From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B4FDA3ED3C2 for ; Wed, 27 May 2026 17:40:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779903659; cv=none; b=sGWZqWZyCWTOeTCGRX+1CtH/emimvRKxMCvOVBLfwGKA5sEe0blaJWqkBO/6DEeNrVjFNk702K6prHyGf7CsmnxzB3quJ7C3IV5aAgfWDIfHn1X+LQcTk11ZyNxS21EAkapdGp6ADH9MRKD/AFbUMUTPXbYOaUsSsVKba1wAYbk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779903659; c=relaxed/simple; bh=NesVSvxjeriy8JrLCo02bPpWiXiqhTNJcG0UfxEm1oI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=UizyPnx6JGoORaiYjWA1QuWQhqhmosGesX82y52y+Q4tmOjCmX+wfD+2U6JfCmssGfAkJnEp3u3VhXlLunL3zFi6uhZC/ou64oo8KKPxDCY0bC9LQcVNAfOd9ZMtVLOTgJoYtwiyD075IgycGXx+pOgam0EyXPgv+5G/3wHo4xs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=cPUVaU6b; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cPUVaU6b" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2ba3245a43dso134096985ad.0 for ; Wed, 27 May 2026 10:40:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779903656; x=1780508456; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=qag9lBdsZqOV4kYaafONmBvRHghB6X57fmrdhvqCEr4=; b=cPUVaU6bGwz4572efz4CeNyXF5ddFGzV2VlGRiZS+OCUQzyH73RTx7A90eC19tpFHA +Nesg50Wx0A6WUMsFePr/Cj8tyya9dukxGgm4xNlqdQnL7vhP8v/kcovDj4Z5O3kLz2R moPdMWYvLA48inVJXO9vh7WGpEbfhuFmMJ7sqK+U3o7CWlTL4rBaxV2LrDethOcJSP/j B0TNsh5FKMcW7gbcCcn2zX1aof0hpRscnaJCre9fRrT5QWQJi8a40ArFCpdbHRVuDxml 6C2CpNC/kJR5Uj/4QqIkj5qmvN2zyLIPHMG19YaUZrGaRigXkTxFN2j3t+exzgbvcGDH Or3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779903656; x=1780508456; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=qag9lBdsZqOV4kYaafONmBvRHghB6X57fmrdhvqCEr4=; b=XoUN6I5vlX9Rcvhtqwnblj1zkxhlSIoPK+8lRXs8iFdqEOQXcEq+pBP7nyWdb5JRbG 3SqktjgAdXrsA8nyKKODZecEPdwhSIjSb3+GLCf5xhhIo8nSegT8KGpF4IOlnhP4Ma9L yNdTl0Xicwt+Gus8sl6MG6dN3YU/elGEaC0EVmhknkzIBFUEaZVVitxOpEZ/YiaHTNZR gPKrl+hNs865znjk+QCt3TXDd8m/SoZd5CObnUbvI/olwHVXxMWN6WF2baXNqwx5ZRs0 bMaqHdM0DnME63Wy08QFS5AHK/8ZFRTBG0zemdhhKMNGCWBCNjA7x7lKUHorfGEjtjO+ wC7Q== X-Forwarded-Encrypted: i=1; AFNElJ8Le0/JH/jqJIESQzgsCs32lFnpQrLuqsGueRReWYyMQ6agorpjeWM9EURTO7zXthcTQXW9AN/F38UsABA=@vger.kernel.org X-Gm-Message-State: AOJu0YzMPVGBypMYdLxGaZB2zNFWdUaCHRXJjj4hqT1mOn7B21bBj858 Uo/V/HggS5iwPf1hKecFt0bXDhCAFCy1eSzR4JVdexqVMDa9UQI0NXMQSfCE9T7aVy1w5KNY7LX rJgRm4Q== X-Received: from pgii35.prod.google.com ([2002:a63:2223:0:b0:c79:22b6:a344]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:9d91:b0:39f:9eb3:1d09 with SMTP id adf61e73a8af0-3b328ee2e52mr24673521637.37.1779903655856; Wed, 27 May 2026 10:40:55 -0700 (PDT) Date: Wed, 27 May 2026 10:40:55 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260518044150.34632-1-gautam@linux.ibm.com> Message-ID: Subject: Re: [PATCH v2] KVM: PPC: Kconfig: Enable CONFIG_VPA_PMU with KVM From: Sean Christopherson To: Gautam Menghani Cc: maddy@linux.ibm.com, npiggin@gmail.com, mpe@ellerman.id.au, chleroy@kernel.org, atrajeev@linux.ibm.com, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Wed, May 27, 2026, Gautam Menghani wrote: > On Mon, May 18, 2026 at 06:01:04PM -0700, Sean Christopherson wrote: > > On Mon, May 18, 2026, Gautam Menghani wrote: > > > Enable CONFIG_VPA_PMU with KVM to enable its usage. Currently, the > > > vpa-pmu driver cannot be used since it is not enabled in distro configs. > > > > That seems like a problem to take up with distros, no? > > Rather than enabling individually for different distros, wouldn't it be > better if it is enabled with KVM automatically? I can rephrase the > commit log to emphasize that this config option is only relevant for > KVM (similar to CONFIG_KVM_BOOK3S_HV_PMU). Not if you can't turn it off. As proposed, CONFIG_VPA_PMU gets forced to whatever CONFIG_KVM_BOOK3S_64_HV is set to. At that point, the existence of the VPA_PMU Kconfig is pointless. If you want it enabled by _default_, then turn it on by default, e.g. diff --git arch/powerpc/platforms/pseries/Kconfig arch/powerpc/platforms/pseries/Kconfig index f7052b131a4c..74910ce3a541 100644 --- arch/powerpc/platforms/pseries/Kconfig +++ arch/powerpc/platforms/pseries/Kconfig @@ -154,6 +154,7 @@ config HV_PERF_CTRS config VPA_PMU tristate "VPA PMU events" depends on KVM_BOOK3S_64_HV && HV_PERF_CTRS + default m help Enable access to the VPA PMU counters via perf. This enables code that support measurement for KVM on PowerVM(KoP) feature.