linux-stable.git/drivers/hv, branch v5.8.8

hv_utils: drain the timesync packets on onchannelcallback

2020-09-09T17:14:10+00:00

[ Upstream commit b46b4a8a57c377b72a98c7930a9f6969d2d4784e ]

There could be instances where a system stall prevents the timesync
packets to be consumed. And this might lead to more than one packet
pending in the ring buffer. Current code empties one packet per callback
and it might be a stale one. So drain all the packets from ring buffer
on each callback.

Signed-off-by: Vineeth Pillai 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20200821152849.99517-1-viremana@linux.microsoft.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

hv_utils: return error if host timesysnc update is stale

2020-09-09T17:14:09+00:00

[ Upstream commit 90b125f4cd2697f949f5877df723a0b710693dd0 ]

If for any reason, host timesync messages were not processed by
the guest, hv_ptp_gettime() returns a stale value and the
caller (clock_gettime, PTP ioctl etc) has no means to know this
now. Return an error so that the caller knows about this.

Signed-off-by: Vineeth Pillai 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20200821152523.99364-1-viremana@linux.microsoft.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: Change flag to write log level in panic msg to false

2020-06-29T10:30:35+00:00

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 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/1593210497-114310-1-git-send-email-joseph.salisbury@microsoft.com
Signed-off-by: Wei Liu

Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2020-06-03T22:00:05+00:00

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
  ...

Drivers: hv: vmbus: Resolve more races involving init_vp_index()

2020-05-23T09:07:00+00:00

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) 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20200522171901.204127-3-parri.andrea@gmail.com
Signed-off-by: Wei Liu

Drivers: hv: vmbus: Resolve race between init_vp_index() and CPU hotplug

2020-05-23T09:06:42+00:00

vmbus_process_offer() does two things (among others):

 1) first, it sets the channel's target CPU with cpu_hotplug_lock;
 2) it then adds the channel to the channel list(s) with channel_mutex.

Since cpu_hotplug_lock is released before (2), the channel's target CPU
(as designated in (1)) can be deemed "free" by hv_synic_cleanup() and go
offline before the channel is added to the list.

Fix the race condition by "extending" the cpu_hotplug_lock critical
section to include (2) (and (1)), nesting the channel_mutex critical
section within the cpu_hotplug_lock critical section as done elsewhere
(hv_synic_cleanup(), target_cpu_store()) in the hyperv drivers code.

Move even further by extending the channel_mutex critical section to
include (1) (and (2)): this change allows to remove (the now redundant)
bind_channel_to_cpu_lock, and generally simplifies the handling of the
target CPUs (that are now always modified with channel_mutex held).

Fixes: d570aec0f2154e ("Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug")
Signed-off-by: Andrea Parri (Microsoft) 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20200522171901.204127-2-parri.andrea@gmail.com
Signed-off-by: Wei Liu

Driver: hv: vmbus: drop a no long applicable comment

2020-05-20T09:13:59+00:00

None of the things mentioned in the comment is initialized in hv_init.
They've been moved elsewhere.

Signed-off-by: Wei Liu 
Link: https://lore.kernel.org/r/20200506160806.118965-1-wei.liu@kernel.org
Reviewed-by:  Michael Kelley

hyper-v: Replace open-coded variant of %*phN specifier

2020-05-20T09:13:59+00:00

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 
Link: https://lore.kernel.org/r/20200423134505.78221-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Wei Liu

hyper-v: Supply GUID pointer to printf() like functions

2020-05-20T09:13:59+00:00

Drop dereference when printing the GUID with printf() like functions.
This allows to hide the uuid_t internals.

Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20200423134505.78221-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Wei Liu

hyper-v: Use UUID API for exporting the GUID (part 2)

2020-05-20T09:13:58+00:00

This is a follow up to the commit 1d3c9c075462
  ("hyper-v: Use UUID API for exporting the GUID")
which starts the conversion.

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 
Link: https://lore.kernel.org/r/20200423134505.78221-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Wei Liu