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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C60A1C43613 for ; Mon, 24 Jun 2019 12:59:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A507D212F5 for ; Mon, 24 Jun 2019 12:59:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728701AbfFXM7c (ORCPT ); Mon, 24 Jun 2019 08:59:32 -0400 Received: from foss.arm.com ([217.140.110.172]:49532 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728070AbfFXM7c (ORCPT ); Mon, 24 Jun 2019 08:59:32 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D4638344; Mon, 24 Jun 2019 05:59:31 -0700 (PDT) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7FC913F718; Mon, 24 Jun 2019 05:59:30 -0700 (PDT) Date: Mon, 24 Jun 2019 13:59:28 +0100 From: Dave Martin To: Marc Zyngier Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Julien Thierry , Andre Przywara , Suzuki K Poulose , Christoffer Dall , James Morse , Jintack Lim Subject: Re: [PATCH 08/59] KVM: arm64: nv: Reset VMPIDR_EL2 and VPIDR_EL2 to sane values Message-ID: <20190624125928.GR2790@e103592.cambridge.arm.com> References: <20190621093843.220980-1-marc.zyngier@arm.com> <20190621093843.220980-9-marc.zyngier@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190621093843.220980-9-marc.zyngier@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Jun 21, 2019 at 10:37:52AM +0100, Marc Zyngier wrote: > The VMPIDR_EL2 and VPIDR_EL2 are architecturally UNKNOWN at reset, but > let's be nice to a guest hypervisor behaving foolishly and reset these > to something reasonable anyway. Why be nice? Generally we do try to initialise UNKNOWN regs to garbage, to help trip up badly-written guests. Cheers ---Dave > > Signed-off-by: Christoffer Dall > Signed-off-by: Marc Zyngier > --- > arch/arm64/kvm/sys_regs.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index e81be6debe07..693dd063c9c2 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -624,7 +624,7 @@ static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) > vcpu_write_sys_reg(vcpu, amair, AMAIR_EL1); > } > > -static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) > +static u64 compute_reset_mpidr(struct kvm_vcpu *vcpu) > { > u64 mpidr; > > @@ -638,7 +638,24 @@ static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) > mpidr = (vcpu->vcpu_id & 0x0f) << MPIDR_LEVEL_SHIFT(0); > mpidr |= ((vcpu->vcpu_id >> 4) & 0xff) << MPIDR_LEVEL_SHIFT(1); > mpidr |= ((vcpu->vcpu_id >> 12) & 0xff) << MPIDR_LEVEL_SHIFT(2); > - vcpu_write_sys_reg(vcpu, (1ULL << 31) | mpidr, MPIDR_EL1); > + mpidr |= (1ULL << 31); > + > + return mpidr; > +} > + > +static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) > +{ > + vcpu_write_sys_reg(vcpu, compute_reset_mpidr(vcpu), MPIDR_EL1); > +} > + > +static void reset_vmpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) > +{ > + vcpu_write_sys_reg(vcpu, compute_reset_mpidr(vcpu), VMPIDR_EL2); > +} > + > +static void reset_vpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) > +{ > + vcpu_write_sys_reg(vcpu, read_cpuid_id(), VPIDR_EL2); > } > > static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) > @@ -1668,8 +1685,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { > */ > { SYS_DESC(SYS_PMCCFILTR_EL0), access_pmu_evtyper, reset_val, PMCCFILTR_EL0, 0 }, > > - { SYS_DESC(SYS_VPIDR_EL2), access_rw, reset_val, VPIDR_EL2, 0 }, > - { SYS_DESC(SYS_VMPIDR_EL2), access_rw, reset_val, VMPIDR_EL2, 0 }, > + { SYS_DESC(SYS_VPIDR_EL2), access_rw, reset_vpidr, VPIDR_EL2 }, > + { SYS_DESC(SYS_VMPIDR_EL2), access_rw, reset_vmpidr, VMPIDR_EL2 }, > > { SYS_DESC(SYS_SCTLR_EL2), access_rw, reset_val, SCTLR_EL2, 0 }, > { SYS_DESC(SYS_ACTLR_EL2), access_rw, reset_val, ACTLR_EL2, 0 }, > -- > 2.20.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel