pmc_cpuid was uninitialized for most AMD processor families. We can still
populate this string for unimplemented families.
Also added a CPUID_TO_STEPPING macro and converted existing code to use it.
Reviewed by: mav
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D25673
Stop using smp_ipi_mtx to protect global shootdown state, and
move/multiply the global state into pcpu. Now each CPU can initiate
shootdown IPI independently from other CPUs. Initiator enters
critical section, then fills its local PCPU shootdown info
(pc_smp_tlb_XXX), then clears scoreboard generation at location (cpu,
my_cpuid) for each target cpu. After that IPI is sent to all targets
which scan for zeroed scoreboard generation words. Upon finding such
word the shootdown data is read from corresponding cpu' pcpu, and
generation is set. Meantime initiator loops waiting for all zeroed
generations in scoreboard to update.
Initiator does not disable interrupts, which should allow
non-invalidation IPIs from deadlocking, it only needs to disable
preemption to pin itself to the instance of the pcpu smp_tlb data.
The generation is set before the actual invalidation is performed in
handler. It is safe because target CPU cannot return to userspace
before handler finishes. In principle only NMI can preempt the
handler, but NMI would see the kernel handler frame and not touch
not-invalidated user page table.
Handlers loop until they do not see zeroed scoreboard generations.
This, together with hardware keeping one pending IPI in LAPIC IRR
should prevent lost shootdowns.
Notes.
1. The code does protect writes to LAPIC ICR with exclusion. I believe
this is fine because we in fact do not send IPIs from interrupt
handlers. More for !x2APIC mode where ICR access for write requires
two registers write, we disable interrupts around it. If considered
incorrect, I can add per-cpu spinlock around ipi_send().
2. Scoreboard lines owned by given target CPU can be padded to the
cache line, to reduce ping-pong.
Reviewed by: markj (previous version)
Discussed with: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D25510
Right now code first flushes all local TLB entries that needs to be
flushed, then signals IPI to remote cores, and then waits for
acknowledgements while spinning idle. In the VMWare article 'Don’t
shoot down TLB shootdowns!' it was noted that the time spent spinning
is lost, and can be more usefully used doing local TLB invalidation.
We could use the same invalidation handler for local TLB as for
remote, but typically for pmap == curpmap we can use INVLPG for locals
instead of INVPCID on remotes, since we cannot control context
switches on them. Due to that, keep the local code and provide the
callbacks to be called from smp_targeted_tlb_shootdown() after IPIs
are fired but before spin wait starts.
Reviewed by: alc, cem, markj, Anton Rang <rang at acm.org>
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D25188
The flush is needed to prevent cross-process ret2spec, which is not handled
on kernel entry if IBPB is enabled but SMEP is present.
While there, add i386 RSB flush.
Reported by: Anthony Steinhauser <asteinhauser@google.com>
Reviewed by: markj, Anthony Steinhauser
Discussed with: philip
admbugs: 961
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
When turning IBRS mitigation using sysctl, as opposed to loader tunable,
send IPI to tweak MSR on all cores. Right now code only performed MSR write
onr the CPU where sysctl was run.
Properly report hw.ibrs_active for IBRS_ALL. Split hw_ibrs_ibpb_active out
from ibrs_active, to keep the current semantic of guiding kernel entry and
exit handlers.
Reported and tested by: mav
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
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.
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
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
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
Rather than a few scattered places in the tree. Organize flag names in a
contiguous region of specialreg.h.
While here, delete deprecated PCOMMIT from leaf 7.
No functional change.
The former spelling probably confused MOVDIR64B with MOVDIRI64.
MOVDIR_64B is the 64-*byte* direct store instruction; MOVDIR_I64 is the
64-*bit* direct store instruction (underscores added here for clarity; they are
not part of the canonical instruction name).
No functional change.
Sponsored by: Dell EMC Isilon
ABI already guarantees the direction is forward. Note this does not take care
of i386-specific cld's.
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21906
This is needed for AMD SMCA processors, as SMCA uses different
MSR address for access MCA banks.
Use IA32 specific msr_ops as defualt, and use SMCA-specific msr_ops
when on an SMCA-enabled processor
Submitted by: chandu from amd dot com
Reviewed by: cem
Differential Revision: https://reviews.freebsd.org/D18055
type, use a table to make it easier to add more in the future, if needed.
Add VirtualBox detection to the table ("VBoxVBoxVBox" is the hypervisor
vendor string to look for.) Also add VM_GUEST_VBOX to the VM_GUEST
enumeration to indicate VirtualBox.
Save the CPUID base for the hypervisor entry that we detected. Driver code
may need to know about it in order to obtain additional CPUID features.
Approved by: bryanv, jhb
Differential Revision: https://reviews.freebsd.org/D16305
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
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
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
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
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
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
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
These definitions will be used by a driver to implement Hardware
P-States (autonomous control of HWP, via Intel Speed Shift technology).
Reviewed by: kib
Approved by: emaste (mentor)
Differential Revision: https://reviews.freebsd.org/D18050
Just allow MSI interrupts to always start at the end of the I/O APIC
pins. Since existing machines already have more than 255 I/O APIC
pins, IRQ 255 is no longer reliably invalid, so just remove the
minimum starting value for MSI.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D17991
