From patchwork Fri Jun 21 09:38:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11009225 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4406E1398 for ; Fri, 21 Jun 2019 09:39:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 34454289A6 for ; Fri, 21 Jun 2019 09:39:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2861D289E5; Fri, 21 Jun 2019 09:39:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AB964289A6 for ; Fri, 21 Jun 2019 09:39:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726732AbfFUJju (ORCPT ); Fri, 21 Jun 2019 05:39:50 -0400 Received: from foss.arm.com ([217.140.110.172]:54066 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726666AbfFUJju (ORCPT ); Fri, 21 Jun 2019 05:39:50 -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 2B9751478; Fri, 21 Jun 2019 02:39:50 -0700 (PDT) Received: from filthy-habits.cambridge.arm.com (filthy-habits.cambridge.arm.com [10.1.197.61]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C664C3F246; Fri, 21 Jun 2019 02:39:48 -0700 (PDT) From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara , Christoffer Dall , Dave Martin , Jintack Lim , Julien Thierry , James Morse , Suzuki K Poulose Subject: [PATCH 24/59] KVM: arm64: nv: Respect virtual CPTR_EL2.TFP setting Date: Fri, 21 Jun 2019 10:38:08 +0100 Message-Id: <20190621093843.220980-25-marc.zyngier@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190621093843.220980-1-marc.zyngier@arm.com> References: <20190621093843.220980-1-marc.zyngier@arm.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jintack Lim Forward traps due to FP/ASIMD register accesses to the virtual EL2 if virtual CPTR_EL2.TFP is set. Note that if TFP bit is set, then even accesses to FP/ASIMD register from EL2 as well as NS EL0/1 will trap to EL2. So, we don't check the VM's exception level. Signed-off-by: Jintack Lim Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_emulate.h | 7 +++++++ arch/arm64/kvm/handle_exit.c | 16 ++++++++++++---- arch/arm64/kvm/hyp/switch.c | 11 +++++++++-- 3 files changed, 28 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 2644258e96ba..73d8c54a52c6 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -357,6 +358,12 @@ static inline bool vcpu_mode_priv(const struct kvm_vcpu *vcpu) return mode != PSR_MODE_EL0t; } +static inline bool guest_hyp_fpsimd_traps_enabled(const struct kvm_vcpu *vcpu) +{ + return nested_virt_in_use(vcpu) && + (vcpu_read_sys_reg(vcpu, CPTR_EL2) & CPTR_EL2_TFP); +} + static inline u32 kvm_vcpu_get_hsr(const struct kvm_vcpu *vcpu) { return vcpu->arch.fault.esr_el2; diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index ddba212fd6ec..39602a4c1d61 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -104,11 +104,19 @@ static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) } /* - * Guest access to FP/ASIMD registers are routed to this handler only - * when the system doesn't support FP/ASIMD. + * This handles the cases where the system does not support FP/ASIMD or when + * we are running nested virtualization and the guest hypervisor is trapping + * FP/ASIMD accesses by its guest guest. + * + * All other handling of guest vs. host FP/ASIMD register state is handled in + * fixup_guest_exit(). */ -static int handle_no_fpsimd(struct kvm_vcpu *vcpu, struct kvm_run *run) +static int kvm_handle_fpasimd(struct kvm_vcpu *vcpu, struct kvm_run *run) { + if (guest_hyp_fpsimd_traps_enabled(vcpu)) + return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu)); + + /* This is the case when the system doesn't support FP/ASIMD. */ kvm_inject_undefined(vcpu); return 1; } @@ -277,7 +285,7 @@ static exit_handle_fn arm_exit_handlers[] = { [ESR_ELx_EC_BREAKPT_LOW]= kvm_handle_guest_debug, [ESR_ELx_EC_BKPT32] = kvm_handle_guest_debug, [ESR_ELx_EC_BRK64] = kvm_handle_guest_debug, - [ESR_ELx_EC_FP_ASIMD] = handle_no_fpsimd, + [ESR_ELx_EC_FP_ASIMD] = kvm_handle_fpasimd, [ESR_ELx_EC_PAC] = kvm_handle_ptrauth, }; diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 62359c7c3d6b..9b5129cdc26a 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -351,11 +351,18 @@ static bool __hyp_text __hyp_handle_fpsimd(struct kvm_vcpu *vcpu) hsr_ec != ESR_ELx_EC_SVE) return false; - /* Don't handle SVE traps for non-SVE vcpus here: */ - if (!sve_guest) + /* + * Don't handle SVE traps for non-SVE vcpus here. This + * includes NV guests for the time beeing. + */ + if (!sve_guest) { if (hsr_ec != ESR_ELx_EC_FP_ASIMD) return false; + if (guest_hyp_fpsimd_traps_enabled(vcpu)) + return false; + } + /* Valid trap. Switch the context: */ if (vhe) {