| Commit message (Collapse) | Author | Age | Files | Lines |
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Theoretically, ktime_get_mono_fast_ns() may be executed after
timekeeping has been suspended (or before it is resumed) which
in turn may lead to undefined behavior, for example, when the
clocksource read from timekeeping_get_ns() called by it is
not accessible at that time.
Prevent that from happening by setting up a dummy readout base for
the fast timekeeper during timekeeping_suspend() such that it will
always return the same number of cycles.
After the last timekeeping_update() in timekeeping_suspend() the
clocksource is read and the result is stored as cycles_at_suspend.
The readout base from the current timekeeper is copied onto the
dummy and the ->read pointer of the dummy is set to a routine
unconditionally returning cycles_at_suspend. Next, the dummy is
passed to update_fast_timekeeper().
Then, ktime_get_mono_fast_ns() will work until the subsequent
timekeeping_resume() and the proper readout base for the fast
timekeeper will be restored by the timekeeping_update() called
right after clearing timekeeping_suspended.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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Modify update_fast_timekeeper() to take a struct tk_read_base
pointer as its argument (instead of a struct timekeeper pointer)
and update its kerneldoc comment to reflect that.
That will allow a struct tk_read_base that is not part of a
struct timekeeper to be passed to it in the next patch.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: John Stultz <john.stultz@linaro.org>
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In preparation for adding support for quiescing timers in the final
stage of suspend-to-idle transitions, rework the freeze_enter()
function making the system wait on a wakeup event, the freeze_wake()
function terminating the suspend-to-idle loop and the mechanism by
which deep idle states are entered during suspend-to-idle.
First of all, introduce a simple state machine for suspend-to-idle
and make the code in question use it.
Second, prevent freeze_enter() from losing wakeup events due to race
conditions and ensure that the number of online CPUs won't change
while it is being executed. In addition to that, make it force
all of the CPUs re-enter the idle loop in case they are in idle
states already (so they can enter deeper idle states if possible).
Next, drop cpuidle_use_deepest_state() and replace use_deepest_state
checks in cpuidle_select() and cpuidle_reflect() with a single
suspend-to-idle state check in cpuidle_idle_call().
Finally, introduce cpuidle_enter_freeze() that will simply find the
deepest idle state available to the given CPU and enter it using
cpuidle_enter().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more ACPI and power management updates from Rafael Wysocki:
"These are two reverts related to system suspend breakage by one of a
recent commits, a fix for a recently introduced bug in devfreq and a
bunch of other things that didn't make it into my previous pull
request, but otherwise are ready to go.
Specifics:
- Revert two ACPI EC driver commits, one that broke system suspend on
Acer Aspire S5 and one that depends on it (Rafael J Wysocki).
- Fix a typo leading to an incorrect check in the exynos-ppmu devfreq
driver (Dan Carpenter).
- Add support for one more Broadwell CPU model to intel_idle (Len Brown).
- Fix an obscure problem with state transitions related to interrupts
in the speedstep-smi cpufreq driver (Mikulas Patocka).
- Remove some unnecessary messages related to the "out of memory"
condition from the core PM code (Quentin Lambert).
- Update turbostat parameters and documentation, add support for one
more Broadwell CPU model to it and modify it to skip printing
disabled package C-states (Len Brown)"
* tag 'pm+acpi-3.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / devfreq: event: testing the wrong variable
cpufreq: speedstep-smi: enable interrupts when waiting
PM / OPP / clk: Remove unnecessary OOM message
Revert "ACPI / EC: Add query flushing support"
Revert "ACPI / EC: Add GPE reference counting debugging messages"
tools/power turbostat: support additional Broadwell model
intel_idle: support additional Broadwell model
tools/power turbostat: update parameters, documentation
tools/power turbostat: Skip printing disabled package C-states
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* pm-cpufreq:
cpufreq: speedstep-smi: enable interrupts when waiting
* pm-cpuidle:
intel_idle: support additional Broadwell model
* pm-devfreq:
PM / devfreq: event: testing the wrong variable
* pm-opp:
PM / OPP / clk: Remove unnecessary OOM message
* pm-tools:
tools/power turbostat: support additional Broadwell model
tools/power turbostat: update parameters, documentation
tools/power turbostat: Skip printing disabled package C-states
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git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux into pm-tools
Pull additional turbostat updates for v3.20 from Len Brown.
* 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
tools/power turbostat: support additional Broadwell model
tools/power turbostat: update parameters, documentation
tools/power turbostat: Skip printing disabled package C-states
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Signed-off-by: Len Brown <len.brown@intel.com>
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Long format options added, though the short ones should still work.
eg. the new "--Counter 0x10" is the same as the old "-C 0x10"
Note this Incompatibility:
Old:
-v displayed verbose debug output
New:
-v and --version simpaly display version
Additional parameters:
-d and --debug display verbose debug output
-h and --help display a help message
Updated turbosat.8 man page accordingly.
Signed-off-by: Len Brown <len.brown@intel.com>
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Replaced previously open-coded Package C-state Limit decoding
with table-driven decoding. In doing so, updated to match January 2015
"Intel(R) 64 and IA-23 Architectures Software Developer's Manual".
In the past, turbostat would print package C-state residency columns
for all package states supported by the model's architecture, even though
a particular SKU may not support them, or they may be disabled by the BIOS.
Now turbostat will skip printing colunns if MSRs indicate that they are not enabled.
eg. many SKUs don't support PC7, and so that column will no longer be printed.
Signed-off-by: Len Brown <len.brown@intel.com>
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This patch reduces the kernel size by removing error messages that duplicate
the normal OOM message.
A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr)
@@
identifier f,print,l;
expression e;
constant char[] c;
@@
e = \(kzalloc\|kmalloc\|devm_kzalloc\|devm_kmalloc\)(...);
if (e == NULL) {
<+...
- print(...,c,...);
... when any
(
goto l;
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return ...;
)
...+> }
Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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There is a typo here so we test "edev" but we intended to test
"edev[i]".
Fixes: f262f28c1470 ('PM / devfreq: event: Add devfreq_event class')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux into pm-cpuidle
Pull intel_idle update for v3.20 from Len Brown.
* 'cpuidle' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
intel_idle: support additional Broadwell model
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Signed-off-by: Len Brown <len.brown@intel.com>
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On Dell Latitude C600 laptop with Pentium 3 850MHz processor, the
speedstep-smi driver sometimes loads and sometimes doesn't load with
"change to state X failed" message.
The hardware sometimes refuses to change frequency and in this case, we
need to retry later. I found out that we need to enable interrupts while
waiting. When we enable interrupts, the hardware blockage that prevents
frequency transition resolves and the transition is possible. With
disabled interrupts, the blockage doesn't resolve (no matter how long do
we wait). The exact reasons for this hardware behavior are unknown.
This patch enables interrupts in the function speedstep_set_state that can
be called with disabled interrupts. However, this function is called with
disabled interrupts only from speedstep_get_freqs, so it shouldn't cause
any problem.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com
Cc: All applicable <stable@vger.kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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* acpi-ec:
Revert "ACPI / EC: Add query flushing support"
Revert "ACPI / EC: Add GPE reference counting debugging messages"
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Revert commit f252cb09e1cb (ACPI / EC: Add query flushing support),
because it breaks system suspend on Acer Aspire S5. The machine
just hangs solid at the last stage of suspend (after taking non-boot
CPUs offline).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Revert commit b5bca896ef3c (ACPI / EC: Add GPE reference counting
debugging messages), because it depends on commit f252cb09e1cb
(ACPI / EC: Add query flushing support) which breaks system suspend
on Acer Aspire S5 and needs to be reverted.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds
Pull LED subsystem update from Bryan Wu:
"The big change of LED subsystem is introducing a new LED class for
Flash type LEDs which will be used for V4L2 subsystem.
Also we got some cleanup and fixes"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds:
leds: leds-gpio: Pass on error codes unmodified
DT: leds: Add led-sources property
leds: Add LED Flash class extension to the LED subsystem
leds: leds-mc13783: Use of_get_child_by_name() instead of refcount hack
leds: Use setup_timer
leds: Don't allow brightness values greater than max_brightness
DT: leds: Add flash LED devices related properties
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Instead of overriding error codes, pass them on unmodified. This
way a EPROBE_DEFER is correctly passed to the driver core. This results
in the LED driver correctly requesting probe deferral in cases the GPIO
controller is not yet available.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reported-and-tested-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
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Add a property for defining device outputs the LED
represented by the DT child node is connected to.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: devicetree@vger.kernel.org
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
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Some LED devices support two operation modes - torch and flash.
This patch provides support for flash LED devices in the LED subsystem
by introducing new sysfs attributes and kernel internal interface.
The attributes being introduced are: flash_brightness, flash_strobe,
flash_timeout, max_flash_timeout, max_flash_brightness, flash_fault,
flash_sync_strobe and available_sync_leds. All the flash related
features are placed in a separate module.
The modifications aim to be compatible with V4L2 framework requirements
related to the flash devices management. The design assumes that V4L2
sub-device can take of the LED class device control and communicate
with it through the kernel internal interface. When V4L2 Flash sub-device
file is opened, the LED class device sysfs interface is made
unavailable.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
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of_find_node_by_name() calls of_node_put() on its "from" parameter.
To counter this, mc13xxx_led_probe_dt() calls of_node_get() first.
Use of_get_child_by_name() instead to get rid of the refcount hack.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: linux-leds@vger.kernel.org
Signed-off-by: Bryan Wu <cooloney@gmail.com>
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Convert a call to init_timer and accompanying intializations of
the timer's data and function fields to a call to setup_timer.
A simplified version of the semantic match that fixes this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression t,f,d;
@@
-init_timer(&t);
+setup_timer(&t,f,d);
-t.function = f;
-t.data = d;
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
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Since commit 4d71a4a12b13 ("leds: Add support for setting brightness in
a synchronous way") the value passed to brightness_set() is no longer
limited to max_brightness and can be different from the internally saved
brightness value.
Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
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Addition of a LED Flash class extension entails the need for flash LED
specific device tree properties. The properties being added are:
max-microamp, flash-max-microamp, flash-timeout-microsec.
(cooloney@gmail.com: remove white spaces)
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module update from Rusty Russell:
"Trivial cleanups, mainly"
* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
module: Replace over-engineered nested sleep
module: Annotate nested sleep in resolve_symbol()
module: Remove double spaces in module verification taint message
kernel/module.c: Free lock-classes if parse_args failed
module: set ksymtab/kcrctab* section addresses to 0x0
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Since the introduction of the nested sleep warning; we've established
that the occasional sleep inside a wait_event() is fine.
wait_event() loops are invariant wrt. spurious wakeups, and the
occasional sleep has a similar effect on them. As long as its occasional
its harmless.
Therefore replace the 'correct' but verbose wait_woken() thing with
a simple annotation to shut up the warning.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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Because wait_event() loops are safe vs spurious wakeups we can allow the
occasional sleep -- which ends up being very similar.
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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The warning message when loading modules with a wrong signature has
two spaces in it:
"module verification failed: signature and/or required key missing"
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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parse_args call module parameters' .set handlers, which may use locks defined in the module.
So, these classes should be freed in case parse_args returns error(e.g. due to incorrect parameter passed).
Signed-off-by: Andrey Tsyvarev <tsyvarev@ispras.ru>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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These __ksymtab*/__kcrctab* sections currently have non-zero addresses.
Non-zero section addresses in a relocatable ELF confuse GDB and it ends
up not relocating all symbols when add-symbol-file is used on modules
which have exports. The kernel's module loader does not care about
these addresses, so let's just set them to zero.
Before:
$ readelf -S lib/notifier-error-inject.ko | grep 'Name\| __ksymtab_gpl'
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[ 8] __ksymtab_gpl PROGBITS 0000000c 0001b4 000010 00 A 0 0 4
(gdb) add-symbol-file lib/notifier-error-inject.ko 0x500000 -s .bss 0x700000
add symbol table from file "lib/notifier-error-inject.ko" at
.text_addr = 0x500000
.bss_addr = 0x700000
(gdb) p ¬ifier_err_inject_dir
$3 = (struct dentry **) 0x0
After:
$ readelf -S lib/notifier-error-inject.ko | grep 'Name\| __ksymtab_gpl'
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[ 8] __ksymtab_gpl PROGBITS 00000000 0001b4 000010 00 A 0 0 4
(gdb) add-symbol-file lib/notifier-error-inject.ko 0x500000 -s .bss 0x700000
add symbol table from file "lib/notifier-error-inject.ko" at
.text_addr = 0x500000
.bss_addr = 0x700000
(gdb) p ¬ifier_err_inject_dir
$3 = (struct dentry **) 0x700000
Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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Pull arch/tile changes from Chris Metcalf:
"Not much in this batch, just some minor cleanups"
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
tile: change MAINTAINERS website from tilera.com to ezchip.com
tile: enable sparse checks for get/put_user
tile: fix put_user sparse errors
tile: default to little endian on older toolchains
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Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
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Add an extra intermediate variable to __get_user and __put_user
to give sparse an opportunity to detect mismatches.
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
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Use x86's __inttype macro instead of using the typeof(x-x) trick to
generate a suitable integer size type. This avoids a sparse warning
when examining the x-x type with a bitwise type.
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
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Older toolchains may not specify __LITTLE_ENDIAN__, but older
toolchains were all little endian. Don't make things unnecessarily
hard for those toolchains.
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
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This reverts commit 5fcee53ce705d49c766f8a302c7e93bdfc33c124.
It causes the suspend to fail on at least the Chromebook Pixel, possibly
other platforms too.
Joerg Roedel points out that the logic should probably have been
if (max_physical_apicid > 255 ||
!(IS_ENABLED(CONFIG_HYPERVISOR_GUEST) &&
hypervisor_x2apic_available())) {
instead, but since the code is not in any fast-path, so we can just live
without that optimization and just revert to the original code.
Acked-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull KVM update from Paolo Bonzini:
"Fairly small update, but there are some interesting new features.
Common:
Optional support for adding a small amount of polling on each HLT
instruction executed in the guest (or equivalent for other
architectures). This can improve latency up to 50% on some
scenarios (e.g. O_DSYNC writes or TCP_RR netperf tests). This
also has to be enabled manually for now, but the plan is to
auto-tune this in the future.
ARM/ARM64:
The highlights are support for GICv3 emulation and dirty page
tracking
s390:
Several optimizations and bugfixes. Also a first: a feature
exposed by KVM (UUID and long guest name in /proc/sysinfo) before
it is available in IBM's hypervisor! :)
MIPS:
Bugfixes.
x86:
Support for PML (page modification logging, a new feature in
Broadwell Xeons that speeds up dirty page tracking), nested
virtualization improvements (nested APICv---a nice optimization),
usual round of emulation fixes.
There is also a new option to reduce latency of the TSC deadline
timer in the guest; this needs to be tuned manually.
Some commits are common between this pull and Catalin's; I see you
have already included his tree.
Powerpc:
Nothing yet.
The KVM/PPC changes will come in through the PPC maintainers,
because I haven't received them yet and I might end up being
offline for some part of next week"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (130 commits)
KVM: ia64: drop kvm.h from installed user headers
KVM: x86: fix build with !CONFIG_SMP
KVM: x86: emulate: correct page fault error code for NoWrite instructions
KVM: Disable compat ioctl for s390
KVM: s390: add cpu model support
KVM: s390: use facilities and cpu_id per KVM
KVM: s390/CPACF: Choose crypto control block format
s390/kernel: Update /proc/sysinfo file with Extended Name and UUID
KVM: s390: reenable LPP facility
KVM: s390: floating irqs: fix user triggerable endless loop
kvm: add halt_poll_ns module parameter
kvm: remove KVM_MMIO_SIZE
KVM: MIPS: Don't leak FPU/DSP to guest
KVM: MIPS: Disable HTW while in guest
KVM: nVMX: Enable nested posted interrupt processing
KVM: nVMX: Enable nested virtual interrupt delivery
KVM: nVMX: Enable nested apic register virtualization
KVM: nVMX: Make nested control MSRs per-cpu
KVM: nVMX: Enable nested virtualize x2apic mode
KVM: nVMX: Prepare for using hardware MSR bitmap
...
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The header was deleted, so stop trying to install it.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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<asm/apic.h> isn't included directly and without CONFIG_SMP, an option
that automagically pulls it can't be enabled.
Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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NoWrite instructions (e.g. cmp or test) never set the "write access"
bit in the error code, even if one of the operands is treated as a
destination.
Fixes: c205fb7d7d4f81e46fc577b707ceb9e356af1456
Cc: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390: fixes and features for kvm/next (3.20)
1. Fixes
- Fix user triggerable endless loop
- reenable LPP facility
- disable KVM compat ioctl on s390 (untested and broken)
2. cpu models for s390
- provide facilities and instruction blocking per VM
- add s390 specific vm attributes for setting values
3. crypto
- toleration patch for z13 support
4. add uuid and long name to /proc/sysinfo (stsi 322)
- patch Acked by Heiko Carstens (touches non-kvm s390 code)
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We never had a 31bit QEMU/kuli running. We would need to review several
ioctls to check if this creates holes, bugs or whatever to make it work.
Lets just disable compat support for KVM on s390.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
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This patch enables cpu model support in kvm/s390 via the vm attribute
interface.
During KVM initialization, the host properties cpuid, IBC value and the
facility list are stored in the architecture specific cpu model structure.
During vcpu setup, these properties are taken to initialize the related SIE
state. This mechanism allows to adjust the properties from user space and thus
to implement different selectable cpu models.
This patch uses the IBC functionality to block instructions that have not
been implemented at the requested CPU type and GA level compared to the
full host capability.
Userspace has to initialize the cpu model before vcpu creation. A cpu model
change of running vcpus is not possible.
Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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The patch introduces facilities and cpu_ids per virtual machine.
Different virtual machines may want to expose different facilities and
cpu ids to the guest, so let's make them per-vm instead of global.
Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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We need to specify a different format for the crypto control block
depending on whether the APXA facility is installed or not. Let's
test for it by executing the PQAP(QCI) function and use either a
format-1 or a format-2 crypto control block accordingly. This is a
host only change for z13 and does not affect the guest view.
Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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A new architecture extends STSI 3.2.2 with UUID and long names. KVM
will provide the first implementation. This patch adds the additional
data fields (Extended Name and UUID) from the 4KB block returned by
the STSI 3.2.2 command and reflect this information in the
/proc/sysinfo file accordingly.
Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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commit 7be81a46695d ("KVM: s390/facilities: allow TOD-CLOCK steering
facility bit") accidentially disabled the "load program parameter"
facility bit during rebase for upstream submission (my fault).
Re-add that bit.
As this is only for a performance measurement helper instruction
(used by KVM itself) cc stable is not necessary see
http://www-01.ibm.com/support/docview.wss?uid=isg26fcd1cc32246f4c8852574ce0044734a
(SA23-2260 The Load-Program-Parameter and CPU-Measurement Facilities)
for details about LPP and its usecase.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Fixes: 7be81a46695d ("KVM: s390/facilities: allow TOD-CLOCK steering")
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If a vm with no VCPUs is created, the injection of a floating irq
leads to an endless loop in the kernel.
Let's skip the search for a destination VCPU for a floating irq if no
VCPUs were created.
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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This patch introduces a new module parameter for the KVM module; when it
is present, KVM attempts a bit of polling on every HLT before scheduling
itself out via kvm_vcpu_block.
This parameter helps a lot for latency-bound workloads---in particular
I tested it with O_DSYNC writes with a battery-backed disk in the host.
In this case, writes are fast (because the data doesn't have to go all
the way to the platters) but they cannot be merged by either the host or
the guest. KVM's performance here is usually around 30% of bare metal,
or 50% if you use cache=directsync or cache=writethrough (these
parameters avoid that the guest sends pointless flush requests, and
at the same time they are not slow because of the battery-backed cache).
The bad performance happens because on every halt the host CPU decides
to halt itself too. When the interrupt comes, the vCPU thread is then
migrated to a new physical CPU, and in general the latency is horrible
because the vCPU thread has to be scheduled back in.
With this patch performance reaches 60-65% of bare metal and, more
important, 99% of what you get if you use idle=poll in the guest. This
means that the tunable gets rid of this particular bottleneck, and more
work can be done to improve performance in the kernel or QEMU.
Of course there is some price to pay; every time an otherwise idle vCPUs
is interrupted by an interrupt, it will poll unnecessarily and thus
impose a little load on the host. The above results were obtained with
a mostly random value of the parameter (500000), and the load was around
1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU.
The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll,
that can be used to tune the parameter. It counts how many HLT
instructions received an interrupt during the polling period; each
successful poll avoids that Linux schedules the VCPU thread out and back
in, and may also avoid a likely trip to C1 and back for the physical CPU.
While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second.
Of these halts, almost all are failed polls. During the benchmark,
instead, basically all halts end within the polling period, except a more
or less constant stream of 50 per second coming from vCPUs that are not
running the benchmark. The wasted time is thus very low. Things may
be slightly different for Windows VMs, which have a ~10 ms timer tick.
The effect is also visible on Marcelo's recently-introduced latency
test for the TSC deadline timer. Though of course a non-RT kernel has
awful latency bounds, the latency of the timer is around 8000-10000 clock
cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC
deadline timer, thus, the effect is both a smaller average latency and
a smaller variance.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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