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git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools
Pull perf tools updates from Namhyung Kim:
"perf record:
- Introduce latency profiling using scheduler information.
The latency profiling is to show impacts on wall-time rather than
cpu-time. By tracking context switches, it can weight samples and
find which part of the code contributed more to the execution
latency.
The value (period) of the sample is weighted by dividing it by the
number of parallel execution at the moment. The parallelism is
tracked in perf report with sched-switch records. This will reduce
the portion that are run in parallel and in turn increase the
portion of serial executions.
For now, it's limited to profile processes, IOW system-wide
profiling is not supported. You can add --latency option to enable
this.
$ perf record --latency -- make -C tools/perf
I've run the above command for perf build which adds -j option to
make with the number of CPUs in the system internally. Normally
it'd show something like below:
$ perf report -F overhead,comm
...
#
# Overhead Command
# ........ ...............
#
78.97% cc1
6.54% python3
4.21% shellcheck
3.28% ld
1.80% as
1.37% cc1plus
0.80% sh
0.62% clang
0.56% gcc
0.44% perl
0.39% make
...
The cc1 takes around 80% of the overhead as it's the actual
compiler. However it runs in parallel so its contribution to
latency may be less than that. Now, perf report will show both
overhead and latency (if --latency was given at record time) like
below:
$ perf report -s comm
...
#
# Overhead Latency Command
# ........ ........ ...............
#
78.97% 48.66% cc1
6.54% 25.68% python3
4.21% 0.39% shellcheck
3.28% 13.70% ld
1.80% 2.56% as
1.37% 3.08% cc1plus
0.80% 0.98% sh
0.62% 0.61% clang
0.56% 0.33% gcc
0.44% 1.71% perl
0.39% 0.83% make
...
You can see latency of cc1 goes down to around 50% and python3 and
ld contribute a lot more than their overhead. You can use --latency
option in perf report to get the same result but ordered by
latency.
$ perf report --latency -s comm
perf report:
- As a side effect of the latency profiling work, it adds a new
output field 'latency' and a sort key 'parallelism'. The below is a
result from my system with 64 CPUs. The build was well-parallelized
but contained some serial portions.
$ perf report -s parallelism
...
#
# Overhead Latency Parallelism
# ........ ........ ...........
#
16.95% 1.54% 62
13.38% 1.24% 61
12.50% 70.47% 1
11.81% 1.06% 63
7.59% 0.71% 60
4.33% 12.20% 2
3.41% 0.33% 59
2.05% 0.18% 64
1.75% 1.09% 9
1.64% 1.85% 5
...
- Support Feodra mini-debuginfo which is a LZMA compressed symbol
table inside ".gnu_debugdata" ELF section.
perf annotate:
- Add --code-with-type option to enable data-type profiling with the
usual annotate output.
Instead of focusing on data structure, it shows code annotation
together with data type it accesses in case the instruction refers
to a memory location (and it was able to resolve the target data
type). Currently it only works with --stdio.
$ perf annotate --stdio --code-with-type
...
Percent | Source code & Disassembly of vmlinux for cpu/mem-loads,ldlat=30/pp (18 samples, percent: local period)
----------------------------------------------------------------------------------------------------------------------
: 0 0xffffffff81050610 <__fdget>:
0.00 : ffffffff81050610: callq 0xffffffff81c01b80 <__fentry__> # data-type: (stack operation)
0.00 : ffffffff81050615: pushq %rbp # data-type: (stack operation)
0.00 : ffffffff81050616: movq %rsp, %rbp
0.00 : ffffffff81050619: pushq %r15 # data-type: (stack operation)
0.00 : ffffffff8105061b: pushq %r14 # data-type: (stack operation)
0.00 : ffffffff8105061d: pushq %rbx # data-type: (stack operation)
0.00 : ffffffff8105061e: subq $0x10, %rsp
0.00 : ffffffff81050622: movl %edi, %ebx
0.00 : ffffffff81050624: movq %gs:0x7efc4814(%rip), %rax # 0x14e40 <current_task> # data-type: struct task_struct* +0
0.00 : ffffffff8105062c: movq 0x8d0(%rax), %r14 # data-type: struct task_struct +0x8d0 (files)
0.00 : ffffffff81050633: movl (%r14), %eax # data-type: struct files_struct +0 (count.counter)
0.00 : ffffffff81050636: cmpl $0x1, %eax
0.00 : ffffffff81050639: je 0xffffffff810506a9 <__fdget+0x99>
0.00 : ffffffff8105063b: movq 0x20(%r14), %rcx # data-type: struct files_struct +0x20 (fdt)
0.00 : ffffffff8105063f: movl (%rcx), %eax # data-type: struct fdtable +0 (max_fds)
0.00 : ffffffff81050641: cmpl %ebx, %eax
0.00 : ffffffff81050643: jbe 0xffffffff810506ef <__fdget+0xdf>
0.00 : ffffffff81050649: movl %ebx, %r15d
5.56 : ffffffff8105064c: movq 0x8(%rcx), %rdx # data-type: struct fdtable +0x8 (fd)
...
The "# data-type:" part was added with this change. The first few
entries are not very interesting. But later you can it accesses a
couple of fields in the task_struct, files_struct and fdtable.
perf trace:
- Support syscall tracing for different ABI. For example it can trace
system calls for 32-bit applications on 64-bit kernel
transparently.
- Add --summary-mode=total option to show global syscall summary. The
default is 'thread' to show per-thread syscall summary.
Python support:
- Add more interfaces to 'perf' module to parse events, and config,
enable or disable the event list properly so that it can implement
basic functionalities purely in Python. There is an example code
for these new interfaces in python/tracepoint.py.
- Add mypy and pylint support to enable build time checking. Fix some
code based on the findings from these tools.
Internals:
- Introduce io_dir__readdir() API to make directory traveral (usually
for proc or sysfs) efficient with less memory footprint.
JSON vendor events:
- Add events and metrics for ARM Neoverse N3 and V3
- Update events and metrics on various Intel CPUs
- Add/update events for a number of SiFive processors"
* tag 'perf-tools-for-v6.15-2025-03-27' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (229 commits)
perf bpf-filter: Fix a parsing error with comma
perf report: Fix a memory leak for perf_env on AMD
perf trace: Fix wrong size to bpf_map__update_elem call
perf tools: annotate asm_pure_loop.S
perf python: Fix setup.py mypy errors
perf test: Address attr.py mypy error
perf build: Add pylint build tests
perf build: Add mypy build tests
perf build: Rename TEST_LOGS to SHELL_TEST_LOGS
tools/build: Don't pass test log files to linker
perf bench sched pipe: fix enforced blocking reads in worker_thread
perf tools: Fix is_compat_mode build break in ppc64
perf build: filter all combinations of -flto for libperl
perf vendor events arm64 AmpereOneX: Fix frontend_bound calculation
perf vendor events arm64: AmpereOne/AmpereOneX: Mark LD_RETIRED impacted by errata
perf trace: Fix evlist memory leak
perf trace: Fix BTF memory leak
perf trace: Make syscall table stable
perf syscalltbl: Mask off ABI type for MIPS system calls
perf build: Remove Makefile.syscalls
...
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Pull kvm updates from Paolo Bonzini:
"ARM:
- Nested virtualization support for VGICv3, giving the nested
hypervisor control of the VGIC hardware when running an L2 VM
- Removal of 'late' nested virtualization feature register masking,
making the supported feature set directly visible to userspace
- Support for emulating FEAT_PMUv3 on Apple silicon, taking advantage
of an IMPLEMENTATION DEFINED trap that covers all PMUv3 registers
- Paravirtual interface for discovering the set of CPU
implementations where a VM may run, addressing a longstanding issue
of guest CPU errata awareness in big-little systems and
cross-implementation VM migration
- Userspace control of the registers responsible for identifying a
particular CPU implementation (MIDR_EL1, REVIDR_EL1, AIDR_EL1),
allowing VMs to be migrated cross-implementation
- pKVM updates, including support for tracking stage-2 page table
allocations in the protected hypervisor in the 'SecPageTable' stat
- Fixes to vPMU, ensuring that userspace updates to the vPMU after
KVM_RUN are reflected into the backing perf events
LoongArch:
- Remove unnecessary header include path
- Assume constant PGD during VM context switch
- Add perf events support for guest VM
RISC-V:
- Disable the kernel perf counter during configure
- KVM selftests improvements for PMU
- Fix warning at the time of KVM module removal
x86:
- Add support for aging of SPTEs without holding mmu_lock.
Not taking mmu_lock allows multiple aging actions to run in
parallel, and more importantly avoids stalling vCPUs. This includes
an implementation of per-rmap-entry locking; aging the gfn is done
with only a per-rmap single-bin spinlock taken, whereas locking an
rmap for write requires taking both the per-rmap spinlock and the
mmu_lock.
Note that this decreases slightly the accuracy of accessed-page
information, because changes to the SPTE outside aging might not
use atomic operations even if they could race against a clear of
the Accessed bit.
This is deliberate because KVM and mm/ tolerate false
positives/negatives for accessed information, and testing has shown
that reducing the latency of aging is far more beneficial to
overall system performance than providing "perfect" young/old
information.
- Defer runtime CPUID updates until KVM emulates a CPUID instruction,
to coalesce updates when multiple pieces of vCPU state are
changing, e.g. as part of a nested transition
- Fix a variety of nested emulation bugs, and add VMX support for
synthesizing nested VM-Exit on interception (instead of injecting
#UD into L2)
- Drop "support" for async page faults for protected guests that do
not set SEND_ALWAYS (i.e. that only want async page faults at CPL3)
- Bring a bit of sanity to x86's VM teardown code, which has
accumulated a lot of cruft over the years. Particularly, destroy
vCPUs before the MMU, despite the latter being a VM-wide operation
- Add common secure TSC infrastructure for use within SNP and in the
future TDX
- Block KVM_CAP_SYNC_REGS if guest state is protected. It does not
make sense to use the capability if the relevant registers are not
available for reading or writing
- Don't take kvm->lock when iterating over vCPUs in the suspend
notifier to fix a largely theoretical deadlock
- Use the vCPU's actual Xen PV clock information when starting the
Xen timer, as the cached state in arch.hv_clock can be stale/bogus
- Fix a bug where KVM could bleed PVCLOCK_GUEST_STOPPED across
different PV clocks; restrict PVCLOCK_GUEST_STOPPED to kvmclock, as
KVM's suspend notifier only accounts for kvmclock, and there's no
evidence that the flag is actually supported by Xen guests
- Clean up the per-vCPU "cache" of its reference pvclock, and instead
only track the vCPU's TSC scaling (multipler+shift) metadata (which
is moderately expensive to compute, and rarely changes for modern
setups)
- Don't write to the Xen hypercall page on MSR writes that are
initiated by the host (userspace or KVM) to fix a class of bugs
where KVM can write to guest memory at unexpected times, e.g.
during vCPU creation if userspace has set the Xen hypercall MSR
index to collide with an MSR that KVM emulates
- Restrict the Xen hypercall MSR index to the unofficial synthetic
range to reduce the set of possible collisions with MSRs that are
emulated by KVM (collisions can still happen as KVM emulates
Hyper-V MSRs, which also reside in the synthetic range)
- Clean up and optimize KVM's handling of Xen MSR writes and
xen_hvm_config
- Update Xen TSC leaves during CPUID emulation instead of modifying
the CPUID entries when updating PV clocks; there is no guarantee PV
clocks will be updated between TSC frequency changes and CPUID
emulation, and guest reads of the TSC leaves should be rare, i.e.
are not a hot path
x86 (Intel):
- Fix a bug where KVM unnecessarily reads XFD_ERR from hardware and
thus modifies the vCPU's XFD_ERR on a #NM due to CR0.TS=1
- Pass XFD_ERR as the payload when injecting #NM, as a preparatory
step for upcoming FRED virtualization support
- Decouple the EPT entry RWX protection bit macros from the EPT
Violation bits, both as a general cleanup and in anticipation of
adding support for emulating Mode-Based Execution Control (MBEC)
- Reject KVM_RUN if userspace manages to gain control and stuff
invalid guest state while KVM is in the middle of emulating nested
VM-Enter
- Add a macro to handle KVM's sanity checks on entry/exit VMCS
control pairs in anticipation of adding sanity checks for secondary
exit controls (the primary field is out of bits)
x86 (AMD):
- Ensure the PSP driver is initialized when both the PSP and KVM
modules are built-in (the initcall framework doesn't handle
dependencies)
- Use long-term pins when registering encrypted memory regions, so
that the pages are migrated out of MIGRATE_CMA/ZONE_MOVABLE and
don't lead to excessive fragmentation
- Add macros and helpers for setting GHCB return/error codes
- Add support for Idle HLT interception, which elides interception if
the vCPU has a pending, unmasked virtual IRQ when HLT is executed
- Fix a bug in INVPCID emulation where KVM fails to check for a
non-canonical address
- Don't attempt VMRUN for SEV-ES+ guests if the vCPU's VMSA is
invalid, e.g. because the vCPU was "destroyed" via SNP's AP
Creation hypercall
- Reject SNP AP Creation if the requested SEV features for the vCPU
don't match the VM's configured set of features
Selftests:
- Fix again the Intel PMU counters test; add a data load and do
CLFLUSH{OPT} on the data instead of executing code. The theory is
that modern Intel CPUs have learned new code prefetching tricks
that bypass the PMU counters
- Fix a flaw in the Intel PMU counters test where it asserts that an
event is counting correctly without actually knowing what the event
counts on the underlying hardware
- Fix a variety of flaws, bugs, and false failures/passes
dirty_log_test, and improve its coverage by collecting all dirty
entries on each iteration
- Fix a few minor bugs related to handling of stats FDs
- Add infrastructure to make vCPU and VM stats FDs available to tests
by default (open the FDs during VM/vCPU creation)
- Relax an assertion on the number of HLT exits in the xAPIC IPI test
when running on a CPU that supports AMD's Idle HLT (which elides
interception of HLT if a virtual IRQ is pending and unmasked)"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (216 commits)
RISC-V: KVM: Optimize comments in kvm_riscv_vcpu_isa_disable_allowed
RISC-V: KVM: Teardown riscv specific bits after kvm_exit
LoongArch: KVM: Register perf callbacks for guest
LoongArch: KVM: Implement arch-specific functions for guest perf
LoongArch: KVM: Add stub for kvm_arch_vcpu_preempted_in_kernel()
LoongArch: KVM: Remove PGD saving during VM context switch
LoongArch: KVM: Remove unnecessary header include path
KVM: arm64: Tear down vGIC on failed vCPU creation
KVM: arm64: PMU: Reload when resetting
KVM: arm64: PMU: Reload when user modifies registers
KVM: arm64: PMU: Fix SET_ONE_REG for vPMC regs
KVM: arm64: PMU: Assume PMU presence in pmu-emul.c
KVM: arm64: PMU: Set raw values from user to PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
KVM: arm64: Create each pKVM hyp vcpu after its corresponding host vcpu
KVM: arm64: Factor out pKVM hyp vcpu creation to separate function
KVM: arm64: Initialize HCRX_EL2 traps in pKVM
KVM: arm64: Factor out setting HCRX_EL2 traps into separate function
KVM: x86: block KVM_CAP_SYNC_REGS if guest state is protected
KVM: x86: Add infrastructure for secure TSC
KVM: x86: Push down setting vcpu.arch.user_set_tsc
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 speculation mitigation updates from Borislav Petkov:
- Some preparatory work to convert the mitigations machinery to
mitigating attack vectors instead of single vulnerabilities
- Untangle and remove a now unneeded X86_FEATURE_USE_IBPB flag
- Add support for a Zen5-specific SRSO mitigation
- Cleanups and minor improvements
* tag 'x86_bugs_for_v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/bugs: Make spectre user default depend on MITIGATION_SPECTRE_V2
x86/bugs: Use the cpu_smt_possible() helper instead of open-coded code
x86/bugs: Add AUTO mitigations for mds/taa/mmio/rfds
x86/bugs: Relocate mds/taa/mmio/rfds defines
x86/bugs: Add X86_BUG_SPECTRE_V2_USER
x86/bugs: Remove X86_FEATURE_USE_IBPB
KVM: nVMX: Always use IBPB to properly virtualize IBRS
x86/bugs: Use a static branch to guard IBPB on vCPU switch
x86/bugs: Remove the X86_FEATURE_USE_IBPB check in ib_prctl_set()
x86/mm: Remove X86_FEATURE_USE_IBPB checks in cond_mitigation()
x86/bugs: Move the X86_FEATURE_USE_IBPB check into callers
x86/bugs: KVM: Add support for SRSO_MSR_FIX
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core x86 updates from Ingo Molnar:
"x86 CPU features support:
- Generate the <asm/cpufeaturemasks.h> header based on build config
(H. Peter Anvin, Xin Li)
- x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
- Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
- Enable modifying CPU bug flags with '{clear,set}puid=' (Brendan
Jackman)
- Utilize CPU-type for CPU matching (Pawan Gupta)
- Warn about unmet CPU feature dependencies (Sohil Mehta)
- Prepare for new Intel Family numbers (Sohil Mehta)
Percpu code:
- Standardize & reorganize the x86 percpu layout and related cleanups
(Brian Gerst)
- Convert the stackprotector canary to a regular percpu variable
(Brian Gerst)
- Add a percpu subsection for cache hot data (Brian Gerst)
- Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
- Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)
MM:
- Add support for broadcast TLB invalidation using AMD's INVLPGB
instruction (Rik van Riel)
- Rework ROX cache to avoid writable copy (Mike Rapoport)
- PAT: restore large ROX pages after fragmentation (Kirill A.
Shutemov, Mike Rapoport)
- Make memremap(MEMREMAP_WB) map memory as encrypted by default
(Kirill A. Shutemov)
- Robustify page table initialization (Kirill A. Shutemov)
- Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
- Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
(Matthew Wilcox)
KASLR:
- x86/kaslr: Reduce KASLR entropy on most x86 systems, to support PCI
BAR space beyond the 10TiB region (CONFIG_PCI_P2PDMA=y) (Balbir
Singh)
CPU bugs:
- Implement FineIBT-BHI mitigation (Peter Zijlstra)
- speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
- speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan
Gupta)
- RFDS: Exclude P-only parts from the RFDS affected list (Pawan
Gupta)
System calls:
- Break up entry/common.c (Brian Gerst)
- Move sysctls into arch/x86 (Joel Granados)
Intel LAM support updates: (Maciej Wieczor-Retman)
- selftests/lam: Move cpu_has_la57() to use cpuinfo flag
- selftests/lam: Skip test if LAM is disabled
- selftests/lam: Test get_user() LAM pointer handling
AMD SMN access updates:
- Add SMN offsets to exclusive region access (Mario Limonciello)
- Add support for debugfs access to SMN registers (Mario Limonciello)
- Have HSMP use SMN through AMD_NODE (Yazen Ghannam)
Power management updates: (Patryk Wlazlyn)
- Allow calling mwait_play_dead with an arbitrary hint
- ACPI/processor_idle: Add FFH state handling
- intel_idle: Provide the default enter_dead() handler
- Eliminate mwait_play_dead_cpuid_hint()
Build system:
- Raise the minimum GCC version to 8.1 (Brian Gerst)
- Raise the minimum LLVM version to 15.0.0 (Nathan Chancellor)
Kconfig: (Arnd Bergmann)
- Add cmpxchg8b support back to Geode CPUs
- Drop 32-bit "bigsmp" machine support
- Rework CONFIG_GENERIC_CPU compiler flags
- Drop configuration options for early 64-bit CPUs
- Remove CONFIG_HIGHMEM64G support
- Drop CONFIG_SWIOTLB for PAE
- Drop support for CONFIG_HIGHPTE
- Document CONFIG_X86_INTEL_MID as 64-bit-only
- Remove old STA2x11 support
- Only allow CONFIG_EISA for 32-bit
Headers:
- Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI
headers (Thomas Huth)
Assembly code & machine code patching:
- x86/alternatives: Simplify alternative_call() interface (Josh
Poimboeuf)
- x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
- KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
- x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
- x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
- x86/kexec: Merge x86_32 and x86_64 code using macros from
<asm/asm.h> (Uros Bizjak)
- Use named operands in inline asm (Uros Bizjak)
- Improve performance by using asm_inline() for atomic locking
instructions (Uros Bizjak)
Earlyprintk:
- Harden early_serial (Peter Zijlstra)
NMI handler:
- Add an emergency handler in nmi_desc & use it in
nmi_shootdown_cpus() (Waiman Long)
Miscellaneous fixes and cleanups:
- by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel, Artem
Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst, Dan
Carpenter, Dr. David Alan Gilbert, H. Peter Anvin, Ingo Molnar,
Josh Poimboeuf, Kevin Brodsky, Mike Rapoport, Lukas Bulwahn, Maciej
Wieczor-Retman, Max Grobecker, Patryk Wlazlyn, Pawan Gupta, Peter
Zijlstra, Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak, Vitaly
Kuznetsov, Xin Li, liuye"
* tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (211 commits)
zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault
x86/asm: Make asm export of __ref_stack_chk_guard unconditional
x86/mm: Only do broadcast flush from reclaim if pages were unmapped
perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM ones
perf/x86/intel, x86/cpu: Simplify Intel PMU initialization
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI headers
x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions
x86/asm: Use asm_inline() instead of asm() in clwb()
x86/asm: Use CLFLUSHOPT and CLWB mnemonics in <asm/special_insns.h>
x86/hweight: Use asm_inline() instead of asm()
x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm()
x86/hweight: Use named operands in inline asm()
x86/stackprotector/64: Only export __ref_stack_chk_guard on CONFIG_SMP
x86/head/64: Avoid Clang < 17 stack protector in startup code
x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro
x86/cpu/intel: Limit the non-architectural constant_tsc model checks
x86/mm/pat: Replace Intel x86_model checks with VFM ones
x86/cpu/intel: Fix fast string initialization for extended Families
...
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* kvm-arm64/pv-cpuid:
: Paravirtualized implementation ID, courtesy of Shameer Kolothum
:
: Big-little has historically been a pain in the ass to virtualize. The
: implementation ID (MIDR, REVIDR, AIDR) of a vCPU can change at the whim
: of vCPU scheduling. This can be particularly annoying when the guest
: needs to know the underlying implementation to mitigate errata.
:
: "Hyperscalers" face a similar scheduling problem, where VMs may freely
: migrate between hosts in a pool of heterogenous hardware. And yes, our
: server-class friends are equally riddled with errata too.
:
: In absence of an architected solution to this wart on the ecosystem,
: introduce support for paravirtualizing the implementation exposed
: to a VM, allowing the VMM to describe the pool of implementations that a
: VM may be exposed to due to scheduling/migration.
:
: Userspace is expected to intercept and handle these hypercalls using the
: SMCCC filter UAPI, should it choose to do so.
smccc: kvm_guest: Fix kernel builds for 32 bit arm
KVM: selftests: Add test for KVM_REG_ARM_VENDOR_HYP_BMAP_2
smccc/kvm_guest: Enable errata based on implementation CPUs
arm64: Make _midr_in_range_list() an exported function
KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2
KVM: arm64: Specify hypercall ABI for retrieving target implementations
arm64: Modify _midr_range() functions to read MIDR/REVIDR internally
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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* kvm-arm64/nv-vgic:
: NV VGICv3 support, courtesy of Marc Zyngier
:
: Support for emulating the GIC hypervisor controls and managing shadow
: VGICv3 state for the L1 hypervisor. As part of it, bring in support for
: taking IRQs to the L1 and UAPI to manage the VGIC maintenance interrupt.
KVM: arm64: nv: Fail KVM init if asking for NV without GICv3
KVM: arm64: nv: Allow userland to set VGIC maintenance IRQ
KVM: arm64: nv: Fold GICv3 host trapping requirements into guest setup
KVM: arm64: nv: Propagate used_lrs between L1 and L0 contexts
KVM: arm64: nv: Request vPE doorbell upon nested ERET to L2
KVM: arm64: nv: Respect virtual HCR_EL2.TWx setting
KVM: arm64: nv: Add Maintenance Interrupt emulation
KVM: arm64: nv: Handle L2->L1 transition on interrupt injection
KVM: arm64: nv: Nested GICv3 emulation
KVM: arm64: nv: Sanitise ICH_HCR_EL2 accesses
KVM: arm64: nv: Plumb handling of GICv3 EL2 accesses
KVM: arm64: nv: Add ICH_*_EL2 registers to vpcu_sysreg
KVM: arm64: nv: Load timer before the GIC
arm64: sysreg: Add layout for ICH_MISR_EL2
arm64: sysreg: Add layout for ICH_VTR_EL2
arm64: sysreg: Add layout for ICH_HCR_EL2
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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While the GCC and Clang compilers already define __ASSEMBLER__
automatically when compiling assembly code, __ASSEMBLY__ is a
macro that only gets defined by the Makefiles in the kernel.
This can be very confusing when switching between userspace
and kernelspace coding, or when dealing with UAPI headers that
rather should use __ASSEMBLER__ instead. So let's standardize on
the __ASSEMBLER__ macro that is provided by the compilers now.
This is mostly a mechanical patch (done with a simple "sed -i"
statement), with some manual tweaks in <asm/frame.h>, <asm/hw_irq.h>
and <asm/setup.h> that mentioned this macro in comments with some
missing underscores.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250314071013.1575167-38-thuth@redhat.com
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The functionalities of {disabled,required}-features.h have been replaced with
the auto-generated generated/<asm/cpufeaturemasks.h> header.
Thus they are no longer needed and can be removed.
None of the macros defined in {disabled,required}-features.h is used in tools,
delete them too.
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250305184725.3341760-4-xin@zytor.com
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With AMD TCE (translation cache extensions) only the intermediate mappings
that cover the address range zapped by INVLPG / INVLPGB get invalidated,
rather than all intermediate mappings getting zapped at every TLB invalidation.
This can help reduce the TLB miss rate, by keeping more intermediate mappings
in the cache.
From the AMD manual:
Translation Cache Extension (TCE) Bit. Bit 15, read/write. Setting this bit to
1 changes how the INVLPG, INVLPGB, and INVPCID instructions operate on TLB
entries. When this bit is 0, these instructions remove the target PTE from the
TLB as well as all upper-level table entries that are cached in the TLB,
whether or not they are associated with the target PTE. When this bit is set,
these instructions will remove the target PTE and only those upper-level
entries that lead to the target PTE in the page table hierarchy, leaving
unrelated upper-level entries intact.
[ bp: use cpu_has()... I know, it is a mess. ]
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250226030129.530345-13-riel@surriel.com
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The VGIC maintenance IRQ signals various conditions about the LRs, when
the GIC's virtualization extension is used.
So far we didn't need it, but nested virtualization needs to know about
this interrupt, so add a userland interface to setup the IRQ number.
The architecture mandates that it must be a PPI, on top of that this code
only exports a per-device option, so the PPI is the same on all VCPUs.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[added some bits of documentation]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-16-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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The ICH_MISR_EL2-related macros are missing a number of status
bits that we are about to handle. Take this opportunity to fully
describe the layout of that register as part of the automatic
generation infrastructure.
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-4-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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The ICH_VTR_EL2-related macros are missing a number of config
bits that we are about to handle. Take this opportunity to fully
describe the layout of that register as part of the automatic
generation infrastructure.
This results in a bit of churn to repaint constants that are now
generated with a different format.
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-3-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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The ICH_HCR_EL2-related macros are missing a number of control
bits that we are about to handle. Take this opportunity to fully
describe the layout of that register as part of the automatic
generation infrastructure.
This results in a bit of churn, unfortunately.
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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tools/arch/x86/include/linux doesn't exist but building is working by
virtue of a -I. Building using bazel this fails. Use angle brackets to
include unaligned.h so there isn't an invalid relative include.
Fixes: 5f60d5f6bbc1 ("move asm/unaligned.h to linux/unaligned.h")
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20250225193600.90037-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Replace X86_CMPXCHG64 with X86_CX8, as CX8 is the name of the CPUID
flag, thus to make it consistent with X86_FEATURE_CX8 defined in
<asm/cpufeatures.h>.
No functional change intended.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250228082338.73859-2-xin@zytor.com
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X86_FEATURE_USE_IBPB was introduced in:
2961298efe1e ("x86/cpufeatures: Clean up Spectre v2 related CPUID flags")
to have separate flags for when the CPU supports IBPB (i.e. X86_FEATURE_IBPB)
and when an IBPB is actually used to mitigate Spectre v2.
Ever since then, the uses of IBPB expanded. The name became confusing
because it does not control all IBPB executions in the kernel.
Furthermore, because its name is generic and it's buried within
indirect_branch_prediction_barrier(), it's easy to use it not knowing
that it is specific to Spectre v2.
X86_FEATURE_USE_IBPB is no longer needed because all the IBPB executions
it used to control are now controlled through other means (e.g.
switch_mm_*_ibpb static branches).
Remove the unused feature bit.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20250227012712.3193063-7-yosry.ahmed@linux.dev
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One difference here with other pseudo-firmware bitmap registers
is that the default/reset value for the supported hypercall
function-ids is 0 at present. Hence, modify the test accordingly.
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20250221140229.12588-7-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools
Pull perf tools fixes from Arnaldo Carvalho de Melo:
- Fix tools/ quiet build Makefile infrastructure that was broken when
working on tools/perf/ without testing on other tools/ living
utilities.
* tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
tools: Remove redundant quiet setup
tools: Unify top-level quiet infrastructure
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Q is exported from Makefile.include so it is not necessary to manually
set it.
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Benjamin Tissoires <bentiss@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Lukasz Luba <lukasz.luba@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Mykola Lysenko <mykolal@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20250213-quiet_tools-v3-2-07de4482a581@rivosinc.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Sync load latency related bit fields into the tool's header copy
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250205060547.1337-4-ravi.bangoria@amd.com
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Convert TRFCR to automatic generation. Add separate definitions for ELx
and EL2 as TRFCR_EL1 doesn't have CX. This also mirrors the previous
definition so no code change is required.
Also add TRFCR_EL12 which will start to be used in a later commit.
Unfortunately, to avoid breaking the Perf build with duplicate
definition errors, the tools copy of the sysreg.h header needs to be
updated at the same time rather than the usual second commit. This is
because the generated version of sysreg
(arch/arm64/include/generated/asm/sysreg-defs.h), is currently shared
and tools/ does not have its own copy.
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250106142446.628923-4-james.clark@linaro.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Created with the following:
cp include/linux/kasan-tags.h tools/include/linux/
cp arch/arm64/include/asm/sysreg.h tools/arch/arm64/include/asm/
Update the tools copy of sysreg.h so that the next commit to add a new
register doesn't have unrelated changes in it. Because the new version
of sysreg.h includes kasan-tags.h, that file also now needs to be copied
into tools.
Acked-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250106142446.628923-3-james.clark@linaro.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
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To pick up the changes in this cset:
97413cea1c48cc05 ("KVM: arm64: Add PSCI v1.3 SYSTEM_OFF2 function for hibernation")
This addresses these perf build warnings:
Warning: Kernel ABI header differences:
diff -u tools/arch/arm64/include/uapi/asm/kvm.h arch/arm64/include/uapi/asm/kvm.h
Please see tools/include/uapi/README for further details.
Reviewed-by: James Clark <james.clark@linaro.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: kvmarm@lists.linux.dev
Link: https://lore.kernel.org/r/20241203035349.1901262-6-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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To pick up the changes in this cset:
a0423af92cb31e6f ("x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest")
0c487010cb4f79e4 ("x86/cpufeatures: Add X86_FEATURE_AMD_WORKLOAD_CLASS feature bit")
1ad4667066714369 ("x86/cpufeatures: Add X86_FEATURE_AMD_HETEROGENEOUS_CORES")
104edc6efca62838 ("x86/cpufeatures: Rename X86_FEATURE_FAST_CPPC to have AMD prefix")
3ea87dfa31a7b0bb ("x86/cpufeatures: Add a IBPB_NO_RET BUG flag")
ff898623af2ed564 ("x86/cpufeatures: Define X86_FEATURE_AMD_IBPB_RET")
dcb988cdac85bad1 ("KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration")
This addresses these perf build warnings:
Warning: Kernel ABI header differences:
diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h
diff -u tools/arch/x86/include/uapi/asm/kvm.h arch/x86/include/uapi/asm/kvm.h
Please see tools/include/uapi/README for further details.
Reviewed-by: James Clark <james.clark@linaro.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20241203035349.1901262-5-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Pull kvm updates from Paolo Bonzini:
"The biggest change here is eliminating the awful idea that KVM had of
essentially guessing which pfns are refcounted pages.
The reason to do so was that KVM needs to map both non-refcounted
pages (for example BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP
VMAs that contain refcounted pages.
However, the result was security issues in the past, and more recently
the inability to map VM_IO and VM_PFNMAP memory that _is_ backed by
struct page but is not refcounted. In particular this broke virtio-gpu
blob resources (which directly map host graphics buffers into the
guest as "vram" for the virtio-gpu device) with the amdgpu driver,
because amdgpu allocates non-compound higher order pages and the tail
pages could not be mapped into KVM.
This requires adjusting all uses of struct page in the
per-architecture code, to always work on the pfn whenever possible.
The large series that did this, from David Stevens and Sean
Christopherson, also cleaned up substantially the set of functions
that provided arch code with the pfn for a host virtual addresses.
The previous maze of twisty little passages, all different, is
replaced by five functions (__gfn_to_page, __kvm_faultin_pfn, the
non-__ versions of these two, and kvm_prefetch_pages) saving almost
200 lines of code.
ARM:
- Support for stage-1 permission indirection (FEAT_S1PIE) and
permission overlays (FEAT_S1POE), including nested virt + the
emulated page table walker
- Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This
call was introduced in PSCIv1.3 as a mechanism to request
hibernation, similar to the S4 state in ACPI
- Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
part of it, introduce trivial initialization of the host's MPAM
context so KVM can use the corresponding traps
- PMU support under nested virtualization, honoring the guest
hypervisor's trap configuration and event filtering when running a
nested guest
- Fixes to vgic ITS serialization where stale device/interrupt table
entries are not zeroed when the mapping is invalidated by the VM
- Avoid emulated MMIO completion if userspace has requested
synchronous external abort injection
- Various fixes and cleanups affecting pKVM, vCPU initialization, and
selftests
LoongArch:
- Add iocsr and mmio bus simulation in kernel.
- Add in-kernel interrupt controller emulation.
- Add support for virtualization extensions to the eiointc irqchip.
PPC:
- Drop lingering and utterly obsolete references to PPC970 KVM, which
was removed 10 years ago.
- Fix incorrect documentation references to non-existing ioctls
RISC-V:
- Accelerate KVM RISC-V when running as a guest
- Perf support to collect KVM guest statistics from host side
s390:
- New selftests: more ucontrol selftests and CPU model sanity checks
- Support for the gen17 CPU model
- List registers supported by KVM_GET/SET_ONE_REG in the
documentation
x86:
- Cleanup KVM's handling of Accessed and Dirty bits to dedup code,
improve documentation, harden against unexpected changes.
Even if the hardware A/D tracking is disabled, it is possible to
use the hardware-defined A/D bits to track if a PFN is Accessed
and/or Dirty, and that removes a lot of special cases.
- Elide TLB flushes when aging secondary PTEs, as has been done in
x86's primary MMU for over 10 years.
- Recover huge pages in-place in the TDP MMU when dirty page logging
is toggled off, instead of zapping them and waiting until the page
is re-accessed to create a huge mapping. This reduces vCPU jitter.
- Batch TLB flushes when dirty page logging is toggled off. This
reduces the time it takes to disable dirty logging by ~3x.
- Remove the shrinker that was (poorly) attempting to reclaim shadow
page tables in low-memory situations.
- Clean up and optimize KVM's handling of writes to
MSR_IA32_APICBASE.
- Advertise CPUIDs for new instructions in Clearwater Forest
- Quirk KVM's misguided behavior of initialized certain feature MSRs
to their maximum supported feature set, which can result in KVM
creating invalid vCPU state. E.g. initializing PERF_CAPABILITIES to
a non-zero value results in the vCPU having invalid state if
userspace hides PDCM from the guest, which in turn can lead to
save/restore failures.
- Fix KVM's handling of non-canonical checks for vCPUs that support
LA57 to better follow the "architecture", in quotes because the
actual behavior is poorly documented. E.g. most MSR writes and
descriptor table loads ignore CR4.LA57 and operate purely on
whether the CPU supports LA57.
- Bypass the register cache when querying CPL from kvm_sched_out(),
as filling the cache from IRQ context is generally unsafe; harden
the cache accessors to try to prevent similar issues from occuring
in the future. The issue that triggered this change was already
fixed in 6.12, but was still kinda latent.
- Advertise AMD_IBPB_RET to userspace, and fix a related bug where
KVM over-advertises SPEC_CTRL when trying to support cross-vendor
VMs.
- Minor cleanups
- Switch hugepage recovery thread to use vhost_task.
These kthreads can consume significant amounts of CPU time on
behalf of a VM or in response to how the VM behaves (for example
how it accesses its memory); therefore KVM tried to place the
thread in the VM's cgroups and charge the CPU time consumed by that
work to the VM's container.
However the kthreads did not process SIGSTOP/SIGCONT, and therefore
cgroups which had KVM instances inside could not complete freezing.
Fix this by replacing the kthread with a PF_USER_WORKER thread, via
the vhost_task abstraction. Another 100+ lines removed, with
generally better behavior too like having these threads properly
parented in the process tree.
- Revert a workaround for an old CPU erratum (Nehalem/Westmere) that
didn't really work; there was really nothing to work around anyway:
the broken patch was meant to fix nested virtualization, but the
PERF_GLOBAL_CTRL MSR is virtualized and therefore unaffected by the
erratum.
- Fix 6.12 regression where CONFIG_KVM will be built as a module even
if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is
'y'.
x86 selftests:
- x86 selftests can now use AVX.
Documentation:
- Use rST internal links
- Reorganize the introduction to the API document
Generic:
- Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock
instead of RCU, so that running a vCPU on a different task do |
