- Use local labels in the exception table macros to avoid symbol
conflicts with clang LTO builds
- A couple of fixes to objtool checking of the relatively newly added
SLS and IBT code
- Rename a local var in the WARN* macro machinery to prevent shadowing
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Merge tag 'x86_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Fix the MSI message data struct definition
- Use local labels in the exception table macros to avoid symbol
conflicts with clang LTO builds
- A couple of fixes to objtool checking of the relatively newly added
SLS and IBT code
- Rename a local var in the WARN* macro machinery to prevent shadowing
* tag 'x86_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/msi: Fix msi message data shadow struct
x86/extable: Prefer local labels in .set directives
x86,bpf: Avoid IBT objtool warning
objtool: Fix SLS validation for kcov tail-call replacement
objtool: Fix IBT tail-call detection
x86/bug: Prevent shadowing in __WARN_FLAGS
x86/mm/tlb: Revert retpoline avoidance approach
- A couple of fixes to event encoding on Sapphire Rapids
- Pass event caps of inherited events so that perf doesn't fail wrongly at fork()
- Add support for a new Raptor Lake CPU
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Merge tag 'perf_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:
- A couple of fixes to cgroup-related handling of perf events
- A couple of fixes to event encoding on Sapphire Rapids
- Pass event caps of inherited events so that perf doesn't fail wrongly
at fork()
- Add support for a new Raptor Lake CPU
* tag 'perf_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Always set cpuctx cgrp when enable cgroup event
perf/core: Fix perf_cgroup_switch()
perf/core: Use perf_cgroup_info->active to check if cgroup is active
perf/core: Don't pass task around when ctx sched in
perf/x86/intel: Update the FRONTEND MSR mask on Sapphire Rapids
perf/x86/intel: Don't extend the pseudo-encoding to GP counters
perf/core: Inherit event_caps
perf/x86/uncore: Add Raptor Lake uncore support
perf/x86/msr: Add Raptor Lake CPU support
perf/x86/cstate: Add Raptor Lake support
perf/x86: Add Intel Raptor Lake support
the local_lock_* macros back to inline functions
- A couple of fixes to static call insn patching
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Merge tag 'locking_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Borislav Petkov:
- Allow the compiler to optimize away unused percpu accesses and change
the local_lock_* macros back to inline functions
- A couple of fixes to static call insn patching
* tag 'locking_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Revert "mm/page_alloc: mark pagesets as __maybe_unused"
Revert "locking/local_lock: Make the empty local_lock_*() function a macro."
x86/percpu: Remove volatile from arch_raw_cpu_ptr().
static_call: Remove __DEFINE_STATIC_CALL macro
static_call: Properly initialise DEFINE_STATIC_CALL_RET0()
static_call: Don't make __static_call_return0 static
x86,static_call: Fix __static_call_return0 for i386
The x86 MSI message data is 32 bits in total and is either in
compatibility or remappable format, see Intel Virtualization Technology
for Directed I/O, section 5.1.2.
Fixes: 6285aa5073 ("x86/msi: Provide msi message shadow structs")
Co-developed-by: Adrian-Ken Rueegsegger <ken@codelabs.ch>
Signed-off-by: Adrian-Ken Rueegsegger <ken@codelabs.ch>
Signed-off-by: Reto Buerki <reet@codelabs.ch>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220407110647.67372-1-reet@codelabs.ch
Bernardo reported an error that Nathan bisected down to
(x86_64) defconfig+LTO_CLANG_FULL+X86_PMEM_LEGACY.
LTO vmlinux.o
ld.lld: error: <instantiation>:1:13: redefinition of 'found'
.set found, 0
^
<inline asm>:29:1: while in macro instantiation
extable_type_reg reg=%eax, type=(17 | ((0) << 16))
^
This appears to be another LTO specific issue similar to what was folded
into commit 4b5305decc ("x86/extable: Extend extable functionality"),
where the `.set found, 0` in DEFINE_EXTABLE_TYPE_REG in
arch/x86/include/asm/asm.h conflicts with the symbol for the static
function `found` in arch/x86/kernel/pmem.c.
Assembler .set directive declare symbols with global visibility, so the
assembler may not rename such symbols in the event of a conflict. LTO
could rename static functions if there was a conflict in C sources, but
it cannot see into symbols defined in inline asm.
The symbols are also retained in the symbol table, regardless of LTO.
Give the symbols .L prefixes making them locally visible, so that they
may be renamed for LTO to avoid conflicts, and to drop them from the
symbol table regardless of LTO.
Fixes: 4b5305decc ("x86/extable: Extend extable functionality")
Reported-by: Bernardo Meurer Costa <beme@google.com>
Debugged-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20220329202148.2379697-1-ndesaulniers@google.com
Clang can inline emit_indirect_jump() and then folds constants, which
results in:
| vmlinux.o: warning: objtool: emit_bpf_dispatcher()+0x6a4: relocation to !ENDBR: .text.__x86.indirect_thunk+0x40
| vmlinux.o: warning: objtool: emit_bpf_dispatcher()+0x67d: relocation to !ENDBR: .text.__x86.indirect_thunk+0x40
| vmlinux.o: warning: objtool: emit_bpf_tail_call_indirect()+0x386: relocation to !ENDBR: .text.__x86.indirect_thunk+0x20
| vmlinux.o: warning: objtool: emit_bpf_tail_call_indirect()+0x35d: relocation to !ENDBR: .text.__x86.indirect_thunk+0x20
Suppress the optimization such that it must emit a code reference to
the __x86_indirect_thunk_array[] base.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lkml.kernel.org/r/20220405075531.GB30877@worktop.programming.kicks-ass.net
After resuming from suspend-to-RAM, the MSRs that control CPU's
speculative execution behavior are not being restored on the boot CPU.
These MSRs are used to mitigate speculative execution vulnerabilities.
Not restoring them correctly may leave the CPU vulnerable. Secondary
CPU's MSRs are correctly being restored at S3 resume by
identify_secondary_cpu().
During S3 resume, restore these MSRs for boot CPU when restoring its
processor state.
Fixes: 772439717d ("x86/bugs/intel: Set proper CPU features and setup RDS")
Reported-by: Neelima Krishnan <neelima.krishnan@intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The mechanism to save/restore MSRs during S3 suspend/resume checks for
the MSR validity during suspend, and only restores the MSR if its a
valid MSR. This is not optimal, as an invalid MSR will unnecessarily
throw an exception for every suspend cycle. The more invalid MSRs,
higher the impact will be.
Check and save the MSR validity at setup. This ensures that only valid
MSRs that are guaranteed to not throw an exception will be attempted
during suspend.
Fixes: 7a9c2dd08e ("x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume")
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The macro __WARN_FLAGS() uses a local variable named "f". This being a
common name, there is a risk of shadowing other variables.
For example, GCC would yield:
| In file included from ./include/linux/bug.h:5,
| from ./include/linux/cpumask.h:14,
| from ./arch/x86/include/asm/cpumask.h:5,
| from ./arch/x86/include/asm/msr.h:11,
| from ./arch/x86/include/asm/processor.h:22,
| from ./arch/x86/include/asm/timex.h:5,
| from ./include/linux/timex.h:65,
| from ./include/linux/time32.h:13,
| from ./include/linux/time.h:60,
| from ./include/linux/stat.h:19,
| from ./include/linux/module.h:13,
| from virt/lib/irqbypass.mod.c:1:
| ./include/linux/rcupdate.h: In function 'rcu_head_after_call_rcu':
| ./arch/x86/include/asm/bug.h:80:21: warning: declaration of 'f' shadows a parameter [-Wshadow]
| 80 | __auto_type f = BUGFLAG_WARNING|(flags); \
| | ^
| ./include/asm-generic/bug.h:106:17: note: in expansion of macro '__WARN_FLAGS'
| 106 | __WARN_FLAGS(BUGFLAG_ONCE | \
| | ^~~~~~~~~~~~
| ./include/linux/rcupdate.h:1007:9: note: in expansion of macro 'WARN_ON_ONCE'
| 1007 | WARN_ON_ONCE(func != (rcu_callback_t)~0L);
| | ^~~~~~~~~~~~
| In file included from ./include/linux/rbtree.h:24,
| from ./include/linux/mm_types.h:11,
| from ./include/linux/buildid.h:5,
| from ./include/linux/module.h:14,
| from virt/lib/irqbypass.mod.c:1:
| ./include/linux/rcupdate.h:1001:62: note: shadowed declaration is here
| 1001 | rcu_head_after_call_rcu(struct rcu_head *rhp, rcu_callback_t f)
| | ~~~~~~~~~~~~~~~^
For reference, sparse also warns about it, c.f. [1].
This patch renames the variable from f to __flags (with two underscore
prefixes as suggested in the Linux kernel coding style [2]) in order
to prevent collisions.
[1] https://lore.kernel.org/all/CAFGhKbyifH1a+nAMCvWM88TK6fpNPdzFtUXPmRGnnQeePV+1sw@mail.gmail.com/
[2] Linux kernel coding style, section 12) Macros, Enums and RTL,
paragraph 5) namespace collisions when defining local variables in
macros resembling functions
https://www.kernel.org/doc/html/latest/process/coding-style.html#macros-enums-and-rtl
Fixes: bfb1a7c91f ("x86/bug: Merge annotate_reachable() into_BUG_FLAGS() asm")
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20220324023742.106546-1-mailhol.vincent@wanadoo.fr
On Sapphire Rapids, the FRONTEND_RETIRED.MS_FLOWS event requires the
FRONTEND MSR value 0x8. However, the current FRONTEND MSR mask doesn't
support it.
Update intel_spr_extra_regs[] to support it.
Fixes: 61b985e3e7 ("perf/x86/intel: Add perf core PMU support for Sapphire Rapids")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1648482543-14923-2-git-send-email-kan.liang@linux.intel.com
The INST_RETIRED.PREC_DIST event (0x0100) doesn't count on SPR.
perf stat -e cpu/event=0xc0,umask=0x0/,cpu/event=0x0,umask=0x1/ -C0
Performance counter stats for 'CPU(s) 0':
607,246 cpu/event=0xc0,umask=0x0/
0 cpu/event=0x0,umask=0x1/
The encoding for INST_RETIRED.PREC_DIST is pseudo-encoding, which
doesn't work on the generic counters. However, current perf extends its
mask to the generic counters.
The pseudo event-code for a fixed counter must be 0x00. Check and avoid
extending the mask for the fixed counter event which using the
pseudo-encoding, e.g., ref-cycles and PREC_DIST event.
With the patch,
perf stat -e cpu/event=0xc0,umask=0x0/,cpu/event=0x0,umask=0x1/ -C0
Performance counter stats for 'CPU(s) 0':
583,184 cpu/event=0xc0,umask=0x0/
583,048 cpu/event=0x0,umask=0x1/
Fixes: 2de71ee153 ("perf/x86/intel: Fix ICL/SPR INST_RETIRED.PREC_DIST encodings")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1648482543-14923-1-git-send-email-kan.liang@linux.intel.com
Raptor Lake is Intel's successor to Alder lake. From the perspective of
Intel cstate residency counters, there is nothing changed compared with
Alder lake.
Share adl_cstates with Alder lake.
Update the comments for Raptor Lake.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/1647366360-82824-2-git-send-email-kan.liang@linux.intel.com
From PMU's perspective, Raptor Lake is the same as the Alder Lake. The
only difference is the event list, which will be supported in the perf
tool later.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/1647366360-82824-1-git-send-email-kan.liang@linux.intel.com
The volatile attribute in the inline assembly of arch_raw_cpu_ptr()
forces the compiler to always generate the code, even if the compiler
can decide upfront that its result is not needed.
For instance invoking __intel_pmu_disable_all(false) (like
intel_pmu_snapshot_arch_branch_stack() does) leads to loading the
address of &cpu_hw_events into the register while compiler knows that it
has no need for it. This ends up with code like:
| movq $cpu_hw_events, %rax #, tcp_ptr__
| add %gs:this_cpu_off(%rip), %rax # this_cpu_off, tcp_ptr__
| xorl %eax, %eax # tmp93
It also creates additional code within local_lock() with !RT &&
!LOCKDEP which is not desired.
By removing the volatile attribute the compiler can place the
function freely and avoid it if it is not needed in the end.
By using the function twice the compiler properly caches only the
variable offset and always loads the CPU-offset.
this_cpu_ptr() also remains properly placed within a preempt_disable()
sections because
- arch_raw_cpu_ptr() assembly has a memory input ("m" (this_cpu_off))
- prempt_{dis,en}able() fundamentally has a 'barrier()' in it
Therefore this_cpu_ptr() is already properly serialized and does not
rely on the 'volatile' attribute.
Remove volatile from arch_raw_cpu_ptr().
[ bigeasy: Added Linus' explanation why this_cpu_ptr() is not moved out
of a preempt_disable() section without the 'volatile' attribute. ]
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220328145810.86783-2-bigeasy@linutronix.de
When a static call is updated with __static_call_return0() as target,
arch_static_call_transform() set it to use an optimised set of
instructions which are meant to lay in the same cacheline.
But when initialising a static call with DEFINE_STATIC_CALL_RET0(),
we get a branch to the real __static_call_return0() function instead
of getting the optimised setup:
c00d8120 <__SCT__perf_snapshot_branch_stack>:
c00d8120: 4b ff ff f4 b c00d8114 <__static_call_return0>
c00d8124: 3d 80 c0 0e lis r12,-16370
c00d8128: 81 8c 81 3c lwz r12,-32452(r12)
c00d812c: 7d 89 03 a6 mtctr r12
c00d8130: 4e 80 04 20 bctr
c00d8134: 38 60 00 00 li r3,0
c00d8138: 4e 80 00 20 blr
c00d813c: 00 00 00 00 .long 0x0
Add ARCH_DEFINE_STATIC_CALL_RET0_TRAMP() defined by each architecture
to setup the optimised configuration, and rework
DEFINE_STATIC_CALL_RET0() to call it:
c00d8120 <__SCT__perf_snapshot_branch_stack>:
c00d8120: 48 00 00 14 b c00d8134 <__SCT__perf_snapshot_branch_stack+0x14>
c00d8124: 3d 80 c0 0e lis r12,-16370
c00d8128: 81 8c 81 3c lwz r12,-32452(r12)
c00d812c: 7d 89 03 a6 mtctr r12
c00d8130: 4e 80 04 20 bctr
c00d8134: 38 60 00 00 li r3,0
c00d8138: 4e 80 00 20 blr
c00d813c: 00 00 00 00 .long 0x0
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/1e0a61a88f52a460f62a58ffc2a5f847d1f7d9d8.1647253456.git.christophe.leroy@csgroup.eu
Paolo reported that the instruction sequence that is used to replace:
call __static_call_return0
namely:
66 66 48 31 c0 data16 data16 xor %rax,%rax
decodes to something else on i386, namely:
66 66 48 data16 dec %ax
31 c0 xor %eax,%eax
Which is a nonsensical sequence that happens to have the same outcome.
*However* an important distinction is that it consists of 2
instructions which is a problem when the thing needs to be overwriten
with a regular call instruction again.
As such, replace the instruction with something that decodes the same
on both i386 and x86_64.
Fixes: 3f2a8fc4b1 ("static_call/x86: Add __static_call_return0()")
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220318204419.GT8939@worktop.programming.kicks-ass.net
0day reported a regression on a microbenchmark which is intended to
stress the TLB flushing path:
https://lore.kernel.org/all/20220317090415.GE735@xsang-OptiPlex-9020/
It pointed at a commit from Nadav which intended to remove retpoline
overhead in the TLB flushing path by taking the 'cond'-ition in
on_each_cpu_cond_mask(), pre-calculating it, and incorporating it into
'cpumask'. That allowed the code to use a bunch of earlier direct
calls instead of later indirect calls that need a retpoline.
But, in practice, threads can go idle (and into lazy TLB mode where
they don't need to flush their TLB) between the early and late calls.
It works in this direction and not in the other because TLB-flushing
threads tend to hold mmap_lock for write. Contention on that lock
causes threads to _go_ idle right in this early/late window.
There was not any performance data in the original commit specific
to the retpoline overhead. I did a few tests on a system with
retpolines:
https://lore.kernel.org/all/dd8be93c-ded6-b962-50d4-96b1c3afb2b7@intel.com/
which showed a possible small win. But, that small win pales in
comparison with the bigger loss induced on non-retpoline systems.
Revert the patch that removed the retpolines. This was not a
clean revert, but it was self-contained enough not to be too painful.
Fixes: 6035152d8e ("x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Nadav Amit <namit@vmware.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/164874672286.389.7021457716635788197.tip-bot2@tip-bot2
- Make the prctl() for enabling dynamic XSTATE components correct so it
adds the newly requested feature to the permission bitmap instead of
overwriting it. Add a selftest which validates that.
- Unroll string MMIO for encrypted SEV guests as the hypervisor cannot
emulate it.
- Handle supervisor states correctly in the FPU/XSTATE code so it takes
the feature set of the fpstate buffer into account. The feature sets
can differ between host and guest buffers. Guest buffers do not contain
supervisor states. So far this was not an issue, but with enabling
PASID it needs to be handled in the buffer offset calculation and in
the permission bitmaps.
- Avoid a gazillion of repeated CPUID invocations in by caching the values
early in the FPU/XSTATE code.
- Enable CONFIG_WERROR for X86.
- Make the X86 defconfigs more useful by adapting them to Y2022 reality.
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Merge tag 'x86-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A set of x86 fixes and updates:
- Make the prctl() for enabling dynamic XSTATE components correct so
it adds the newly requested feature to the permission bitmap
instead of overwriting it. Add a selftest which validates that.
- Unroll string MMIO for encrypted SEV guests as the hypervisor
cannot emulate it.
- Handle supervisor states correctly in the FPU/XSTATE code so it
takes the feature set of the fpstate buffer into account. The
feature sets can differ between host and guest buffers. Guest
buffers do not contain supervisor states. So far this was not an
issue, but with enabling PASID it needs to be handled in the buffer
offset calculation and in the permission bitmaps.
- Avoid a gazillion of repeated CPUID invocations in by caching the
values early in the FPU/XSTATE code.
- Enable CONFIG_WERROR in x86 defconfig.
- Make the X86 defconfigs more useful by adapting them to Y2022
reality"
* tag 'x86-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu/xstate: Consolidate size calculations
x86/fpu/xstate: Handle supervisor states in XSTATE permissions
x86/fpu/xsave: Handle compacted offsets correctly with supervisor states
x86/fpu: Cache xfeature flags from CPUID
x86/fpu/xsave: Initialize offset/size cache early
x86/fpu: Remove unused supervisor only offsets
x86/fpu: Remove redundant XCOMP_BV initialization
x86/sev: Unroll string mmio with CC_ATTR_GUEST_UNROLL_STRING_IO
x86/config: Make the x86 defconfigs a bit more usable
x86/defconfig: Enable WERROR
selftests/x86/amx: Update the ARCH_REQ_XCOMP_PERM test
x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation
generalized.
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Merge tag 'core-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RT signal fix from Thomas Gleixner:
"Revert the RT related signal changes. They need to be reworked and
generalized"
* tag 'core-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels"
* Documentation improvements
* Prevent module exit until all VMs are freed
* PMU Virtualization fixes
* Fix for kvm_irq_delivery_to_apic_fast() NULL-pointer dereferences
* Other miscellaneous bugfixes
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
- Only do MSR filtering for MSRs accessed by rdmsr/wrmsr
- Documentation improvements
- Prevent module exit until all VMs are freed
- PMU Virtualization fixes
- Fix for kvm_irq_delivery_to_apic_fast() NULL-pointer dereferences
- Other miscellaneous bugfixes
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits)
KVM: x86: fix sending PV IPI
KVM: x86/mmu: do compare-and-exchange of gPTE via the user address
KVM: x86: Remove redundant vm_entry_controls_clearbit() call
KVM: x86: cleanup enter_rmode()
KVM: x86: SVM: fix tsc scaling when the host doesn't support it
kvm: x86: SVM: remove unused defines
KVM: x86: SVM: move tsc ratio definitions to svm.h
KVM: x86: SVM: fix avic spec based definitions again
KVM: MIPS: remove reference to trap&emulate virtualization
KVM: x86: document limitations of MSR filtering
KVM: x86: Only do MSR filtering when access MSR by rdmsr/wrmsr
KVM: x86/emulator: Emulate RDPID only if it is enabled in guest
KVM: x86/pmu: Fix and isolate TSX-specific performance event logic
KVM: x86: mmu: trace kvm_mmu_set_spte after the new SPTE was set
KVM: x86/svm: Clear reserved bits written to PerfEvtSeln MSRs
KVM: x86: Trace all APICv inhibit changes and capture overall status
KVM: x86: Add wrappers for setting/clearing APICv inhibits
KVM: x86: Make APICv inhibit reasons an enum and cleanup naming
KVM: X86: Handle implicit supervisor access with SMAP
KVM: X86: Rename variable smap to not_smap in permission_fault()
...
If apic_id is less than min, and (max - apic_id) is greater than
KVM_IPI_CLUSTER_SIZE, then the third check condition is satisfied but
the new apic_id does not fit the bitmask. In this case __send_ipi_mask
should send the IPI.
This is mostly theoretical, but it can happen if the apic_ids on three
iterations of the loop are for example 1, KVM_IPI_CLUSTER_SIZE, 0.
Fixes: aaffcfd1e8 ("KVM: X86: Implement PV IPIs in linux guest")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Message-Id: <1646814944-51801-1-git-send-email-lirongqing@baidu.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
FNAME(cmpxchg_gpte) is an inefficient mess. It is at least decent if it
can go through get_user_pages_fast(), but if it cannot then it tries to
use memremap(); that is not just terribly slow, it is also wrong because
it assumes that the VM_PFNMAP VMA is contiguous.
The right way to do it would be to do the same thing as
hva_to_pfn_remapped() does since commit add6a0cd1c ("KVM: MMU: try to
fix up page faults before giving up", 2016-07-05), using follow_pte()
and fixup_user_fault() to determine the correct address to use for
memremap(). To do this, one could for example extract hva_to_pfn()
for use outside virt/kvm/kvm_main.c. But really there is no reason to
do that either, because there is already a perfectly valid address to
do the cmpxchg() on, only it is a userspace address. That means doing
user_access_begin()/user_access_end() and writing the code in assembly
to handle exceptions correctly. Worse, the guest PTE can be 8-byte
even on i686 so there is the extra complication of using cmpxchg8b to
account for. But at least it is an efficient mess.
(Thanks to Linus for suggesting improvement on the inline assembly).
Reported-by: Qiuhao Li <qiuhao@sysec.org>
Reported-by: Gaoning Pan <pgn@zju.edu.cn>
Reported-by: Yongkang Jia <kangel@zju.edu.cn>
Reported-by: syzbot+6cde2282daa792c49ab8@syzkaller.appspotmail.com
Debugged-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Tested-by: Maxim Levitsky <mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd53cb35a3 ("X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When emulating exit from long mode, EFER_LMA is cleared with
vmx_set_efer(). This will already unset the VM_ENTRY_IA32E_MODE control
bit as requested by SDM, so there is no need to unset VM_ENTRY_IA32E_MODE
again in exit_lmode() explicitly. In case EFER isn't supported by
hardware, long mode isn't supported, so exit_lmode() cannot be reached.
Note that, thanks to the shadow controls mechanism, this change doesn't
eliminate vmread or vmwrite.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Message-Id: <20220311102643.807507-3-zhenzhong.duan@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
vmx_set_efer() sets uret->data but, in fact if the value of uret->data
will be used vmx_setup_uret_msrs() will have rewritten it with the value
returned by update_transition_efer(). uret->data is consumed if and only
if uret->load_into_hardware is true, and vmx_setup_uret_msrs() takes care
of (a) updating uret->data before setting uret->load_into_hardware to true
(b) setting uret->load_into_hardware to false if uret->data isn't updated.
Opportunistically use "vmx" directly instead of redoing to_vmx().
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Message-Id: <20220311102643.807507-2-zhenzhong.duan@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It was decided that when TSC scaling is not supported,
the virtual MSR_AMD64_TSC_RATIO should still have the default '1.0'
value.
However in this case kvm_max_tsc_scaling_ratio is not set,
which breaks various assumptions.
Fix this by always calculating kvm_max_tsc_scaling_ratio regardless of
host support. For consistency, do the same for VMX.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220322172449.235575-8-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Another piece of SVM spec which should be in the header file
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220322172449.235575-6-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Due to wrong rebase, commit
4a204f7895 ("KVM: SVM: Allow AVIC support on system w/ physical APIC ID > 255")
moved avic spec #defines back to avic.c.
Move them back, and while at it extend AVIC_DOORBELL_PHYSICAL_ID_MASK to 12
bits as well (it will be used in nested avic)
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220322172449.235575-5-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If MSR access is rejected by MSR filtering,
kvm_set_msr()/kvm_get_msr() would return KVM_MSR_RET_FILTERED,
and the return value is only handled well for rdmsr/wrmsr.
However, some instruction emulation and state transition also
use kvm_set_msr()/kvm_get_msr() to do msr access but may trigger
some unexpected results if MSR access is rejected, E.g. RDPID
emulation would inject a #UD but RDPID wouldn't cause a exit
when RDPID is supported in hardware and ENABLE_RDTSCP is set.
And it would also cause failure when load MSR at nested entry/exit.
Since msr filtering is based on MSR bitmap, it is better to only
do MSR filtering for rdmsr/wrmsr.
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Message-Id: <2b2774154f7532c96a6f04d71c82a8bec7d9e80b.1646655860.git.houwenlong.hwl@antgroup.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When RDTSCP is supported but RDPID is not supported in host,
RDPID emulation is available. However, __kvm_get_msr() would
only fail when RDTSCP/RDPID both are disabled in guest, so
the emulator wouldn't inject a #UD when RDPID is disabled but
RDTSCP is enabled in guest.
Fixes: fb6d4d340e ("KVM: x86: emulate RDPID")
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Message-Id: <1dfd46ae5b76d3ed87bde3154d51c64ea64c99c1.1646226788.git.houwenlong.hwl@antgroup.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
HSW_IN_TX* bits are used in generic code which are not supported on
AMD. Worse, these bits overlap with AMD EventSelect[11:8] and hence
using HSW_IN_TX* bits unconditionally in generic code is resulting in
unintentional pmu behavior on AMD. For example, if EventSelect[11:8]
is 0x2, pmc_reprogram_counter() wrongly assumes that
HSW_IN_TX_CHECKPOINTED is set and thus forces sampling period to be 0.
Also per the SDM, both bits 32 and 33 "may only be set if the processor
supports HLE or RTM" and for "IN_TXCP (bit 33): this bit may only be set
for IA32_PERFEVTSEL2."
Opportunistically eliminate code redundancy, because if the HSW_IN_TX*
bit is set in pmc->eventsel, it is already set in attr.config.
Reported-by: Ravi Bangoria <ravi.bangoria@amd.com>
Reported-by: Jim Mattson <jmattson@google.com>
Fixes: 103af0a987 ("perf, kvm: Support the in_tx/in_tx_cp modifiers in KVM arch perfmon emulation v5")
Co-developed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220309084257.88931-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It makes more sense to print new SPTE value than the
old value.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220302102457.588450-1-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
AMD EPYC CPUs never raise a #GP for a WRMSR to a PerfEvtSeln MSR. Some
reserved bits are cleared, and some are not. Specifically, on
Zen3/Milan, bits 19 and 42 are not cleared.
When emulating such a WRMSR, KVM should not synthesize a #GP,
regardless of which bits are set. However, undocumented bits should
not be passed through to the hardware MSR. So, rather than checking
for reserved bits and synthesizing a #GP, just clear the reserved
bits.
This may seem pedantic, but since KVM currently does not support the
"Host/Guest Only" bits (41:40), it is necessary to clear these bits
rather than synthesizing #GP, because some popular guests (e.g Linux)
will set the "Host Only" bit even on CPUs that don't support
EFER.SVME, and they don't expect a #GP.
For example,
root@Ubuntu1804:~# perf stat -e r26 -a sleep 1
Performance counter stats for 'system wide':
0 r26
1.001070977 seconds time elapsed
Feb 23 03:59:58 Ubuntu1804 kernel: [ 405.379957] unchecked MSR access error: WRMSR to 0xc0010200 (tried to write 0x0000020000130026) at rIP: 0xffffffff9b276a28 (native_write_msr+0x8/0x30)
Feb 23 03:59:58 Ubuntu1804 kernel: [ 405.379958] Call Trace:
Feb 23 03:59:58 Ubuntu1804 kernel: [ 405.379963] amd_pmu_disable_event+0x27/0x90
Fixes: ca724305a2 ("KVM: x86/vPMU: Implement AMD vPMU code for KVM")
Reported-by: Lotus Fenn <lotusf@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Like Xu <likexu@tencent.com>
Reviewed-by: David Dunn <daviddunn@google.com>
Message-Id: <20220226234131.2167175-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Trace all APICv inhibit changes instead of just those that result in
APICv being (un)inhibited, and log the current state. Debugging why
APICv isn't working is frustrating as it's hard to see why APICv is still
inhibited, and logging only the first inhibition means unnecessary onion
peeling.
Opportunistically drop the export of the tracepoint, it is not and should
not be used by vendor code due to the need to serialize toggling via
apicv_update_lock.
Note, using the common flow means kvm_apicv_init() switched from atomic
to non-atomic bitwise operations. The VM is unreachable at init, so
non-atomic is perfectly ok.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220311043517.17027-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add set/clear wrappers for toggling APICv inhibits to make the call sites
more readable, and opportunistically rename the inner helpers to align
with the new wrappers and to make them more readable as well. Invert the
flag from "activate" to "set"; activate is painfully ambiguous as it's
not obvious if the inhibit is being activated, or if APICv is being
activated, in which case the inhibit is being deactivated.
For the functions that take @set, swap the order of the inhibit reason
and @set so that the call sites are visually similar to those that bounce
through the wrapper.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220311043517.17027-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use an enum for the APICv inhibit reasons, there is no meaning behind
their values and they most definitely are not "unsigned longs". Rename
the various params to "reason" for consistency and clarity (inhibit may
be confused as a command, i.e. inhibit APICv, instead of the reason that
is getting toggled/checked).
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220311043517.17027-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There are two kinds of implicit supervisor access
implicit supervisor access when CPL = 3
implicit supervisor access when CPL < 3
Current permission_fault() handles only the first kind for SMAP.
But if the access is implicit when SMAP is on, data may not be read
nor write from any user-mode address regardless the current CPL.
So the second kind should be also supported.
The first kind can be detect via CPL and access mode: if it is
supervisor access and CPL = 3, it must be implicit supervisor access.
But it is not possible to detect the second kind without extra
information, so this patch adds an artificial PFERR_EXPLICIT_ACCESS
into @access. This extra information also works for the first kind, so
the logic is changed to use this information for both cases.
The value of PFERR_EXPLICIT_ACCESS is deliberately chosen to be bit 48
which is in the most significant 16 bits of u64 and less likely to be
forced to change due to future hardware uses it.
This patch removes the call to ->get_cpl() for access mode is determined
by @access. Not only does it reduce a function call, but also remove
confusions when the permission is checked for nested TDP. The nested
TDP shouldn't have SMAP checking nor even the L2's CPL have any bearing
on it. The original code works just because it is always user walk for
NPT and SMAP fault is not set for EPT in update_permission_bitmask.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20220311070346.45023-5-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Comments above the variable says the bit is set when SMAP is overridden
or the same meaning in update_permission_bitmask(): it is not subjected
to SMAP restriction.
Renaming it to reflect the negative implication and make the code better
readability.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20220311070346.45023-4-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The commit 09f037aa48 ("KVM: MMU: speedup update_permission_bitmask")
refactored the code of update_permission_bitmask() and change the
comments. It added a condition into a list to match the new code,
so the number/order for conditions in the comments should be updated
too.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20220311070346.45023-3-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Change the type of access u32 to u64 for FNAME(walk_addr) and
->gva_to_gpa().
The kinds of accesses are usually combinations of UWX, and VMX/SVM's
nested paging adds a new factor of access: is it an access for a guest
page table or for a final guest physical address.
And SMAP relies a factor for supervisor access: explicit or implicit.
So @access in FNAME(walk_addr) and ->gva_to_gpa() is better to include
all these information to do the walk.
Although @access(u32) has enough bits to encode all the kinds, this
patch extends it to u64:
o Extra bits will be in the higher 32 bits, so that we can
easily obtain the traditional access mode (UWX) by converting
it to u32.
o Reuse the value for the access kind defined by SVM's nested
paging (PFERR_GUEST_FINAL_MASK and PFERR_GUEST_PAGE_MASK) as
@error_code in kvm_handle_page_fault().
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20220311070346.45023-2-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It isn't OK to cache the dirty status of a page in internal structures
for an indefinite period of time.
Any time a vCPU exits the run loop to userspace might be its last; the
VMM might do its final check of the dirty log, flush the last remaining
dirty pages to the destination and complete a live migration. If we
have internal 'dirty' state which doesn't get flushed until the vCPU
is finally destroyed on the source after migration is complete, then
we have lost data because that will escape the final copy.
This problem already exists with the use of kvm_vcpu_unmap() to mark
pages dirty in e.g. VMX nesting.
Note that the actual Linux MM already considers the page to be dirty
since we have a writeable mapping of it. This is just about the KVM
dirty logging.
For the nesting-style use cases (KVM_GUEST_USES_PFN) we will need to
track which gfn_to_pfn_caches have been used and explicitly mark the
corresponding pages dirty before returning to userspace. But we would
have needed external tracking of that anyway, rather than walking the
full list of GPCs to find those belonging to this vCPU which are dirty.
So let's rely *solely* on that external tracking, and keep it simple
rather than laying a tempting trap for callers to fall into.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220303154127.202856-3-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace the guest_uses_pa and kernel_map booleans in the PFN cache code
with a unified enum/bitmask. Using explicit names makes it easier to
review and audit call sites.
Opportunistically add a WARN to prevent passing garbage; instantating a
cache without declaring its usage is either buggy or pointless.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220303154127.202856-2-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Include kvm_cache_regs.h to pick up the definition of is_guest_mode(),
which is referenced by nested_svm_virtualize_tpr() in svm.h. Remove
include from svm_onhpyerv.c which was done only because of lack of
include in svm.h.
Fixes: 883b0a91f4 ("KVM: SVM: Move Nested SVM Implementation to nested.c")
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Peter Gonda <pgonda@google.com>
Message-Id: <20220304161032.2270688-1-pgonda@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The third nybble of AMD's event select overlaps with Intel's IN_TX and
IN_TXCP bits. Therefore, we can't use AMD64_RAW_EVENT_MASK on Intel
platforms that support TSX.
Declare a raw_event_mask in the kvm_pmu structure, initialize it in
the vendor-specific pmu_refresh() functions, and use that mask for
PERF_TYPE_RAW configurations in reprogram_gp_counter().
Fixes: 710c476514 ("KVM: x86/pmu: Use AMD64_RAW_EVENT_MASK for PERF_TYPE_RAW")
Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20220308012452.3468611-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Re-introduce zapping only leaf SPTEs in kvm_zap_gfn_range() and
kvm_tdp_mmu_unmap_gfn_range(), this time without losing a pending TLB
flush when processing multiple roots (including nested TDP shadow roots).
Dropping the TLB flush resulted in random crashes when running Hyper-V
Server 2019 in a guest with KSM enabled in the host (or any source of
mmu_notifier invalidations, KSM is just the easiest to force).
This effectively revert commits 873dd12217
and fcb93eb6d0, and thus restores commit
cf3e26427c, plus this delta on top:
bool kvm_tdp_mmu_zap_leafs(struct kvm *kvm, int as_id, gfn_t start, gfn_t end,
struct kvm_mmu_page *root;
for_each_tdp_mmu_root_yield_safe(kvm, root, as_id)
- flush = tdp_mmu_zap_leafs(kvm, root, start, end, can_yield, false);
+ flush = tdp_mmu_zap_leafs(kvm, root, start, end, can_yield, flush);
return flush;
}
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220325230348.2587437-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If kvm->arch.tdp_mmu_zap_wq cannot be created, the failure has
to be propagated up to kvm_mmu_init_vm and kvm_arch_init_vm.
kvm_arch_init_vm also has to undo all the initialization, so
group all the MMU initialization code at the beginning and
handle cleaning up of kvm_page_track_init.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull vfs updates from Al Viro:
"Assorted bits and pieces"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
aio: drop needless assignment in aio_read()
clean overflow checks in count_mounts() a bit
seq_file: fix NULL pointer arithmetic warning
uml/x86: use x86 load_unaligned_zeropad()
asm/user.h: killed unused macros
constify struct path argument of finish_automount()/do_add_mount()
fs: Remove FIXME comment in generic_write_checks()
