In dmar_gas_uppermatch, skip searching a subtree if all its gaps-between-alloctions are too small.
Reviewed by: kib
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D23391
If package-level control is present, we default to using it. Per-core
software control may be enabled by setting the machdep.hwpstate_pkg_ctrl
tunable to "0" in loader.conf(5).
Per Intel SDM (Vol 3b Part 2), if HWP indicates EPP (energy-performance
preference) is not supported, the hardware instead uses the ENERGY_PERF_BIAS
MSR. In the epp sysctl handler, fall back to that MSR if HWP does not
support EPP and CPUID indicates the ENERGY_PERF_BIAS MSR is supported.
I don't know why a Skylake CPU with the HWP feature bit present would trap
on MSR reads of the HWP registers, but if this occurs, do not leave the
attach thread bound. This could conceivably cause reported hangs, although
I have no evidence that this is the cause.
Reported by: ae@, Andreas Nilsson <andrnils AT gmail.com>
X-MFC-With: r357002
Add a sysctl knob to allow users to re-enable it, and document the knob and
default in cpufreq.4. (While here, add a few unrelated updates to
cpufreq.4.)
It seems that the register value in some hardware simply reflects the
configured P-state. This results in an inadvertent and unintended outcome
where the P-state can only walk down, and then the driver becomes "stuck" in
the slowest possible P-state.
The Linux driver never consults this register, so that's some evidence that
ignoring the contents are relatively harmless.
PR: 234733
Reported by: sigsys AT gmail.com, Erich Dollanksy <freebsd.ed.lists AT
sumeritec.com>
After r355784 the td_oncpu field is no longer synchronized by the thread
lock, so the stack capture interrupt cannot be delievered precisely.
Fix this using a loop which drops the thread lock and restarts if the
wrong thread was sampled from the stack capture interrupt handler.
Change the implementation to use a regular interrupt instead of an NMI.
Now that we drop the thread lock, there is no advantage to the latter.
Simplify the KPIs. Remove stack_save_td_running() and add a return
value to stack_save_td(). On platforms that do not support stack
capture of running threads, stack_save_td() returns EOPNOTSUPP. If the
target thread is running in user mode, stack_save_td() returns EBUSY.
Reviewed by: kib
Reported by: mjg, pho
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23355
These were all introduced in the initial import of hwpstate_intel(4).
Reported by: Coverity
CIDs: 1413161, 1413164, 1413165, 1413167
X-MFC-With: r357002
at the root of every subtree that changes in an insert or delete, and
only once, and ordered from the bottom of the tree to the top. For
intel_gas.c, the only user of RB_AUGMENT I can find, change the
augmenting routine so that it does not climb from entry to tree root
on every call, and remove a 'tree correcting' function that can be
supplanted by proper tree augmentation.
Reviewed by: kib
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D23189
If we're going to throttle user requested P-states, we should at least produce
a debug log line indicating the surprising behavior.
PR: inspired by 234733
DRIVER_MODULE does not actually define a MODULE_VERSION, which is required
to satisfy a MODULE_DEPENDency. Declare one explicitly in
hwpstate_intel(4).
Reported by: flo
X-MFC-With: r357002
Instead of waiting for pc_curthread which is overwritten by
init_secondary_tail(), wait for non-NULL pc_curpcb, to be set by the
first context switch.
Assert that pc_curpcb is not set too early.
Reported and tested by: rlibby
Reviewed by: markj, rlibby
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23330
Intel Speed Shift is Intel's technology to control frequency in hardware,
with hints from software.
Let's get a working version of this in the tree and we can refine it from
here.
Submitted by: bwidawsk, scottph
Reviewed by: bcr (manpages), myself
Discussed with: jhb, kib (earlier versions)
With feedback from: Greg V, gallatin, freebsdnewbie AT freenet.de
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D18028
As a new x86 CPU vendor, Chengdu Haiguang IC Design Co., Ltd (Hygon)
is a joint venture between AMD and Haiguang Information Technology Co.,
Ltd., aims at providing x86 processors for China server market.
The first generation Hygon processor(Dhyana) shares most architecture
with AMD's family 17h, but with different CPU vendor ID("HygonGenuine")
and PCI vendor ID(0x1d94) and family series number 18h(Hygon negotiated
with AMD to confirm that only Hygon use family 18h).
To enable Hygon Dhyana support in FreeBSD, add new definitions
HYGON_VENDOR_ID("HygonGenuine") and X86_VENDOR_HYGON(0x1d94) to identify
Hygon Dhyana CPU.
Initialize the CPU features(topology, local APIC ext, MSI, TSC, hwpstate,
MCA, DEBUG_CTL, etc) for amd64 and i386 mode by sharing the code path of
AMD family 17h.
The changes have been applied on FreeBSD 13.0-CURRENT and tested
successfully on Hygon Dhyana processor.
References:
[1] Linux kernel patches for Hygon Dhyana, merged in 4.20:
https://git.kernel.org/tip/c9661c1e80b609cd038db7c908e061f0535804ef
[2] MSR and CPUID definition:
https://www.amd.com/system/files/TechDocs/54945_PPR_Family_17h_Models_00h-0Fh.pdf
Submitted by: Pu Wen <puwen@hygon.cn>
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23163
is no longer used.
pc_curthread is set by cpu_switch after it stopped using the old
thread (or boot) stack. This makes the smp_after_idle_runnable()
function not dependent on the internals of the scheduler operations.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23276
off the stack, initialized to default values, and then filled in with
driver-specific values, all without having to worry about the numerous
other fields in the tag. The resulting template is then passed into
busdma and the normal opaque tag object created. See the man page for
details on how to initialize a template.
Templates do not support tag filters. Filters have been broken for many
years, and only existed for an ancient make/model of hardware that had a
quirky DMA engine. Instead of breaking the ABI/API and changing the
arugment signature of bus_dma_tag_create() to remove the filter arguments,
templates allow us to ignore them, and also significantly reduce the
complexity of creating and managing tags.
Reviewed by: imp, kib
Differential Revision: https://reviews.freebsd.org/D22906
s/BIT_NAND/BIT_ANDNOT/, and for CPU and DOMAINSET too. The actual
implementation is "and not" (or "but not"), i.e. A but not B.
Fortunately this does appear to be what all existing callers want.
Don't supply a NAND (not (A and B)) operation at this time.
Discussed with: jeff
Reviewed by: cem
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D22791
migitation is available in microcode and the operator has set
the sysctl to automatic mode.
Reported by: Coverity
CID: 1408334
MFC after: 3 days
Sponsored by: Intel
hardclock IPI is delivered.
In the current code after r355311, critical section is taken only
around hardclockintr() call, and sched_preempt() is called after the
section is exited. If we reschedule after exit, as we typically would
due to conditions that caused IPI, in ULE the runq tdq_ipipending is
not cleared, which blocks generation of further preempt IPIs.
Since all relatively modern (10 years) hardware has per-cpu event
timers, restoring the critical section conditionally does not affect
it.
Reported and tested by: cy
Diagnosed and reviewed by: jeff (previous version)
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D22716
They're in both the old and new places in HEAD for the moment for
discussion and transition. The old locations will be garbage collected
in 4 weeks. MFCs to 12 an 11 will keep the old and new for transition
purposes.
Reviewed by: kib
MFC after: 4 weeks
Sponsored by: Intel
Differential Revision: https://reviews.freebsd.org/D22590
Just a typo that Coverity identified.
Coverity also identified an unused store in the same functional area (x86 TAA
stuff), but this commit does not address that issue (CID 1408334).
Reported by: Coverity
CID: 1408328, 1408332
tightening constraints on busy as a precursor to lockless page lookup and
should largely be a NOP for these cases.
Reviewed by: alc, kib, markj
Differential Revision: https://reviews.freebsd.org/D22611
the sched_preempt() switch optimization and causes the sched lock to be dropped
and immediately reacquired.
Reviewed by: jhb, kib, mav, markj (with changes)
Differential Revision: https://reviews.freebsd.org/D22623
The header is abused for inclusion into userspace, and on stable
branches neither device_t nor bool types are not defined when used
from userspace.
Sponsored by: The FreeBSD Foundation
X-MFC after: now
Update the NetBSD Kernel Concurrency Sanitizer (KCSAN) runtime to work in
the FreeBSD kernel. It is a useful tool for finding data races between
threads executing on different CPUs.
This can be enabled by enabling KCSAN in the kernel config, or by using the
GENERIC-KCSAN amd64 kernel. It works on amd64 and arm64, however the later
needs a compiler change to allow -fsanitize=thread that KCSAN uses.
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22315
context should share page tables.
Practically it means that dma requests from any device on the bus are
translated according to the entries loaded for the bus:0:0 device.
KPI requires that the slot and function of the device be 0:0, and that
no tags for other devices on the bus were used.
The intended use are NTBs which pass TLPs from the downstream to the
host with slot:func of the downstream originator.
Reviewed and tested by: mav
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D22434
Use the KPI to tweak MSRs in mitigation code.
Reviewed by: markj, scottl
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D22431
This CVE has already been announced in FreeBSD SA-19:26.mcu.
Mitigation for TAA involves either turning off TSX or turning on the
VERW mitigation used for MDS. Some CPUs will also be self-mitigating
for TAA and require no software workaround.
Control knobs are:
machdep.mitigations.taa.enable:
0 - no software mitigation is enabled
1 - attempt to disable TSX
2 - use the VERW mitigation
3 - automatically select the mitigation based on processor
features.
machdep.mitigations.taa.state:
inactive - no mitigation is active/enabled
TSX disable - TSX is disabled in the bare metal CPU as well as
- any virtualized CPUs
VERW - VERW instruction clears CPU buffers
not vulnerable - The CPU has identified itself as not being
vulnerable
Nothing in the base FreeBSD system uses TSX. However, the instructions
are straight-forward to add to custom applications and require no kernel
support, so the mitigation is provided for users with untrusted
applications and tenants.
Reviewed by: emaste, imp, kib, scottph
Sponsored by: Intel
Differential Revision: 22374
Disable the use of executable 2M page mappings in EPT-format page
tables on affected CPUs. For bhyve virtual machines, this effectively
disables all use of superpage mappings on affected CPUs. The
vm.pmap.allow_2m_x_ept sysctl can be set to override the default and
enable mappings on affected CPUs.
Alternate approaches have been suggested, but at present we do not
believe the complexity is warranted for typical bhyve's use cases.
Reviewed by: alc, emaste, markj, scottl
Security: CVE-2018-12207
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D21884
Currently NMIs are sent over event channels, but that defeats the
purpose of NMIs since event channels can be masked. Fix this by
issuing NMIs using a hypercall, which injects a NMI (vector #2) to the
desired vCPU.
Note that NMIs could also be triggered using the emulated local APIC,
but using a hypercall is better from a performance point of view
since it doesn't involve instruction decoding when not using x2APIC
mode.
Reported and Tested by: avg
Sponsored by: Citrix Systems R&D
x86 stack_save_td_running() can work safely only if IPI_TRACE is a
non-maskable interrupt. But at the moment FreeBSD/Xen does not provide
support for the NMI delivery mode. So, mark the functionality as
unsupported similarly to other platforms without NMI.
Maybe there is a way to provide a Xen-specific working
stack_save_td_running(), but I couldn't figure it out.
MFC after: 3 weeks
Sponsored by: Panzura
Enabling interrupts on htt cores has benefits to workloads which are primarily
interrupt driven by increasing the logical cores available for interrupt handling.
The tunable is named machdep.hyperthreading_intr_allowed
Reviewed by: kib, jhb
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D22233
