fcopy is too big to be on stack on i386, the following warning is reported: >> drivers/hv/hv_fcopy.c:159:1: warning: the frame size of 1088 bytes is larger than 1024 bytes [-Wframe-larger-than=] Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04Drivers: hv: kvp: check kzalloc return valueVitaly Kuznetsov
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>
2015-08-04Drivers: hv: vmbus: prefer 'die' notification chain to 'panic'Vitaly Kuznetsov
current_pt_regs() sometimes returns regs of the userspace process and in case of a kernel crash this is not what we need to report. E.g. when we trigger crash with sysrq we see the following: ... RIP: 0010:[<ffffffff815b8696>] [<ffffffff815b8696>] sysrq_handle_crash+0x16/0x20 RSP: 0018:ffff8800db0a7d88 EFLAGS: 00010246 RAX: 000000000000000f RBX: ffffffff820a0660 RCX: 0000000000000000 ... at the same time current_pt_regs() give us: ip=7f899ea7e9e0, ax=ffffffffffffffda, bx=26c81a0, cx=7f899ea7e9e0, ... These registers come from the userspace process triggered the crash. As we don't even know which process it was this information is rather useless. When kernel crash happens through 'die' proper regs are being passed to all receivers on the die_chain (and panic_notifier_list is being notified with the string passed to panic() only). If panic() is called manually (e.g. on BUG()) we won't get 'die' notification so keep the 'panic' notification reporter as well but guard against double reporting. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04Drivers: hv: vmbus: add special crash handlerVitaly Kuznetsov
Full kernel hang is observed when kdump kernel starts after a crash. This hang happens in vmbus_negotiate_version() function on wait_for_completion() as Hyper-V host (Win2012R2 in my testing) never responds to CHANNELMSG_INITIATE_CONTACT as it thinks the connection is already established. We need to perform some mandatory minimalistic cleanup before we start new kernel. Reported-by: K. Y. Srinivasan <kys@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>
2015-08-04Drivers: hv: don't do hypercalls when hypercall_page is NULLVitaly Kuznetsov
At the very late stage of kexec a driver (which are not being unloaded) can try to post a message or signal an event. This will crash the kernel as we already did hv_cleanup() and the hypercall page is NULL. Move all common (between 32 and 64 bit code) declarations to the beginning of the do_hypercall() function. Unfortunately we have to write the !hypercall_page check twice to not mix declarations and code. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04Drivers: hv: vmbus: add special kexec handlerVitaly Kuznetsov
When general-purpose kexec (not kdump) is being performed in Hyper-V guest the newly booted kernel fails with an MCE error coming from the host. It is the same error which was fixed in the "Drivers: hv: vmbus: Implement the protocol for tearing down vmbus state" commit - monitor pages remain special and when they're being written to (as the new kernel doesn't know these pages are special) bad things happen. We need to perform some minimalistic cleanup before booting a new kernel on kexec. To do so we need to register a special machine_ops.shutdown handler to be executed before the native_machine_shutdown(). Registering a shutdown notification handler via the register_reboot_notifier() call is not sufficient as it happens to early for our purposes. machine_ops is not being exported to modules (and I don't think we want to export it) so let's do this in mshyperv.c The minimalistic cleanup consists of cleaning up clockevents, synic MSRs, guest os id MSR, and hypercall MSR. Kdump doesn't require all this stuff as it lives in a separate memory space. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04Drivers: hv: vmbus: remove hv_synic_free_cpu() call from hv_synic_cleanup()Vitaly Kuznetsov
We already have hv_synic_free() which frees all per-cpu pages for all CPUs, let's remove the hv_synic_free_cpu() call from hv_synic_cleanup() so it will be possible to do separate cleanup (writing to MSRs) and final freeing. This is going to be used to assist kexec. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-12Drivers: hv: vmbus: Allocate ring buffer memory in NUMA aware fashionK. Y. Srinivasan
Allocate ring buffer memory from the NUMA node assigned to the channel. Since this is a performance and not a correctness issue, if the node specific allocation were to fail, fall back and allocate without specifying the node. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01Drivers: hv: vmbus: Implement NUMA aware CPU affinity for channelsK. Y. Srinivasan
Channels/sub-channels can be affinitized to VCPUs in the guest. Implement this affinity in a way that is NUMA aware. The current protocol distributed the primary channels uniformly across all available CPUs. The new protocol is NUMA aware: primary channels are distributed across the available NUMA nodes while the sub-channels within a primary channel are distributed amongst CPUs within the NUMA node assigned to the primary channel. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01Drivers: hv: vmbus: Use the vp_index map even for channels bound to CPU 0K. Y. Srinivasan
Map target_cpu to target_vcpu using the mapping table. We should use the mapping table to transform guest CPU ID to VP Index as is done for the non-performance critical channels. While the value CPU 0 is special and will map to VP index 0, it is good to be consistent. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01Drivers: hv: balloon: check if ha_region_mutex was acquired in ↵Vitaly Kuznetsov
MEM_CANCEL_ONLINE case Memory notifiers are being executed in a sequential order and when one of them fails returning something different from NOTIFY_OK the remainder of the notification chain is not being executed. When a memory block is being onlined in online_pages() we do memory_notify(MEM_GOING_ONLINE, ) and if one of the notifiers in the chain fails we end up doing memory_notify(MEM_CANCEL_ONLINE, ) so it is possible for a notifier to see MEM_CANCEL_ONLINE without seeing the corresponding MEM_GOING_ONLINE event. E.g. when CONFIG_KASAN is enabled the kasan_mem_notifier() is being used to prevent memory hotplug, it returns NOTIFY_BAD for all MEM_GOING_ONLINE events. As kasan_mem_notifier() comes before the hv_memory_notifier() in the notification chain we don't see the MEM_GOING_ONLINE event and we do not take the ha_region_mutex. We, however, see the MEM_CANCEL_ONLINE event and unconditionally try to release the lock, the following is observed: [ 110.850927] ===================================== [ 110.850927] [ BUG: bad unlock balance detected! ] [ 110.850927] 4.1.0-rc3_bugxxxxxxx_test_xxxx #595 Not tainted [ 110.850927] ------------------------------------- [ 110.850927] systemd-udevd/920 is trying to release lock (&dm_device.ha_region_mutex) at: [ 110.850927] [<ffffffff81acda0e>] mutex_unlock+0xe/0x10 [ 110.850927] but there are no more locks to release! At the same time we can have the ha_region_mutex taken when we get the MEM_CANCEL_ONLINE event in case one of the memory notifiers after the hv_memory_notifier() in the notification chain failed so we need to add the mutex_is_locked() check. In case of MEM_ONLINE we are always supposed to have the mutex locked. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01Drivers: hv: vmbus:Update preferred vmbus protocol version to windows 10.Keith Mange
Add support for Windows 10. Signed-off-by: Keith Mange <keith.mange@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vmbus: distribute subchannels among all vcpusVitaly Kuznetsov
Primary channels are distributed evenly across all vcpus we have. When the host asks us to create subchannels it usually makes us num_cpus-1 offers and we are supposed to distribute the work evenly among the channel itself and all its subchannels. Make sure they are all assigned to different vcpus. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vmbus: move init_vp_index() call to vmbus_process_offer()Vitaly Kuznetsov
We need to call init_vp_index() after we added the channel to the appropriate list (global or subchannel) to be able to use this information when assigning the channel to the particular vcpu. To do so we need to move a couple of functions around. The only real change is the init_vp_index() call. This is a small refactoring without a functional change. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vmbus: decrease num_sc on subchannel removalVitaly Kuznetsov
It is unlikely that that host will ask us to close only one subchannel for a device but let's be consistent. Do both num_sc++ and num_sc-- with channel->lock to be on the safe side. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vmbus: unify calls to percpu_channel_enq()Vitaly Kuznetsov
Remove some code duplication, no functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vmbus: kill tasklets on module unloadVitaly Kuznetsov
Explicitly kill tasklets we create on module unload. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vmbus: do cleanup on all vmbus_open() failure pathsVitaly Kuznetsov
In case there was an error reported in the response to the CHANNELMSG_OPENCHANNEL call we need to do the cleanup as a vmbus_open() user won't be doing it after receiving an error. The cleanup should be done on all failure paths. We also need to avoid returning open_info->response.open_result.status as the return value as all other errors we return from vmbus_open() are -EXXX and vmbus_open() callers are not supposed to analyze host error codes. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vmbus: Implement the protocol for tearing down vmbus stateK. Y. Srinivasan
Implement the protocol for tearing down the monitor state established with the host. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24hv: vmbus_free_channels(): remove the redundant free_channel()Dexuan Cui
free_channel() has been invoked in vmbus_remove() -> hv_process_channel_removal(), or vmbus_remove() -> ... -> vmbus_close_internal() -> hv_process_channel_removal(). We also change to use list_for_each_entry_safe(), because the entry is removed in hv_process_channel_removal(). This patch fixes a bug in the vmbus unload path. Thank Dan Carpenter for finding the issue! Signed-off-by: Dexuan Cui <decui@microsoft.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vmbus: unregister panic notifier on module unloadVitaly Kuznetsov
Commit 96c1d0581d00f7abe033350edb021a9d947d8d81 ("Drivers: hv: vmbus: Add support for VMBus panic notifier handler") introduced atomic_notifier_chain_register() call on module load. We also need to call atomic_notifier_chain_unregister() on module unload as otherwise the following crash is observed when we bring hv_vmbus back: [ 39.788877] BUG: unable to handle kernel paging request at ffffffffa00078a8 [ 39.788877] IP: [<ffffffff8109d63f>] notifier_call_chain+0x3f/0x80 ... [ 39.788877] Call Trace: [ 39.788877] [<ffffffff8109de7d>] __atomic_notifier_call_chain+0x5d/0x90 ... [ 39.788877] [<ffffffff8109d788>] ? atomic_notifier_chain_register+0x38/0x70 [ 39.788877] [<ffffffff8109d767>] ? atomic_notifier_chain_register+0x17/0x70 [ 39.788877] [<ffffffffa002814f>] hv_acpi_init+0x14f/0x1000 [hv_vmbus] [ 39.788877] [<ffffffff81002144>] do_one_initcall+0xd4/0x210 Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vmbus: introduce vmbus_acpi_removeVitaly Kuznetsov
In case we do request_resource() in vmbus_acpi_add() we need to tear it down to be able to load the driver again. Otherwise the following crash in observed when hv_vmbus unload/load sequence is performed on a Generation2 instance: [ 38.165701] BUG: unable to handle kernel paging request at ffffffffa00075a0 [ 38.166315] IP: [<ffffffff8107dc5f>] __request_resource+0x2f/0x50 [ 38.166315] PGD 1f34067 PUD 1f35063 PMD 3f723067 PTE 0 [ 38.166315] Oops: 0000 [#1] SMP [ 38.166315] Modules linked in: hv_vmbus(+) [last unloaded: hv_vmbus] [ 38.166315] CPU: 0 PID: 267 Comm: modprobe Not tainted 3.19.0-rc5_bug923184+ #486 [ 38.166315] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012 [ 38.166315] task: ffff88003f401cb0 ti: ffff88003f60c000 task.ti: ffff88003f60c000 [ 38.166315] RIP: 0010:[<ffffffff8107dc5f>] [<ffffffff8107dc5f>] __request_resource+0x2f/0x50 [ 38.166315] RSP: 0018:ffff88003f60fb58 EFLAGS: 00010286 Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: utils: unify driver registration reportingVitaly Kuznetsov
Unify driver registration reporting and move it to debug level as normally daemons write to syslog themselves and these kernel messages are useless. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: fcopy: full handshake supportVitaly Kuznetsov
Introduce FCOPY_VERSION_1 to support kernel replying to the negotiation message with its own version. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vss: full handshake supportVitaly Kuznetsov
Introduce VSS_OP_REGISTER1 to support kernel replying to the negotiation message with its own version. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: kvp: convert to hv_utils_transportVitaly Kuznetsov
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>
2015-05-24Drivers: hv: fcopy: convert to hv_utils_transportVitaly Kuznetsov
Unify the code with the recently introduced hv_utils_transport. Netlink communication is disabled for fcopy. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vss: convert to hv_utils_transportVitaly Kuznetsov
Convert to hv_utils_transport to support both netlink and /dev/vmbus/hv_vss 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>
2015-05-24Drivers: hv: util: introduce hv_utils_transport abstractionVitaly Kuznetsov
The intention is to make KVP/VSS drivers work through misc char devices. Introduce an abstraction for kernel/userspace communication to make the migration smoother. Transport operational mode (netlink or char device) is determined by the first received message. To support driver upgrades the switch from netlink to chardev operational mode is supported. Every hv_util daemon is supposed to register 2 callbacks: 1) on_msg() to get notified when the userspace daemon sent a message; 2) on_reset() to get notified when the userspace daemon drops the connection. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: fcopy: set .owner reference for file operationsVitaly Kuznetsov
Get an additional reference otherwise a crash is observed when hv_utils module is being unloaded while fcopy daemon is still running. .owner gives us an additional reference when someone holds a descriptor for the device. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: fcopy: switch to using the hvutil_device_state state machineVitaly Kuznetsov
Switch to using the hvutil_device_state state machine from using 3 different state variables: fcopy_transaction.active, opened, and in_hand_shake. State transitions are: -> HVUTIL_DEVICE_INIT when driver loads or on device release -> HVUTIL_READY if the handshake was successful -> HVUTIL_HOSTMSG_RECEIVED when there is a non-negotiation message from the host -> HVUTIL_USERSPACE_REQ after userspace daemon read the message -> HVUTIL_USERSPACE_RECV after/if userspace has replied -> HVUTIL_READY after we respond to the host -> HVUTIL_DEVICE_DYING on driver unload In hv_fcopy_onchannelcallback() process ICMSGTYPE_NEGOTIATE messages even when the userspace daemon is disconnected, otherwise we can make the host think we don't support FCOPY and disable the service completely. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: vss: switch to using the hvutil_device_state state machineVitaly Kuznetsov
Switch to using the hvutil_device_state state machine from using kvp_transaction.active. 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_vss_onchannelcallback() process ICMSGTYPE_NEGOTIATE messages even when the userspace daemon is disconnected, otherwise we can make the host think we don't support VSS 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), add a protection against processing new VSS_OP_REGISTER messages while being in the middle of a transaction (HVUTIL_USERSPACE_REQ or HVUTIL_USERSPACE_RECV state). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Alex Ng <alexng@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24Drivers: hv: kvp: switch to using the hvutil_device_state state machineVitaly Kuznetsov
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>
2015-05-24Drivers: hv: util: introduce state machine for util driversVitaly Kuznetsov
KVP/VSS/FCOPY drivers work in fully serialized mode: we wait till userspace daemon registers, wait for a message from the host, send this message to the daemon, get the reply, send it back to host, wait for another message. Introduce enum hvutil_device_state to represend this state in all 3 drivers. 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>