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 4AF0DD116EA for ; Fri, 28 Nov 2025 18:48:21 +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=nxb7kF1mQ5Q711JdUVnxSpLmaN0ALGx+03mNw9RSIoo=; b=pVqfaPeU/mJnLZ3Yc9bCtzrNgm FLPLEYmtyYJP0iau9hdfn1r8OMA+onZYP6OtRR2qpm7Zy+zK6EjyzPzm4egfQihMZTGXFy8B/tgpw kpPoiGTJyH/HFUkmrauP2DeMEGxHcb7qSVnA7j7gmmOXHG8f0Rrdwf71vdBtTuRkydguE93v2wfuD I7W2m6604/QxVRAyvhmM1yJz1OfOAUkAVdZS0holOUHqfKltvQ+mZP5VG76ntUDQh8en2CLQtIxmm eAxxb5cZ9o/+jd93brNd6/To+dWCSC4iMXCcr4l6CSCXsqDMx6GRxzPQgpdCgaqrOdDvzCS+o01he MqWQz1Dw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vP3Vx-00000000n0C-0bsA; Fri, 28 Nov 2025 18:48:17 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vP3Vu-00000000mze-3Yf5 for linux-arm-kernel@lists.infradead.org; Fri, 28 Nov 2025 18:48:15 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id A338340320; Fri, 28 Nov 2025 18:48:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A6BEC4CEF1; Fri, 28 Nov 2025 18:48:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764355692; bh=FSDNcDjcSHNEpBt47zKm4TaQeFx3bDhR+BL9MuiqZ+s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=COincvZmdF6AYs666DRcJHlpv2QVyg8rvNVSTKD724SSpnQ6rH2bApNmStmgePXqv ukqfRFpKUdTqqPQmwY6lg8vBNwAgx6g3KJjL8F7zrIn18/kQ4Vk3WKM1THsGmzt1tU qdIA5TL601IayzwlIzvBa6RKpZ0kcISaJrRVPEGNZVPDrlhsknOwtEvlfdwrC6UjBa +1R6vC/g2fUp0NC9FBf6mMzUFnRvjzMUkMM/9E2aN2ql8rxh0/VWb//fK8hdtJP6nP tRb1nRlcCQE+NJ2o5apZEcyOa3rAzAYyzK/WeLIx/O/6nvsxYJ55eIHUYl24hClKWr F0pazRWMAPswQ== Date: Fri, 28 Nov 2025 10:48:10 -0800 From: Oliver Upton To: Marc Zyngier Cc: Alexandru Elisei , oliver.upton@linux.dev, joey.gouly@arm.com, yuzenghui@huawei.com, suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Subject: Re: [PATCH 3/4] KVM: arm64: nv: Don't mask VTCR_EL2.HA if FEAT_HAFDBS is present Message-ID: References: <20251128100946.74210-1-alexandru.elisei@arm.com> <20251128100946.74210-4-alexandru.elisei@arm.com> <86v7iup3bv.wl-maz@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86v7iup3bv.wl-maz@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251128_104814_932950_A7A0F390 X-CRM114-Status: GOOD ( 22.66 ) 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 Fri, Nov 28, 2025 at 03:46:44PM +0000, Marc Zyngier wrote: > On Fri, 28 Nov 2025 10:09:45 +0000, > Alexandru Elisei wrote: > > > > Commit 39db933ba67f ("KVM: arm64: nv: Implement HW access flag management > > in stage-2 SW PTW") added support for hardware updates to the access flag > > to stage 2 if the feature is available to the virtual machine, but forgot > > to remove the VTCR_EL2.HA bit from the res0 mask for the register. Remove > > it from the mask to allow the VM to use the feature. > > > > Fixes: 39db933ba67f ("KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW") > > Signed-off-by: Alexandru Elisei > > --- > > arch/arm64/kvm/nested.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c > > index 911fc99ed99d..7a34163f6c68 100644 > > --- a/arch/arm64/kvm/nested.c > > +++ b/arch/arm64/kvm/nested.c > > @@ -1719,7 +1719,9 @@ int kvm_init_nv_sysregs(struct kvm_vcpu *vcpu) > > set_sysreg_masks(kvm, VTTBR_EL2, res0, res1); > > > > /* VTCR_EL2 */ > > - res0 = GENMASK(63, 32) | GENMASK(30, 20); > > + res0 = GENMASK(63, 32) | GENMASK(30, 22) | BIT(20); > > + if (!kvm_has_feat(kvm, ID_AA64MMFR1_EL1, HAFDBS, AF)) > > + res0 |= VTCR_EL2_HA; > > res1 = BIT(31); > > set_sysreg_masks(kvm, VTCR_EL2, res0, res1); > > > > The fix is correct, but I really do not want to add more of these > tedious checks, one after the other. We should fix this once and for > all by converting VTCR_EL2 to the feature dependency infrastructure > and be done with it. > > I've pushed a small series at [1] that does that (very lightly > tested). This looks alright to me, do you want to post it? Thanks, Oliver