In all practical situations, the resolver visibility is static.
Requested by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: so (emaste)
Differential revision: https://reviews.freebsd.org/D20281
A static analyzer complained about a couple instances of checking a
variable against NULL after already having dereferenced it.
- dmar_gas_alloc_region: remove the tautological NULL checks
- dmar_release_resources / dmar_fini_fault_log: don't deref unit->regs
unless initialized.
And while here, fix an inverted initialization check in dmar_fini_qi.
Reviewed by: kib
Sponsored by: Dell EMC Isilon
Differential revision: https://reviews.freebsd.org/D20263
Microarchitectural buffers on some Intel processors utilizing
speculative execution may allow a local process to obtain a memory
disclosure. An attacker may be able to read secret data from the
kernel or from a process when executing untrusted code (for example,
in a web browser).
Reference: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00233.html
Security: CVE-2018-12126, CVE-2018-12127, CVE-2018-12130, CVE-2019-11091
Security: FreeBSD-SA-19:07.mds
Reviewed by: jhb
Tested by: emaste, lwhsu
Approved by: so (gtetlow)
This gets rid of the global cpu_ipi_pending array.
While replace cmpset with fcmpset in the delivery code and opportunistically
check if given IPI is already pending.
Sponsored by: The FreeBSD Foundation
IPI_STOP is used after panic or when ddb is entered manually. MONITOR/
MWAIT allows CPUs that support the feature to sleep in a low power way
instead of spinning. Something similar is already used at idle.
It is perhaps especially useful in oversubscribed VM environments, and is
safe to use even if the panic/ddb thread is not the BSP. (Except in the
presence of MWAIT errata, which are detected automatically on platforms with
known wakeup problems.)
It can be tuned/sysctled with "machdep.stop_mwait," which defaults to 0
(off). This commit also introduces the tunable
"machdep.mwait_cpustop_broken," which defaults to 0, unless the CPU has
known errata, but may be set to "1" in loader.conf to signal that mwait
wakeup is broken on CPUs FreeBSD does not yet know about.
Unfortunately, Bhyve doesn't yet support MONITOR extensions, so this doesn't
help bhyve hypervisors running FreeBSD guests.
Submitted by: Anton Rang <rang AT acm.org> (earlier version)
Reviewed by: kib
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20135
Rather than just accessing it via pointer cast.
No functional change intended.
Discussed with: kib (earlier version)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20135
We may need the BSP to reboot, but we don't need any AP CPU that isn't the
panic thread. Any CPU landing in this routine during panic isn't the panic
thread, so we can just detect !BSP && panic and shut down the logical core.
The savings can be demonstrated in a bhyve guest with multiple cores; before
this change, N guest threads would spin at 100% CPU. After this change,
only one or two threads spin (depending on if the panicing CPU was the BSP
or not).
Konstantin points out that this may break any future patches which allow
switching ddb(4) CPUs after panic and examining CPU-local state that cannot
be inspected remotely. In the event that such a mechanism is incorporated,
this behavior could be made configurable by tunable/sysctl.
Reviewed by: kib
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20019
On some machines, DMAR contexts must be created before all devices
under the scope of the corresponding DMAR unit are enumerated.
Current code has two problems with that:
- scope lookup returns NULL device_t, which causes to skip creating a
context with RMRR, which is fatal for the affected device.
- calculation of the final pci dbsf address fails if any bridge in the
scope is not yet enumerated, because code relies on pcib_get_bus().
Make creation of contexts work either with device_t, or with DMAR PCI
scope paths. Scope provides enough information to infer context
address, and it is directly matched against DMAR tables scopes.
When calculating bus addresses for the scope or device, use direct
pci_cfgregread(PCIR_SECBUS_1) to get the secondary bus number, instead
of pcib_get_bus().
The issue was observed on HP Gen servers, where iLO PCI devices are
located behind south bridge switch. Turning on translation without
satisfying RMRR requests caused iLO to mostly hang, up to the level of
being unusable to control the server.
While there, remove hw.dmar.dmar_match_verbose tunable, and make the
normal logging under bootverbose useful and sufficient to diagnose
DRHD and RMRR parsing and matching.
Sponsored by: Mellanox Technologies
MFC after: 1 week
Some early PCIe chipsets are explicitly listed in the white-list to
enable use of the MMIO config space accesses, perhaps because ACPI
tables were not reliable source of the base MCFG address at that time.
For that chipsets, MCFG base was read from the known chipset MCFGbase
config register.
During very early stage of boot, when access to the PCI config space
is performed (see e.g. pci_early_quirks.c), we cannot map 255MB of
registers because the method used with pre-boot pmap overflows initial
kernel page tables.
Move fallback to read MCFGbase to the attachment method of the
x86/legacy device, which removes code duplication, and results in the
use of io accesses until MCFG is parsed or legacy attach called.
For amd64, pre-initialize cfgmech with CFGMECH_1, right now we
dynamically assign CFGMECH_1 to it anyway, and remove checks for
CFGMECH_NONE.
There is a mention in the Intel documentation for corresponding
chipsets that OS must use either io port or MMIO access method, but we
already break this rule by reading MCFGbase register, so one more
access seems to be innocent.
Reported by: longwitz@incore.de
PR: 236838
Reviewed by: avg (other version), jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D19833
Add the infrastructure to allow MD procctl(2) commands, and use it to
introduce amd64 PTI control and reporting. PTI mode cannot be
modified for existing pmap, the knob controls PTI of the new vmspace
created on exec.
Requested by: jhb
Reviewed by: jhb, markj (previous version)
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D19514
FreeBSD base system does not provide an ACPI handler for the PC/AT RTC/CMOS
device with PnP ID PNP0B00; on some HP laptops, the absence of this handler
causes suspend/resume and poweroff(8) to hang or fail [1], [2]. On these
laptops EC _REG method queries the RTC date/time registers via ACPI
before suspending/powering off. The handler should be registered before
acpi_ec driver is loaded.
This change adds handler to access CMOS RTC operation region described in
section 9.15 of ACPI-6.2 specification [3]. It is installed only for ACPI
version of atrtc(4) so it should not affect old ACPI-less i386 systems.
It is possible to disable the handler with loader tunable:
debug.acpi.disabled=atrtc
Informational debugging printf can be enabled by setting hw.acpi.verbose=1
in loader.conf
[1] https://wiki.freebsd.org/Laptops/HP_Envy_6Z-1100
[2] https://wiki.freebsd.org/Laptops/HP_Notebook_15-af104ur
[3] https://uefi.org/sites/default/files/resources/ACPI_6_2.pdf
PR: 207419, 213039
Submitted by: Anthony Jenkins <Scoobi_doo@yahoo.com>
Reviewed by: ian
Discussed on: acpi@, 2013-2015, several threads
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D19314
Skylake Xeons.
See SDM rev. 68 Vol 3 4.6.2 Protection Keys and the description of the
RDPKRU and WRPKRU instructions.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D18893
idle_td is dereferenced without thread-locking it to make its contents is
invariant, and was accessed without telling the compiler that its contents
is invariant. Some compilers optimized accesses to the supposedly invariant
contents by moving the critical checks for changes outside of the loop that
waits for changes. Fix this using atomic ops.
This bug only showed up for the following configuration: a Turion2
system, amd64 kernels, compiled by gcc, and SCHED_4BSD. clang fails
to do the optimization with all CFLAGS that I tried, because it doesn't
fully optimize the '__asm __volatile' for cpu_spinwait() although this
asm has no memory clobber. gcc only does the optimization with most
CFLAGS. I mostly used -Os with all compilers. i386 works because gcc
-m32 -Os only moves 1 or the 2 accesses outside of the loop.
Non-Turion2 systems and SCHED_ULE worked due to different timing (when
all APs start before the BP checks them outside of the loop).
Reviewed by: kib
Make it more comprehensive on i386, by not setting nx bit for any
mapping, not just adding PF_X to all kernel-loaded ELF segments. This
is needed for the compatibility with older i386 programs that assume
that read access implies exec, e.g. old X servers with hand-rolled
module loader.
Reported and tested by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
It was broken before PAE/no-PAE merge, but since now PAE is the
default, resume is apparently becomes for all machines.
The corrected issues:
- the trampoline page is not mapped executable, so machine faults when
paging is on;
- MSR.EFER and %cr4 both should be loaded before paging is enabled,
otherwise paging structures are invalid (cr4.PAE and EFER.NX).
- MSR.EFER and %cr4 should be only loaded if present. I attempt to handle
this by not touching the registers if the value is zero.
There are some more bits still not quite correct, e.g. unconditional
access to %cr4 in resumectx.
Reported and debugging help by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
CPU and buses can manage up to the limit reported by cpu_maxphyaddr,
so set mem_rman to the value returned by cpu_getmaxphyaddr(). For the
PAE mode, it was missed both when rman_res_t was increased to
uintmax_t, and from the PAE merge commit.
When importing smaps or dump_avail chunks into memory rman, do not
blindly ignore resources which ends above the limit, chomp them
instead if start is below the limit. The same change was already done
to i386 add_physmap_entry().
Based on the submission by: bde
MFC after: 2 months
The main differences with the currently implemented method are:
- Requires a local APIC EOI, since it doesn't bypass the local APIC
as the previous method used to do.
- Can be set to use different IDT vectors on each vCPU. Note that
FreeBSD doesn't make use of this feature since the event channel
IDT vector is reserved system wide.
Note that the old method of setting the event channel upcall is
not removed, and will be used as a fallback if this newly introduced
method is not available.
MFC after: 1 month
Sponsored by: Citrix Systems R&D
Effectively all i386 kernels now have two pmaps compiled in: one
managing PAE pagetables, and another non-PAE. The implementation is
selected at cold time depending on the CPU features. The vm_paddr_t is
always 64bit now. As result, nx bit can be used on all capable CPUs.
Option PAE only affects the bus_addr_t: it is still 32bit for non-PAE
configs, for drivers compatibility. Kernel layout, esp. max kernel
address, low memory PDEs and max user address (same as trampoline
start) are now same for PAE and for non-PAE regardless of the type of
page tables used.
Non-PAE kernel (when using PAE pagetables) can handle physical memory
up to 24G now, larger memory requires re-tuning the KVA consumers and
instead the code caps the maximum at 24G. Unfortunately, a lot of
drivers do not use busdma(9) properly so by default even 4G barrier is
not easy. There are two tunables added: hw.above4g_allow and
hw.above24g_allow, the first one is kept enabled for now to evaluate
the status on HEAD, second is only for dev use.
i386 now creates three freelists if there is any memory above 4G, to
allow proper bounce pages allocation. Also, VM_KMEM_SIZE_SCALE changed
from 3 to 1.
The PAE_TABLES kernel config option is retired.
In collaboarion with: pho
Discussed with: emaste
Reviewed by: markj
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D18894
If i386 has more than 4G of memory, allow the same number of busdma
bounce pages as for amd64. In fact, in this case bouncing sometimes
is much heavier than on amd64.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D18854
Right now bus_addr_t and vm_paddr_t are always aliased to the same
underlying integer type on x86, which makes the interchange hard to
detect. Shortly, i386 kernel would use uint64_t for vm_paddr_t to
enable automatic use of PAE paging structures if hardware allows it,
while bus_addr_t would be extended to 64bit only when PAE option is
specified.
Fix all places that were identified as using bus_addr_t while page
address was assumed. This was performed by testing the complete PAE
merging patch on machine with > 4G of RAM enabled.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D18854
vmm's CPUID emulation presented Intel topology information to the guest, but
disabled AMD topology information and in some cases passed through garbage.
I.e., CPUID leaves 0x8000_001[de] were passed through to the guest, but
guest CPUs can migrate between host threads, so the information presented
was not consistent. This could easily be observed with 'cpucontrol -i 0xfoo
/dev/cpuctl0'.
Slightly improve this situation by enabling the AMD topology feature flag
and presenting at least the CPUID fields used by FreeBSD itself to probe
topology on more modern AMD64 hardware (Family 15h+). Older stuff is
probably less interesting. I have not been able to empirically confirm it
is sufficient, but it should not regress anything either.
Reviewed by: araujo (previous version)
Relnotes: sure
With new sysctls (to the best of our ability do detect them). Restructured
smp.4 slightly for clarity (keep relevant stuff closer to the top) while
documenting.
Reviewed by: markj, jhibbits (ppc parts)
MFC after: 3 days
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D18322
The goal of this change is to fix a problem with PCI shared interrupts
during suspend and resume.
I have observed a couple of variations of the following scenario.
Devices A and B are on the same PCI bus and share the same interrupt.
Device A's driver is suspended first and the device is powered down.
Device B generates an interrupt. Interrupt handlers of both drivers are
called. Device A's interrupt handler accesses registers of the powered
down device and gets back bogus values (I assume all 0xff). That data is
interpreted as interrupt status bits, etc. So, the interrupt handler
gets confused and may produce some noise or enter an infinite loop, etc.
This change affects only PCI devices. The pci(4) bus driver marks a
child's interrupt handler as suspended after the child's suspend method
is called and before the device is powered down. This is done only for
traditional PCI interrupts, because only they can be shared.
At the moment the change is only for x86.
Notable changes in core subsystems / interfaces:
- BUS_SUSPEND_INTR and BUS_RESUME_INTR methods are added to bus
interface along with convenience functions bus_suspend_intr and
bus_resume_intr;
- rman_set_irq_cookie and rman_get_irq_cookie functions are added to
provide a way to associate an interrupt resource with an interrupt
cookie;
- intr_event_suspend_handler and intr_event_resume_handler functions
are added to the MI interrupt handler interface.
I added two new interrupt handler flags, IH_SUSP and IH_CHANGED, to
implement the new intr_event functions. IH_SUSP marks a suspended
interrupt handler. IH_CHANGED is used to implement a barrier that
ensures that a change to the interrupt handler's state is visible
to future interrupts.
While there, I fixed some whitespace issues in comments and changed a
couple of logically boolean variables to be bool.
MFC after: 1 month (maybe)
Differential Revision: https://reviews.freebsd.org/D15755
The error was caused by map_ucode() casting a vm_paddr_t to a void *.
Use a uintptr_t instead to match the caller. Fix some style bugs while
here.
Reported by: bde
Reviewed by: bde
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Bootstacks are unused after APs executed sched_throw() in
init_secondary_tail() and started executing on proper idle thread
stack. Add sysinit that detects that the idle thread for each CPU was
scheduled at least once, and free corresponding bootstack.
Slight addition of the code (~200 bytes) is compensated by the saving,
because even on typical small modern desktop CPU we leak 128K of
memory otherwise (4 pages x 8 threads).
Reviewed by: jhb
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D18486
This moves the architecture independent parts of sys/x86/acpica/srat.c
to sys/dev/acpica/acpi_pxm.c, to be used later on arm64. The function
declarations are moved to sys/dev/acpica/acpivar.h
We also need to update sys/conf/files.{i386,amd64} to use the new file.
No functional changes.
Reviewed by: markj, imp
Differential Revision: https://reviews.freebsd.org/D17941
The SLIT and SRAT ACPI tables needs to be parsed on arm64 as well, on
systems that use UEFI/ACPI firmware and support NUMA. To do this, we
need to move most of the logic of x86/acpica/srat.c to dev/acpica and
provide an API that architectures can use to parse and configure ACPI
NUMA information.
This commit adds the API in srat.c as a first step, without making any
functional changes. We will move the common code to sys/dev/acpica
as the next step.
The functions added are:
* int acpi_pxm_init(int ncpus, vm_paddr_t maxphys) - to allocate and
initialize data structures used
* void acpi_pxm_parse_tables(void) - parse SRAT/SLIT, save the cpu and
memory proximity information
* void acpi_pxm_set_mem_locality(void) - use the saved data to set
memory locality
* void acpi_pxm_set_cpu_locality(void) - use the saved data to set cpu
locality
* void acpi_pxm_free(void) - free data structures allocated by init
On arm64, we do not have an cpu APIC id that can be used as index to
store CPU data, we need to use the Processor Uid. To help with this,
define internal functions cpu_add, cpu_find, cpu_get_info to store
and get CPU proximity information.
Reviewed by: markj, jhb (previous version)
Differential Revision: https://reviews.freebsd.org/D17940
