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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 182C5C433F5 for ; Thu, 18 Nov 2021 14:36:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDD4861BD4 for ; Thu, 18 Nov 2021 14:36:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233552AbhKROiL (ORCPT ); Thu, 18 Nov 2021 09:38:11 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:39250 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233228AbhKROhs (ORCPT ); Thu, 18 Nov 2021 09:37:48 -0500 Date: Thu, 18 Nov 2021 14:34:46 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1637246087; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2QjHGt3ySaTeGh3PrFYQQSBoVtSN9jX6Ks1rDr/XRCo=; b=diDPc5pTlWclqiilZ+TU9lnMD2c96x71GQv2pt25GRbL63wn1mGo1WYH8zUlkooX4csBro h/H8M4WDLj++7URh341CB7VlOmni6Ywz6o9yqB6T1fY9iPZ1bgHyzi1fUBkov48tg6qpQX zAXQrl/uJRzo50pFsaefXMn7UoZ6lri1yutkUUTrbPjkfVJ5K9ggaFFq8VGw3gaPFt/fyr UR+IMcOaW7me94+xW8EEoQ25iU4ebNBNRunCaHDxP2W2Cs7DgLCMHmu9QM1Q6yQrW9PJeN LSFqvbZToB/11IYB9/ur+u7cASHJGzTA7WJtX8LYRU2nRsP+1gSEbYBpUfjZQg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1637246087; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2QjHGt3ySaTeGh3PrFYQQSBoVtSN9jX6Ks1rDr/XRCo=; b=sdRNDSMJPCvrfKGfIGelVv/gYWWvbpf9MNE8R1WegdBW9uIAFNfj6PA7RLqdLMRG+gMpfO zo0BjOvujoPcFCAA== From: "tip-bot2 for Sean Christopherson" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf: Stop pretending that perf can handle multiple guest callbacks Cc: Sean Christopherson , "Peter Zijlstra (Intel)" , Paolo Bonzini , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20211111020738.2512932-5-seanjc@google.com> References: <20211111020738.2512932-5-seanjc@google.com> MIME-Version: 1.0 Message-ID: <163724608671.11128.10950352397891299823.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the perf/core branch of tip: Commit-ID: 2934e3d09350c1a7ca2433fbeabfcd831e48a575 Gitweb: https://git.kernel.org/tip/2934e3d09350c1a7ca2433fbeabfcd831e48a575 Author: Sean Christopherson AuthorDate: Thu, 11 Nov 2021 02:07:25 Committer: Peter Zijlstra CommitterDate: Wed, 17 Nov 2021 14:49:07 +01:00 perf: Stop pretending that perf can handle multiple guest callbacks 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 Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Paolo Bonzini Link: https://lore.kernel.org/r/20211111020738.2512932-5-seanjc@google.com --- arch/arm64/include/asm/kvm_host.h | 4 ++-- arch/arm64/kvm/perf.c | 8 ++++---- include/linux/perf_event.h | 12 ++++++------ kernel/events/core.c | 15 ++++----------- 4 files changed, 16 insertions(+), 23 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 2a5f7f3..f680f30 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -675,8 +675,8 @@ 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 c84fe24..a0d660c 100644 --- a/arch/arm64/kvm/perf.c +++ b/arch/arm64/kvm/perf.c @@ -48,12 +48,12 @@ 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) { - 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 318c489..98c2044 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1252,8 +1252,8 @@ static inline struct perf_guest_info_callbacks *perf_get_guest_cbs(void) */ return rcu_dereference(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); @@ -1497,10 +1497,10 @@ 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 c552e1b..17e5b20 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6521,31 +6521,24 @@ 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 __rcu *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(rcu_access_pointer(perf_guest_cbs))) - return -EBUSY; + return; rcu_assign_pointer(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(rcu_access_pointer(perf_guest_cbs) != cbs)) - return -EINVAL; + return; rcu_assign_pointer(perf_guest_cbs, NULL); synchronize_rcu(); - return 0; } EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);