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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F2F07C44500 for ; Tue, 7 Jul 2026 08:10:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=lnlzL0KpJ9QqM6hC9iBx7qV7lok+T8DRt7jvPTT0Rec=; b=w99ohw9+CjVWGM7r4WN9EpqyWl rDYo+HtpoG0EATuhu7VF/gi6wmGV8HW1/hFVyvkl1SUlXroqv3GmUPUR+tRElqIvx2pouZu0c5Fgh elkR7D9chyXO+vXFtL3v0JIxopJl0moZxVsG6KUw+CDbkMdxphMGNP20qEO+qTv4W1TBgNn8a9cjF tvgpysYED1pWF9ia1LVUJ8plElU8TePIE/0J53/FZNA3zsYeszpZoeHoBinrOwittYfnqfd85Kylx TO7ljoksvOlSxTLgOalUXfaHI/NXUDuriMXlE2u9AUDvkDmlOKyh2nZ/I7/ZUSpH5M5Atf8IAsIKX C/Lkd6zA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wh0sn-0000000EQRE-0bWu; Tue, 07 Jul 2026 08:10:21 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wh0sl-0000000EQR6-2y7I for linux-arm-kernel@lists.infradead.org; Tue, 07 Jul 2026 08:10:19 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 29E45618A8; Tue, 7 Jul 2026 08:10:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90DE31F00A3A; Tue, 7 Jul 2026 08:10:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783411818; bh=lnlzL0KpJ9QqM6hC9iBx7qV7lok+T8DRt7jvPTT0Rec=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=iz6ynNHyejKVsbakGkrHkbKba2CbrnlOqJjuKQSYnFwqiYr/UzDW6vVpNFfQ3BuWU 6pNNZ7rFUfkZUkffMXJWIc2S658G8QwKxCH4HoN8hsaMOJFYfZs54ArAfDieA0TvYU +qd/3m6a++PuRtOUrEELCHrY0RFP2cGf6hFxMVPGDaVlR6n8FMWJDTwdzsTq1SWPAh U2EOmsq2JENnhHbBgGJlZAojIoR6RPLnl+cAVCIVnLqzAFdMA9Vg0rAEOYfk4zDpjJ 1AbKJGJ0FnNRDHVRW/GYsPhIW2ykD8JIGQE5/0aR1S9TeyFKRd8F+3lCxInOVa5Yi8 31Z4DGG69kdwA== Date: Tue, 7 Jul 2026 01:10:17 -0700 From: Oliver Upton To: Marc Zyngier 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 Message-ID: References: <20260706-hybrid-v8-0-de459617b59d@rsg.ci.i.u-tokyo.ac.jp> <86bjcjp6x1.wl-maz@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86bjcjp6x1.wl-maz@kernel.org> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jul 07, 2026 at 08:58:50AM +0100, Marc Zyngier wrote: > 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. > Patch 1 [*] of the series I linked does exactly this, no? Needs some attention like a KVM_CAP to make the bit discoverable by the VMM but gets the general idea across. [*]: https://lore.kernel.org/kvmarm/20260702190421.420992-2-congkai@amazon.com/ Thanks, Oliver