init: Fix initcall0 name as it is "pure" not "early"
The early_initcall() functions get assigned to __initcall_start[]. These are
called by do_pre_smp_initcalls(). The initcall_levels[] array starts with
__initcall0_start[], and initcall_levels[] are to match the
initcall_level_names[] array. The first name in that array is "early", but
that is not correct. As pure_initcall() functions get assigned to
__initcall0_start[] array.
Change the first name in initcall_level_names[] array to "pure".
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Dan Carpenter [Fri, 23 Mar 2018 11:37:36 +0000 (14:37 +0300)]
tracing: Fix a potential NULL dereference
We forgot to set the error code on this path so we return ERR_PTR(0)
which is NULL. It results in a NULL dereference in the caller.
Link: http://lkml.kernel.org/r/20180323113735.GC28518@mwanda Fixes: 100719dcef44 ("tracing: Add simple expression support to hist triggers") Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing: Rewrite filter logic to be simpler and faster
Al Viro reviewed the filter logic of ftrace trace events and found it to be
very troubling. It creates a binary tree based on the logic operators and
walks it during tracing. He sent myself and Tom Zanussi a long explanation
(and formal proof) of how to do the string parsing better and end up with a
program array that can be simply iterated to come up with the correct
results.
I took his ideas and his pseudo code and rewrote the filter logic based on
them. In doing so, I was able to remove a lot of code, and have a much more
condensed filter logic in the process. I wrote a very long comment
describing the methadology that Al proposed in my own words. For more info
on how this works, read the comment above predicate_parse().
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing: Clean up and document pred_funcs_##type creation and use
The pred_funcs_##type arrays consist of five functions that are assigned
based on the ops. The array must be in the same order of the ops each
function represents. The PRED_FUNC_START macro denotes the op enum that
starts the op that maps to the pred_funcs_##type arrays. This is all very
subtle and prone to bugs if the code is changed.
Add comments describing how PRED_FUNC_START and pred_funcs_##type array is
used, and also a PRED_FUNC_MAX that is the maximum number of functions in
the arrays.
Clean up select_comparison_fn() that assigns the predicates to the
pred_funcs_##type array function as well as add protection in case an op is
passed in that does not map correctly to the array.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing: Combine enum and arrays into single macro in filter code
Instead of having a separate enum that is the index into another array, like
a string array, make a single macro that combines them into a single list,
and then the two can not get out of sync. This makes it easier to add and
remove items.
tracing: Embed replace_filter_string() helper function
The replace_filter_string() frees the current string and then copies a given
string. But in the two locations that it was used, the allocation happened
right after the filter was allocated (nothing to replace). There's no need
for this to be a helper function. Embedding the allocation in the two places
where it was called will make changing the code in the future easier.
Also make the variable consistent (always use "filter_string" as the name,
as it was used in one instance as "filter_str")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
replace_system_preds() creates a filter list to free even when it doesn't
really need to have it. Only save filters that require synchronize_sched()
in the filter list to free. This will allow the code to be updated a bit
easier in the future.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing: Use the ring-buffer nesting to allow synthetic events to be traced
Synthetic events can be done within the recording of other events. Notify
the ring buffer via ring_buffer_nest_start() and ring_buffer_nest_end() that
this is intended and not to block it due to its recursion protection.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
ring-buffer: Add nesting for adding events within events
The ring-buffer code has recusion protection in case tracing ends up tracing
itself, the ring-buffer will detect that it was called at the same context
(normal, softirq, interrupt or NMI), and not continue to record the event.
With the histogram synthetic events, they are called while tracing another
event at the same context. The recusion protection triggers because it
detects tracing at the same context and stops it.
Add ring_buffer_nest_start() and ring_buffer_nest_end() that will notify the
ring buffer that a trace is about to happen within another trace and that it
is intended, and not to trigger the recursion blocking.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Tom Zanussi [Tue, 16 Jan 2018 02:52:05 +0000 (20:52 -0600)]
tracing: Add 'last error' error facility for hist triggers
With the addition of variables and actions, it's become necessary to
provide more detailed error information to users about syntax errors.
Add a 'last error' facility accessible via the erroring event's 'hist'
file. Reading the hist file after an error will display more detailed
information about what went wrong, if information is available. This
extended error information will be available until the next hist
trigger command for that event.
Tom Zanussi [Tue, 16 Jan 2018 02:52:04 +0000 (20:52 -0600)]
tracing: Add hist trigger support for variable reference aliases
Add support for alias=$somevar where alias can be used as
onmatch.xxx($alias).
Aliases are a way of creating a new name for an existing variable, for
flexibly in making naming more clear in certain cases. For example in
the below the user perhaps feels that using $new_lat in the synthetic
event invocation is opaque or doesn't fit well stylistically with
previous triggers, so creates an alias of $new_lat named $latency and
uses that in the call instead:
Tom Zanussi [Tue, 16 Jan 2018 02:52:02 +0000 (20:52 -0600)]
tracing: Allow whitespace to surround hist trigger filter
The existing code only allows for one space before and after the 'if'
specifying the filter for a hist trigger. Add code to make that more
permissive as far as whitespace goes. Specifically, we want to allow
spaces in the trigger itself now that we have additional syntax
(onmatch/onmax) where spaces are more natural e.g. spaces after commas
in param lists.
Tom Zanussi [Tue, 16 Jan 2018 02:52:01 +0000 (20:52 -0600)]
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
Tom Zanussi [Tue, 16 Jan 2018 02:52:00 +0000 (20:52 -0600)]
tracing: Add 'onmatch' hist trigger action support
Add an 'onmatch(matching.event).<synthetic_event_name>(param list)'
hist trigger action which is invoked with the set of variables or
event fields named in the 'param list'. The result is the generation
of a synthetic event that consists of the values contained in those
variables and/or fields at the time the invoking event was hit.
As an example the below defines a simple synthetic event using a
variable defined on the sched_wakeup_new event, and shows the event
definition with unresolved fields, since the sched_wakeup_new event
with the testpid variable hasn't been defined yet:
# echo 'wakeup_new_test pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_new_test pid_t pid; int prio
The following hist trigger both defines a testpid variable and
specifies an onmatch() trace action that uses that variable along with
a non-variable field to generate a wakeup_new_test synthetic event
whenever a sched_wakeup_new event occurs, which because of the 'if
comm == "cyclictest"' filter only happens when the executable is
cyclictest:
Creating and displaying a histogram based on those events is now just
a matter of using the fields and new synthetic event in the
tracing/events/synthetic directory, as usual:
Tom Zanussi [Tue, 16 Jan 2018 02:51:59 +0000 (20:51 -0600)]
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
Tom Zanussi [Tue, 16 Jan 2018 02:51:58 +0000 (20:51 -0600)]
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Tom Zanussi [Tue, 16 Jan 2018 02:51:57 +0000 (20:51 -0600)]
tracing: Add hist trigger action hook
Add a hook for executing extra actions whenever a histogram entry is
added or updated.
The default 'action' when a hist entry is added to a histogram is to
update the set of values associated with it. Some applications may
want to perform additional actions at that point, such as generate
another event, or compare and save a maximum.
Add a simple framework for doing that; specific actions will be
implemented on top of it in later patches.
Tom Zanussi [Tue, 16 Jan 2018 02:51:56 +0000 (20:51 -0600)]
tracing: Add variable reference handling to hist triggers
Add the necessary infrastructure to allow the variables defined on one
event to be referenced in another. This allows variables set by a
previous event to be referenced and used in expressions combining the
variable values saved by that previous event and the event fields of
the current event. For example, here's how a latency can be
calculated and saved into yet another variable named 'wakeup_lat':
In the first event, the event's timetamp is saved into the variable
ts0. In the next line, ts0 is subtracted from the second event's
timestamp to produce the latency.
Further users of variable references will be described in subsequent
patches, such as for instance how the 'wakeup_lat' variable above can
be displayed in a latency histogram.
Tom Zanussi [Tue, 16 Jan 2018 02:51:53 +0000 (20:51 -0600)]
tracing: Generalize per-element hist trigger data
Up until now, hist triggers only needed per-element support for saving
'comm' data, which was saved directly as a private data pointer.
In anticipation of the need to save other data besides 'comm', add a
new hist_elt_data struct for the purpose, and switch the current
'comm'-related code over to that.
Tom Zanussi [Tue, 16 Jan 2018 02:51:52 +0000 (20:51 -0600)]
tracing: Add simple expression support to hist triggers
Add support for simple addition, subtraction, and unary expressions
(-(expr) and expr, where expr = b-a, a+b, a+b+c) to hist triggers, in
order to support a minimal set of useful inter-event calculations.
These operations are needed for calculating latencies between events
(timestamp1-timestamp0) and for combined latencies (latencies over 3
or more events).
In the process, factor out some common code from key and value
parsing.
Tom Zanussi [Tue, 16 Jan 2018 02:51:49 +0000 (20:51 -0600)]
tracing: Add variable support to hist triggers
Add support for saving the value of a current event's event field by
assigning it to a variable that can be read by a subsequent event.
The basic syntax for saving a variable is to simply prefix a unique
variable name not corresponding to any keyword along with an '=' sign
to any event field.
Both keys and values can be saved and retrieved in this way:
Tom Zanussi [Tue, 16 Jan 2018 02:51:48 +0000 (20:51 -0600)]
tracing: Add usecs modifier for hist trigger timestamps
Appending .usecs onto a common_timestamp field will cause the
timestamp value to be in microseconds instead of the default
nanoseconds. A typical latency histogram using usecs would look like
this:
Tom Zanussi [Tue, 16 Jan 2018 02:51:46 +0000 (20:51 -0600)]
tracing: Add per-element variable support to tracing_map
In order to allow information to be passed between trace events, add
support for per-element variables to tracing_map. This provides a
means for histograms to associate a value or values with an entry when
it's saved or updated, and retrieved by a subsequent event occurrences.
Variables can be set using tracing_map_set_var() and read using
tracing_map_read_var(). tracing_map_var_set() returns true or false
depending on whether or not the variable has been set or not, which is
important for event-matching applications.
tracing_map_read_var_once() reads the variable and resets it to the
'unset' state, implementing read-once variables, which are also
important for event-matching uses.
Tom Zanussi [Tue, 16 Jan 2018 02:51:45 +0000 (20:51 -0600)]
tracing: Add hist trigger timestamp support
Add support for a timestamp event field. This is actually a 'pseudo-'
event field in that it behaves like it's part of the event record, but
is really part of the corresponding ring buffer event.
To make use of the timestamp field, users can specify
"common_timestamp" as a field name for any histogram. Note that this
doesn't make much sense on its own either as either a key or value,
but needs to be supported even so, since follow-on patches will add
support for making use of this field in time deltas. The
common_timestamp 'field' is not a bona fide event field - so you won't
find it in the event description - but rather it's a synthetic field
that can be used like a real field.
Note that the use of this field requires the ring buffer be put into
'absolute timestamp' mode, which saves the complete timestamp for each
event rather than an offset. This mode will be enabled if and only if
a histogram makes use of the "common_timestamp" field.
Tom Zanussi [Tue, 16 Jan 2018 02:51:41 +0000 (20:51 -0600)]
tracing: Add timestamp_mode trace file
Add a new option flag indicating whether or not the ring buffer is in
'absolute timestamp' mode.
Currently this is only set/unset by hist triggers that make use of a
common_timestamp. As such, there's no reason to make this writeable
for users - its purpose is only to allow users to determine
unequivocally whether or not the ring buffer is in that mode (although
absolute timestamps can coexist with the normal delta timestamps, when
the ring buffer is in absolute mode, timestamps written while absolute
mode is in effect take up more space in the buffer, and are not as
efficient).
Tom Zanussi [Tue, 16 Jan 2018 02:51:40 +0000 (20:51 -0600)]
ring-buffer: Redefine the unimplemented RINGBUF_TYPE_TIME_STAMP
RINGBUF_TYPE_TIME_STAMP is defined but not used, and from what I can
gather was reserved for something like an absolute timestamp feature
for the ring buffer, if not a complete replacement of the current
time_delta scheme.
This code redefines RINGBUF_TYPE_TIME_STAMP to implement absolute time
stamps. Another way to look at it is that it essentially forces
extended time_deltas for all events.
The motivation for doing this is to enable time_deltas that aren't
dependent on previous events in the ring buffer, making it feasible to
use the ring_buffer_event timetamps in a more random-access way, for
purposes other than serial event printing.
To set/reset this mode, use tracing_set_timestamp_abs() from the
previous interface patch.
Tom Zanussi [Tue, 16 Jan 2018 02:51:39 +0000 (20:51 -0600)]
ring-buffer: Add interface for setting absolute time stamps
Define a new function, tracing_set_time_stamp_abs(), which can be used
to enable or disable the use of absolute timestamps rather than time
deltas for a trace array.
Only the interface is added here; a subsequent patch will add the
underlying implementation.
Vedang Patel [Tue, 16 Jan 2018 02:51:38 +0000 (20:51 -0600)]
tracing: Remove code which merges duplicates
We now have the logic to detect and remove duplicates in the
tracing_map hash table. The code which merges duplicates in the
histogram is redundant now. So, modify this code just to detect
duplicates. The duplication detection code is still kept to ensure
that any rare race condition which might cause duplicates does not go
unnoticed.
Vedang Patel [Tue, 16 Jan 2018 02:51:37 +0000 (20:51 -0600)]
tracing: Add support to detect and avoid duplicates
A duplicate in the tracing_map hash table is when 2 different entries
have the same key and, as a result, the key_hash. This is possible due
to a race condition in the algorithm. This race condition is inherent to
the algorithm and not a bug. This was fine because, until now, we were
only interested in the sum of all the values related to a particular
key (the duplicates are dealt with in tracing_map_sort_entries()). But,
with the inclusion of variables[1], we are interested in individual
values. So, it will not be clear what value to choose when
there are duplicates. So, the duplicates need to be removed.
The duplicates can occur in the code in the following scenarios:
- A thread is in the process of adding a new element. It has
successfully executed cmpxchg() and inserted the key. But, it is still
not done acquiring the trace_map_elt struct, populating it and storing
the pointer to the struct in the value field of tracing_map hash table.
If another thread comes in at this time and wants to add an element with
the same key, it will not see the current element and add a new one.
- There are multiple threads trying to execute cmpxchg at the same time,
one of the threads will succeed and the others will fail. The ones which
fail will go ahead increment 'idx' and add a new element there creating
a duplicate.
This patch detects and avoids the first condition by asking the thread
which detects the duplicate to loop one more time. There is also a
possibility of infinite loop if the thread which is trying to insert
goes to sleep indefinitely and the one which is trying to insert a new
element detects a duplicate. Which is why, the thread loops for
map_size iterations before returning NULL.
The second scenario is avoided by preventing the threads which failed
cmpxchg() from incrementing idx. This way, they will loop
around and check if the thread which succeeded in executing cmpxchg()
had the same key.
Linus Torvalds [Sun, 4 Mar 2018 20:12:48 +0000 (12:12 -0800)]
Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A small set of fixes for x86:
- Add missing instruction suffixes to assembly code so it can be
compiled by newer GAS versions without warnings.
- Switch refcount WARN exceptions to UD2 as we did in general
- Make the reboot on Intel Edison platforms work
- A small documentation update so text and sample command match"
* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Documentation, x86, resctrl: Make text and sample command match
x86/platform/intel-mid: Handle Intel Edison reboot correctly
x86/asm: Add instruction suffixes to bitops
x86/entry/64: Add instruction suffix
x86/refcounts: Switch to UD2 for exceptions
Linus Torvalds [Sun, 4 Mar 2018 19:40:16 +0000 (11:40 -0800)]
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/pti fixes from Thomas Gleixner:
"Three fixes related to melted spectrum:
- Sync the cpu_entry_area page table to initial_page_table on 32 bit.
Otherwise suspend/resume fails because resume uses
initial_page_table and triggers a triple fault when accessing the
cpu entry area.
- Zero the SPEC_CTL MRS on XEN before suspend to address a
shortcoming in the hypervisor.
- Fix another switch table detection issue in objtool"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu_entry_area: Sync cpu_entry_area to initial_page_table
objtool: Fix another switch table detection issue
x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
Linus Torvalds [Sun, 4 Mar 2018 19:34:49 +0000 (11:34 -0800)]
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"A small set of fixes from the timer departement:
- Add a missing timer wheel clock forward when migrating timers off a
unplugged CPU to prevent operating on a stale clock base and
missing timer deadlines.
- Use the proper shift count to extract data from a register value to
prevent evaluating unrelated bits
- Make the error return check in the FSL timer driver work correctly.
Checking an unsigned variable for less than zero does not really
work well.
- Clarify the confusing comments in the ARC timer code"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers: Forward timer base before migrating timers
clocksource/drivers/arc_timer: Update some comments
clocksource/drivers/mips-gic-timer: Use correct shift count to extract data
clocksource/drivers/fsl_ftm_timer: Fix error return checking
Linus Torvalds [Sun, 4 Mar 2018 19:04:27 +0000 (11:04 -0800)]
Merge tag 'for-4.16-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- when NR_CPUS is large, a SRCU structure can significantly inflate
size of the main filesystem structure that would not be possible to
allocate by kmalloc, so the kvalloc fallback is used
- improved error handling
- fix endiannes when printing some filesystem attributes via sysfs,
this is could happen when a filesystem is moved between different
endianity hosts
- send fixes: the NO_HOLE mode should not send a write operation for a
file hole
- fix log replay for for special files followed by file hardlinks
- fix log replay failure after unlink and link combination
- fix max chunk size calculation for DUP allocation
* tag 'for-4.16-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Btrfs: fix log replay failure after unlink and link combination
Btrfs: fix log replay failure after linking special file and fsync
Btrfs: send, fix issuing write op when processing hole in no data mode
btrfs: use proper endianness accessors for super_copy
btrfs: alloc_chunk: fix DUP stripe size handling
btrfs: Handle btrfs_set_extent_delalloc failure in relocate_file_extent_cluster
btrfs: handle failure of add_pending_csums
btrfs: use kvzalloc to allocate btrfs_fs_info
Linus Torvalds [Sat, 3 Mar 2018 22:32:00 +0000 (14:32 -0800)]
Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:
"A 4.16 regression fix, three fixes for -stable, and a cleanup fix:
- During the merge window support for the new ACPI NVDIMM Platform
Capabilities structure disabled support for "deep flush", a
force-unit- access like mechanism for persistent memory. Restore
that mechanism.
- VFIO like RDMA is yet one more memory registration / pinning
interface that is incompatible with Filesystem-DAX. Disable long
term pins of Filesystem-DAX mappings via VFIO.
- The Filesystem-DAX detection to prevent long terms pins mistakenly
also disabled Device-DAX pins which are not subject to the same
block- map collision concerns.
- Similar to the setup path, softlockup warnings can trigger in the
shutdown path for large persistent memory namespaces. Teach
for_each_device_pfn() to perform cond_resched() in all cases.
- Boaz noticed that the might_sleep() in dax_direct_access() is stale
as of the v4.15 kernel.
These have received a build success notification from the 0day robot,
and the longterm pin fixes have appeared in -next. However, I recently
rebased the tree to remove some other fixes that need to be reworked
after review feedback.
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
memremap: fix softlockup reports at teardown
libnvdimm: re-enable deep flush for pmem devices via fsync()
vfio: disable filesystem-dax page pinning
dax: fix vma_is_fsdax() helper
dax: ->direct_access does not sleep anymore
Linus Torvalds [Sat, 3 Mar 2018 18:37:01 +0000 (10:37 -0800)]
Merge tag 'kbuild-fixes-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- suppress sparse warnings about unknown attributes
- fix typos and stale comments
- fix build error of arch/sh
- fix wrong use of ld-option vs cc-ldoption
- remove redundant GCC_PLUGINS_CFLAGS assignment
- fix another memory leak of Kconfig
- fix line number in error messages of Kconfig
- do not write confusing CONFIG_DEFCONFIG_LIST out to .config
- add xstrdup() to Kconfig to handle memory shortage errors
- show also a Debian package name if ncurses is missing
* tag 'kbuild-fixes-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
MAINTAINERS: take over Kconfig maintainership
kconfig: fix line number in recursive inclusion error message
Coccinelle: memdup: Fix typo in warning messages
kconfig: Update ncurses package names for menuconfig
kbuild/kallsyms: trivial typo fix
kbuild: test --build-id linker flag by ld-option instead of cc-ldoption
kbuild: drop superfluous GCC_PLUGINS_CFLAGS assignment
kconfig: Don't leak choice names during parsing
sh: fix build error for empty CONFIG_BUILTIN_DTB_SOURCE
kconfig: set SYMBOL_AUTO to the symbol marked with defconfig_list
kconfig: add xstrdup() helper
kbuild: disable sparse warnings about unknown attributes
Makefile: Fix lying comment re. silentoldconfig
Linus Torvalds [Sat, 3 Mar 2018 18:27:14 +0000 (10:27 -0800)]
Merge tag 'media/v4.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media fixes from Mauro Carvalho Chehab:
- some build fixes with randconfigs
- an m88ds3103 fix to prevent an OOPS if the chip doesn't provide the
right version during probe (with can happen if the hardware hangs)
- a potential out of array bounds reference in tvp5150
- some fixes and improvements in the DVB memory mapped API (added for
kernel 4.16)
* tag 'media/v4.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
media: vb2: Makefile: place vb2-trace together with vb2-core
media: Don't let tvp5150_get_vbi() go out of vbi_ram_default array
media: dvb: update buffer mmaped flags and frame counter
media: dvb: add continuity error indicators for memory mapped buffers
media: dmxdev: Fix the logic that enables DMA mmap support
media: dmxdev: fix error code for invalid ioctls
media: m88ds3103: don't call a non-initalized function
media: au0828: add VIDEO_V4L2 dependency
media: dvb: fix DVB_MMAP dependency
media: dvb: fix DVB_MMAP symbol name
media: videobuf2: fix build issues with vb2-trace
media: videobuf2: Add VIDEOBUF2_V4L2 Kconfig option for VB2 V4L2 part
Linus Torvalds [Sat, 3 Mar 2018 03:40:43 +0000 (19:40 -0800)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Radim Krčmář:
"x86:
- fix NULL dereference when using userspace lapic
- optimize spectre v1 mitigations by allowing guests to use LFENCE
- make microcode revision configurable to prevent guests from
unnecessarily blacklisting spectre v2 mitigation feature"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: fix vcpu initialization with userspace lapic
KVM: X86: Allow userspace to define the microcode version
KVM: X86: Introduce kvm_get_msr_feature()
KVM: SVM: Add MSR-based feature support for serializing LFENCE
KVM: x86: Add a framework for supporting MSR-based features
Dan Williams [Wed, 7 Feb 2018 03:34:11 +0000 (19:34 -0800)]
memremap: fix softlockup reports at teardown
The cond_resched() currently in the setup path needs to be duplicated in
the teardown path. Rather than require each instance of
for_each_device_pfn() to open code the same sequence, embed it in the
helper.
Link: https://github.com/intel/ixpdimm_sw/issues/11 Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: <stable@vger.kernel.org> Fixes: 71389703839e ("mm, zone_device: Replace {get, put}_zone_device_page()...") Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Dave Jiang [Sat, 3 Mar 2018 03:31:40 +0000 (19:31 -0800)]
libnvdimm: re-enable deep flush for pmem devices via fsync()
Re-enable deep flush so that users always have a way to be sure that a
write makes it all the way out to media. Writes from the PMEM driver
always arrive at the NVDIMM since movnt is used to bypass the cache, and
the driver relies on the ADR (Asynchronous DRAM Refresh) mechanism to
flush write buffers on power failure. The Deep Flush mechanism is there
to explicitly write buffers to protect against (rare) ADR failure. This
change prevents a regression in deep flush behavior so that applications
can continue to depend on fsync() as a mechanism to trigger deep flush
in the filesystem-DAX case.
Fixes: 06e8ccdab15f4 ("acpi: nfit: Add support for detect platform CPU cache...") Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Dan Williams [Sun, 4 Feb 2018 18:34:02 +0000 (10:34 -0800)]
vfio: disable filesystem-dax page pinning
Filesystem-DAX is incompatible with 'longterm' page pinning. Without
page cache indirection a DAX mapping maps filesystem blocks directly.
This means that the filesystem must not modify a file's block map while
any page in a mapping is pinned. In order to prevent the situation of
userspace holding of filesystem operations indefinitely, disallow
'longterm' Filesystem-DAX mappings.
RDMA has the same conflict and the plan there is to add a 'with lease'
mechanism to allow the kernel to notify userspace that the mapping is
being torn down for block-map maintenance. Perhaps something similar can
be put in place for vfio.
Note that xfs and ext4 still report:
"DAX enabled. Warning: EXPERIMENTAL, use at your own risk"
...at mount time, and resolving the dax-dma-vs-truncate problem is one
of the last hurdles to remove that designation.
Acked-by: Alex Williamson <alex.williamson@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: kvm@vger.kernel.org Cc: <stable@vger.kernel.org> Reported-by: Haozhong Zhang <haozhong.zhang@intel.com> Tested-by: Haozhong Zhang <haozhong.zhang@intel.com> Fixes: d475c6346a38 ("dax,ext2: replace XIP read and write with DAX I/O") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
- Fix a crash when BIOS didn't assign a BAR and we try to enlarge it
(Christian König)
* tag 'pci-v4.16-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
PCI: Allow release of resources that were never assigned
PCI: Update location of pci.ids file
Linus Torvalds [Fri, 2 Mar 2018 21:05:20 +0000 (13:05 -0800)]
Merge branch 'parisc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller:
- a patch to change the ordering of cache and TLB flushes to hopefully
fix the random segfaults we very rarely face (by Dave Anglin).
- a patch to hide the virtual kernel memory layout due to security
reasons.
- two small patches to make the kernel run more smoothly under qemu.
* 'parisc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Reduce irq overhead when run in qemu
parisc: Use cr16 interval timers unconditionally on qemu
parisc: Check if secondary CPUs want own PDC calls
parisc: Hide virtual kernel memory layout
parisc: Fix ordering of cache and TLB flushes
Linus Torvalds [Fri, 2 Mar 2018 18:19:57 +0000 (10:19 -0800)]
Merge tag 'for-linus-4.16a-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"Five minor fixes for Xen-specific drivers"
* tag 'for-linus-4.16a-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
pvcalls-front: 64-bit align flags
x86/xen: add tty0 and hvc0 as preferred consoles for dom0
xen-netfront: Fix hang on device removal
xen/pirq: fix error path cleanup when binding MSIs
xen/pvcalls: fix null pointer dereference on map->sock
Linus Torvalds [Fri, 2 Mar 2018 18:05:10 +0000 (10:05 -0800)]
Merge tag 'ceph-for-4.16-rc4' of git://github.com/ceph/ceph-client
Pull ceph fixes from Ilya Dryomov:
"A cap handling fix from Zhi that ensures that metadata writeback isn't
delayed and three error path memory leak fixups from Chengguang"
* tag 'ceph-for-4.16-rc4' of git://github.com/ceph/ceph-client:
ceph: fix potential memory leak in init_caches()
ceph: fix dentry leak when failing to init debugfs
libceph, ceph: avoid memory leak when specifying same option several times
ceph: flush dirty caps of unlinked inode ASAP
Linus Torvalds [Fri, 2 Mar 2018 17:35:36 +0000 (09:35 -0800)]
Merge tag 'for-linus-20180302' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"A collection of fixes for this series. This is a little larger than
usual at this time, but that's mainly because I was out on vacation
last week. Nothing in here is major in any way, it's just two weeks of
fixes. This contains:
- NVMe pull from Keith, with a set of fixes from the usual suspects.
- mq-deadline zone unlock fix from Damien, fixing an issue with the
SMR zone locking added for 4.16.
- two bcache fixes sent in by Michael, with changes from Coly and
Tang.
- comment typo fix from Eric for blktrace.
- return-value error handling fix for nbd, from Gustavo.
- fix a direct-io case where we don't defer to a completion handler,
making us sleep from IRQ device completion. From Jan.
- a small series from Jan fixing up holes around handling of bdev
references.
- small set of regression fixes from Jiufei, mostly fixing problems
around the gendisk pointer -> partition index change.
- regression fix from Ming, fixing a boundary issue with the discard
page cache invalidation.
- two-patch series from Ming, fixing both a core blk-mq-sched and
kyber issue around token freeing on a requeue condition"
* tag 'for-linus-20180302' of git://git.kernel.dk/linux-block: (24 commits)
block: fix a typo
block: display the correct diskname for bio
block: fix the count of PGPGOUT for WRITE_SAME
mq-deadline: Make sure to always unlock zones
nvmet: fix PSDT field check in command format
nvme-multipath: fix sysfs dangerously created links
nbd: fix return value in error handling path
bcache: fix kcrashes with fio in RAID5 backend dev
bcache: correct flash only vols (check all uuids)
blktrace_api.h: fix comment for struct blk_user_trace_setup
blockdev: Avoid two active bdev inodes for one device
genhd: Fix BUG in blkdev_open()
genhd: Fix use after free in __blkdev_get()
genhd: Add helper put_disk_and_module()
genhd: Rename get_disk() to get_disk_and_module()
genhd: Fix leaked module reference for NVME devices
direct-io: Fix sleep in atomic due to sync AIO
nvme-pci: Fix nvme queue cleanup if IRQ setup fails
block: kyber: fix domain token leak during requeue
blk-mq: don't call io sched's .requeue_request when requeueing rq to ->dispatch
...
Linus Torvalds [Fri, 2 Mar 2018 16:44:11 +0000 (08:44 -0800)]
Merge tag 'mmc-v4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc
Pull MMC fixes from Ulf Hansson:
"MMC core:
- mmc: core: Avoid hang when claiming host
MMC host:
- dw_mmc: Avoid hang when accessing registers
- dw_mmc: Fix out-of-bounds access for slot's caps
- dw_mmc-k3: Fix out-of-bounds access through DT alias
- sdhci-pci: Fix S0i3 for Intel BYT-based controllers"
* tag 'mmc-v4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
mmc: core: Avoid hanging to claim host for mmc via some nested calls
mmc: dw_mmc: Avoid accessing registers in runtime suspended state
mmc: dw_mmc: Fix out-of-bounds access for slot's caps
mmc: dw_mmc: Factor out dw_mci_init_slot_caps
mmc: dw_mmc-k3: Fix out-of-bounds access through DT alias
mmc: sdhci-pci: Fix S0i3 for Intel BYT-based controllers
Linus Torvalds [Fri, 2 Mar 2018 16:17:49 +0000 (08:17 -0800)]
Merge tag 'pm-4.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These fix three issues in cpufreq drivers: one recent regression, one
leftover Kconfig dependency and one old but "stable" material.
Specifics:
- Make the task scheduler load and utilization signals be
frequency-invariant again after recent changes in the SCPI cpufreq
driver (Dietmar Eggemann).
- Drop an unnecessary leftover Kconfig dependency from the SCPI
cpufreq driver (Sudeep Holla).
- Fix the initialization of the s3c24xx cpufreq driver (Viresh
Kumar)"
* tag 'pm-4.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: s3c24xx: Fix broken s3c_cpufreq_init()
cpufreq: scpi: Fix incorrect arm_big_little config dependency
cpufreq: scpi: invoke frequency-invariance setter function
Helge Deller [Mon, 12 Feb 2018 20:43:55 +0000 (21:43 +0100)]
parisc: Reduce irq overhead when run in qemu
When run under QEMU, calling mfctl(16) creates some overhead because the
qemu timer has to be scaled and moved into the register. This patch
reduces the number of calls to mfctl(16) by moving the calls out of the
loops.
Additionally, increase the minimal time interval to 8000 cycles instead
of 500 to compensate possible QEMU delays when delivering interrupts.
Helge Deller [Fri, 12 Jan 2018 21:51:22 +0000 (22:51 +0100)]
parisc: Check if secondary CPUs want own PDC calls
The architecture specification says (for 64-bit systems): PDC is a per
processor resource, and operating system software must be prepared to
manage separate pointers to PDCE_PROC for each processor. The address
of PDCE_PROC for the monarch processor is stored in the Page Zero
location MEM_PDC. The address of PDCE_PROC for each non-monarch
processor is passed in gr26 when PDCE_RESET invokes OS_RENDEZ.
Currently we still use one PDC for all CPUs, but in case we face a
machine which is following the specification let's warn about it.
The change to flush_kernel_vmap_range() wasn't sufficient to avoid the
SMP stalls. The problem is some drivers call these routines with
interrupts disabled. Interrupts need to be enabled for flush_tlb_all()
and flush_cache_all() to work. This version adds checks to ensure
interrupts are not disabled before calling routines that need IPI
interrupts. When interrupts are disabled, we now drop into slower code.
The attached change fixes the ordering of cache and TLB flushes in
several cases. When we flush the cache using the existing PTE/TLB
entries, we need to flush the TLB after doing the cache flush. We don't
need to do this when we flush the entire instruction and data caches as
these flushes don't use the existing TLB entries. The same is true for
tmpalias region flushes.
The flush_kernel_vmap_range() and invalidate_kernel_vmap_range()
routines have been updated.
Secondly, we added a new purge_kernel_dcache_range_asm() routine to
pacache.S and use it in invalidate_kernel_vmap_range(). Nominally,
purges are faster than flushes as the cache lines don't have to be
written back to memory.
Hopefully, this is sufficient to resolve the remaining problems due to
cache speculation. So far, testing indicates that this is the case. I
did work up a patch using tmpalias flushes, but there is a performance
hit because we need the physical address for each page, and we also need
to sequence access to the tmpalias flush code. This increases the
probability of stalls.
Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # 4.9+ Signed-off-by: Helge Deller <deller@gmx.de>
Masahiro Yamada [Fri, 16 Feb 2018 18:38:32 +0000 (03:38 +0900)]
kconfig: set SYMBOL_AUTO to the symbol marked with defconfig_list
The 'defconfig_list' is a weird attribute. If the '.config' is
missing, conf_read_simple() iterates over all visible defaults,
then it uses the first one for which fopen() succeeds.
However, like other symbols, the first visible default is always
written out to the .config file. This might be different from what
has been actually used.
For example, on my machine, the third one "/boot/config-$UNAME_RELEASE"
is opened, like follows:
$ rm .config
$ make oldconfig 2>/dev/null
scripts/kconfig/conf --oldconfig Kconfig
#
# using defaults found in /boot/config-4.4.0-112-generic
#
*
* Restart config...
*
*
* IRQ subsystem
*
Expose irq internals in debugfs (GENERIC_IRQ_DEBUGFS) [N/y/?] (NEW)
However, the resulted .config file contains the first one since it is
visible:
Linus Torvalds [Thu, 1 Mar 2018 23:56:15 +0000 (15:56 -0800)]
Merge tag 'drm-fixes-for-v4.16-rc4' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"Pretty much run of the mill drm fixes.
amdgpu:
- power management fixes
- some display fixes
- one ppc 32-bit dma fix
i915:
- two display fixes
- three gem fixes
sun4i:
- display regression fixes
nouveau:
- display regression fix
virtio-gpu:
- dumb airlied ioctl fix"
* tag 'drm-fixes-for-v4.16-rc4' of git://people.freedesktop.org/~airlied/linux: (25 commits)
drm/amdgpu: skip ECC for SRIOV in gmc late_init
drm/amd/amdgpu: Correct VRAM width for APUs with GMC9
drm/amdgpu: fix&cleanups for wb_clear
drm/amdgpu: Correct sdma_v4 get_wptr(v2)
drm/amd/powerplay: fix power over limit on Fiji
drm/amdgpu:Fixed wrong emit frame size for enc
drm/amdgpu: move WB_FREE to correct place
drm/amdgpu: only flush hotplug work without DC
drm/amd/display: check for ipp before calling cursor operations
drm/i915: Make global seqno known in i915_gem_request_execute tracepoint
drm/i915: Clear the in-use marker on execbuf failure
drm/i915/cnl: Fix PORT_TX_DW5/7 register address
drm/i915/audio: fix check for av_enc_map overflow
drm/i915: Fix rsvd2 mask when out-fence is returned
virtio-gpu: fix ioctl and expose the fixed status to userspace.
drm/sun4i: Protect the TCON pixel clocks
drm/sun4i: Enable the output on the pins (tcon0)
drm/nouveau: prefer XBGR2101010 for addfb ioctl
drm/radeon: insist on 32-bit DMA for Cedar on PPC64/PPC64LE
drm/amd/display: VGA black screen from s3 when attached to hook
...
Linus Torvalds [Thu, 1 Mar 2018 22:32:23 +0000 (14:32 -0800)]
Merge tag 'arc-4.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC fixes from Vineet Gupta:
- MCIP aka ARconnect fixes for SMP builds [Euginey]
- preventive fix for SLC (L2 cache) flushing [Euginey]
- Kconfig default fix [Ulf Magnusson]
- trailing semicolon fixes [Luis de Bethencourt]
- other assorted minor fixes
* tag 'arc-4.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: setup cpu possible mask according to possible-cpus dts property
ARC: mcip: update MCIP debug mask when the new cpu came online
ARC: mcip: halt GFRC counter when ARC cores halt
ARCv2: boot log: fix HS48 release number
arc: dts: use 'atmel' as manufacturer for at24 in axs10x_mb
ARC: Fix malformed ARC_EMUL_UNALIGNED default
ARC: boot log: Fix trailing semicolon
ARC: dw2 unwind: Fix trailing semicolon
ARC: Enable fatal signals on boot for dev platforms
ARCv2: Don't pretend we may set L-bit in STATUS32 with kflag instruction
ARCv2: cache: fix slc_entire_op: flush only instead of flush-n-inv
Wanpeng Li [Wed, 28 Feb 2018 06:03:31 +0000 (14:03 +0800)]
KVM: X86: Allow userspace to define the microcode version
Linux (among the others) has checks to make sure that certain features
aren't enabled on a certain family/model/stepping if the microcode version
isn't greater than or equal to a known good version.
By exposing the real microcode version, we're preventing buggy guests that
don't check that they are running virtualized (i.e., they should trust the
hypervisor) from disabling features that are effectively not buggy.
Suggested-by: Filippo Sironi <sironi@amazon.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Liran Alon <liran.alon@oracle.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Linus Torvalds [Thu, 1 Mar 2018 18:50:01 +0000 (10:50 -0800)]
Merge tag 'platform-drivers-x86-v4.16-5' of git://git.infradead.org/linux-platform-drivers-x86
Pull x86 platform drivers fixes from Andy Shevchenko:
- fix a regression on laptops like Dell XPS 9360 where keyboard stopped
working.
- correct sysfs wakeup attribute after removal of some drivers to
reflect that they are not able to wake system up anymore.
* tag 'platform-drivers-x86-v4.16-5' of git://git.infradead.org/linux-platform-drivers-x86:
platform/x86: wmi: Fix misuse of vsprintf extension %pULL
platform/x86: intel-hid: Reset wakeup capable flag on removal
platform/x86: intel-vbtn: Reset wakeup capable flag on removal
platform/x86: intel-vbtn: Only activate tablet mode switch on 2-in-1's
Linus Torvalds [Thu, 1 Mar 2018 18:06:39 +0000 (10:06 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk fix from Petr Mladek:
"Make sure that we wake up userspace loggers. This fixes a race
introduced by the console waiter logic during this merge window"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
printk: Wake klogd when passing console_lock owner
Tom Lendacky [Fri, 23 Feb 2018 23:18:20 +0000 (00:18 +0100)]
KVM: SVM: Add MSR-based feature support for serializing LFENCE
In order to determine if LFENCE is a serializing instruction on AMD
processors, MSR 0xc0011029 (MSR_F10H_DECFG) must be read and the state
of bit 1 checked. This patch will add support to allow a guest to
properly make this determination.
Add the MSR feature callback operation to svm.c and add MSR 0xc0011029
to the list of MSR-based features. If LFENCE is serializing, then the
feature is supported, allowing the hypervisor to set the value of the
MSR that guest will see. Support is also added to write (hypervisor only)
and read the MSR value for the guest. A write by the guest will result in
a #GP. A read by the guest will return the value as set by the host. In
this way, the support to expose the feature to the guest is controlled by
the hypervisor.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Tom Lendacky [Wed, 21 Feb 2018 19:39:51 +0000 (13:39 -0600)]
KVM: x86: Add a framework for supporting MSR-based features
Provide a new KVM capability that allows bits within MSRs to be recognized
as features. Two new ioctls are added to the /dev/kvm ioctl routine to
retrieve the list of these MSRs and then retrieve their values. A kvm_x86_ops
callback is used to determine support for the listed MSR-based features.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Tweaked documentation. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
projects / linux.git / log