From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 BA3AF320CD9; Tue, 7 Jul 2026 07:58:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783411134; cv=none; b=tzPSnNSv1NpU7IfxcZgO5hQpukX42qlfVG4So1WrlofzzMmmuCG6WNrRJhjnRlPrDxI59LJ0eBcq4Tl5/OAxa0F3Pn8Ryw55hV5oILSZiSABVyWXKsI/WHwo2quHKcwQVMuEKKxQwnk6T0LnqNXDm2ihn9McRelSC0BbECTmpIs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783411134; c=relaxed/simple; bh=GAtw8czhd2aMhjWO4X9p/ubNApLmoZ7OyAVteOFs1kA=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=YFJMNoL3j1cwI+UrJcAWRcL15Znlg+eSAgshWhigmY8J8V7KxNsCxxojwbVa3cm2gJ/sv1M2b2VzBIjAjBgfYvCnvSG/Z8kjpRegnmMvbEXtFycGrZpwVgbnGTQZo9UVD1yQ1iVYf9P21OhgFkChbcaUSwrMsw+Y0lCf9xk/X+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F9dO4cZw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="F9dO4cZw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B1E41F000E9; Tue, 7 Jul 2026 07:58:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783411133; bh=tpIOncymRCGSppNzLVX19mro9eWiUYLlNmVFoYEKqAI=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=F9dO4cZwh1Vri6X2ijnhDlSIeGJOGovGYffqHyySj7nzYEr2MILNdMg3efat6xdz3 5Ej2/E5dObGvSw3d/Q9kdz2yamr7Sbv1eGDcdL8t051hapZVIlF7hV3lHBJgYNjsvU i3vQfU/QdAaktekq4NtBAUy1WNHsXsEDzsLZWMAXA5pCsW8CQzVRDBe0meaHOC0w/l WgaxpM+DiBSUkS7ZKgTLHAiPmzDZVZ2qGD4lLNBmXFXz4s0OlYElT3DVdt8cEHq1be MUDdt1KW/xM50igh6KWtmse79REct2ygy6jJ15qjiFTUf6i3Y151sUTUxjqPrnthLo uytkDo8ScI+qg== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1wh0hf-00000002I1m-0pfp; Tue, 07 Jul 2026 07:58:51 +0000 Date: Tue, 07 Jul 2026 08:58:50 +0100 Message-ID: <86bjcjp6x1.wl-maz@kernel.org> From: Marc Zyngier To: Oliver Upton Cc: Akihiko Odaki , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Kees Cook , "Gustavo A. R. Silva" , Paolo Bonzini , Jonathan Corbet , Shuah Khan , Shuah Khan , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, devel@daynix.com, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v8 0/7] KVM: arm64: PMU: Use multiple host PMUs In-Reply-To: References: <20260706-hybrid-v8-0-de459617b59d@rsg.ci.i.u-tokyo.ac.jp> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: oupton@kernel.org, odaki@rsg.ci.i.u-tokyo.ac.jp, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, kees@kernel.org, gustavoars@kernel.org, pbonzini@redhat.com, corbet@lwn.net, shuah@kernel.org, skhan@linuxfoundation.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, devel@daynix.com, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Mon, 06 Jul 2026 19:28:20 +0100, Oliver Upton wrote: > > On Mon, Jul 06, 2026 at 07:03:23PM +0900, Akihiko Odaki wrote: > > Akihiko Odaki (7): > > KVM: arm64: Disallow vPMU when pPMUs do not cover all CPUs > > KVM: arm64: PMU: Protect the list of PMUs with RCU > > KVM: arm64: PMU: Pass the pPMU to kvm_map_pmu_event() > > KVM: arm64: PMU: Pass the target CPU to kvm_pmu_probe_armpmu() > > KVM: arm64: PMU: Implement fixed-counters-only emulation > > KVM: arm64: PMU: Introduce FIXED_COUNTERS_ONLY > > KVM: arm64: selftests: Test PMU_V3_FIXED_COUNTERS_ONLY > > Thanks for respinning the series, I left some comments. I'd really like > to get this feature picked up, hope you have cycles to work on it soon. > > FWIW, we're considering adding a new vCPU feature flag to deprecate all > the ugliness of the old PMUv3 UAPI. I'm tempted to say that the > FIXED_COUNTERS_ONLY feature is conditioned on the new feature flag... It'd be good to have a strawman proposal on the list if we are going to change add a new API, specially if this is likely to gate new code. Thanks, M. -- Without deviation from the norm, progress is not possible.