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* 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>
* Drivers: hv: vmbus: handle various crash scenariosVitaly Kuznetsov2016-05-013-20/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Kdump keeps biting. Turns out CHANNELMSG_UNLOAD_RESPONSE is always delivered to the CPU which was used for initial contact or to CPU0 depending on host version. vmbus_wait_for_unload() doesn't account for the fact that in case we're crashing on some other CPU we won't get the CHANNELMSG_UNLOAD_RESPONSE message and our wait on the current CPU will never end. Do the following: 1) Check for completion_done() in the loop. In case interrupt handler is still alive we'll get the confirmation we need. 2) Read message pages for all CPUs message page as we're unsure where CHANNELMSG_UNLOAD_RESPONSE is going to be delivered to. We can race with still-alive interrupt handler doing the same, add cmpxchg() to vmbus_signal_eom() to not lose CHANNELMSG_UNLOAD_RESPONSE message. 3) Cleanup message pages on all CPUs. This is required (at least for the current CPU as we're clearing CPU0 messages now but we may want to bring up additional CPUs on crash) as new messages won't be delivered till we consume what's pending. On boot we'll place message pages somewhere else and we won't be able to read stale messages. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: kvp: fix IP FailoverVitaly Kuznetsov2016-05-012-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | Hyper-V VMs can be replicated to another hosts and there is a feature to set different IP for replicas, it is called 'Failover TCP/IP'. When such guest starts Hyper-V host sends it KVP_OP_SET_IP_INFO message as soon as we finish negotiation procedure. The problem is that it can happen (and it actually happens) before userspace daemon connects and we reply with HV_E_FAIL to the message. As there are no repetitions we fail to set the requested IP. Solve the issue by postponing our reply to the negotiation message till userspace daemon is connected. We can't wait too long as there is a host-side timeout (cca. 75 seconds) and if we fail to reply in this time frame the whole KVP service will become inactive. The solution is not ideal - if it takes userspace daemon more than 60 seconds to connect IP Failover will still fail but I don't see a solution with our current separation between kernel and userspace parts. Other two modules (VSS and FCOPY) don't require such delay, leave them untouched. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers:hv: Separate out frame buffer logic when picking MMIO rangeJake Oshins2016-04-301-45/+35
| | | | | | | | | | Simplify the logic that picks MMIO ranges by pulling out the logic related to trying to lay frame buffer claim on top of where the firmware placed the frame buffer. 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>
* drivers:hv: Record MMIO range in use by frame bufferJake Oshins2016-04-301-1/+36
| | | | | | | | | | | | | Later in the boot sequence, we need to figure out which memory ranges can be given out to various paravirtual drivers. The hyperv_fb driver should, ideally, be placed right on top of the frame buffer, without some other device getting plopped on top of this range in the meantime. Recording this now allows that to be guaranteed. 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>
* drivers:hv: Track allocations of children of hv_vmbus in private resource treeJake Oshins2016-04-301-1/+21
| | | | | | | | | | | | | | | | | | | | | | This patch changes vmbus_allocate_mmio() and vmbus_free_mmio() so that when child paravirtual devices allocate memory-mapped I/O space, they allocate it privately from a resource tree pointed at by hyperv_mmio and also by the public resource tree iomem_resource. This allows the region to be marked as "busy" in the private tree, but a "bridge window" in the public tree, guaranteeing that no two bridge windows will overlap each other but while also allowing the PCI device children of the bridge windows to overlap that window. One might conclude that this belongs in the pnp layer, rather than in this driver. Rafael Wysocki, the maintainter of the pnp layer, has previously asked that we not modify the pnp layer as it is considered deprecated. This patch is thus essentially a workaround. 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>
* drivers:hv: Reverse order of resources in hyperv_mmioJake Oshins2016-04-301-2/+1
| | | | | | | | | | A patch later in this series allocates child nodes in this resource tree. For that to work, this tree needs to be sorted in ascending order. 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>
* drivers:hv: Make a function to free mmio regions through vmbusJake Oshins2016-04-301-0/+15
| | | | | | | | | | | | This patch introduces a function that reverses everything done by vmbus_allocate_mmio(). Existing code just called release_mem_region(). Future patches in this series require a more complex sequence of actions, so this function is introduced to wrap those actions. 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>
* drivers:hv: Lock access to hyperv_mmio resource treeJake Oshins2016-04-301-4/+12
| | | | | | | | | | | | | In existing code, this tree of resources is created in single-threaded code and never modified after it is created, and thus needs no locking. This patch introduces a semaphore for tree access, as other patches in this series introduce run-time modifications of this resource tree which can happen on multiple threads. 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>
* Drivers: hv: vmbus: Implement APIs to support "in place" consumption of ↵K. Y. Srinivasan2016-04-301-0/+1
| | | | | | | | | | | | | | | | | | vmbus packets Implement APIs for in-place consumption of vmbus packets. Currently, each packet is copied and processed one at a time and as part of processing each packet we potentially may signal the host (if it is waiting for room to produce a packet). These APIs help batched in-place processing of vmbus packets. We also optimize host signaling by having a separate API to signal the end of in-place consumption. With netvsc using these APIs, on an iperf run on average I see about 20X reduction in checks to signal the host. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Move some ring buffer functions to hyperv.hK. Y. Srinivasan2016-04-301-55/+0
| | | | | | | | In preparation for implementing APIs for in-place consumption of VMBUS packets, movve some ring buffer functionality into hyperv.h Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Export the vmbus_set_event() APIK. Y. Srinivasan2016-04-302-2/+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>
* Drivers: hv: vmbus: Use the new virt_xx barrier codeK. Y. Srinivasan2016-04-301-7/+7
| | | | | | | Use the virt_xx barriers that have been defined for use in virtual machines. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Use READ_ONCE() to read variables that are volatileK. Y. Srinivasan2016-04-301-3/+3
| | | | | | | | | Use the READ_ONCE macro to access variabes that can change asynchronously. This is the recommended mechanism for dealing with "unsafe" compiler optimizations. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Introduce functions for estimating room in the ring bufferK. Y. Srinivasan2016-04-301-21/+4
| | | | | | | | Introduce separate functions for estimating how much can be read from and written to the ring buffer. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()K. Y. Srinivasan2016-04-301-6/+20
| | | | | | | | | | | | | | | | | | | | | On the consumer side, we have interrupt driven flow management of the producer. It is sufficient to base the signaling decision on the amount of space that is available to write after the read is complete. The current code samples the previous available space and uses this in making the signaling decision. This state can be stale and is unnecessary. Since the state can be stale, we end up not signaling the host (when we should) and this can result in a hang. Fix this problem by removing the unnecessary check. I would like to thank Arseney Romanenko <arseneyr@microsoft.com> for pointing out this issue. Also, issue a full memory barrier before making the signaling descision to correctly deal with potential reordering of the write (read index) followed by the read of pending_sz. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Dexuan Cui <decui@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'char-misc-4.6-rc1' of ↵Linus Torvalds2016-03-1712-171/+377
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc updates from Greg KH: "Here is the big char/misc driver update for 4.6-rc1. The majority of the patches here is hwtracing and some new mic drivers, but there's a lot of other driver updates as well. Full details in the shortlog. All have been in linux-next for a while with no reported issues" * tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (238 commits) goldfish: Fix build error of missing ioremap on UM nvmem: mediatek: Fix later provider initialization nvmem: imx-ocotp: Fix return value of imx_ocotp_read nvmem: Fix dependencies for !HAS_IOMEM archs char: genrtc: replace blacklist with whitelist drivers/hwtracing: make coresight-etm-perf.c explicitly non-modular drivers: char: mem: fix IS_ERROR_VALUE usage char: xillybus: Fix internal data structure initialization pch_phub: return -ENODATA if ROM can't be mapped Drivers: hv: vmbus: Support kexec on ws2012 r2 and above Drivers: hv: vmbus: Support handling messages on multiple CPUs Drivers: hv: utils: Remove util transport handler from list if registration fails Drivers: hv: util: Pass the channel information during the init call Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload() Drivers: hv: vmbus: remove code duplication in message handling Drivers: hv: vmbus: avoid wait_for_completion() on crash Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages misc: at24: replace memory_accessor with nvmem_device_read eeprom: 93xx46: extend driver to plug into the NVMEM framework eeprom: at25: extend driver to plug into the NVMEM framework ...
| * Drivers: hv: vmbus: Support kexec on ws2012 r2 and aboveAlex Ng2016-03-021-1/+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>
| * Drivers: hv: vmbus: Support handling messages on multiple CPUsK. Y. Srinivasan2016-03-023-7/+17
| | | | | | | | | | | | | | | | Starting with Windows 2012 R2, message inteerupts can be delivered on any VCPU in the guest. Support this functionality. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: utils: Remove util transport handler from list if registration ↵Alex Ng2016-03-021-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | fails If util transport fails to initialize for any reason, the list of transport handlers may become corrupted due to freeing the transport handler without removing it from the list. Fix this by cleaning it up from the list. 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: util: Pass the channel information during the init callK. Y. Srinivasan2016-03-024-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass the channel information to the util drivers that need to defer reading the channel while they are processing a request. This would address the following issue reported by Vitaly: Commit 3cace4a61610 ("Drivers: hv: utils: run polling callback always in interrupt context") removed direct *_transaction.state = HVUTIL_READY assignments from *_handle_handshake() functions introducing the following race: if a userspace daemon connects before we get first non-negotiation request from the server hv_poll_channel() won't set transaction state to HVUTIL_READY as (!channel) condition will fail, we set it to non-NULL on the first real request from the server. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: vmbus: avoid unneeded compiler optimizations in ↵Vitaly Kuznetsov2016-03-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | vmbus_wait_for_unload() Message header is modified by the hypervisor and we read it in a loop, we need to prevent compilers from optimizing accesses. There are no such optimizations at this moment, this is just a future proof. Suggested-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>
| * Drivers: hv: vmbus: remove code duplication in message handlingVitaly Kuznetsov2016-03-023-47/+27
| | | | | | | | | | | | | | | | | | | | | | We have 3 functions dealing with messages and they all implement the same logic to finalize reads, move it to vmbus_signal_eom(). Suggested-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>
| * Drivers: hv: vmbus: avoid wait_for_completion() on crashVitaly Kuznetsov2016-03-024-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messagesVitaly Kuznetsov2016-03-021-35/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We must handle HVMSG_TIMER_EXPIRED messages in the interrupt context and we offload all the rest to vmbus_on_msg_dpc() tasklet. This functions loops to see if there are new messages pending. In case we'll ever see HVMSG_TIMER_EXPIRED message there we're going to lose it as we can't handle it from there. Avoid looping in vmbus_on_msg_dpc(), we're OK with handling one message per interrupt. 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>
| * Drivers: hv: vmbus: Give control over how the ring access is serializedK. Y. Srinivasan2016-02-084-10/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | On the channel send side, many of the VMBUS device drivers explicity serialize access to the outgoing ring buffer. Give more control to the VMBUS device drivers in terms how to serialize accesss to the outgoing ring buffer. The default behavior will be to aquire the ring lock to preserve the current behavior. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: vmbus: Eliminate the spin lock on the read pathK. Y. Srinivasan2016-02-081-13/+5
| | | | | | | | | | | | | | | | | | | | The function hv_ringbuffer_read() is called always on a pre-assigned CPU. Each chnnel is bound to a specific CPU and this function is always called on the CPU the channel is bound. There is no need to acquire the spin lock; get rid of this overhead. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()Dexuan Cui2016-02-082-7/+30
| | | | | | | | | | | | | | | | | | 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>
| * Drivers: hv: vmbus: add a per-channel rescind callbackDexuan Cui2016-02-081-0/+11
| | | | | | | | | | | | | | | | This will be used by the coming hv_sock driver. 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: vmbus: add a hvsock flag in struct hv_driverDexuan Cui2016-02-081-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | Only the coming hv_sock driver has a "true" value for this flag. We treat the hvsock offers/channels as special VMBus devices. Since the hv_sock driver handles all the hvsock offers/channels, we need to tweak vmbus_match() for hv_sock driver, so we introduce this flag. 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: vmbus: define a new VMBus message type for hvsockDexuan Cui2016-02-082-0/+19
| | | | | | | | | | | | | | | | | | | | | | A function to send the type of message is also added. The coming net/hvsock driver will use this function to proactively request the host to offer a VMBus channel for a new hvsock connection. 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: vmbus: vmbus_sendpacket_ctl: hvsock: avoid unnecessary signalingDexuan Cui2016-02-081-1/+5
| | | | | | | | | | | | | | | | | | | | When the hvsock channel's outbound ringbuffer is full (i.e., hv_ringbuffer_write() returns -EAGAIN), we should avoid the unnecessary signaling the host. 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: vmbus: don't manipulate with clocksources on crashVitaly Kuznetsov2016-02-081-2/+8
| | | | | | | | | | | | | | | | | | | | clocksource_change_rating() involves mutex usage and can't be called in interrupt context. It also makes sense to avoid doing redundant work 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>
| * Drivers: hv: vmbus: avoid scheduling in interrupt context in ↵Vitaly Kuznetsov2016-02-081-1/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vmbus_initiate_unload() We have to call vmbus_initiate_unload() on crash to make kdump work but the crash can also be happening in interrupt (e.g. Sysrq + c results in such) where we can't schedule or the following will happen: [ 314.905786] bad: scheduling from the idle thread! Just skipping the wait (and even adding some random wait here) won't help: to make host-side magic working we're supposed to receive CHANNELMSG_UNLOAD (and actually confirm the fact that we received it) but we can't use interrupt-base path (vmbus_isr()-> vmbus_on_msg_dpc()). Implement a simple busy wait ignoring all the other messages and use it if we're in an interrupt context. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: vmbus: avoid infinite loop in init_vp_index()Vitaly Kuznetsov2016-02-081-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we pick a CPU to use for a new subchannel we try find a non-used one on the appropriate NUMA node, we keep track of them with the primary->alloced_cpus_in_node mask. Under normal circumstances we don't run out of available CPUs but it is possible when we we don't initialize some cpus in Linux, e.g. when we boot with 'nr_cpus=' limitation. Avoid the infinite loop in init_vp_index() by checking that we still have non-used CPUs in the alloced_cpus_in_node mask and resetting it in case we don'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: vmbus: Add vendor and device atttributesK. Y. Srinivasan2016-02-082-43/+144
| | | | | | | | | | | | | | | | | | Add vendor and device attributes to VMBUS devices. These will be used by Hyper-V tools as well user-level RDMA libraries that will use the vendor/device tuple to discover the RDMA device. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: vmbus: Cleanup vmbus_set_event()K. Y. Srinivasan2016-02-083-21/+3
| | | | | | | | | | | | | | | | | | | | 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>
* | drivers/hv: Move VMBus hypercall codes into Hyper-V UAPI headerAndrey Smetanin2016-02-161-6/+0
|/ | | | | | | | | | | | | | | | | | | | VMBus hypercall codes inside Hyper-V UAPI header will be used by QEMU to implement VMBus host devices support. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Joerg Roedel <joro@8bytes.org> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org [Do not rename the constant at the same time as moving it, as that would cause semantic conflicts with the Hyper-V tree. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* Merge tag 'char-misc-4.5-rc1' of ↵Linus Torvalds2016-01-1312-410/+388
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc updates from Greg KH: "Here's the big set of char/misc patches for 4.5-rc1. Nothing major, lots of different driver subsystem updates, full details in the shortlog. All of these have been in linux-next for a while" * tag 'char-misc-4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (71 commits) mei: fix fasync return value on error parport: avoid assignment in if parport: remove unneeded space parport: change style of NULL comparison parport: remove unnecessary out of memory message parport: remove braces parport: quoted strings should not be split parport: code indent should use tabs parport: fix coding style parport: EXPORT_SYMBOL should follow function parport: remove trailing white space parport: fix a trivial typo coresight: Fix a typo in Kconfig coresight: checking for NULL string in coresight_name_match() Drivers: hv: vmbus: Treat Fibre Channel devices as performance critical Drivers: hv: utils: fix hvt_op_poll() return value on transport destroy Drivers: hv: vmbus: fix the building warning with hyperv-keyboard extcon: add Maxim MAX3355 driver Drivers: hv: ring_buffer: eliminate hv_ringbuffer_peek() Drivers: hv: remove code duplication between vmbus_recvpacket()/vmbus_recvpacket_raw() ...
| * Drivers: hv: vmbus: Treat Fibre Channel devices as performance criticalK. Y. Srinivasan2015-12-211-0/+3
| | | | | | | | | | | | | | | | | | | | For performance critical devices, we distribute the incoming channel interrupt load across available CPUs in the guest. Include Fibre channel devices in the set of devices for which we would distribute the interrupt load. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: utils: fix hvt_op_poll() return value on transport destroyVitaly Kuznetsov2015-12-211-1/+1
| | | | | | | | | | | | | | | | | | | | The return type of hvt_op_poll() is unsigned int and -EBADF is inappropriate, poll functions return POLL* statuses. Reported-by: Dexuan Cui <decui@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>
| * Drivers: hv: ring_buffer: eliminate hv_ringbuffer_peek()Vitaly Kuznetsov2015-12-153-64/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, there is only one user for hv_ringbuffer_read()/ hv_ringbuffer_peak() functions and the usage of these functions is: - insecure as we drop ring_lock between them, someone else (in theory only) can acquire it in between; - non-optimal as we do a number of things (acquire/release the above mentioned lock, calculate available space on the ring, ...) twice and this path is performance-critical. Remove hv_ringbuffer_peek() moving the logic from __vmbus_recvpacket() to hv_ringbuffer_read(). 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: remove code duplication between ↵Vitaly Kuznetsov2015-12-151-43/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vmbus_recvpacket()/vmbus_recvpacket_raw() vmbus_recvpacket() and vmbus_recvpacket_raw() are almost identical but there are two discrepancies: 1) vmbus_recvpacket() doesn't propagate errors from hv_ringbuffer_read() which looks like it is not desired. 2) There is an error message printed in packetlen > bufferlen case in vmbus_recvpacket(). I'm removing it as it is usless for users to see such messages and /vmbus_recvpacket_raw() doesn't have 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: ring_buffer: remove code duplication from hv_ringbuffer_peek/read()Vitaly Kuznetsov2015-12-151-43/+25
| | | | | | | | | | | | | | | | | | | | | | hv_ringbuffer_peek() does the same as hv_ringbuffer_read() without advancing the read index. The only functional change this patch brings is moving hv_need_to_signal_on_read() call under the ring_lock but this function is just a couple of comparisons. 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: ring_buffer.c: fix comment styleVitaly Kuznetsov2015-12-151-109/+26
| | | | | | | | | | | | | | | | | | | | Convert 6+-string comments repeating function names to normal kernel-style comments and fix a couple of other comment style issues. No textual or functional changes 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>
| * Drivers: hv: utils: fix crash when device is removed from host sideVitaly Kuznetsov2015-12-151-3/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The crash is observed when a service is being disabled host side while userspace daemon is connected to the device: [ 90.244859] general protection fault: 0000 [#1] SMP ... [ 90.800082] Call Trace: [ 90.800082] [<ffffffff81187008>] __fput+0xc8/0x1f0 [ 90.800082] [<ffffffff8118716e>] ____fput+0xe/0x10 ... [ 90.800082] [<ffffffff81015278>] do_signal+0x28/0x580 [ 90.800082] [<ffffffff81086656>] ? finish_task_switch+0xa6/0x180 [ 90.800082] [<ffffffff81443ebf>] ? __schedule+0x28f/0x870 [ 90.800082] [<ffffffffa01ebbaa>] ? hvt_op_read+0x12a/0x140 [hv_utils] ... The problem is that hvutil_transport_destroy() which does misc_deregister() freeing the appropriate device is reachable by two paths: module unload and from util_remove(). While module unload path is protected by .owner in struct file_operations util_remove() path is not. Freeing the device while someone holds an open fd for it is a show stopper. In general, it is not possible to revoke an fd from all users so the only way to solve the issue is to defer freeing the hvutil_transport structure. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: utils: introduce HVUTIL_TRANSPORT_DESTROY modeVitaly Kuznetsov2015-12-152-15/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When Hyper-V host asks us to remove some util driver by closing the appropriate channel there is no easy way to force the current file descriptor holder to hang up but we can start to respond -EBADF to all operations asking it to exit gracefully. As we're setting hvt->mode from two separate contexts now we need to use a proper locking. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: utils: rename outmsg_lockVitaly Kuznetsov2015-12-152-8/+8
| | | | | | | | | | | | | | | | | | As a preparation to reusing outmsg_lock to protect test-and-set openrations on 'mode' rename it the more general 'lock'. 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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