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* clocksource: Use a plain u64 instead of cycle_tThomas Gleixner2016-12-251-4/+4
| | | | | | | | | | | | | | | | | | | | | There is no point in having an extra type for extra confusion. u64 is unambiguous. Conversion was done with the following coccinelle script: @rem@ @@ -typedef u64 cycle_t; @fix@ typedef cycle_t; @@ -cycle_t +u64 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org>
* uio-hv-generic: new userspace i/o driver for VMBusStephen Hemminger2016-12-061-0/+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>
* vmbus: add support for dynamic device id'sStephen Hemminger2016-12-061-8/+166
| | | | | | | | | | This patch adds sysfs interface to dynamically bind new UUID values to existing VMBus device. This is useful for generic UIO driver to act similar to uio_pci_generic. 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>
* hv: change clockevents unbind tacticsVitaly Kuznetsov2016-12-061-2/+4
| | | | | | | | | | | | | | | | | To get prepared to CPU offlining support we need co change the way how we unbind clockevent devices. As one CPU may go online/offline multiple times we need to bind it in hv_synic_init() and unbind it in hv_synic_cleanup(). There is an additional corner case: when we unload the module completely we need to switch to some other clockevent mechanism before stopping VMBus or we will hang. We can't call hv_synic_cleanup() before unloading VMBus as we won't be able to send UNLOAD request and get a response so hv_synic_clockevents_cleanup() has to live. Luckily, we can always call clockevents_unbind_device(), even if it wasn't bound before and there is no issue if we call it twice. 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>
* hv: acquire vmbus_connection.channel_mutex in vmbus_free_channels()Vitaly Kuznetsov2016-12-061-0/+2
| | | | | | | | | | | | | | "kernel BUG at drivers/hv/channel_mgmt.c:350!" is observed when hv_vmbus module is unloaded. BUG_ON() was introduced in commit 85d9aa705184 ("Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()") as vmbus_free_channels() codepath was apparently forgotten. Fixes: 85d9aa705184 ("Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()") 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>
* hyperv: Fix spelling of HV_UNKOWNHaiyang Zhang2016-12-061-3/+3
| | | | | | | | Changed it to HV_UNKNOWN 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>
* Merge 4.9-rc5 into char-misc-nextGreg Kroah-Hartman2016-11-141-1/+1
|\ | | | | | | | | | | We want those fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * vmbus: make sysfs names consistent with PCIStephen Hemminger2016-11-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 9a56e5d6a0ba ("Drivers: hv: make VMBus bus ids persistent") the name of vmbus devices in sysfs changed to be (in 4.9-rc1): /sys/bus/vmbus/vmbus-6aebe374-9ba0-11e6-933c-00259086b36b The prefix ("vmbus-") is redundant and differs from how PCI is represented in sysfs. Therefore simplify to: /sys/bus/vmbus/6aebe374-9ba0-11e6-933c-00259086b36b Please merge this before 4.9 is released and the old format has to live forever. 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>
* | Drivers: hv: vmbus: On the read path cleanup the logic to interrupt the hostK. Y. Srinivasan2016-11-073-14/+8
| | | | | | | | | | | | | | | | | | | | | | Signal the host when we determine the host is to be signaled - on th read path. The currrent code determines the need to signal in the ringbuffer code and actually issues the signal elsewhere. This can result in the host viewing this interrupt as spurious since the host may also poll the channel. Make the necessary adjustments. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Drivers: hv: vmbus: On write cleanup the logic to interrupt the hostK. Y. Srinivasan2016-11-073-101/+34
| | | | | | | | | | | | | | | | | | | | | | Signal the host when we determine the host is to be signaled. The currrent code determines the need to signal in the ringbuffer code and actually issues the signal elsewhere. This can result in the host viewing this interrupt as spurious since the host may also poll the channel. Make the necessary adjustments. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Drivers: hv: vmbus: Base host signaling strictly on the ring stateK. Y. Srinivasan2016-11-073-12/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the factors that can result in the host concluding that a given guest in mounting a DOS attack is if the guest generates interrupts to the host when the host is not expecting it. If these "spurious" interrupts reach a certain rate, the host can throttle the guest to minimize the impact. The host computation of the "expected number of interrupts" is strictly based on the ring transitions. Until the host logic is fixed, base the guest logic to interrupt solely on the ring state. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Drivers: hv: balloon: Fix info request to show max page countAlex Ng2016-11-071-2/+7
| | | | | | | | | | | | | | | | | | | | Balloon driver was only printing the size of the info blob and not the actual content. This fixes it so that the info blob (max page count as configured in Hyper-V) is printed out. 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>
* | Drivers: hv: vss: Operation timeouts should match host expectationAlex Ng2016-11-071-2/+6
| | | | | | | | | | | | | | | | | | | | Increase the timeout of backup operations. When system is under I/O load, it needs more time to freeze. These timeout values should also match the host timeout values more closely. 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>
* | Drivers: hv: vss: Improve log messages.Alex Ng2016-11-071-6/+19
| | | | | | | | | | | | | | | | | | Adding log messages to help troubleshoot error cases and transaction handling. 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>
* | Drivers: hv: balloon: Add logging for dynamic memory operationsAlex Ng2016-11-071-3/+28
| | | | | | | | | | | | | | | | | | Added logging to help troubleshoot common ballooning, hot add, and versioning issues. 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>
* | Drivers: hv: balloon: Disable hot add when CONFIG_MEMORY_HOTPLUG is not setAlex Ng2016-11-071-0/+4
| | | | | | | | | | | | | | | | | | | | | | If the guest does not support memory hotplugging, it should respond to the host with zero pages added and successful result code. This signals to the host that hotplugging is not supported and the host will avoid sending future hot-add requests. 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>
* | Drivers: hv: utils: Fix the mapping between host version and protocol to useAlex Ng2016-11-071-3/+6
| | | | | | | | | | | | | | | | | | We should intentionally declare the protocols to use for every known host and default to using the latest protocol if the host is unknown or new. 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>
* | Drivers: hv: utils: reduce HV_UTIL_NEGO_TIMEOUT timeoutVitaly Kuznetsov2016-11-071-1/+1
|/ | | | | | | | | | I discovered that at least WS2016TP5 host has 60 seconds timeout for the ICMSGTYPE_NEGOTIATE message so we need to lower guest's timeout a little bit to make sure we always respond in time. Let's make it 55 seconds. 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>
* hv: do not lose pending heartbeat vmbus packetsLong Li2016-10-251-3/+7
| | | | | | | | | | | | | | | The host keeps sending heartbeat packets independent of the guest responding to them. Even though we respond to the heartbeat messages at interrupt level, we can have situations where there maybe multiple heartbeat messages pending that have not been responded to. For instance this occurs when the VM is paused and the host continues to send the heartbeat messages. Address this issue by draining and responding to all the heartbeat messages that maybe pending. Signed-off-by: Long Li <longli@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> CC: Stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: get rid of id in struct vmbus_channelVitaly Kuznetsov2016-09-271-2/+0
| | | | | | | | The auto incremented counter is not being used anymore, get rid of it. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: make VMBus bus ids persistentVitaly Kuznetsov2016-09-271-2/+2
| | | | | | | | | | | | Some tools use bus ids to identify devices and they count on the fact that these ids are persistent across reboot. This may be not true for VMBus as we use auto incremented counter from alloc_channel() as such id. Switch to using if_instance from channel offer, this id is supposed to be persistent. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_util: Avoid dynamic allocation in time synchVivek yadav2016-09-091-11/+28
| | | | | | | | | Under stress, we have seen allocation failure in time synch code. Avoid this dynamic allocation. Signed-off-by: Vivek Yadav <vyadav@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: utils: Support TimeSync version 4.0 protocol samples.Alex Ng2016-09-081-23/+59
| | | | | | | | | | | | | | This enables support for more accurate TimeSync v4 samples when hosted under Windows Server 2016 and newer hosts. The new time samples include a "vmreferencetime" field that represents the guest's TSC value when the host generated its time sample. This value lets the guest calculate the latency in receiving the time sample. The latency is added to the sample host time prior to updating the clock. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: utils: Use TimeSync samples to adjust the clock after boot.Alex Ng2016-09-081-13/+7
| | | | | | | | | | | | | Only the first 50 samples after boot were being used to discipline the clock. After the first 50 samples, any samples from the host were ignored and the guest clock would eventually drift from the host clock. This patch allows TimeSync-enabled guests to continuously synchronize the clock with the host clock, even after the first 50 samples. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: utils: Rename version definitions to reflect protocol version.Alex Ng2016-09-081-10/+10
| | | | | | | | | | Different Windows host versions may reuse the same protocol version when negotiating the TimeSync, Shutdown, and Heartbeat protocols. We should only refer to the protocol version to avoid conflating the two concepts. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: suppress some "hv_vmbus: Unknown GUID" warningsDexuan Cui2016-09-071-2/+24
| | | | | | | | | | | | | Some VMBus devices are not needed by Linux guest[1][2], and, VMBus channels of Hyper-V Sockets don't really mean usual synthetic devices, so let's suppress the warnings for them. [1] https://support.microsoft.com/en-us/kb/2925727 [2] https://msdn.microsoft.com/en-us/library/jj980180(v=winembedded.81).aspx 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>
* Driver: hv: vmbus: Make mmio resource localStephen Hemminger2016-09-071-2/+2
| | | | | | | | | This fixes a sparse warning because hyperv_mmio resources are only used in this one file and should be static. 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>
* Drivers: hv: utils: Check VSS daemon is listening before a hot backupAlex Ng2016-09-021-3/+6
| | | | | | | | | | | | Hyper-V host will send a VSS_OP_HOT_BACKUP request to check if guest is ready for a live backup/snapshot. The driver should respond to the check only if the daemon is running and listening to requests. This allows the host to fallback to standard snapshots in case the VSS daemon is not running. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: utils: Continue to poll VSS channel after handling requests.Alex Ng2016-09-021-47/+43
| | | | | | | | | | | Multiple VSS_OP_HOT_BACKUP requests may arrive in quick succession, even though the host only signals once. The driver wass handling the first request while ignoring the others in the ring buffer. We should poll the VSS channel after handling a request to continue processing other requests. 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>
* Drivers: hv: Introduce a policy for controlling channel affinityK. Y. Srinivasan2016-09-021-29/+39
| | | | | | | | | | | | | | | | | | | Introduce a mechanism to control how channels will be affinitized. We will support two policies: 1. HV_BALANCED: All performance critical channels will be dstributed evenly amongst all the available NUMA nodes. Once the Node is assigned, we will assign the CPU based on a simple round robin scheme. 2. HV_LOCALIZED: Only the primary channels are distributed across all NUMA nodes. Sub-channels will be in the same NUMA node as the primary channel. This is the current behaviour. The default policy will be the HV_BALANCED as it can minimize the remote memory access on NUMA machines with applications that span NUMA nodes. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: ring_buffer: use wrap around mappings in hv_copy{from, ↵Vitaly Kuznetsov2016-09-021-21/+3
| | | | | | | | | | | | to}_ringbuffer() With wrap around mappings for ring buffers we can always use a single memcpy() to do the job. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: ring_buffer: wrap around mappings for ring buffersVitaly Kuznetsov2016-09-023-23/+49
| | | | | | | | | | | | | | | Make it possible to always use a single memcpy() or to provide a direct link to a packet on the ring buffer by creating virtual mapping for two copies of the ring buffer with vmap(). Utilize currently empty hv_ringbuffer_cleanup() to do the unmap. While on it, replace sizeof(struct hv_ring_buffer) check in hv_ringbuffer_init() with BUILD_BUG_ON() as it is a compile time check. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: cleanup vmbus_open() for wrap around mappingsVitaly Kuznetsov2016-09-021-19/+22
| | | | | | | | | | | | | | | | | In preparation for doing wrap around mappings for ring buffers cleanup vmbus_open() function: - check that ring sizes are PAGE_SIZE aligned (they are for all in-kernel drivers now); - kfree(open_info) on error only after we kzalloc() it (not an issue as it is valid to call kfree(NULL); - rename poorly named labels; - use alloc_pages() instead of __get_free_pages() as we need struct page pointer for future. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: balloon: Use available memory value in pressure reportAlex Ng2016-08-311-8/+5
| | | | | | | | | Reports for available memory should use the si_mem_available() value. The previous freeram value does not include available page cache memory. Signed-off-by: Alex Ng <alexng@messages.microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: balloon: replace ha_region_mutex with spinlockVitaly Kuznetsov2016-08-311-45/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | lockdep reports possible circular locking dependency when udev is used for memory onlining: systemd-udevd/3996 is trying to acquire lock: ((memory_chain).rwsem){++++.+}, at: [<ffffffff810d137e>] __blocking_notifier_call_chain+0x4e/0xc0 but task is already holding lock: (&dm_device.ha_region_mutex){+.+.+.}, at: [<ffffffffa015382e>] hv_memory_notifier+0x5e/0xc0 [hv_balloon] ... which is probably a false positive because we take and release ha_region_mutex from memory notifier chain depending on the arg. No real deadlocks were reported so far (though I'm not really sure about preemptible kernels...) but we don't really need to hold the mutex for so long. We use it to protect ha_region_list (and its members) and the num_pages_onlined counter. None of these operations require us to sleep and nothing is slow, switch to using spinlock with interrupts disabled. While on it, replace list_for_each -> list_for_each_entry as we actually need entries in all these cases, drop meaningless list_empty() checks. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: balloon: don't wait for ol_waitevent when memhp_auto_online is ↵Vitaly Kuznetsov2016-08-311-6/+9
| | | | | | | | | | | | enabled With the recently introduced in-kernel memory onlining (MEMORY_HOTPLUG_DEFAULT_ONLINE) these is no point in waiting for pages to come online in the driver and we can get rid of the waiting. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: balloon: account for gaps in hot add regionsVitaly Kuznetsov2016-08-311-37/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: balloon: keep track of where ha_region startsVitaly Kuznetsov2016-08-311-2/+5
| | | | | | | | | | | | | | | | | | | Windows 2012 (non-R2) does not specify hot add region in hot add requests and the logic in hot_add_req() is trying to find a 128Mb-aligned region covering the request. It may also happen that host's requests are not 128Mb aligned and the created ha_region will start before the first specified PFN. We can't online these non-present pages but we don't remember the real start of the region. This is a regression introduced by the commit 5abbbb75d733 ("Drivers: hv: hv_balloon: don't lose memory when onlining order is not natural"). While the idea of keeping the 'moving window' was wrong (as there is no guarantee that hot add requests come ordered) we should still keep track of covered_start_pfn. This is not a revert, the logic is different. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Implement a mechanism to tag the channel for low latencyK. Y. Srinivasan2016-08-311-1/+6
| | | | | | | | | | | | | | | On Hyper-V, performance critical channels use the monitor mechanism to signal the host when the guest posts mesages for the host. This mechanism minimizes the hypervisor intercepts and also makes the host more efficient in that each time the host is woken up, it processes a batch of messages as opposed to just one. The goal here is improve the throughput and this is at the expense of increased latency. Implement a mechanism to let the client driver decide if latency is important. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Reduce the delay between retries in vmbus_post_msg()K. Y. Srinivasan2016-08-311-4/+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>
* Drivers: hv: vmbus: Enable explicit signaling policy for NIC channelsK. Y. Srinivasan2016-08-314-18/+20
| | | | | | | | For synthetic NIC channels, enable explicit signaling policy as netvsc wants to explicitly control when the host is to be signaled. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: fix the race when querying & updating the percpu listDexuan Cui2016-08-312-8/+30
| | | | | | | | | | | | | | | | | | | | | There is a rare race when we remove an entry from the global list hv_context.percpu_list[cpu] in hv_process_channel_removal() -> percpu_channel_deq() -> list_del(): at this time, if vmbus_on_event() -> process_chn_event() -> pcpu_relid2channel() is trying to query the list, we can get the kernel fault. Similarly, we also have the issue in the code path: vmbus_process_offer() -> percpu_channel_enq(). We can resolve the issue by disabling the tasklet when updating the list. The patch also moves vmbus_release_relid() to a later place where the channel has been removed from the per-cpu and the global lists. Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.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>
* Drivers: hv: utils: fix a race on userspace daemons registrationVitaly Kuznetsov2016-08-315-22/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Background: userspace daemons registration protocol for Hyper-V utilities drivers has two steps: 1) daemon writes its own version to kernel 2) kernel reads it and replies with module version at this point we consider the handshake procedure being completed and we do hv_poll_channel() transitioning the utility device to HVUTIL_READY state. At this point we're ready to handle messages from kernel. When hvutil_transport is in HVUTIL_TRANSPORT_CHARDEV mode we have a single buffer for outgoing message. hvutil_transport_send() puts to this buffer and till the buffer is cleared with hvt_op_read() returns -EFAULT to all consequent calls. Host<->guest protocol guarantees there is no more than one request at a time and we will not get new requests till we reply to the previous one so this single message buffer is enough. Now to the race. When we finish negotiation procedure and send kernel module version to userspace with hvutil_transport_send() it goes into the above mentioned buffer and if the daemon is slow enough to read it from there we can get a collision when a request from the host comes, we won't be able to put anything to the buffer so the request will be lost. To solve the issue we need to know when the negotiation is really done (when the version message is read by the daemon) and transition to HVUTIL_READY state after this happens. Implement a callback on read to support this. Old style netlink communication is not affected by the change, we don't really know when these messages are delivered but we don't have a single message buffer there. Reported-by: Barry Davis <barry_davis@stormagic.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: get rid of timeout in vmbus_open()Vitaly Kuznetsov2016-08-311-6/+1
| | | | | | | | | | | | vmbus_teardown_gpadl() can result in infinite wait when it is called on 5 second timeout in vmbus_open(). The issue is caused by the fact that gpadl teardown operation won't ever succeed for an opened channel and the timeout isn't always enough. As a guest, we can always trust the host to respond to our request (and there is nothing we can do if it doesn't). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: don't leak memory in vmbus_establish_gpadl()Vitaly Kuznetsov2016-08-311-1/+5
| | | | | | | | | In some cases create_gpadl_header() allocates submessages but we never free them. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: get rid of redundant messagecount in create_gpadl_header()Vitaly Kuznetsov2016-08-311-22/+16
| | | | | | | | | | We use messagecount only once in vmbus_establish_gpadl() to check if it is safe to iterate through the submsglist. We can just initialize the list header in all cases in create_gpadl_header() instead. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: avoid vfree() on crashVitaly Kuznetsov2016-08-313-8/+10
| | | | | | | | | | | | | | | | When we crash from NMI context (e.g. after NMI injection from host when 'sysctl -w kernel.unknown_nmi_panic=1' is set) we hit kernel BUG at mm/vmalloc.c:1530! as vfree() is denied. While the issue could be solved with in_nmi() check instead I opted for skipping vfree on all sorts of crashes to reduce the amount of work which can cause consequent crashes. We don't really need to free anything on crash. 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>
* random: add interrupt callback to VMBus IRQ handlerStephan Mueller2016-06-131-0/+3
| | | | | | | | | | | | | | | The Hyper-V Linux Integration Services use the VMBus implementation for communication with the Hypervisor. VMBus registers its own interrupt handler that completely bypasses the common Linux interrupt handling. This implies that the interrupt entropy collector is not triggered. This patch adds the interrupt entropy collection callback into the VMBus interrupt handler function. Cc: stable@kernel.org Signed-off-by: Stephan Mueller <stephan.mueller@atsec.com> Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* Drivers: hv: balloon: reset host_specified_ha_regionVitaly Kuznetsov2016-05-011-0/+1
| | | | | | | | | | | We set host_specified_ha_region = true on certain request but this is a global state which stays 'true' forever. We need to reset it when we receive a request where ha_region is not specified. I did not see any real issues, the bug was found by code inspection. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: balloon: don't crash when memory is added in non-sorted orderVitaly Kuznetsov2016-05-011-2/+2
| | | | | | | | | | | | | | | When we iterate through all HA regions in handle_pg_range() we have an assumption that all these regions are sorted in the list and the 'start_pfn >= has->end_pfn' check is enough to find the proper region. Unfortunately it's not the case with WS2016 where host can hot-add regions in a different order. We end up modifying the wrong HA region and crashing later on pages online. Modify the check to make sure we found the region we were searching for while iterating. Fix the same check in pfn_covered() as well. 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>
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