user/sven/linux.git/include/linux/context_tracking.h, branch v5.10.74

context_tracking: Move guest exit vtime accounting to separate helpers

2021-05-28T11:17:43Z

commit 88d8220bbf06dd8045b2ac4be1046290eaa7773a upstream. Provide separate vtime accounting functions for guest exit instead of open coding the logic within the context tracking code. This will allow KVM x86 to handle vtime accounting slightly differently when using tick-based accounting. Suggested-by: Thomas Gleixner Signed-off-by: Wanpeng Li Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Thomas Gleixner Reviewed-by: Christian Borntraeger Link: https://lore.kernel.org/r/20210505002735.1684165-3-seanjc@google.com Signed-off-by: Greg Kroah-Hartman

context_tracking: Move guest exit context tracking to separate helpers

2021-05-28T11:17:43Z

commit 866a6dadbb027b2955a7ae00bab9705d382def12 upstream. Provide separate context tracking helpers for guest exit, the standalone helpers will be called separately by KVM x86 in later patches to fix tick-based accounting. Suggested-by: Thomas Gleixner Signed-off-by: Wanpeng Li Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210505002735.1684165-2-seanjc@google.com Signed-off-by: Greg Kroah-Hartman

compiler.h: Move instrumentation_begin()/end() to new header

2020-07-24T11:56:23Z

Linus pointed out that compiler.h - which is a key header that gets included in every single one of the 28,000+ kernel files during a kernel build - was bloated in: 655389666643: ("vmlinux.lds.h: Create section for protection against instrumentation") Linus noted: > I have pulled this, but do we really want to add this to a header file > that is _so_ core that it gets included for basically every single > file built? > > I don't even see those instrumentation_begin/end() things used > anywhere right now. > > It seems excessive. That 53 lines is maybe not a lot, but it pushed > that header file to over 12kB, and while it's mostly comments, it's > extra IO and parsing basically for _every_ single file compiled in the > kernel. > > For what appears to be absolutely zero upside right now, and I really > don't see why this should be in such a core header file! Move these primitives into a new header: , and include that header in the headers that make use of it. Unfortunately one of these headers is asm-generic/bug.h, which does get included in a lot of places, similarly to compiler.h. So the de-bloating effect isn't as good as we'd like it to be - but at least the interfaces are defined separately. No change to functionality intended. Reported-by: Linus Torvalds Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200604071921.GA1361070@gmail.com Cc: Thomas Gleixner Cc: Borislav Petkov Cc: Peter Zijlstra

context_tracking: Ensure that the critical path cannot be instrumented

2020-06-11T13:14:36Z

context tracking lacks a few protection mechanisms against instrumentation: - While the core functions are marked NOKPROBE they lack protection against function tracing which is required as the function entry/exit points can be utilized by BPF. - static functions invoked from the protected functions need to be marked as well as they can be instrumented otherwise. - using plain inline allows the compiler to emit traceable and probable functions. Fix this by marking the functions noinstr and converting the plain inlines to __always_inline. The NOKPROBE_SYMBOL() annotations are removed as the .noinstr.text section is already excluded from being probed. Cures the following objtool warnings: vmlinux.o: warning: objtool: enter_from_user_mode()+0x34: call to __context_tracking_exit() leaves .noinstr.text section vmlinux.o: warning: objtool: prepare_exit_to_usermode()+0x29: call to __context_tracking_enter() leaves .noinstr.text section vmlinux.o: warning: objtool: syscall_return_slowpath()+0x29: call to __context_tracking_enter() leaves .noinstr.text section vmlinux.o: warning: objtool: do_syscall_64()+0x7f: call to __context_tracking_enter() leaves .noinstr.text section vmlinux.o: warning: objtool: do_int80_syscall_32()+0x3d: call to __context_tracking_enter() leaves .noinstr.text section vmlinux.o: warning: objtool: do_fast_syscall_32()+0x9c: call to __context_tracking_enter() leaves .noinstr.text section and generates new ones... Signed-off-by: Thomas Gleixner Reviewed-by: Masami Hiramatsu Reviewed-by: Alexandre Chartre Acked-by: Peter Zijlstra Link: https://lkml.kernel.org/r/20200505134340.811520478@linutronix.de

context_tracking: Make guest_enter/exit() .noinstr ready

2020-05-19T13:47:21Z

Force inlining of the helpers and mark the instrumentable parts accordingly. Signed-off-by: Thomas Gleixner Reviewed-by: Alexandre Chartre Acked-by: Peter Zijlstra Link: https://lkml.kernel.org/r/20200505134341.672545766@linutronix.de

KVM: remove unused guest_enter

2020-01-27T18:59:55Z

After commit 61bd0f66ff92 ("KVM: PPC: Book3S HV: Fix guest time accounting with VIRT_CPU_ACCOUNTING_GEN"), no one use this function anymore, So better to remove it. Signed-off-by: Alex Shi Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org Signed-off-by: Paolo Bonzini

sched/vtime: Rename vtime_accounting_cpu_enabled() to vtime_accounting_enabled_this_cpu()

2019-10-29T09:01:14Z

Standardize the naming on top of the vtime_accounting_enabled_*() base. Also make it clear we are checking the vtime state of the *current* CPU with this function. We'll need to add an API to check that state on remote CPUs as well, so we must disambiguate the naming. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Jacek Anaszewski Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191016025700.31277-9-frederic@kernel.org Signed-off-by: Ingo Molnar

context_tracking: Rename context_tracking_is_cpu_enabled() to context_tracking_enabled_this_cpu()

2019-10-29T09:01:12Z

Standardize the naming on top of the context_tracking_enabled_*() base. Also make it clear we are checking the context tracking state of the *current* CPU with this function. We'll need to add an API to check that state on remote CPUs as well, so we must disambiguate the naming. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Jacek Anaszewski Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191016025700.31277-7-frederic@kernel.org Signed-off-by: Ingo Molnar

context_tracking: Rename context_tracking_is_enabled() => context_tracking_enabled()

2019-10-29T09:01:12Z

Remove the superfluous "is" in the middle of the name. We want to standardize the naming so that it can be expanded through suffixes: context_tracking_enabled() context_tracking_enabled_cpu() context_tracking_enabled_this_cpu() Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Jacek Anaszewski Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191016025700.31277-6-frederic@kernel.org Signed-off-by: Ingo Molnar

sched/cputime: Rename vtime_account_system() to vtime_account_kernel()

2019-10-09T10:39:25Z

vtime_account_system() decides if we need to account the time to the system (__vtime_account_system()) or to the guest (vtime_account_guest()). So this function is a misnomer as we are on a higher level than "system". All we know when we call that function is that we are accounting kernel cputime. Whether it belongs to guest or system time is a lower level detail. Rename this function to vtime_account_kernel(). This will clarify things and avoid too many underscored vtime_account_system() versions. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191003161745.28464-2-frederic@kernel.org Signed-off-by: Ingo Molnar