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 1C2C23845CB; Fri, 16 Oct 2026 14:30:32 +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=1792161034; cv=none; b=Bj1px/adAmrmGWCPmR6Gg9Xmto70HoTaC5HJqVeLz58GL0xgXa4+RcwlXbsMVMPNSx/Oy1deJYjPQ4immIMH+DxNd9qm/roYyWwh2RYBOVkupV4sS2C+c4tuct3ABp6tS4bBR2Hx+MXE72rakXHdL1vS2/eHY0ltmg3PBhdoqR0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792161034; c=relaxed/simple; bh=d4MPPdO5XHaBgijKwR4djxJZCTl14g1N2pr5fKJ6MpA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UPdQIoMmGKwp4sA6SzkeitpAoEhgRIXARVzf8E2BaJ0LuDJi5BpK0xXVBN0a41YgA7zXAQ9Y277/mXPmpu+tY58iUwjqh60BL1L3VDUASrZlub1020J3ix0UxuCZX6CDFojb/ny+Z2Wgd6z8YJJWoOj+zZYKyR0ws6WG0VDa75Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=J/zQhxy3; 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="J/zQhxy3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99C791F000C5; Fri, 16 Oct 2026 14:30:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792161032; bh=BC2GgbK+WoFQXcV9V5/6mo0si8p848r+VKvD9YiR8iA=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=J/zQhxy3DvvHtqlJgPR2wCD6FtIcCpZDGlMxgpqkGGOcbZPi2Z5FSg5pav4I9SOZM eUcBaIxHIKW/XlnIizLNd3Tp11ed8og4XnvEHSiRuJgaOXacO5qcUAmjpUzZb6CJoh SZaasebWVHsUO16EJIFaKgGPd9zMhEjvqTEf0yBosyZqdJaSorlkhev3BOdjy1WHKj CjX/fsi/oM4Fn9vcH/TdwrRjtOKjB7mnl5+0VLiMWEvYuFwoc7jgcxY2vVYiZu4YUt R1Q7VGkl/Qt+Wt5PJRSjKnuaSHJXN4E01nYVDhdGQaQ1LS7TkAsECRJBWThOnWtz9/ uojxREGTx2JhA== Date: Fri, 16 Oct 2026 15:30:26 +0100 From: "Lorenzo Stoakes (ARM)" To: Alexandru Elisei Cc: maz@kernel.org, oupton@kernel.org, fuad.tabba@linux.dev, joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, will@kernel.org, mark.rutland@arm.com, linux-perf-users@vger.kernel.org, catalin.marinas@arm.com, james.clark@linaro.org Subject: Re: [RFC PATCH v7 08/28] HACK! KVM: arm64: Disable SPE virtualization if protected KVM is enabled Message-ID: References: <20260903160623.315525-1-alexandru.elisei@arm.com> <20260903160623.315525-9-alexandru.elisei@arm.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260903160623.315525-9-alexandru.elisei@arm.com> On Thu, Sep 03, 2026 at 05:06:03PM +0100, Alexandru Elisei wrote: > For RFC only. > I realise this isn't intended for the final series :) but be good to put something here briefly for reviewers to explain why this is here, e.g. pKVM needs special attention etc. Similar comment for 9, 10 if there's an RFC respin. So for this and patches 9, 10 in general it seems you disable the feature for: - pKVM (at global level) - non-VHE - nested virt Are these temporary for proof-of-concept reasons or do you plan to make them permanent limitations for the initial implementation of SPE? If the former it'd be good to know what your plans are to provide support for these, if the latter it seems sensible to put these all in one patch that describes why you are limiting each. > Signed-off-by: Alexandru Elisei I won't bother actually reviewing the hacks, so just the queries above for 8, 9, 10. Will resume review at 11 :) > --- > arch/arm64/kvm/spe.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm64/kvm/spe.c b/arch/arm64/kvm/spe.c > index 646806a60d66..97160d1fae81 100644 > --- a/arch/arm64/kvm/spe.c > +++ b/arch/arm64/kvm/spe.c > @@ -22,6 +22,10 @@ void kvm_spe_add_instance(struct arm_spe_pmu *spe_pmu) > { > struct spe_pmu_entry *entry; > > + /* TODO: pKVM support */ > + if (is_protected_kvm_enabled()) > + return; > + > guard(mutex)(&spe_pmus_lock); > > entry = kmalloc(sizeof(*entry), GFP_KERNEL); > -- > 2.43.0 > > -- Cheers, Lorenzo