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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=sNDCyCpfsN1q6fRIAZGHe8t08fZK9DQU77lycxeDgvE=; b=TxVY+vK+qfnUBplcTcyuv7sRCGjQ2f9BsLIcsXnhGM7SQ1hMqkbmEYxpjP7Ltb48Y9 XyfTo63RqsgAAuV9CuD9I1A3tb5meS1VGwkBOBS6iiOy82UWlAlQMdv6AFtyyKR2K+aV LbClEY0zGwdjNUJGuTkk1RrPu7aWL8s5grnurXqERlY6cp6Q6aT8LBMjv/ih85skUebx zAtEZuj7fZSn9UWbcLBuNK6/Zl6gpn8OoyLj7K2Eq9d9EEGyeXM91ocWmU6aST+4rKB8 mAuQTrv0s3RooIspSw0UT9uRsDKFiho9oLmajuOIJQF3FCuVE0FMX9uNKSTgYHY9Dd6E IhEg== X-Gm-Message-State: AOAM532y1IpTvWGK1KHcjQ/48iNf7Cb1PsZ2lghbQhFXg0GAs18g4GDa ZhWbWGs3Nzsi18WcuyLoe3cKudBtL08= X-Google-Smtp-Source: ABdhPJzkQ+TPTNghaiyjopK2Q9UXHXirkFCk7bz7Y2wHOEucRILtEQweuapuUXRwLMTZlbJ4rzpjCo5gfvs= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:90:200:b022:92d6:d37b:686c]) (user=seanjc job=sendgmr) by 2002:a25:1884:: with SMTP id 126mr25006798yby.114.1632269158936; Tue, 21 Sep 2021 17:05:58 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 21 Sep 2021 17:05:24 -0700 In-Reply-To: <20210922000533.713300-1-seanjc@google.com> Message-Id: <20210922000533.713300-8-seanjc@google.com> Mime-Version: 1.0 References: <20210922000533.713300-1-seanjc@google.com> X-Mailer: git-send-email 2.33.0.464.g1972c5931b-goog Subject: [PATCH v3 07/16] perf: Add wrappers for invoking guest callbacks From: Sean Christopherson To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Will Deacon , Mark Rutland , Marc Zyngier , Guo Ren , Nick Hu , Greentime Hu , Vincent Chen , Paul Walmsley , Palmer Dabbelt , Albert Ou , Paolo Bonzini , Boris Ostrovsky , Juergen Gross Cc: Alexander Shishkin , Jiri Olsa , Namhyung Kim , James Morse , Alexandru Elisei , Suzuki K Poulose , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Stefano Stabellini , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-csky@vger.kernel.org, linux-riscv@lists.infradead.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org, Artem Kashkanov , Like Xu , Zhu Lingshan Add helpers for the guest callbacks to prepare for burying the callbacks behind a Kconfig (it's a lot easier to provide a few stubs than to #ifdef piles of code), and also to prepare for converting the callbacks to static_call(). perf_instruction_pointer() in particular will have subtle semantics with static_call(), as the "no callbacks" case will return 0 if the callbacks are unregistered between querying guest state and getting the IP. Implement the change now to avoid a functional change when adding static_call() support, and because the new helper needs to return _something_ in this case. Signed-off-by: Sean Christopherson Reviewed-by: Paolo Bonzini --- arch/arm64/kernel/perf_callchain.c | 16 +++++----------- arch/x86/events/core.c | 15 +++++---------- arch/x86/events/intel/core.c | 5 +---- include/linux/perf_event.h | 24 ++++++++++++++++++++++++ 4 files changed, 35 insertions(+), 25 deletions(-) diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c index 274dc3e11b6d..db04a55cee7e 100644 --- a/arch/arm64/kernel/perf_callchain.c +++ b/arch/arm64/kernel/perf_callchain.c @@ -102,9 +102,7 @@ compat_user_backtrace(struct compat_frame_tail __user *tail, void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - - if (guest_cbs && guest_cbs->state()) { + if (perf_guest_state()) { /* We don't support guest os callchain now */ return; } @@ -149,10 +147,9 @@ static bool callchain_trace(void *data, unsigned long pc) void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); struct stackframe frame; - if (guest_cbs && guest_cbs->state()) { + if (perf_guest_state()) { /* We don't support guest os callchain now */ return; } @@ -163,18 +160,15 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, unsigned long perf_instruction_pointer(struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - - if (guest_cbs && guest_cbs->state()) - return guest_cbs->get_ip(); + if (perf_guest_state()) + return perf_guest_get_ip(); return instruction_pointer(regs); } unsigned long perf_misc_flags(struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - unsigned int guest_state = guest_cbs ? guest_cbs->state() : 0; + unsigned int guest_state = perf_guest_state(); int misc = 0; if (guest_state) { diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 3a7630fdd340..d20e4f8d1aef 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2761,11 +2761,10 @@ static bool perf_hw_regs(struct pt_regs *regs) void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); struct unwind_state state; unsigned long addr; - if (guest_cbs && guest_cbs->state()) { + if (perf_guest_state()) { /* TODO: We don't support guest os callchain now */ return; } @@ -2865,11 +2864,10 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *ent void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); struct stack_frame frame; const struct stack_frame __user *fp; - if (guest_cbs && guest_cbs->state()) { + if (perf_guest_state()) { /* TODO: We don't support guest os callchain now */ return; } @@ -2946,18 +2944,15 @@ static unsigned long code_segment_base(struct pt_regs *regs) unsigned long perf_instruction_pointer(struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - - if (guest_cbs && guest_cbs->state()) - return guest_cbs->get_ip(); + if (perf_guest_state()) + return perf_guest_get_ip(); return regs->ip + code_segment_base(regs); } unsigned long perf_misc_flags(struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - unsigned int guest_state = guest_cbs ? guest_cbs->state() : 0; + unsigned int guest_state = perf_guest_state(); int misc = 0; if (guest_state) { diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 524ad1f747bd..f5b02017ba16 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2786,7 +2786,6 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) { struct perf_sample_data data; struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - struct perf_guest_info_callbacks *guest_cbs; int bit; int handled = 0; u64 intel_ctrl = hybrid(cpuc->pmu, intel_ctrl); @@ -2853,9 +2852,7 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) */ if (__test_and_clear_bit(GLOBAL_STATUS_TRACE_TOPAPMI_BIT, (unsigned long *)&status)) { handled++; - - guest_cbs = perf_get_guest_cbs(); - if (likely(!guest_cbs || !guest_cbs->handle_intel_pt_intr())) + if (!perf_guest_handle_intel_pt_intr()) intel_pt_interrupt(); } diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index f9be88a47434..c0a6eaf55fb1 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1247,6 +1247,30 @@ static inline struct perf_guest_info_callbacks *perf_get_guest_cbs(void) /* Prevent reloading between a !NULL check and dereferences. */ return READ_ONCE(perf_guest_cbs); } +static inline unsigned int perf_guest_state(void) +{ + struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); + + return guest_cbs ? guest_cbs->state() : 0; +} +static inline unsigned long perf_guest_get_ip(void) +{ + struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); + + /* + * Arbitrarily return '0' in the unlikely scenario that the callbacks + * are unregistered between checking guest state and getting the IP. + */ + return guest_cbs ? guest_cbs->get_ip() : 0; +} +static inline unsigned int perf_guest_handle_intel_pt_intr(void) +{ + struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); + + if (guest_cbs && guest_cbs->handle_intel_pt_intr) + return guest_cbs->handle_intel_pt_intr(); + return 0; +} extern void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs); extern void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs);