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=-16.6 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 344CBC433EF for ; Wed, 22 Sep 2021 13:12:08 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id C2F1761178 for ; Wed, 22 Sep 2021 13:12:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C2F1761178 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 75B504B13A; Wed, 22 Sep 2021 09:12:07 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@google.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id q933AkV4Nuiq; Wed, 22 Sep 2021 09:12:06 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 4E45A4B1A5; Wed, 22 Sep 2021 09:11:54 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id CB24E4A1B0 for ; Tue, 21 Sep 2021 20:05:53 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YBAuHxePZbpj for ; Tue, 21 Sep 2021 20:05:52 -0400 (EDT) Received: from mail-qk1-f202.google.com (mail-qk1-f202.google.com [209.85.222.202]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id C08D4405EE for ; Tue, 21 Sep 2021 20:05:52 -0400 (EDT) Received: by mail-qk1-f202.google.com with SMTP id u22-20020a05620a455600b004333191e844so5514394qkp.14 for ; Tue, 21 Sep 2021 17:05:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=6hT+pcsgsamW9lRK8DKVDgsjod6WnUckxdik+rJgRjs=; b=Bj8VBEV1iZnqxOhTLHlm7aJLEpzWR4VK7K7aD+jVIOItnRKO4fixETcLObR8Fp3wpi qen4ySzqMv29aPJAGQYTFE7wmMMI1j5Rtph6tALMy5t0Vpqs3rbEz84bRIN0kMxKLv8c UqqsOh2SdMvnju4og/DFPHA2mwLIV2Kbl8jNiHyAx8ZaTn+CIt8xR9Nfe8u7VO9K9/eN +2x8JLd22AxcRq3kDSstvt/WqN7tY/+xYd3wvpQsDoKFQCmzoF+iYRzBtZMgOAMbDudK wnTLWwmn+3bAAzltBQAbNmJfxESz4LUX9Bp79xTAk2sjGVMJKof74Y995u9shdQ30fbC IW7Q== X-Google-DKIM-Signature: v=1; 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=6hT+pcsgsamW9lRK8DKVDgsjod6WnUckxdik+rJgRjs=; b=SJE/DfCo4dPQYPcfOKag9UI3jl6t7U55535id0LhQv2rIerN3usWX9bfBBXfgXnhcB ZMu6nGIxzROJ6kFotk8EqmNztCYZoB7bUBTGYxePSM+G0gcLsXH4/70voVXjON/WxRR5 2G1R/CRVUJxBa9jjxEkoqYrD9KCp563eXk4JsvIuV1H+Um+EGyALTxk2N8V0B80+PyuH FbR1b4f2QX7ftK+kQVLT95FjTUOlywAAFKE2mWN50rcSxRSkftgaKj+tfy7lWIkGBTzO uID8lzoNtDSuZRCA7DlwixiZ4+mis/o3zAA16cR2tnIfz+c5PxxdLY4V/X8t6ewHZWHN gWIA== X-Gm-Message-State: AOAM531E3WDK01pi+rXmvkPXnjyBDcNTGOiy6dd0sn4zzyYuq5VvZaKi savEaLqhFLBT3NFUcBroSpsKayN0UOs= X-Google-Smtp-Source: ABdhPJw55E4dI/IAyKkR+ZKkmH8bPHTaStHFj1pC0lhS1Eeb6cv6+uuItqqgA18GAeXeV2SBtT0zyEX+kRs= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:90:200:b022:92d6:d37b:686c]) (user=seanjc job=sendgmr) by 2002:a0c:8e83:: with SMTP id x3mr34844810qvb.40.1632269152245; Tue, 21 Sep 2021 17:05:52 -0700 (PDT) Date: Tue, 21 Sep 2021 17:05:21 -0700 In-Reply-To: <20210922000533.713300-1-seanjc@google.com> Message-Id: <20210922000533.713300-5-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 04/16] perf: Stop pretending that perf can handle multiple 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 X-Mailman-Approved-At: Wed, 22 Sep 2021 09:11:52 -0400 Cc: Wanpeng Li , kvm@vger.kernel.org, Alexander Shishkin , linux-riscv@lists.infradead.org, Jiri Olsa , kvmarm@lists.cs.columbia.edu, Stefano Stabellini , Joerg Roedel , linux-csky@vger.kernel.org, xen-devel@lists.xenproject.org, Zhu Lingshan , Namhyung Kim , Artem Kashkanov , linux-arm-kernel@lists.infradead.org, Jim Mattson , Like Xu , Sean Christopherson , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Vitaly Kuznetsov X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list Reply-To: Sean Christopherson List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu 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 co-tenant hypervisors, and if there are, that allowing multiple callbacks to be registered is desirable or even correct. Opportunistically rename callbacks=>cbs in the affected declarations to match their definitions. No functional change intended. Signed-off-by: Sean Christopherson --- arch/arm64/include/asm/kvm_host.h | 4 ++-- arch/arm64/kvm/perf.c | 8 ++++---- include/linux/perf_event.h | 12 ++++++------ kernel/events/core.c | 16 ++++------------ 4 files changed, 16 insertions(+), 24 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..c37c0cf1bfe9 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(&kvm_guest_cbs); } diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 6b0405e578c1..317d4658afe9 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1245,8 +1245,8 @@ 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); } -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 *cbs); +extern void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs); extern void perf_event_exec(void); extern void perf_event_comm(struct task_struct *tsk, bool exec); @@ -1489,10 +1489,10 @@ 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 *cbs) { } +static inline void perf_unregister_guest_info_callbacks +(struct perf_guest_info_callbacks *cbs) { } static inline void perf_event_mmap(struct vm_area_struct *vma) { } diff --git a/kernel/events/core.c b/kernel/events/core.c index 80ff050a7b55..d90a43572400 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6482,31 +6482,23 @@ 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) { if (WARN_ON_ONCE(perf_guest_cbs)) - return -EBUSY; + return; WRITE_ONCE(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(struct perf_guest_info_callbacks *cbs) { if (WARN_ON_ONCE(perf_guest_cbs != cbs)) - return -EINVAL; + return; WRITE_ONCE(perf_guest_cbs, NULL); synchronize_rcu(); - return 0; } EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); -- 2.33.0.464.g1972c5931b-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm