From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 356DB2147FB; Thu, 18 Dec 2025 08:33:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766046841; cv=none; b=cXULk4xZAp+Jz6gwG3qnQ7kb3/WhJkTjVBaHmV0R19ft0LCYYKLTJb1Wkw5sS7P+lXpUXAUiyaqHvFJxqDPTECXpZqAD6cy2deMzSfzG6EQmp8y9DYStjVs7zyENgIl6g7D96vlnDxHo5IHIXox/PkhrC//E09+FdZtHFsOGYE4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766046841; c=relaxed/simple; bh=A9HEH6e9DfkdNSl+qx4MSHwGrDpvTREJchXDMev3nWA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GmPfsFxoi8DbMrp1tSpWfG8gi9wevqnT68u+r9jV6H2tpeJ/LhrE/ncYpr9QZpn8XQGEg5f1Zn4MxhWpYH60Yj3u23sG6CQ28bQI9eBrmwI6bHucCjXHtKY+0j2i/CQDisKb+92LuI82NzZqqtxEaXMt3QGLebuk81u9h1OW+Wo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=FnufwIZz; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="FnufwIZz" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=udKtZC5V08ugl6h8GymizkRPGV7cNBOnmpw7k4Dc21k=; b=FnufwIZzi2TPpsqyx0z46oDcLK f5r3rcSxKZsPqGdYhuMFCG9lCDNi08OQx6Tyo2e/tJX2SeNw8+boIsCUaPhyy/VGLLunUOaChARxA yJdmIAbD+mdHWfth2kKYZ8MJu5IDrk28bo2ADgOVD60oscfIgu2VUz6fSAWjD1p60Yvp189DS+MEs 8IRDi55x8cu03bdQRprVzvhEDWM+6lR7+RHL4y5UJSdsFDKw4C/yH5Va3LPk9mz3v9ad8MFK1nq71 XcjsKez6fhg8Mcufei0NrAeutnwLJrtu+3QOAjcC1jYNyClmqMz1BsTcR+2ld7HeCXUmMIt1hb6Tf VbofWLeA==; Received: from 2001-1c00-8d85-5700-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:5700:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vW8an-00000008Lue-2EHo; Thu, 18 Dec 2025 07:38:35 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 8891E30056B; Thu, 18 Dec 2025 09:33:46 +0100 (CET) Date: Thu, 18 Dec 2025 09:33:46 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org, seanjc@google.com, sfr@canb.auug.org.au Cc: linux-tip-commits@vger.kernel.org, x86@kernel.org, pbonzini@redhat.com, kvm@vger.kernel.org Subject: Re: [tip: perf/core] perf: Use EXPORT_SYMBOL_FOR_KVM() for the mediated APIs Message-ID: <20251218083346.GG3708021@noisy.programming.kicks-ass.net> References: <20251208115156.GE3707891@noisy.programming.kicks-ass.net> <176597507731.510.6380001909229389563.tip-bot2@tip-bot2> <20251218083109.GH3707891@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251218083109.GH3707891@noisy.programming.kicks-ass.net> On Thu, Dec 18, 2025 at 09:31:09AM +0100, Peter Zijlstra wrote: > On Wed, Dec 17, 2025 at 12:37:57PM -0000, tip-bot2 for Peter Zijlstra wrote: > > diff --git a/kernel/events/core.c b/kernel/events/core.c > > index e6a4b1e..376fb07 100644 > > --- a/kernel/events/core.c > > +++ b/kernel/events/core.c > > @@ -57,6 +57,7 @@ > > #include > > #include > > #include > > +#include > > > > #include "internal.h" > > > > @@ -6388,7 +6389,7 @@ int perf_create_mediated_pmu(void) > > atomic_inc(&nr_mediated_pmu_vms); > > return 0; > > } > > -EXPORT_SYMBOL_GPL(perf_create_mediated_pmu); > > +EXPORT_SYMBOL_FOR_KVM(perf_create_mediated_pmu); > > > > void perf_release_mediated_pmu(void) > > { > > @@ -6397,7 +6398,7 @@ void perf_release_mediated_pmu(void) > > > > atomic_dec(&nr_mediated_pmu_vms); > > } > > -EXPORT_SYMBOL_GPL(perf_release_mediated_pmu); > > +EXPORT_SYMBOL_FOR_KVM(perf_release_mediated_pmu); > > > > /* When loading a guest's mediated PMU, schedule out all exclude_guest events. */ > > void perf_load_guest_context(void) > > Bah, so the !KVM architectures hate on this. > > Sean, would something like this be acceptable? Hmm, the other option is doing something like so: diff --git a/kernel/events/core.c b/kernel/events/core.c index 376fb07d869b..014d832e8eaa 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -57,7 +57,6 @@ #include #include #include -#include #include "internal.h" @@ -6325,6 +6324,8 @@ u64 perf_event_pause(struct perf_event *event, bool reset) EXPORT_SYMBOL_GPL(perf_event_pause); #ifdef CONFIG_PERF_GUEST_MEDIATED_PMU +#include + static atomic_t nr_include_guest_events __read_mostly; static atomic_t nr_mediated_pmu_vms __read_mostly; > --- > Subject: kvm: Fix linux/kvm_types.h for !KVM architectures > > As is, hard relies on architectures having > which (obviously) breaks for architectures that don't > have KVM support. > > This means generic code (kernel/events/ in this case) cannot use > EXPORT_SYMBOL_FOR_KVM(). > > Rearrange things just so that becomes usable and > provides the (expected) empty stub for EXPORT_SYMBOL_FOR_KVM() for !KVM. > > Signed-off-by: Peter Zijlstra (Intel) > --- > diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h > index a568d8e6f4e8..a4cc13e41eec 100644 > --- a/include/linux/kvm_types.h > +++ b/include/linux/kvm_types.h > @@ -6,6 +6,8 @@ > #include > #include > #include > + > +#ifdef CONFIG_KVM > #include > > #ifdef KVM_SUB_MODULES > @@ -20,13 +22,14 @@ > * if there are no submodules, e.g. to allow suppressing exports if KVM=m, but > * kvm.ko won't actually be built (due to lack of at least one submodule). > */ > -#ifndef EXPORT_SYMBOL_FOR_KVM > -#if IS_MODULE(CONFIG_KVM) > +#if defined(EXPORT_SYMBOL_FOR_KVM) && IS_MODULE(CONFIG_KVM) > #define EXPORT_SYMBOL_FOR_KVM(symbol) EXPORT_SYMBOL_FOR_MODULES(symbol, "kvm") > -#else > -#define EXPORT_SYMBOL_FOR_KVM(symbol) > #endif /* IS_MODULE(CONFIG_KVM) */ > -#endif /* EXPORT_SYMBOL_FOR_KVM */ > +#endif /* KVM_SUB_MODULES */ > +#endif > + > +#ifndef EXPORT_SYMBOL_FOR_KVM > +#define EXPORTEXPORT_SYMBOL_FOR_KVM(symbol) > #endif > > #ifndef __ASSEMBLER__