From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75C1DC43214 for ; Fri, 27 Aug 2021 00:57:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59DE661053 for ; Fri, 27 Aug 2021 00:57:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243965AbhH0A6e (ORCPT ); Thu, 26 Aug 2021 20:58:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243874AbhH0A60 (ORCPT ); Thu, 26 Aug 2021 20:58:26 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07A8BC0617AD for ; Thu, 26 Aug 2021 17:57:37 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id j9-20020a2581490000b02905897d81c63fso1769759ybm.8 for ; Thu, 26 Aug 2021 17:57:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=eP9YaQYNW7r9kDgd3qsENCfayArScJUKtUCsIWC6thw=; b=gOniotWtk3lF6UxW7PdX3cKBegQhQ5iSNPyRKiZnf7i4heaRZqrQ1XCsGWban4SbR3 zT78dU1sNSEA3eGttRbFIpH02VqDw13xoWcy7Sfk4tIv++vO+etrK6M3ti5f11KLiaWk 1daQFTv1q/kqM0brBtb0nHD2u0m8MDQpM5+8PsH3w6Z05mKqPfmuHjU7qM9+5Sj+kcBb gAYqeA/M/6f3cWOzErOPhZXRkPntcLBBVHGFfK6lCV5FFCTaXib0sUPQGN6FqPZYEFCR UHQKuNrOdNIpgxqKsPRBI3amPjQd+V9fPU7ixqHBNtOzNWjW5HvPxd+EPsCi/2nrvxhZ DoRg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=eP9YaQYNW7r9kDgd3qsENCfayArScJUKtUCsIWC6thw=; b=BQGhb+8lYpXjaVrmpwgKaDVLLMTCI25A2aiQsXtoV6+5icLhPIn5Rq2bnaLO3MUemh nz6sYCU3QhpnMSRx5TJULixdHdQHjxqhiz4qMO++PlNwaynr2Nv9/Pzbe9bj7Pj9rbgb xvKPLZh5HZS7wBqxQBjafhGcocNBxI4GQYy+8/d8xYvCFqXdkieis2FpqqAc5LTHwGyK 0NU8aIKInl+yvzWrGCoO8Ozrqu/GdkDprk6oCnj92ldh3+pz9U7yebDCngbep2BMg4wT u18ogrrjJR83gaQp1/aJBOmy3Rf6T5UdrxtHNHSoQM84iAEauM41m0qxPGVP7wyL1eYM iW/Q== X-Gm-Message-State: AOAM5311xV6cxcY03g1LtoIVC8mQaelDXoeQ0BvKk5Pkwm80msBi106s tAiZYlTJ1SbsE9aEQ97rYJZs9dBWnn0= X-Google-Smtp-Source: ABdhPJwZRp53eRz0Z/v+xyvl25SCOdBtWAUo/SC0imtmbIVISGgjbBGEInyTeCMf+kN6ORdJxMuSSuIsoks= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:90:200:c16c:db05:96b2:1475]) (user=seanjc job=sendgmr) by 2002:a25:2785:: with SMTP id n127mr1853573ybn.235.1630025856235; Thu, 26 Aug 2021 17:57:36 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 26 Aug 2021 17:57:06 -0700 In-Reply-To: <20210827005718.585190-1-seanjc@google.com> Message-Id: <20210827005718.585190-4-seanjc@google.com> Mime-Version: 1.0 References: <20210827005718.585190-1-seanjc@google.com> X-Mailer: git-send-email 2.33.0.259.gc128427fd7-goog Subject: [PATCH 03/15] perf: Stop pretending that perf can handle multiple guest callbacks From: Sean Christopherson To: Will Deacon , Mark Rutland , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Catalin Marinas , Marc Zyngier , Guo Ren , Nick Hu , Greentime Hu , Vincent Chen , Paul Walmsley , Palmer Dabbelt , Albert Ou , Thomas Gleixner , Borislav Petkov , x86@kernel.org, Paolo Bonzini , Boris Ostrovsky , Juergen Gross Cc: Alexander Shishkin , Jiri Olsa , Namhyung Kim , James Morse , Alexandru Elisei , Suzuki K Poulose , "H. Peter Anvin" , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Stefano Stabellini , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Drop the 'int' return value from the perf (un)register callbacks helpers and stop pretending perf can support multiple callbacks. The 'int' returns are not future proofing anything as none of the callers take action on an error. It's also not obvious that there will ever be cotenant hypervisors, and if there are, that allowing multiple callbacks to be registered is desirable or even correct. No functional change intended. Signed-off-by: Sean Christopherson --- arch/arm64/include/asm/kvm_host.h | 4 ++-- arch/arm64/kvm/perf.c | 8 ++++---- arch/x86/kvm/x86.c | 2 +- include/linux/perf_event.h | 11 +++++------ kernel/events/core.c | 11 ++--------- 5 files changed, 14 insertions(+), 22 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 41911585ae0c..ed940aec89e0 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -670,8 +670,8 @@ unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len); int kvm_handle_mmio_return(struct kvm_vcpu *vcpu); int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa); -int kvm_perf_init(void); -int kvm_perf_teardown(void); +void kvm_perf_init(void); +void kvm_perf_teardown(void); long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu); gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/perf.c b/arch/arm64/kvm/perf.c index 151c31fb9860..039fe59399a2 100644 --- a/arch/arm64/kvm/perf.c +++ b/arch/arm64/kvm/perf.c @@ -48,15 +48,15 @@ static struct perf_guest_info_callbacks kvm_guest_cbs = { .get_guest_ip = kvm_get_guest_ip, }; -int kvm_perf_init(void) +void kvm_perf_init(void) { if (kvm_pmu_probe_pmuver() != 0xf && !is_protected_kvm_enabled()) static_branch_enable(&kvm_arm_pmu_available); - return perf_register_guest_info_callbacks(&kvm_guest_cbs); + perf_register_guest_info_callbacks(&kvm_guest_cbs); } -int kvm_perf_teardown(void) +void kvm_perf_teardown(void) { - return perf_unregister_guest_info_callbacks(&kvm_guest_cbs); + perf_unregister_guest_info_callbacks(); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ffc6c2d73508..bae951344e28 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11092,7 +11092,7 @@ int kvm_arch_hardware_setup(void *opaque) void kvm_arch_hardware_unsetup(void) { - perf_unregister_guest_info_callbacks(&kvm_guest_cbs); + perf_unregister_guest_info_callbacks(); kvm_guest_cbs.handle_intel_pt_intr = NULL; static_call(kvm_x86_hardware_unsetup)(); diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 2d510ad750ed..05c0efba3cd1 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1237,8 +1237,8 @@ extern void perf_event_bpf_event(struct bpf_prog *prog, u16 flags); extern struct perf_guest_info_callbacks *perf_guest_cbs; -extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); -extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); +extern void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); +extern void perf_unregister_guest_info_callbacks(void); extern void perf_event_exec(void); extern void perf_event_comm(struct task_struct *tsk, bool exec); @@ -1481,10 +1481,9 @@ perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) { } static inline void perf_bp_event(struct perf_event *event, void *data) { } -static inline int perf_register_guest_info_callbacks -(struct perf_guest_info_callbacks *callbacks) { return 0; } -static inline int perf_unregister_guest_info_callbacks -(struct perf_guest_info_callbacks *callbacks) { return 0; } +static inline void perf_register_guest_info_callbacks +(struct perf_guest_info_callbacks *callbacks) { } +static inline void perf_unregister_guest_info_callbacks(void) { } static inline void perf_event_mmap(struct vm_area_struct *vma) { } diff --git a/kernel/events/core.c b/kernel/events/core.c index 464917096e73..baae796612b9 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6482,24 +6482,17 @@ static void perf_pending_event(struct irq_work *entry) perf_swevent_put_recursion_context(rctx); } -/* - * We assume there is only KVM supporting the callbacks. - * Later on, we might change it to a list if there is - * another virtualization implementation supporting the callbacks. - */ struct perf_guest_info_callbacks *perf_guest_cbs; -int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) { perf_guest_cbs = cbs; - return 0; } EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); -int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +void perf_unregister_guest_info_callbacks(void) { perf_guest_cbs = NULL; - return 0; } EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); -- 2.33.0.259.gc128427fd7-goog