Commit Graph

221 Commits

Author SHA1 Message Date
Uwe Kleine-König fc7a6209d5 bus: Make remove callback return void
The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-21 11:53:42 +02:00
Andy Shevchenko f39650de68 kernel.h: split out panic and oops helpers
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out panic and
oops helpers.

There are several purposes of doing this:
- dropping dependency in bug.h
- dropping a loop by moving out panic_notifier.h
- unload kernel.h from something which has its own domain

At the same time convert users tree-wide to use new headers, although for
the time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.

[akpm@linux-foundation.org: thread_info.h needs limits.h]
[andriy.shevchenko@linux.intel.com: ia64 fix]
  Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com

Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:04 -07:00
Linus Torvalds 7f3d08b255 printk changes for 5.13
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEESH4wyp42V4tXvYsjUqAMR0iAlPIFAmCIBMIACgkQUqAMR0iA
 lPIt9w//bbHUN/JsNtLCs/849oExdUn/thVajrD5yELttYZXhdzbXncNdkGX9tlU
 4JmExmUoqKYdN6JhSnrcYvckHj7XXZM7pVh9IdzqRh10MEXIQ+7IUHjQc8034Zs/
 W4/oZmfMtBjszap+cJ9hvdp9qaJkPz/fRLGlrbjc1K4hhxDa1gGmeD35SKswGltm
 q6RzX3uRl5JbBrYsLoqb28MGYRHhjf2+Pvndoj+5Nn9FtwPSot6jAkyqY5Y6iJlS
 W2EsFqOt+Kv7/I93FyQlnXC6Nx7vntmow7knmmGPXDf2BqLb0J8Bxl3fwuzpQoao
 nZzL/p9GQ4ZXF6y8gRV8+RzPIcftBdayOswEDGH0LzlTkbAe/9Sq9Lo7a4Z8jxHW
 ro0P+PSRK5Ksm7jvpVmSTg+Nt+XqDA5zA1lAorX1UjsyeDDNF9ndQ4C+ZNhCKo54
 y+RDgtAArJMIvsHLQ53ReoOct5NnGVNb8G/r3bIAu+Dn6K3nesr6fP1XG8iduseL
 yFlLB7w214BQMr2B/C+8lQvj54wWE4lea2+LNvObxC5b8puYj0fEniUxTYP6bcB5
 QT+LfTToufYz4US7ggJy6hoEfohifGWVvDHbn9tXmyXotSTHH7pHdYypqY+UO+kl
 7BkwzNFCm4qCIKsg8nyJxT2hDOlpcCrQx1dBIjveMqJ0c5+ahXU=
 =ovSn
 -----END PGP SIGNATURE-----

Merge tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Stop synchronizing kernel log buffer readers by logbuf_lock. As a
   result, the access to the buffer is fully lockless now.

   Note that printk() itself still uses locks because it tries to flush
   the messages to the console immediately. Also the per-CPU temporary
   buffers are still there because they prevent infinite recursion and
   serialize backtraces from NMI. All this is going to change in the
   future.

 - kmsg_dump API rework and cleanup as a side effect of the logbuf_lock
   removal.

 - Make bstr_printf() aware that %pf and %pF formats could deference the
   given pointer.

 - Show also page flags by %pGp format.

 - Clarify the documentation for plain pointer printing.

 - Do not show no_hash_pointers warning multiple times.

 - Update Senozhatsky email address.

 - Some clean up.

* tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits)
  lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf()
  printk: clarify the documentation for plain pointer printing
  kernel/printk.c: Fixed mundane typos
  printk: rename vprintk_func to vprintk
  vsprintf: dump full information of page flags in pGp
  mm, slub: don't combine pr_err with INFO
  mm, slub: use pGp to print page flags
  MAINTAINERS: update Senozhatsky email address
  lib/vsprintf: do not show no_hash_pointers message multiple times
  printk: console: remove unnecessary safe buffer usage
  printk: kmsg_dump: remove _nolock() variants
  printk: remove logbuf_lock
  printk: introduce a kmsg_dump iterator
  printk: kmsg_dumper: remove @active field
  printk: add syslog_lock
  printk: use atomic64_t for devkmsg_user.seq
  printk: use seqcount_latch for clear_seq
  printk: introduce CONSOLE_LOG_MAX
  printk: consolidate kmsg_dump_get_buffer/syslog_print_all code
  printk: refactor kmsg_dump_get_buffer()
  ...
2021-04-27 18:09:44 -07:00
Andrea Parri (Microsoft) 870ced0548 Drivers: hv: vmbus: Drivers: hv: vmbus: Introduce CHANNELMSG_MODIFYCHANNEL_RESPONSE
Introduce the CHANNELMSG_MODIFYCHANNEL_RESPONSE message type, and code
to receive and process such a message.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210416143449.16185-3-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-18 13:03:11 +00:00
Michael Kelley d608715d47 Drivers: hv: vmbus: Move handling of VMbus interrupts
VMbus interrupts are most naturally modelled as per-cpu IRQs.  But
because x86/x64 doesn't have per-cpu IRQs, the core VMbus interrupt
handling machinery is done in code under arch/x86 and Linux IRQs are
not used.  Adding support for ARM64 means adding equivalent code
using per-cpu IRQs under arch/arm64.

A better model is to treat per-cpu IRQs as the normal path (which it is
for modern architectures), and the x86/x64 path as the exception.  Do this
by incorporating standard Linux per-cpu IRQ allocation into the main VMbus
driver, and bypassing it in the x86/x64 exception case. For x86/x64,
special case code is retained under arch/x86, but no VMbus interrupt
handling code is needed under arch/arm64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-7-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:33:00 +00:00
Michael Kelley b548a77427 Drivers: hv: vmbus: Move hyperv_report_panic_msg to arch neutral code
With the new Hyper-V MSR set function, hyperv_report_panic_msg() can be
architecture neutral, so move it out from under arch/x86 and merge into
hv_kmsg_dump(). This move also avoids needing a separate implementation
under arch/arm64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-5-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:32:59 +00:00
Michael Kelley f3c5e63c36 Drivers: hv: Redo Hyper-V synthetic MSR get/set functions
Current code defines a separate get and set macro for each Hyper-V
synthetic MSR used by the VMbus driver. Furthermore, the get macro
can't be converted to a standard function because the second argument
is modified in place, which is somewhat bad form.

Redo this by providing a single get and a single set function that
take a parameter specifying the MSR to be operated on. Fixup usage
of the get function. Calling locations are no more complex than before,
but the code under arch/x86 and the upcoming code under arch/arm64
is significantly simplified.

Also standardize the names of Hyper-V synthetic MSRs that are
architecture neutral. But keep the old x86-specific names as aliases
that can be removed later when all references (particularly in KVM
code) have been cleaned up in a separate patch series.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-4-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:32:59 +00:00
John Ogness f9f3f02db9 printk: introduce a kmsg_dump iterator
Rather than storing the iterator information in the registered
kmsg_dumper structure, create a separate iterator structure. The
kmsg_dump_iter structure can reside on the stack of the caller, thus
allowing lockless use of the kmsg_dump functions.

Update code that accesses the kernel logs using the kmsg_dumper
structure to use the new kmsg_dump_iter structure. For kmsg_dumpers,
this also means adding a call to kmsg_dump_rewind() to initialize
the iterator.

All this is in preparation for removal of @logbuf_lock.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org> # pstore
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
2021-03-08 11:43:27 +01:00
Wei Liu 7e279d7866 Drivers: hv: vmbus: skip VMBus initialization if Linux is root
There is no VMBus and the other infrastructures initialized in
hv_acpi_init when Linux is running as the root partition.

Signed-off-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-4-wei.liu@kernel.org
2021-02-11 08:47:06 +00:00
Dexuan Cui c068e3f484 Drivers: hv: vmbus: Add /sys/bus/vmbus/hibernation
When a Linux VM runs on Hyper-V, if the host toolstack doesn't support
hibernation for the VM (this happens on old Hyper-V hosts like Windows
Server 2016, or new Hyper-V hosts if the admin or user doesn't declare
the hibernation intent for the VM), the VM is discouraged from trying
hibernation (because the host doesn't guarantee that the VM's virtual
hardware configuration will remain exactly the same across hibernation),
i.e. the VM should not try to set up the swap partition/file for
hibernation, etc.

x86 Hyper-V uses the presence of the virtual ACPI S4 state as the
indication of the host toolstack support for a VM. Currently there is
no easy and reliable way for the userspace to detect the presence of
the state (see https://lkml.org/lkml/2020/12/11/1097).  Add
/sys/bus/vmbus/hibernation for this purpose.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210107014552.14234-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11 08:47:05 +00:00
Andrea Parri (Microsoft) fe8c1b18a2 Drivers: hv: vmbus: Copy the hv_message in vmbus_on_msg_dpc()
Since the message is in memory shared with the host, an erroneous or a
malicious Hyper-V could 'corrupt' the message while vmbus_on_msg_dpc()
or individual message handlers are executing.  To prevent it, copy the
message into private memory.

Reported-by: Juan Vazquez <juvazq@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201209070827.29335-4-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05 09:55:42 +00:00
Andrea Parri (Microsoft) 9c400d3548 Drivers: hv: vmbus: Reduce number of references to message in vmbus_on_msg_dpc()
Simplify the function by removing various references to the hv_message
'msg', introduce local variables 'msgtype' and 'payload_size'.

Suggested-by: Juan Vazquez <juvazq@microsoft.com>
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201209070827.29335-3-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05 09:55:42 +00:00
Dexuan Cui dfe94d4086 x86/hyperv: Fix kexec panic/hang issues
Currently the kexec kernel can panic or hang due to 2 causes:

1) hv_cpu_die() is not called upon kexec, so the hypervisor corrupts the
old VP Assist Pages when the kexec kernel runs. The same issue is fixed
for hibernation in commit 421f090c81 ("x86/hyperv: Suspend/resume the
VP assist page for hibernation"). Now fix it for kexec.

2) hyperv_cleanup() is called too early. In the kexec path, the other CPUs
are stopped in hv_machine_shutdown() -> native_machine_shutdown(), so
between hv_kexec_handler() and native_machine_shutdown(), the other CPUs
can still try to access the hypercall page and cause panic. The workaround
"hv_hypercall_pg = NULL;" in hyperv_cleanup() is unreliabe. Move
hyperv_cleanup() to a better place.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201222065541.24312-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-01-05 17:52:04 +00:00
Matheus Castello b0c03eff79 drivers: hv: vmbus: Fix checkpatch SPLIT_STRING
Checkpatch emits WARNING: quoted string split across lines.
To keep the code clean and with the 80 column length indentation the
check and registration code for kmsg_dump_register has been transferred
to a new function hv_kmsg_dump_register.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201125032926.17002-1-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-02 11:54:19 +00:00
Matheus Castello 14c685d9eb drivers: hv: vmbus: Fix call msleep using < 20ms
Fixed checkpatch warning: MSLEEP: msleep < 20ms can sleep for up to
20ms; see Documentation/timers/timers-howto.rst

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201115195734.8338-7-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17 10:56:48 +00:00
Matheus Castello e4f2212e53 drivers: hv: vmbus: Fix checkpatch LINE_SPACING
Fixed checkpatch warning: Missing a blank line after declarations
checkpatch(LINE_SPACING)

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201115195734.8338-4-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17 10:56:44 +00:00
Matheus Castello f0434de41a drivers: hv: vmbus: Replace symbolic permissions by octal permissions
This fixed the below checkpatch issue:
WARNING: Symbolic permissions 'S_IRUGO' are not preferred.
Consider using octal permissions '0444'.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201115195734.8338-3-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17 10:56:39 +00:00
Matheus Castello b18e358972 drivers: hv: Fix hyperv_record_panic_msg path on comment
Fix the kernel parameter path in the comment, in the documentation the
parameter is correct but if someone who is studying the code and see
this first can get confused and try to access the wrong path/parameter

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201115195734.8338-2-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17 10:56:24 +00:00
Linus Torvalds 2d0f6b0aab hyperv-next for 5.10, part 2
-----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCAAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAl+IfF4THHdlaS5saXVA
 a2VybmVsLm9yZwAKCRB2FHBfkEGgXgdnCACUnI5sKbEN/uEvWz4JGJzTSwr20VHt
 FkzpbeS4A9vHgl4hXVvGc4eMrwF/RtWY6RrLlJauZSQA1mjU0paAjf2noBFYX41m
 zHX6f8awJrPd0cFChrOKcAlPnQy5OHYTJb7id2EakGGIrd0rmR/TkVAdEku23SDD
 N7wheh5dVLnkSPwfiERz8Iq0CswMrSjgTljKnwU7XqUqwcNt+7rLRDFAH/M3NG/x
 omBrWO8k6t2r0h4otqCQZIyCSLwPO+Wdb9BSaA147eOFHHbhqZlHNJYjIkMROZau
 CJn7S0nZorsAUvka3l7W8nyMQmK4PXOh36bwkXzpkV4b+lgit0euXIzA
 =H2vc
 -----END PGP SIGNATURE-----

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

Pull another Hyper-V update from Wei Liu:
 "One patch from Michael to get VMbus interrupt from ACPI DSDT"

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDT
2020-10-15 15:48:06 -07:00
Michael Kelley 626b901f60 Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDT
On ARM64, Hyper-V now specifies the interrupt to be used by VMbus
in the ACPI DSDT.  This information is not used on x86 because the
interrupt vector must be hardcoded.  But update the generic
VMbus driver to do the parsing and pass the information to the
architecture specific code that sets up the Linux IRQ.  Update
consumers of the interrupt to get it from an architecture specific
function.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1597434304-40631-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-14 19:14:51 +00:00
Linus Torvalds 4907a43da8 hyperv-next for 5.10
-----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCAAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAl+FqrsTHHdlaS5saXVA
 a2VybmVsLm9yZwAKCRB2FHBfkEGgXnN8B/4sRg7j9OTzVBlDiXF2vj6vbuplTIH6
 JR6S5f4PNjUg4gV6ghzSnsx1zqNhPSOr78zDqYto8vv+wqqj3thmld8+gAnSbKtt
 yoAa7mhbbN1ryJiwPlZzvX4ApzGZPC7byqEi3+zPIcag6TEl8eyYJOmvY3x1zv8x
 CsAb57oCC4erD0n4xlTyfuc8TLpO+EiU53PXbR9AovKQHe4m2/8LWyEbmrm5cRUR
 gx8RxoLkkrqK0unzcmanbm47QodiaOTUpycs3IvaBeWZQsqSgFZdI1RAdTZNg+U+
 GT8eMRXAwpgDpilPm/0n1O0PKGAsVh9Lbw8Btb/ggqnjTUlA4Z3Df23E
 =Wy5n
 -----END PGP SIGNATURE-----

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

Pull Hyper-V updates from Wei Liu:

 - a series from Boqun Feng to support page size larger than 4K

 - a few miscellaneous clean-ups

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv: clocksource: Add notrace attribute to read_hv_sched_clock_*() functions
  x86/hyperv: Remove aliases with X64 in their name
  PCI: hv: Document missing hv_pci_protocol_negotiation() parameter
  scsi: storvsc: Support PAGE_SIZE larger than 4K
  Driver: hv: util: Use VMBUS_RING_SIZE() for ringbuffer sizes
  HID: hyperv: Use VMBUS_RING_SIZE() for ringbuffer sizes
  Input: hyperv-keyboard: Use VMBUS_RING_SIZE() for ringbuffer sizes
  hv_netvsc: Use HV_HYP_PAGE_SIZE for Hyper-V communication
  hv: hyperv.h: Introduce some hvpfn helper functions
  Drivers: hv: vmbus: Move virt_to_hvpfn() to hyperv header
  Drivers: hv: Use HV_HYP_PAGE in hv_synic_enable_regs()
  Drivers: hv: vmbus: Introduce types of GPADL
  Drivers: hv: vmbus: Move __vmbus_open()
  Drivers: hv: vmbus: Always use HV_HYP_PAGE_SIZE for gpadl
  drivers: hv: remove cast from hyperv_die_event
2020-10-14 10:32:10 -07:00
Linus Torvalds 00acc50506 hyperv-fixes for 5.9-rc6
-----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCAAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAl9grKITHHdlaS5saXVA
 a2VybmVsLm9yZwAKCRB2FHBfkEGgXu7gB/4+uML5b8rd06pJ3+NC53Mh5ooePvL5
 CdZsLJP+reK8WeG4s3sXSs4kgzwZQcDFEC6k4STvM7B6fOEhvpi2Y7kuhayy75X4
 6mZ7qoAnVvy83RZxAxDdgr0PuPRpL8m3cq1C+2hgOe2JaShhLVOC35IZqcBFKxrL
 pp6blm7BFC2ST93JKQ3rLT0dhuT2CyLVkXheXbUK+36UnR1OxmgZLVp3PuPXVjdm
 1zEkSjWCPAV/I78U7GOoLFx+sUgJwuG+owRQ1o8ZldMO/yj2gfCzfsSDivnjgB10
 Q8ihUYZS2jBxg3L5y1pSYwgkOE/Q0iBRG91PueSq0c06mSuKp8COI0xG
 =VCYI
 -----END PGP SIGNATURE-----

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

Pull hyperv fixes from Wei Liu:
 "Two patches from Michael and Dexuan to fix vmbus hanging issues"

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload
  Drivers: hv: vmbus: hibernation: do not hang forever in vmbus_bus_resume()
2020-09-15 16:20:43 -07:00
Dexuan Cui 19873eec7e Drivers: hv: vmbus: hibernation: do not hang forever in vmbus_bus_resume()
After we Stop and later Start a VM that uses Accelerated Networking (NIC
SR-IOV), currently the VF vmbus device's Instance GUID can change, so after
vmbus_bus_resume() -> vmbus_request_offers(), vmbus_onoffer() can not find
the original vmbus channel of the VF, and hence we can't complete()
vmbus_connection.ready_for_resume_event in check_ready_for_resume_event(),
and the VM hangs in vmbus_bus_resume() forever.

Fix the issue by adding a timeout, so the resuming can still succeed, and
the saved state is not lost, and according to my test, the user can disable
Accelerated Networking and then will be able to SSH into the VM for
further recovery. Also prevent the VM in question from suspending again.

The host will be fixed so in future the Instance GUID will stay the same
across hibernation.

Fixes: d8bd2d442b ("Drivers: hv: vmbus: Resume after fixing up old primary channels")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200905025555.45614-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-09-09 11:37:19 +00:00
Olaf Hering 49971e6bad drivers: hv: remove cast from hyperv_die_event
No need to cast a void pointer.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Link: https://lore.kernel.org/r/20200819090510.28995-1-olaf@aepfle.de
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-19 11:28:54 +00:00
Linus Torvalds cd94257d7a hyperv-fixes for 5.9-rc
-----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCAAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAl82Y6cTHHdlaS5saXVA
 a2VybmVsLm9yZwAKCRB2FHBfkEGgXlcxCACP21ZI7RZvQBcFtTj5MWa0uwoofFqF
 JDG0MvZ5zFKIJFX0pwlZIUrZY5aVJ1NwCDgCI0EXbZEazTaNCD2knFPqrLe3WUFY
 mSDF9df7oW9UvTe9L4g3rYAdqsrkbgqhBypm9Vpbcazg/Ki6QVCgAhIo1lbq62+m
 J2/0kLO1lVY6opr6vyobaWbm/Y4b0fbrx7N6KwUDhZUYGLGKaOc+WvsZinNl4XW6
 VPiEVQUApvVxwG43rLNXjPe83DtassJ2GevSS1whXnZ+K0bViWhyYicbqEl9iV1i
 nlNIkEMX5A1rdwV1zEAGyY/zWi+fi2+IdKGGEbtyUsely1vHtZuaDCiQ
 =DE2Y
 -----END PGP SIGNATURE-----

Merge tag 'hyperv-fixes-signed' of 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
2020-08-14 13:31:25 -07:00
Michael Kelley 608a973bd5 Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops
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: 510f7aef65 ("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>
2020-08-07 13:49:37 +00:00
Linus Torvalds 9ab9bc5115 hyperv-next for 5.9
-----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCAAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAl8pNiATHHdlaS5saXVA
 a2VybmVsLm9yZwAKCRB2FHBfkEGgXuoQCACiOoe/FKHAYZDR6fZzwZSNVJueYu1o
 Pnwj00EjeDWM/M4kmF7u0PVv0v8PlP7fi2b0nvGmOeqwFS4n7Xr6mdDO1ZxRDzpd
 QW9ZoLc8OUpg9UU9WlEqj4IqRalwKsZi0eX3P2jGoeQCEXHcRu5AdjkDYk0s/LNq
 GBAtpHEPADu/uhEVMyya1KrY9DXsgybPGbCml1pZpeNLPbph3m2ld1M0aHJXqap9
 1qBykxPgCSkSd270XfUrHCkYariC/g7khnBP0zAkzsgt90uraqKoUNhihN8GFacF
 eZ6oh45LWWUjCNIAzKBiLlrpt7nuOGQszeIZywAuyvkbo0pdlZ+hu1qB
 =FMf5
 -----END PGP SIGNATURE-----

Merge tag 'hyperv-next-signed' of 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
2020-08-06 09:26:10 -07:00
Joseph Salisbury 77b48bea2f Drivers: hv: Change flag to write log level in panic msg to false
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>
2020-06-29 10:30:35 +00:00
Andrea Parri (Microsoft) 3eb0ac869c Drivers: hv: vmbus: Use channel_mutex in channel_vp_mapping_show()
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>
2020-06-19 15:38:26 +00:00
Andrea Parri (Microsoft) 12d0dd8e72 Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (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>
2020-06-19 15:38:23 +00:00
Andrea Parri (Microsoft) 0a96820929 Drivers: hv: vmbus: Replace cpumask_test_cpu(, cpu_online_mask) with 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>
2020-06-19 15:38:19 +00:00
Andrea Parri (Microsoft) 458d090fba Drivers: hv: vmbus: Remove the numa_node field from the vmbus_channel struct
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>
2020-06-19 15:38:15 +00:00
Andrea Parri (Microsoft) 5bf7468211 Drivers: hv: vmbus: Remove the target_vp field from the vmbus_channel struct
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>
2020-06-19 15:38:10 +00:00
Linus Torvalds 6b2591c212 hyperv-next for 5.8
-----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCAAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAl7WhbkTHHdlaS5saXVA
 a2VybmVsLm9yZwAKCRB2FHBfkEGgXlUnB/0R8dBVSeRfNmyJaadBWKFc/LffwKLD
 CQ8PVv22ffkCaEYV2tpnhS6NmkERLNdson4Uo02tVUsjOJ4CrWHTn7aKqYWZyA+O
 qv/PiD9TBXJVYMVP2kkyaJlK5KoqeAWBr2kM16tT0cxQmlhE7g0Xo2wU9vhRbU+4
 i4F0jffe4lWps65TK392CsPr6UEv1HSel191Py5zLzYqChT+L8WfahmBt3chhsV5
 TIUJYQvBwxecFRla7yo+4sUn37ZfcTqD1hCWSr0zs4psW0ge7d80kuaNZS+EqxND
 fGm3Bp1BlUuDKsJ/D+AaHLCR47PUZ9t9iMDjZS/ovYglLFwi+h3tAV+W
 =LwVR
 -----END PGP SIGNATURE-----

Merge tag 'hyperv-next-signed' of 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
  ...
2020-06-03 15:00:05 -07:00
Andrea Parri (Microsoft) afaa33da08 Drivers: hv: vmbus: Resolve more races involving init_vp_index()
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: 7527810573 ("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>
2020-05-23 09:07:00 +00:00
Wei Liu 723c425f29 Driver: hv: vmbus: drop a no long applicable comment
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>
2020-05-20 09:13:59 +00:00
Andy Shevchenko 0027e3fd6d hyper-v: Replace open-coded variant of %*phN specifier
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>
2020-05-20 09:13:59 +00:00
Andy Shevchenko 458c4475be hyper-v: Supply GUID pointer to printf() like functions
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>
2020-05-20 09:13:59 +00:00
Andrea Parri (Microsoft) 7769e18c20 scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assigned
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>
2020-05-20 09:13:19 +00:00
Andrea Parri (Microsoft) 7527810573 Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type
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>
2020-04-23 13:17:12 +00:00
Andrea Parri (Microsoft) 9403b66e61 Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. 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>
2020-04-23 13:17:12 +00:00
Andrea Parri (Microsoft) 8b6a877c06 Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of 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>
2020-04-23 13:17:11 +00:00
Andrea Parri (Microsoft) b9fa1b8797 Drivers: hv: vmbus: Don't bind the offer&rescind works to a specific CPU
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>
2020-04-23 13:17:11 +00:00
Andrea Parri (Microsoft) 8a857c5542 Drivers: hv: vmbus: Always handle the VMBus messages on CPU0
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>
2020-04-23 13:17:11 +00:00
Vitaly Kuznetsov 52c7803f9b Drivers: hv: check VMBus messages lengths
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>
2020-04-23 13:17:11 +00:00
Vitaly Kuznetsov b0a284dc65 Drivers: hv: make sure that 'struct vmbus_channel_message_header' compiles 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>
2020-04-23 13:17:11 +00:00
Vitaly Kuznetsov 5cc415001b Drivers: hv: avoid passing opaque pointer to vmbus_onmessage()
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>
2020-04-23 13:17:11 +00:00
Vitaly Kuznetsov a276463b7a Drivers: hv: allocate the exact needed memory for messages
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>
2020-04-23 13:17:10 +00:00
Vitaly Kuznetsov ac0f7d4258 Drivers: hv: copy from message page only what's needed
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>
2020-04-23 13:17:10 +00:00
Dexuan Cui 1a06d017fb Drivers: hv: vmbus: Fix Suspend-to-Idle for Generation-2 VM
Before the hibernation patchset (e.g. f53335e328), 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: f53335e328 ("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>
2020-04-14 21:16:35 +01:00