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2020-04-23hv_netvsc: Disable NAPI before closing the VMBus channelAndrea Parri (Microsoft)
vmbus_chan_sched() might call the netvsc driver callback function that ends up scheduling NAPI work. This "work" can access the channel ring buffer, so we must ensure that any such work is completed and that the ring buffer is no longer being accessed before freeing the ring buffer data structure in the channel closure path. To this end, disable NAPI before calling vmbus_close() in netvsc_device_remove(). Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: <netdev@vger.kernel.org> Link: https://lore.kernel.org/r/20200406001514.19876-5-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>
2020-04-22hyper-v: Use UUID API for exporting the GUIDAndy Shevchenko
There is export_guid() function which exports guid_t to the u8 array. Use it instead of open coding variant. This allows to hide the uuid_t internals. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200422125937.38355-1-andriy.shevchenko@linux.intel.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-21Drivers: hv: Move AEOI determination to architecture dependent codeMichael Kelley
Hyper-V on ARM64 doesn't provide a flag for the AEOI recommendation in ms_hyperv.hints, so having the test in architecture independent code doesn't work. Resolve this by moving the check of the flag to an architecture dependent helper function. No functionality is changed. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200420164926.24471-1-mikelley@microsoft.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>
2020-04-14Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - a series from Tianyu Lan to fix crash reporting on Hyper-V - three miscellaneous cleanup patches * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/Hyper-V: Report crash data in die() when panic_on_oops is set x86/Hyper-V: Report crash register data when sysctl_record_panic_msg is not set x86/Hyper-V: Report crash register data or kmsg before running crash kernel x86/Hyper-V: Trigger crash enlightenment only once during system crash. x86/Hyper-V: Free hv_panic_page when fail to register kmsg dump x86/Hyper-V: Unload vmbus channel in hv panic callback x86: hyperv: report value of misc_features hv_debugfs: Make hv_debug_root static hv: hyperv_vmbus.h: Replace zero-length array with flexible-array member
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>
2020-04-07hv_balloon: don't check for memhp_auto_online manuallyDavid Hildenbrand
We get the MEM_ONLINE notifier call if memory is added right from the kernel via add_memory() or later from user space. Let's get rid of the "ha_waiting" flag - the wait event has an inbuilt mechanism (->done) for that. Initialize the wait event only once and reinitialize before adding memory. Unconditionally call complete() and wait_for_completion_timeout(). If there are no waiters, complete() will only increment ->done - which will be reset by reinit_completion(). If complete() has already been called, wait_for_completion_timeout() will not wait. There is still the chance for a small race between concurrent reinit_completion() and complete(). If complete() wins, we would not wait - which is tolerable (and the race exists in current code as well). Note: We only wait for "some" memory to get onlined, which seems to be good enough for now. [akpm@linux-foundation.org: register_memory_notifier() after init_completion(), per David] Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-6-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-04hv_debugfs: Make hv_debug_root staticYueHaibing
Fix sparse warning: drivers/hv/hv_debugfs.c:14:15: warning: symbol 'hv_debug_root' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200403082845.22740-1-yuehaibing@huawei.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-03-21hv: hyperv_vmbus.h: Replace zero-length array with flexible-array memberGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-02-03Merge 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: - Most of the commits here are work to enable host-initiated hibernation support by Dexuan Cui. - Fix for a warning shown when host sends non-aligned balloon requests by Tianyu Lan. * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hv_utils: Add the support of hibernation hv_utils: Support host-initiated hibernation request hv_utils: Support host-initiated restart request Tools: hv: Reopen the devices if read() or write() returns errors video: hyperv: hyperv_fb: Use physical memory for fb on HyperV Gen 1 VMs. Drivers: hv: vmbus: Ignore CHANNELMSG_TL_CONNECT_RESULT(23) video: hyperv_fb: Fix hibernation for the deferred IO feature Input: hyperv-keyboard: Add the support of hibernation hv_balloon: Balloon up according to request page number
2020-01-26hv_utils: Add the support of hibernationDexuan Cui
Add util_pre_suspend() and util_pre_resume() for some hv_utils devices (e.g. kvp/vss/fcopy), because they need special handling before util_suspend() calls vmbus_close(). For kvp, all the possible pending work items should be cancelled. For vss and fcopy, some extra clean-up needs to be done, i.e. fake a THAW message for hv_vss_daemon and fake a CANCEL_FCOPY message for hv_fcopy_daemon, otherwise when the VM resums back, the daemons can end up in an inconsistent state (i.e. the file systems are frozen but will never be thawed; the file transmitted via fcopy may not be complete). Note: there is an extra patch for the daemons: "Tools: hv: Reopen the devices if read() or write() returns errors", because the hv_utils driver can not guarantee the whole transaction finishes completely once util_suspend() starts to run (at this time, all the userspace processes are frozen). util_probe() disables channel->callback_event to avoid the race with the channel callback. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-26hv_utils: Support host-initiated hibernation requestDexuan Cui
Update the Shutdown IC version to 3.2, which is required for the host to send the hibernation request. The user is expected to create the below udev rule file, which is applied upon the host-initiated hibernation request: root@localhost:~# cat /usr/lib/udev/rules.d/40-vm-hibernation.rules SUBSYSTEM=="vmbus", ACTION=="change", DRIVER=="hv_utils", ENV{EVENT}=="hibernate", RUN+="/usr/bin/systemctl hibernate" Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-26hv_utils: Support host-initiated restart requestDexuan Cui
The hv_utils driver currently supports a "shutdown" operation initiated from the Hyper-V host. Newer versions of Hyper-V also support a "restart" operation. So add support for the updated protocol version that has "restart" support, and perform a clean reboot when such a message is received from Hyper-V. To test the restart functionality, run this PowerShell command on the Hyper-V host: Restart-VM <vmname> -Type Reboot Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@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>
2020-01-25hv_balloon: Balloon up according to request page numberTianyu Lan
Current code has assumption that balloon request memory size aligns with 2MB. But actually Hyper-V doesn't guarantee such alignment. When balloon driver receives non-aligned balloon request, it produces warning and balloon up more memory than requested in order to keep 2MB alignment. Remove the warning and balloon up memory according to actual requested memory size. Fixes: f6712238471a ("hv: hv_balloon: avoid memory leak on alloc_error of 2MB memory block") Cc: stable@vger.kernel.org Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-16clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksourcesAndrea Parri
hyperv_timer.c exports hyperv_cs, which is used by stimers and the timesync mechanism. However, the clocksource dependency is not needed: these mechanisms only depend on the partition reference counter (which can be read via a MSR or via the TSC Reference Page). Introduce the (function) pointer hv_read_reference_counter, as an embodiment of the partition reference counter read, and export it in place of the hyperv_cs pointer. The latter can be removed. This should clarify that there's no relationship between Hyper-V stimers & timesync and the Linux clocksource abstractions. No functional or semantic change. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20200109160650.16150-2-parri.andrea@gmail.com
2019-12-01Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge updates from Andrew Morton: "Incoming: - a small number of updates to scripts/, ocfs2 and fs/buffer.c - most of MM I still have quite a lot of material (mostly not MM) staged after linux-next due to -next dependencies. I'll send those across next week as the preprequisites get merged up" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (135 commits) mm/page_io.c: annotate refault stalls from swap_readpage mm/Kconfig: fix trivial help text punctuation mm/Kconfig: fix indentation mm/memory_hotplug.c: remove __online_page_set_limits() mm: fix typos in comments when calling __SetPageUptodate() mm: fix struct member name in function comments mm/shmem.c: cast the type of unmap_start to u64 mm: shmem: use proper gfp flags for shmem_writepage() mm/shmem.c: make array 'values' static const, makes object smaller userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register() userfaultfd: wrap the common dst_vma check into an inlined function userfaultfd: remove unnecessary WARN_ON() in __mcopy_atomic_hugetlb() userfaultfd: use vma_pagesize for all huge page size calculation mm/madvise.c: use PAGE_ALIGN[ED] for range checking mm/madvise.c: replace with page_size() in madvise_inject_error() mm/mmap.c: make vma_merge() comment more easy to understand mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops autonuma: reduce cache footprint when scanning page tables autonuma: fix watermark checking in migrate_balanced_pgdat() ...
2019-12-01mm/memory_hotplug.c: remove __online_page_set_limits()Souptick Joarder
__online_page_set_limits() is a dummy function - remove it and all callers. Link: http://lkml.kernel.org/r/8e1bc9d3b492f6bde16e95ebc1dee11d6aefabd7.1567889743.git.jrdr.linux@gmail.com Link: http://lkml.kernel.org/r/854db2cf8145d9635249c95584d9a91fd774a229.1567889743.git.jrdr.linux@gmail.com Link: http://lkml.kernel.org/r/9afe6c5a18158f3884a6b302ac2c772f3da49ccc.1567889743.git.jrdr.linux@gmail.com Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01hv_balloon: use generic_online_page()David Hildenbrand
Let's use the generic onlining function - which will now also take care of calling kernel_map_pages(). Link: http://lkml.kernel.org/r/20190909114830.662-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sasha Levin <sashal@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Qian Cai <cai@lca.pw> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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>
2019-11-21hv_balloon: Add the support of hibernationDexuan Cui
When hibernation is enabled, we must ignore the balloon up/down and hot-add requests from the host, if any. Signed-off-by: Dexuan Cui <decui@microsoft.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21Drivers: hv: balloon: 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 specific page size and page shift definitions to avoid conflicts between different host and guest page sizes on ARM64. Also, remove some old and incorrect comments and redefine ballooning granularities to handle larger page sizes correctly. 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: 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: util: Specify ring buffer size using Hyper-V page sizeHimadri Pandya
VMbus ring buffers are sized based on the 4K page size used by Hyper-V. The Linux guest page size may not be 4K on all architectures so use the Hyper-V page size to specify the ring buffer size. 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: Specify receive buffer size using Hyper-V page sizeHimadri Pandya
The recv_buffer is used to retrieve data from the VMbus ring buffer. VMbus ring buffers are sized based on the guest page size which Hyper-V assumes to be 4KB. But it may be different on some architectures. So use the Hyper-V page size to allocate the recv_buffer and set the maximum size to receive. 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: Add module parameter to cap the VMBus versionAndrea Parri
Currently, Linux guests negotiate the VMBus version with Hyper-V and use the highest available VMBus version they can connect to. This has some drawbacks: by using the highest available version, certain code paths are never executed and can not be tested when the guest runs on the newest host. Add the module parameter "max_version", to upper-bound the VMBus versions guests can negotiate. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2Andrea Parri
Hyper-V has added VMBus protocol versions 5.1 and 5.2 in recent release versions. Allow Linux guests to negotiate these new protocol versions on versions of Hyper-V that support them. While on this, also allow guests to negotiate the VMBus protocol version 4.1 (which was missing). Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21Drivers: hv: vmbus: Introduce table of VMBus protocol versionsAndrea 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>
2019-09-24Merge 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: - first round of vmbus hibernation support (Dexuan Cui) - remove dependencies on PAGE_SIZE (Maya Nakamura) - move the hyper-v tools/ code into the tools build system (Andy Shevchenko) - hyper-v balloon cleanups (Dexuan Cui) * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Resume after fixing up old primary channels Drivers: hv: vmbus: Suspend after cleaning up hv_sock and sub channels Drivers: hv: vmbus: Clean up hv_sock channels by force upon suspend Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation Drivers: hv: vmbus: Ignore the offers when resuming from hibernation Drivers: hv: vmbus: Implement suspend/resume for VSC drivers for hibernation Drivers: hv: vmbus: Add a helper function is_sub_channel() Drivers: hv: vmbus: Suspend/resume the synic for hibernation Drivers: hv: vmbus: Break out synic enable and disable operations HID: hv: Remove dependencies on PAGE_SIZE for ring buffer Tools: hv: move to tools buildsystem hv_balloon: Reorganize the probe function hv_balloon: Use a static page for the balloon_up send buffer
2019-09-17Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core timer updates from Thomas Gleixner: "Timers and timekeeping updates: - A large overhaul of the posix CPU timer code which is a preparation for moving the CPU timer expiry out into task work so it can be properly accounted on the task/process. An update to the bogus permission checks will come later during the merge window as feedback was not complete before heading of for travel. - Switch the timerqueue code to use cached rbtrees and get rid of the homebrewn caching of the leftmost node. - Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a single function - Implement the separation of hrtimers to be forced to expire in hard interrupt context even when PREEMPT_RT is enabled and mark the affected timers accordingly. - Implement a mechanism for hrtimers and the timer wheel to protect RT against priority inversion and live lock issues when a (hr)timer which should be canceled is currently executing the callback. Instead of infinitely spinning, the task which tries to cancel the timer blocks on a per cpu base expiry lock which is held and released by the (hr)timer expiry code. - Enable the Hyper-V TSC page based sched_clock for Hyper-V guests resulting in faster access to timekeeping functions. - Updates to various clocksource/clockevent drivers and their device tree bindings. - The usual small improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) posix-cpu-timers: Fix permission check regression posix-cpu-timers: Always clear head pointer on dequeue hrtimer: Add a missing bracket and hide `migration_base' on !SMP posix-cpu-timers: Make expiry_active check actually work correctly posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build tick: Mark sched_timer to expire in hard interrupt context hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n posix-cpu-timers: Utilize timerqueue for storage posix-cpu-timers: Move state tracking to struct posix_cputimers posix-cpu-timers: Deduplicate rlimit handling posix-cpu-timers: Remove pointless comparisons posix-cpu-timers: Get rid of 64bit divisions posix-cpu-timers: Consolidate timer expiry further posix-cpu-timers: Get rid of zero checks rlimit: Rewrite non-sensical RLIMIT_CPU comment posix-cpu-timers: Respect INFINITY for hard RTTIME limit posix-cpu-timers: Switch thread group sampling to array posix-cpu-timers: Restructure expiry array posix-cpu-timers: Remove cputime_expires ...
2019-09-16Merge branch 'x86-hyperv-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 hyperv updates from Ingo Molnar: "Misc updates related to page size abstractions within the HyperV code, in preparation for future features" * 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: drivers: hv: vmbus: Replace page definition with Hyper-V specific one x86/hyperv: Add functions to allocate/deallocate page for Hyper-V x86/hyperv: Create and use Hyper-V page definitions
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>