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 0E4D3CA0ED3 for ; Mon, 2 Sep 2024 19:14:05 +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:Content-Type:MIME-Version: References:In-Reply-To:Subject:Cc:To:From:Message-ID: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=MHB6e+iy1hJViyhO+q9PAtLuiiB1OyuXhZ5FE7BFcos=; b=DqkJ7K1fljN85VOebl5zNpJDM9 25rTgm+8TyGHv/a+YvuXXywLNYo/QqGApAKr5KHhL6HpVmfQe5QBZMu5artSCrrpMisRJEt3ggdmL EoiTdb8rwJ0kroHNuuZRpKJ/14qvNYvINAoFF/jQplHjl+M7eVZ7PQLcLIT3lO6x0dlAccIrNq9Hb s2b+OcGDrTwNq5frgi7UG6t2yFrTWJWX3HCvM3JpNaeu2EVrLFflTTsh7nbme19NcHflMntHRSw/a 8s2DGb6kB+cRIwCoC+/BgM0EjLC2R3DGE3iciy8Jx3PuezPZ2Xp2GIDpVcGo4dXguNRK1KPaeOMy2 dr7t5uKg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1slCUq-0000000FNTq-3QXE; Mon, 02 Sep 2024 19:13:52 +0000 Received: from nyc.source.kernel.org ([147.75.193.91]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1slCTw-0000000FNO1-19Zk for linux-arm-kernel@lists.infradead.org; Mon, 02 Sep 2024 19:12:57 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 31C3CA426F9; Mon, 2 Sep 2024 19:12:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8EB3FC4CEC2; Mon, 2 Sep 2024 19:12:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725304374; bh=GMVnn22J0kYs5YTaIdMO4all44aS9lj+6fg+x5dH8D0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=pY5N3Kj/BU1o+ddbmefgRH5itJPL7HzzRHShngaIA00aPwOvX4i416FEgAJU5TzNE yZsQjysi6g2pmEXdy1C5TgF4yxwwklqpPj44O078O/rQGagLwa0mFWTrRIOhO+Q2n9 vKopbc/51ysI+HKKObFXrPx9pXTsADlynHTi4dZc0x3dEfFjSh210EfrgoixlRfESt kMDSdEMmv4/gOSkl5GL1bL1OjnMEvLSCHXLHs9Y+71CFbv13wp/93AaxQAoCCvdadq K5uonAVrDRMQzDLONq1d7XneiA2WW1GfI0suYXoWNSkJ0itOdV0OVDd4ZlVX+9wcH5 xRrQ2OfDeGcQQ== 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 4.95) (envelope-from ) id 1slCTs-0091pX-0Q; Mon, 02 Sep 2024 20:12:52 +0100 Date: Mon, 02 Sep 2024 20:12:51 +0100 Message-ID: <86ttexvpho.wl-maz@kernel.org> From: Marc Zyngier To: Mark Brown Cc: Oliver Upton , James Morse , Suzuki K Poulose , Catalin Marinas , Will Deacon , Joey Gouly , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, 20240813144738.2048302-1-maz@kernel.org Subject: Re: [PATCH v2 2/3] KVM: arm64: Hide TCR2_EL1 from userspace when disabled for guests In-Reply-To: <20240822-kvm-arm64-hide-pie-regs-v2-2-376624fa829c@kernel.org> References: <20240822-kvm-arm64-hide-pie-regs-v2-0-376624fa829c@kernel.org> <20240822-kvm-arm64-hide-pie-regs-v2-2-376624fa829c@kernel.org> 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/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) 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: broonie@kernel.org, oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, joey.gouly@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, 20240813144738.2048302-1-maz@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240902_121256_468909_E459FDE9 X-CRM114-Status: GOOD ( 26.21 ) 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 Thu, 22 Aug 2024 00:35:37 +0100, Mark Brown wrote: > > When the guest does not support FEAT_TCR2 we should not allow any access > to it in order to ensure that we do not create spurious issues with guest > migration. Add a visibility operation for it. > > Fixes: fbff56068232 ("KVM: arm64: Save/restore TCR2_EL1") > Signed-off-by: Mark Brown > --- > arch/arm64/include/asm/kvm_host.h | 3 +++ > arch/arm64/kvm/sys_regs.c | 29 ++++++++++++++++++++++++++--- > 2 files changed, 29 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index ab4c675b491d..7889e5f4009f 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -1476,4 +1476,7 @@ void kvm_set_vm_id_reg(struct kvm *kvm, u32 reg, u64 val); > (pa + pi + pa3) == 1; \ > }) > > +#define kvm_has_tcr2(k) \ > + (kvm_has_feat((k), ID_AA64MMFR3_EL1, TCRX, IMP)) > + > #endif /* __ARM64_KVM_HOST_H__ */ > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index 1af15140e067..6d5f43781042 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -2319,6 +2319,27 @@ static bool access_zcr_el2(struct kvm_vcpu *vcpu, > return true; > } > > +static unsigned int tcr2_visibility(const struct kvm_vcpu *vcpu, > + const struct sys_reg_desc *rd) > +{ > + if (kvm_has_tcr2(vcpu->kvm)) > + return 0; > + > + return REG_HIDDEN; > +} > + > +static unsigned int tcr2_el2_visibility(const struct kvm_vcpu *vcpu, > + const struct sys_reg_desc *rd) > +{ > + unsigned int r; > + > + r = el2_visibility(vcpu, rd); > + if (r) > + return r; > + > + return tcr2_visibility(vcpu, rd); > +} > + > /* > * Architected system registers. > * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2 > @@ -2503,7 +2524,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { > { SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 }, > { SYS_DESC(SYS_TTBR1_EL1), access_vm_reg, reset_unknown, TTBR1_EL1 }, > { SYS_DESC(SYS_TCR_EL1), access_vm_reg, reset_val, TCR_EL1, 0 }, > - { SYS_DESC(SYS_TCR2_EL1), access_vm_reg, reset_val, TCR2_EL1, 0 }, > + { SYS_DESC(SYS_TCR2_EL1), access_vm_reg, reset_val, TCR2_EL1, 0, > + .visibility = tcr2_visibility }, With this, we should be able to simplify the accessor, shouldn't we? > > PTRAUTH_KEY(APIA), > PTRAUTH_KEY(APIB), > @@ -2820,7 +2842,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { > EL2_REG(TTBR0_EL2, access_rw, reset_val, 0), > EL2_REG(TTBR1_EL2, access_rw, reset_val, 0), > EL2_REG(TCR_EL2, access_rw, reset_val, TCR_EL2_RES1), > - EL2_REG(TCR2_EL2, access_tcr2_el2, reset_val, TCR2_EL2_RES1), > + EL2_REG_FILTERED(TCR2_EL2, access_tcr2_el2, reset_val, TCR2_EL2_RES1, > + tcr2_el2_visibility), Same thing here. Thanks, M. -- Without deviation from the norm, progress is not possible.