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path: root/drivers/hv/vmbus_drv.c
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2020-08-14Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyper-v fixes from Wei Liu: - fix oops reporting on Hyper-V - make objtool happy * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Make hv_setup_sched_clock inline Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops
2020-08-07Drivers: hv: vmbus: Only notify Hyper-V for die events that are oopsMichael Kelley
Hyper-V currently may be notified of a panic for any die event. But this results in false panic notifications for various user space traps that are die events. Fix this by ignoring die events that aren't oops. Fixes: 510f7aef65bb ("Drivers: hv: vmbus: prefer 'die' notification chain to 'panic'") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/1596730935-11564-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-06Merge tag 'hyperv-next-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - A patch series from Andrea to improve vmbus code - Two clean-up patches from Alexander and Randy * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hyperv: hyperv.h: drop a duplicated word tools: hv: change http to https in hv_kvp_daemon.c Drivers: hv: vmbus: Remove the lock field from the vmbus_channel struct scsi: storvsc: Introduce the per-storvsc_device spinlock Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list updaters) Drivers: hv: vmbus: Use channel_mutex in channel_vp_mapping_show() Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list readers) Drivers: hv: vmbus: Replace cpumask_test_cpu(, cpu_online_mask) with cpu_online() Drivers: hv: vmbus: Remove the numa_node field from the vmbus_channel struct Drivers: hv: vmbus: Remove the target_vp field from the vmbus_channel struct
2020-06-29Drivers: hv: Change flag to write log level in panic msg to falseJoseph Salisbury
When the kernel panics, one page of kmsg data may be collected and sent to Hyper-V to aid in diagnosing the failure. The collected kmsg data typically contains 50 to 100 lines, each of which has a log level prefix that isn't very useful from a diagnostic standpoint. So tell kmsg_dump_get_buffer() to not include the log level, enabling more information that *is* useful to fit in the page. Requesting in stable kernels, since many kernels running in production are stable releases. Cc: stable@vger.kernel.org Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1593210497-114310-1-git-send-email-joseph.salisbury@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Use channel_mutex in channel_vp_mapping_show()Andrea Parri (Microsoft)
The primitive currently uses channel->lock to protect the loop over sc_list w.r.t. list additions/deletions but it doesn't protect the target_cpu(s) loads w.r.t. a concurrent target_cpu_store(): while the data races on target_cpu are hardly of any concern here, replace the channel->lock critical section with a channel_mutex critical section and extend the latter to include the loads of target_cpu; this same pattern is also used in hv_synic_cleanup(). Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-6-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections ↵Andrea Parri (Microsoft)
(sc_list readers) Additions/deletions to/from sc_list (as well as modifications of target_cpu(s)) are protected by channel_mutex, which hv_synic_cleanup() and vmbus_bus_suspend() own for the duration of the channel->lock critical section in question. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-5-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Replace cpumask_test_cpu(, cpu_online_mask) with ↵Andrea Parri (Microsoft)
cpu_online() A slight improvement in readability, and this does also remove one memory access when NR_CPUS == 1! ;-) Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-4-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Remove the numa_node field from the vmbus_channel structAndrea Parri (Microsoft)
The field is read only in numa_node_show() and it is already stored twice (after a call to cpu_to_node()) in target_cpu_store() and init_vp_index(); there is no need to "cache" its value in the channel data structure. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-3-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Remove the target_vp field from the vmbus_channel structAndrea Parri (Microsoft)
The field is read only in __vmbus_open() and it is already stored twice (after a call to hv_cpu_number_to_vp_number()) in target_cpu_store() and init_vp_index(); there is no need to "cache" its value in the channel data structure. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-2-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-03Merge tag 'hyperv-next-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyper-v updates from Wei Liu: - a series from Andrea to support channel reassignment - a series from Vitaly to clean up Vmbus message handling - a series from Michael to clean up and augment hyperv-tlfs.h - patches from Andy to clean up GUID usage in Hyper-V code - a few other misc patches * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (29 commits) Drivers: hv: vmbus: Resolve more races involving init_vp_index() Drivers: hv: vmbus: Resolve race between init_vp_index() and CPU hotplug vmbus: Replace zero-length array with flexible-array Driver: hv: vmbus: drop a no long applicable comment hyper-v: Switch to use UUID types directly hyper-v: Replace open-coded variant of %*phN specifier hyper-v: Supply GUID pointer to printf() like functions hyper-v: Use UUID API for exporting the GUID (part 2) asm-generic/hyperv: Add definitions for Get/SetVpRegister hypercalls x86/hyperv: Split hyperv-tlfs.h into arch dependent and independent files x86/hyperv: Remove HV_PROCESSOR_POWER_STATE #defines KVM: x86: hyperv: Remove duplicate definitions of Reference TSC Page drivers: hv: remove redundant assignment to pointer primary_channel scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assigned Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity logic PCI: hv: Prepare hv_compose_msi_msg() for the VMBus-channel-interrupt-to-vCPU reassignment functionality Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. channel removal hv_utils: Always execute the fcopy and vss callbacks in a tasklet ...
2020-05-23Drivers: hv: vmbus: Resolve more races involving init_vp_index()Andrea Parri (Microsoft)
init_vp_index() uses the (per-node) hv_numa_map[] masks to record the CPUs allocated for channel interrupts at a given time, and distribute the performance-critical channels across the available CPUs: in part., the mask of "candidate" target CPUs in a given NUMA node, for a newly offered channel, is determined by XOR-ing the node's CPU mask and the node's hv_numa_map. This operation/mechanism assumes that no offline CPUs is set in the hv_numa_map mask, an assumption that does not hold since such mask is currently not updated when a channel is removed or assigned to a different CPU. To address the issues described above, this adds hooks in the channel removal path (hv_process_channel_removal()) and in target_cpu_store() in order to clear, resp. to update, the hv_numa_map[] masks as needed. This also adds a (missed) update of the masks in init_vp_index() (cf., e.g., the memory-allocation failure path in this function). Like in the case of init_vp_index(), such hooks require to determine if the given channel is performance critical. init_vp_index() does this by parsing the channel's offer, it can not rely on the device data structure (device_obj) to retrieve such information because the device data structure has not been allocated/linked with the channel by the time that init_vp_index() executes. A similar situation may hold in hv_is_alloced_cpu() (defined below); the adopted approach is to "cache" the device type of the channel, as computed by parsing the channel's offer, in the channel structure itself. Fixes: 7527810573436f ("Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type") Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200522171901.204127-3-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20Driver: hv: vmbus: drop a no long applicable commentWei Liu
None of the things mentioned in the comment is initialized in hv_init. They've been moved elsewhere. Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20200506160806.118965-1-wei.liu@kernel.org Reviewed-by: Michael Kelley <mikelley@microsoft.com>
2020-05-20hyper-v: Replace open-coded variant of %*phN specifierAndy Shevchenko
printf() like functions in the kernel have extensions, such as %*phN to dump small pieces of memory as hex values. Replace print_alias_name() with the direct use of %*phN. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200423134505.78221-3-andriy.shevchenko@linux.intel.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20hyper-v: Supply GUID pointer to printf() like functionsAndy Shevchenko
Drop dereference when printing the GUID with printf() like functions. This allows to hide the uuid_t internals. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200423134505.78221-2-andriy.shevchenko@linux.intel.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assignedAndrea Parri (Microsoft)
For each storvsc_device, storvsc keeps track of the channel target CPUs associated to the device (alloced_cpus) and it uses this information to fill a "cache" (stor_chns) mapping CPU->channel according to a certain heuristic. Update the alloced_cpus mask and the stor_chns array when a channel of the storvsc device is re-assigned to a different CPU. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: <linux-scsi@vger.kernel.org> Link: https://lore.kernel.org/r/20200406001514.19876-12-parri.andrea@gmail.com Reviewed-by; Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> [ wei: fix a small issue reported by kbuild test robot <lkp@intel.com> ] Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message typeAndrea Parri (Microsoft)
VMBus version 4.1 and later support the CHANNELMSG_MODIFYCHANNEL(22) message type which can be used to request Hyper-V to change the vCPU that a channel will interrupt. Introduce the CHANNELMSG_MODIFYCHANNEL message type, and define the vmbus_send_modifychannel() function to send CHANNELMSG_MODIFYCHANNEL requests to the host via a hypercall. The function is then used to define a sysfs "store" operation, which allows to change the (v)CPU the channel will interrupt by using the sysfs interface. The feature can be used for load balancing or other purposes. One interesting catch here is that Hyper-V can *not* currently ACK CHANNELMSG_MODIFYCHANNEL messages with the promise that (after the ACK is sent) the channel won't send any more interrupts to the "old" CPU. The peculiarity of the CHANNELMSG_MODIFYCHANNEL messages is problematic if the user want to take a CPU offline, since we don't want to take a CPU offline (and, potentially, "lose" channel interrupts on such CPU) if the host is still processing a CHANNELMSG_MODIFYCHANNEL message associated to that CPU. It is worth mentioning, however, that we have been unable to observe the above mentioned "race": in all our tests, CHANNELMSG_MODIFYCHANNEL requests appeared *as if* they were processed synchronously by the host. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-11-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> [ wei: fix conflict in channel_mgmt.c ] Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. ↵Andrea Parri (Microsoft)
channel removal Since vmbus_chan_sched() dereferences the ring buffer pointer, we have to make sure that the ring buffer data structures don't get freed while such dereferencing is happening. Current code does this by sending an IPI to the CPU that is allowed to access that ring buffer from interrupt level, cf., vmbus_reset_channel_cb(). But with the new functionality to allow changing the CPU that a channel will interrupt, we can't be sure what CPU will be running the vmbus_chan_sched() function for a particular channel, so the current IPI mechanism is infeasible. Instead synchronize vmbus_chan_sched() and vmbus_reset_channel_cb() by using the (newly introduced) per-channel spin lock "sched_lock". Move the test for onchannel_callback being NULL before the "switch" control statement in vmbus_chan_sched(), in order to not access the ring buffer if the vmbus_reset_channel_cb() has been completed on the channel. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-7-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of ↵Andrea Parri (Microsoft)
channels When Hyper-V sends an interrupt to the guest, the guest has to figure out which channel the interrupt is associated with. Hyper-V sets a bit in a memory page that is shared with the guest, indicating a particular "relid" that the interrupt is associated with. The current Linux code then uses a set of per-CPU linked lists to map a given "relid" to a pointer to a channel structure. This design introduces a synchronization problem if the CPU that Hyper-V will interrupt for a certain channel is changed. If the interrupt comes on the "old CPU" and the channel was already moved to the per-CPU list of the "new CPU", then the relid -> channel mapping will fail and the interrupt is dropped. Similarly, if the interrupt comes on the new CPU but the channel was not moved to the per-CPU list of the new CPU, then the mapping will fail and the interrupt is dropped. Relids are integers ranging from 0 to 2047. The mapping from relids to channel structures can be done by setting up an array with 2048 entries, each entry being a pointer to a channel structure (hence total size ~16K bytes, which is not a problem). The array is global, so there are no per-CPU linked lists to update. The array can be searched and updated by loading from/storing to the array at the specified index. With no per-CPU data structures, the above mentioned synchronization problem is avoided and the relid2channel() function gets simpler. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-4-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Don't bind the offer&rescind works to a specific CPUAndrea Parri (Microsoft)
The offer and rescind works are currently scheduled on the so called "connect CPU". However, this is not really needed: we can synchronize the works by relying on the usage of the offer_in_progress counter and of the channel_mutex mutex. This synchronization is already in place. So, remove this unnecessary "bind to the connect CPU" constraint and update the inline comments accordingly. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-3-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Always handle the VMBus messages on CPU0Andrea Parri (Microsoft)
A Linux guest have to pick a "connect CPU" to communicate with the Hyper-V host. This CPU can not be taken offline because Hyper-V does not provide a way to change that CPU assignment. Current code sets the connect CPU to whatever CPU ends up running the function vmbus_negotiate_version(), and this will generate problems if that CPU is taken offine. Establish CPU0 as the connect CPU, and add logics to prevents the connect CPU from being taken offline. We could pick some other CPU, and we could pick that "other CPU" dynamically if there was a reason to do so at some point in the future. But for now, #defining the connect CPU to 0 is the most straightforward and least complex solution. While on this, add inline comments explaining "why" offer and rescind messages should not be handled by a same serialized work queue. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/20200406001514.19876-2-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: check VMBus messages lengthsVitaly Kuznetsov
VMBus message handlers (channel_message_table) receive a pointer to 'struct vmbus_channel_message_header' and cast it to a structure of their choice, which is sometimes longer than the header. We, however, don't check that the message is long enough so in case hypervisor screws up we'll be accessing memory beyond what was allocated for temporary buffer. Previously, we used to always allocate and copy 256 bytes from message page to temporary buffer but this is hardly better: in case the message is shorter than we expect we'll be trying to consume garbage as some real data and no memory guarding technique will be able to identify an issue. Introduce 'min_payload_len' to 'struct vmbus_channel_message_table_entry' and check against it in vmbus_on_msg_dpc(). Note, we can't require the exact length as new hypervisor versions may add extra fields to messages, we only check that the message is not shorter than we expect. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104326.45361-1-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: make sure that 'struct vmbus_channel_message_header' compiles ↵Vitaly Kuznetsov
correctly Strictly speaking, compiler is free to use something different from 'u32' for 'enum vmbus_channel_message_type' (e.g. char) but it doesn't happen in real life, just add a BUILD_BUG_ON() guardian. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104316.45303-1-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: avoid passing opaque pointer to vmbus_onmessage()Vitaly Kuznetsov
vmbus_onmessage() doesn't need the header of the message, it only uses it to get to the payload, we can pass the pointer to the payload directly. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104154.45010-4-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: allocate the exact needed memory for messagesVitaly Kuznetsov
When we need to pass a buffer with Hyper-V message we don't need to always allocate 256 bytes for the message: the real message length is known from the header. Change 'struct onmessage_work_context' to make it possible to not over-allocate. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104154.45010-3-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: copy from message page only what's neededVitaly Kuznetsov
Hyper-V Interrupt Message Page (SIMP) has 16 256-byte slots for messages. Each message comes with a header (16 bytes) which specifies the payload length (up to 240 bytes). vmbus_on_msg_dpc(), however, doesn't look at the real message length and copies the whole slot to a temporary buffer before passing it to message handlers. This is potentially dangerous as hypervisor doesn't have to clean the whole slot when putting a new message there and a message handler can get access to some data which belongs to a previous message. Note, this is not currently a problem because all message handlers are in-kernel but eventually we may e.g. get this exported to userspace. Note also, that this is not a performance critical path: messages (unlike events) represent rare events so it doesn't really matter (from performance point of view) if we copy too much. Fix the issue by taking into account the real message length. The temporary buffer allocated by vmbus_on_msg_dpc() remains fixed size for now. Also, check that the supplied payload length is valid (<= 240 bytes). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104154.45010-2-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-14Drivers: hv: vmbus: Fix Suspend-to-Idle for Generation-2 VMDexuan Cui
Before the hibernation patchset (e.g. f53335e3289f), in a Generation-2 Linux VM on Hyper-V, the user can run "echo freeze > /sys/power/state" to freeze the system, i.e. Suspend-to-Idle. The user can press the keyboard or move the mouse to wake up the VM. With the hibernation patchset, Linux VM on Hyper-V can hibernate to disk, but Suspend-to-Idle is broken: when the synthetic keyboard/mouse are suspended, there is no way to wake up the VM. Fix the issue by not suspending and resuming the vmbus devices upon Suspend-to-Idle. Fixes: f53335e3289f ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation") Cc: stable@vger.kernel.org Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Link: https://lore.kernel.org/r/1586663435-36243-1-git-send-email-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-11x86/Hyper-V: Report crash data in die() when panic_on_oops is setTianyu Lan
When oops happens with panic_on_oops unset, the oops thread is killed by die() and system continues to run. In such case, guest should not report crash register data to host since system still runs. Check panic_on_oops and return directly in hyperv_report_panic() when the function is called in the die() and panic_on_oops is unset. Fix it. Fixes: 7ed4325a44ea ("Drivers: hv: vmbus: Make panic reporting to be more useful") Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406155331.2105-7-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-11x86/Hyper-V: Report crash register data when sysctl_record_panic_msg is not setTianyu Lan
When sysctl_record_panic_msg is not set, the panic will not be reported to Hyper-V via hyperv_report_panic_msg(). So the crash should be reported via hyperv_report_panic(). Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic") Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20200406155331.2105-6-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-11x86/Hyper-V: Trigger crash enlightenment only once during system crash.Tianyu Lan
When a guest VM panics, Hyper-V should be notified only once via the crash synthetic MSRs. Current Linux code might write these crash MSRs twice during a system panic: 1) hyperv_panic/die_event() calling hyperv_report_panic() 2) hv_kmsg_dump() calling hyperv_report_panic_msg() Fix this by not calling hyperv_report_panic() if a kmsg dump has been successfully registered. The notification will happen later via hyperv_report_panic_msg(). Fixes: 7ed4325a44ea ("Drivers: hv: vmbus: Make panic reporting to be more useful") Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20200406155331.2105-4-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-10x86/Hyper-V: Free hv_panic_page when fail to register kmsg dumpTianyu Lan
If kmsg_dump_register() fails, hv_panic_page will not be used anywhere. So free and reset it. Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic") Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20200406155331.2105-3-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-10x86/Hyper-V: Unload vmbus channel in hv panic callbackTianyu Lan
When kdump is not configured, a Hyper-V VM might still respond to network traffic after a kernel panic when kernel parameter panic=0. The panic CPU goes into an infinite loop with interrupts enabled, and the VMbus driver interrupt handler still works because the VMbus connection is unloaded only in the kdump path. The network responses make the other end of the connection think the VM is still functional even though it has panic'ed, which could affect any failover actions that should be taken. Fix this by unloading the VMbus connection during the panic process. vmbus_initiate_unload() could then be called twice (e.g., by hyperv_panic_event() and hv_crash_handler(), so reset the connection state in vmbus_initiate_unload() to ensure the unload is done only once. Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic") Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20200406155331.2105-2-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-01-25Drivers: hv: vmbus: Ignore CHANNELMSG_TL_CONNECT_RESULT(23)Dexuan Cui
When a Linux hv_sock app tries to connect to a Service GUID on which no host app is listening, a recent host (RS3+) sends a CHANNELMSG_TL_CONNECT_RESULT (23) message to Linux and this triggers such a warning: unknown msgtype=23 WARNING: CPU: 2 PID: 0 at drivers/hv/vmbus_drv.c:1031 vmbus_on_msg_dpc Actually Linux can safely ignore the message because the Linux app's connect() will time out in 2 seconds: see VSOCK_DEFAULT_CONNECT_TIMEOUT and vsock_stream_connect(). We don't bother to make use of the message because: 1) it's only supported on recent hosts; 2) a non-trivial effort is required to use the message in Linux, but the benefit is small. So, let's not see the warning by silently ignoring the message. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-30Merge tag 'hyperv-next-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull Hyper-V updates from Sasha Levin: - support for new VMBus protocols (Andrea Parri) - hibernation support (Dexuan Cui) - latency testing framework (Branden Bonaby) - decoupling Hyper-V page size from guest page size (Himadri Pandya) * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (22 commits) Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synic drivers/hv: Replace binary semaphore with mutex drivers: iommu: hyperv: Make HYPERV_IOMMU only available on x86 HID: hyperv: Add the support of hibernation hv_balloon: Add the support of hibernation x86/hyperv: Implement hv_is_hibernation_supported() Drivers: hv: balloon: Remove dependencies on guest page size Drivers: hv: vmbus: Remove dependencies on guest page size x86: hv: Add function to allocate zeroed page for Hyper-V Drivers: hv: util: Specify ring buffer size using Hyper-V page size Drivers: hv: Specify receive buffer size using Hyper-V page size tools: hv: add vmbus testing tool drivers: hv: vmbus: Introduce latency testing video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver video: hyperv: hyperv_fb: Obtain screen resolution from Hyper-V host hv_netvsc: Add the support of hibernation hv_sock: Add the support of hibernation video: hyperv_fb: Add the support of hibernation scsi: storvsc: Add the support of hibernation Drivers: hv: vmbus: Add module parameter to cap the VMBus version ...
2019-11-21Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synicMichael Kelley
The crash handler calls hv_synic_cleanup() to shutdown the Hyper-V synthetic interrupt controller. But if the CPU that calls hv_synic_cleanup() has a VMbus channel interrupt assigned to it (which is likely the case in smaller VM sizes), hv_synic_cleanup() returns an error and the synthetic interrupt controller isn't shutdown. While the lack of being shutdown hasn't caused a known problem, it still should be fixed for highest reliability. So directly call hv_synic_disable_regs() instead of hv_synic_cleanup(), which ensures that the synic is always shutdown. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21drivers/hv: Replace binary semaphore with mutexDavidlohr Bueso
At a slight footprint cost (24 vs 32 bytes), mutexes are more optimal than semaphores; it's also a nicer interface for mutual exclusion, which is why they are encouraged over binary semaphores, when possible. Replace the hyperv_mmio_lock, its semantics implies traditional lock ownership; that is, the lock owner is the same for both lock/unlock operations. Therefore it is safe to convert. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21Drivers: hv: vmbus: Remove dependencies on guest page sizeHimadri Pandya
Hyper-V assumes page size to be 4K. This might not be the case for ARM64 architecture. Hence use hyper-v page size and page allocation function to avoid conflicts between different host and guest page size on ARM64. Signed-off-by: Himadri Pandya <himadri18.07@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21drivers: hv: vmbus: Introduce latency testingBranden Bonaby
Introduce user specified latency in the packet reception path By exposing the test parameters as part of the debugfs channel attributes. We will control the testing state via these attributes. Signed-off-by: Branden Bonaby <brandonbonaby94@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21Drivers: hv: vmbus: Introduce table of VMBus protocol versionsAndrea Parri
The technique used to get the next VMBus version seems increasisly clumsy as the number of VMBus versions increases. Performance is not a concern since this is only done once during system boot; it's just that we'll end up with more lines of code than is really needed. As an alternative, introduce a table with the version numbers listed in order (from the most recent to the oldest). vmbus_connect() loops through the versions listed in the table until it gets an accepted connection or gets to the end of the table (invalid version). Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-15x86/hyperv: Initialize clockevents earlier in CPU onliningMichael Kelley
Hyper-V has historically initialized stimer-based clockevents late in the process of onlining a CPU because clockevents depend on stimer interrupts. In the original Hyper-V design, stimer interrupts generate a VMbus message, so the VMbus machinery must be running first, and VMbus can't be initialized until relatively late. On x86/64, LAPIC timer based clockevents are used during early initialization before VMbus and stimer-based clockevents are ready, and again during CPU offlining after the stimer clockevents have been shut down. Unfortunately, this design creates problems when offlining CPUs for hibernation or other purposes. stimer-based clockevents are shut down relatively early in the offlining process, so clockevents_unbind_device() must be used to fallback to the LAPIC-based clockevents for the remainder of the offlining process. Furthermore, the late initialization and early shutdown of stimer-based clockevents doesn't work well on ARM64 since there is no other timer like the LAPIC to fallback to. So CPU onlining and offlining doesn't work properly. Fix this by recognizing that stimer Direct Mode is the normal path for newer versions of Hyper-V on x86/64, and the only path on other architectures. With stimer Direct Mode, stimer interrupts don't require any VMbus machinery. stimer clockevents can be initialized and shut down consistent with how it is done for other clockevent devices. While the old VMbus-based stimer interrupts must still be supported for backward compatibility on x86, that mode of operation can be treated as legacy. So add a new Hyper-V stimer entry in the CPU hotplug state list, and use that new state when in Direct Mode. Update the Hyper-V clocksource driver to allocate and initialize stimer clockevents earlier during boot. Update Hyper-V initialization and the VMbus driver to use this new design. As a result, the LAPIC timer is no longer used during boot or CPU onlining/offlining and clockevents_unbind_device() is not called. But retain the old design as a legacy implementation for older versions of Hyper-V that don't support Direct Mode. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Link: https://lkml.kernel.org/r/1573607467-9456-1-git-send-email-mikelley@microsoft.com
2019-10-01Drivers: hv: vmbus: Fix harmless building warnings without CONFIG_PM_SLEEPDexuan Cui
If CONFIG_PM_SLEEP is not set, we can comment out these functions to avoid the below warnings: drivers/hv/vmbus_drv.c:2208:12: warning: ‘vmbus_bus_resume’ defined but not used [-Wunused-function] drivers/hv/vmbus_drv.c:2128:12: warning: ‘vmbus_bus_suspend’ defined but not used [-Wunused-function] drivers/hv/vmbus_drv.c:937:12: warning: ‘vmbus_resume’ defined but not used [-Wunused-function] drivers/hv/vmbus_drv.c:918:12: warning: ‘vmbus_suspend’ defined but not used [-Wunused-function] Fixes: 271b2224d42f ("Drivers: hv: vmbus: Implement suspend/resume for VSC drivers for hibernation") Fixes: f53335e3289f ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation") Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06Drivers: hv: vmbus: Resume after fixing up old primary channelsDexuan Cui
When the host re-offers the primary channels upon resume, the host only guarantees the Instance GUID doesn't change, so vmbus_bus_suspend() should invalidate channel->offermsg.child_relid and figure out the number of primary channels that need to be fixed up upon resume. Upon resume, vmbus_onoffer() finds the old channel structs, and maps the new offers to the old channels, and fixes up the old structs, and finally the resume callbacks of the VSC drivers will re-open the channels. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06Drivers: hv: vmbus: Suspend after cleaning up hv_sock and sub channelsDexuan Cui
Before suspend, Linux must make sure all the hv_sock channels have been properly cleaned up, because a hv_sock connection can not persist across hibernation, and the user-space app must be properly notified of the state change of the connection. Before suspend, Linux also must make sure all the sub-channels have been destroyed, i.e. the related channel structs of the sub-channels must be properly removed, otherwise they would cause a conflict when the sub-channels are recreated upon resume. Add a counter to track such channels, and vmbus_bus_suspend() should wait for the counter to drop to zero. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06Drivers: hv: vmbus: Clean up hv_sock channels by force upon suspendDexuan Cui
Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for hibernation. There is no better method to clean up the channels since some of the channels may still be referenced by the userspace apps when hibernation is triggered: in this case, with this patch, the "rescind" fields of the channels are set, and the apps will thoroughly destroy the channels after hibernation. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernationDexuan Cui
Before Linux enters hibernation, it sends the CHANNELMSG_UNLOAD message to the host so all the offers are gone. After hibernation, Linux needs to re-negotiate with the host using the same vmbus protocol version (which was in use before hibernation), and ask the host to re-offer the vmbus devices. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06Drivers: hv: vmbus: Implement suspend/resume for VSC drivers for hibernationDexuan Cui
The high-level VSC drivers will implement device-specific callbacks. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06Drivers: hv: vmbus: Suspend/resume the synic for hibernationDexuan Cui
This is needed when we resume the old kernel from the "current" kernel. Note: when hv_synic_suspend() and hv_synic_resume() run, all the non-boot CPUs have been offlined, and interrupts are disabled on CPU0. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-18proc/sysctl: add shared variables for range checkMatteo Croce
In the sysctl code the proc_dointvec_minmax() function is often used to validate the user supplied value between an allowed range. This function uses the extra1 and extra2 members from struct ctl_table as minimum and maximum allowed value. On sysctl handler declaration, in every source file there are some readonly variables containing just an integer which address is assigned to the extra1 and extra2 members, so the sysctl range is enforced. The special values 0, 1 and INT_MAX are very often used as range boundary, leading duplication of variables like zero=0, one=1, int_max=INT_MAX in different source files: $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l 248 Add a const int array containing the most commonly used values, some macros to refer more easily to the correct array member, and use them instead of creating a local one for every object file. This is the bloat-o-meter output comparing the old and new binary compiled with the default Fedora config: # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164) Data old new delta sysctl_vals - 12 +12 __kstrtab_sysctl_vals - 12 +12 max 14 10 -4 int_max 16 - -16 one 68 - -68 zero 128 28 -100 Total: Before=20583249, After=20583085, chg -0.00% [mcroce@redhat.com: tipc: remove two unused variables] Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com [akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c] [arnd@arndb.de: proc/sysctl: make firmware loader table conditional] Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de [akpm@linux-foundation.org: fix fs/eventpoll.c] Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12Merge tag 'hyperv-next-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyper-v updates from Sasha Levin: - Add a module description to the Hyper-V vmbus module. - Rework some vmbus code to separate architecture specifics out to arch/x86/. This is part of the work of adding arm64 support to Hyper-V. * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Break out ISA independent parts of mshyperv.h drivers: hv: Add a module description line to the hv_vmbus driver
2019-07-03clocksource/drivers: Make Hyper-V clocksource ISA agnosticMichael Kelley
Hyper-V clock/timer code and data structures are currently mixed in with other code in the ISA independent drivers/hv directory as well as the ISA dependent Hyper-V code under arch/x86. Consolidate this code and data structures into a Hyper-V clocksource driver to better follow the Linux model. In doing so, separate out the ISA dependent portions so the new clocksource driver works for x86 and for the in-process Hyper-V on ARM64 code. To start, move the existing clockevents code to create the new clocksource driver. Update the VMbus driver to call initialization and cleanup routines since the Hyper-V synthetic timers are not independently enumerated in ACPI. No behavior is changed and no new functionality is added. Suggested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: "bp@alien8.de" <bp@alien8.de> Cc: "will.deacon@arm.com" <will.deacon@arm.com> Cc: "catalin.marinas@arm.com" <catalin.marinas@arm.com> Cc: "mark.rutland@arm.com" <mark.rutland@arm.com> Cc: "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org> Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org> Cc: "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org> Cc: "olaf@aepfle.de" <olaf@aepfle.de> Cc: "apw@canonical.com" <apw@canonical.com> Cc: "jasowang@redhat.com" <jasowang@redhat.com> Cc: "marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com> Cc: Sunil Muthuswamy <sunilmut@microsoft.com> Cc: KY Srinivasan <kys@microsoft.com> Cc: "sashal@kernel.org" <sashal@kernel.org> Cc: "vincenzo.frascino@arm.com" <vincenzo.frascino@arm.com> Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org> Cc: "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org> Cc: "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org> Cc: "arnd@arndb.de" <arnd@arndb.de> Cc: "linux@armlinux.org.uk" <linux@armlinux.org.uk> Cc: "ralf@linux-mips.org" <ralf@linux-mips.org> Cc: "paul.burton@mips.com" <paul.burton@mips.com> Cc: "daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org> Cc: "salyzyn@android.com" <salyzyn@android.com> Cc: "pcc@google.com" <pcc@google.com> Cc: "shuah@kernel.org" <shuah@kernel.org> Cc: "0x7f454c46@gmail.com" <0x7f454c46@gmail.com> Cc: "linux@rasmusvillemoes.dk" <linux@rasmusvillemoes.dk> Cc: "huw@codeweavers.com" <huw@codeweavers.com> Cc: "sfr@canb.auug.org.au" <sfr@canb.auug.org.au> Cc: "pbonzini@redhat.com" <pbonzini@redhat.com> Cc: "rkrcmar@redhat.com" <rkrcmar@redhat.com> Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org> Link: https://lkml.kernel.org/r/1561955054-1838-2-git-send-email-mikelley@microsoft.com
2019-06-23drivers: hv: Add a module description line to the hv_vmbus driverJoseph Salisbury
This patch only adds a MODULE_DESCRIPTION statement to the driver. This change is only cosmetic, so there should be no runtime impact. Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>