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 BD6B9C46CD2 for ; Tue, 30 Jan 2024 12:46:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=++TjTlQXZGyuoXXKxeM7hKPfwFyJbd9vR+lA1uuS7Ug=; b=pVaLKrKUvod2kJ 1uz3wTcDMAWRmewo84UHS/l36908+eBjCGWblQM76EF2np/WAGvcolzcJpUHCILUOHuu23fCZTo0j S5+LermHyNq0rBGTTrE5EluvJv2BW0bijPImPeW0WCDAyhwwvpHuMnBfehhsTcWseSsfugIJHDhAg zslixlEraVxe3rWY/vO5G+YEl1/aRIFj1ovBYCmOoGgXyOgzjSWFn1FveytllYw9TXXC8OTNpYpCi +hQFxV1OQJPYFLnPDMAo5vMyHuwCaRERw9YA8A4ZjP7edFKQyh5ApX7G825v3yl9kGkzXw4gcHpdB ZcXXr9bQWFwrE8Y/iZVw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rUnVM-0000000Gis6-0Mnw; Tue, 30 Jan 2024 12:46:20 +0000 Received: from sin.source.kernel.org ([145.40.73.55]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rUnVI-0000000GiqI-1LzV for linux-arm-kernel@lists.infradead.org; Tue, 30 Jan 2024 12:46:17 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 66E32CE182E; Tue, 30 Jan 2024 12:46:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9CE81C433F1; Tue, 30 Jan 2024 12:46:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706618773; bh=w1qhXVmoOsaAWbr9C1RxDZMhwCNg+pqUUmMOX6zaYbA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=QRETFO35X8lMrWo+JEgnWoqphjJV3lrfFZcZLsBNP2xjRVL4V7ilD1t+9BR3nQL1F MPl14W6Nv0ptOsXb1ODMizRAiA0z2wjXTN0Yvn73skNKdA4j+d3tdA8eeqhG+ZIct+ 7NIer+FrJ3L4SZY+QcKxwH+7oaKFti52gnu87X4Wfqng/dead7/pjmYRubnQNp0k7l Uf9LrMGIwJkuC8kw1PV+0wkKUQec36hGHjJGyxLwjtbHPu4Y3xdx09dI2/7YK5iTXm fQs4yCVNQwWiQt3zRqCAz2fjvGFAfolkBozwhlGRQ/CGZnHMm5OEYzSk2EEWAWLl2U TYvoaiN/e/8ow== Received: from [12.161.88.66] (helo=wait-a-minute.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 1rUnVD-00GG51-9e; Tue, 30 Jan 2024 12:46:11 +0000 Date: Tue, 30 Jan 2024 12:46:07 +0000 Message-ID: <87o7d3vvjk.wl-maz@kernel.org> From: Marc Zyngier To: Joey Gouly Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Catalin Marinas , Will Deacon , Mark Brown Subject: Re: [PATCH 21/25] KVM: arm64: Make TLBI OS/Range UNDEF if not advertised to the guest In-Reply-To: <20240125133047.GD1535978@e124191.cambridge.arm.com> References: <20240122201852.262057-1-maz@kernel.org> <20240122201852.262057-22-maz@kernel.org> <20240125133047.GD1535978@e124191.cambridge.arm.com> 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/28.2 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 12.161.88.66 X-SA-Exim-Rcpt-To: joey.gouly@arm.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, broonie@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-20240130_044616_740546_3C745C8E X-CRM114-Status: GOOD ( 27.66 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, 25 Jan 2024 13:30:47 +0000, Joey Gouly wrote: > > Question, > > On Mon, Jan 22, 2024 at 08:18:48PM +0000, Marc Zyngier wrote: > > Outer Shareable and Range TLBI instructions shouldn't be made available > > to the guest if they are not advertised. Use FGU to disable those, > > and set HCR_EL2.TLBIOS in the case the host doesn't have FGT. > > > > Signed-off-by: Marc Zyngier > > --- > > arch/arm64/kvm/sys_regs.c | 29 +++++++++++++++++++++++++++++ > > 1 file changed, 29 insertions(+) > > > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > > index a62efd8a2959..3c939ea4a28f 100644 > > --- a/arch/arm64/kvm/sys_regs.c > > +++ b/arch/arm64/kvm/sys_regs.c > > @@ -3949,6 +3949,9 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu) > > > > mutex_lock(&kvm->arch.config_lock); > > > > + if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS)) > > + vcpu->arch.hcr_el2 |= HCR_TTLBOS; > > + > > if (test_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags)) > > goto out; > > > > @@ -3961,6 +3964,32 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu) > > HFGxTR_EL2_nSMPRI_EL1_MASK | > > HFGxTR_EL2_nTPIDR2_EL0_MASK); > > > > + if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS)) > > + kvm->arch.fgu[HFGITR_GROUP] |= (HFGITR_EL2_TLBIRVAALE1OS| > > + HFGITR_EL2_TLBIRVALE1OS | > > + HFGITR_EL2_TLBIRVAAE1OS | > > + HFGITR_EL2_TLBIRVAE1OS | > > + HFGITR_EL2_TLBIVAALE1OS | > > + HFGITR_EL2_TLBIVALE1OS | > > + HFGITR_EL2_TLBIVAAE1OS | > > + HFGITR_EL2_TLBIASIDE1OS | > > + HFGITR_EL2_TLBIVAE1OS | > > + HFGITR_EL2_TLBIVMALLE1OS); > > + > > + if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, RANGE)) > > + kvm->arch.fgu[HFGITR_GROUP] |= (HFGITR_EL2_TLBIRVAALE1 | > > + HFGITR_EL2_TLBIRVALE1 | > > + HFGITR_EL2_TLBIRVAAE1 | > > + HFGITR_EL2_TLBIRVAE1 | > > + HFGITR_EL2_TLBIRVAALE1IS| > > + HFGITR_EL2_TLBIRVALE1IS | > > + HFGITR_EL2_TLBIRVAAE1IS | > > + HFGITR_EL2_TLBIRVAE1IS | > > + HFGITR_EL2_TLBIRVAALE1OS| > > + HFGITR_EL2_TLBIRVALE1OS | > > + HFGITR_EL2_TLBIRVAAE1OS | > > + HFGITR_EL2_TLBIRVAE1OS); > > + > > set_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags); > > out: > > mutex_unlock(&kvm->arch.config_lock); > > I think I'm right in saying.. > > If the VM is running on a platform with ID_AA64ISAR0_EL1.TLB=0b010 (Outer > Shareable and TLB range maintenance instructions are implemented.) but without > support for FEAT_FGT, and the VMM sets the ID reg to ID_AA64ISAR0_EL1.TLB=0, > this change will trap the TLBI *OS instructions but not the following: > > TLBI RVAAE1 > TLBI RVAAE1IS > TLBI RVAALE1 > TLBI RVAALE1IS > TLBI RVAE1 > TLBI RVAE1IS > TLBI RVALE1 > TLBI RVALE1IS > > These TLB range instructions only trap with HCR_EL2.TTLB, however that traps > all TLB instructions. You may have left this off intentionally, if so can you > add something to the commit message. You got it exactly right. Setting TTLB would be overkill, and is one of the cases where we have to strike a balance between efficiency and enforcement. I'll leave a comment to that effect to capture this. Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel