From patchwork Tue Mar 16 10:13:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 12141691 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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 47514C4332B for ; Tue, 16 Mar 2021 10:14:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2947164F06 for ; Tue, 16 Mar 2021 10:14:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236583AbhCPKNy (ORCPT ); Tue, 16 Mar 2021 06:13:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:56686 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236573AbhCPKNh (ORCPT ); Tue, 16 Mar 2021 06:13:37 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E477765031; Tue, 16 Mar 2021 10:13:36 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lM6hj-001uep-1q; Tue, 16 Mar 2021 10:13:35 +0000 From: Marc Zyngier To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: dave.martin@arm.com, daniel.kiss@arm.com, Will Deacon , Catalin Marinas , James Morse , Julien Thierry , Suzuki K Poulose , broonie@kernel.org, kernel-team@android.com Subject: [PATCH 09/10] KVM: arm64: Save/restore SVE state for nVHE Date: Tue, 16 Mar 2021 10:13:11 +0000 Message-Id: <20210316101312.102925-10-maz@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210316101312.102925-1-maz@kernel.org> References: <20210316101312.102925-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, dave.martin@arm.com, daniel.kiss@arm.com, will@kernel.org, catalin.marinas@arm.com, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, broonie@kernel.org, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Implement the SVE save/restore for nVHE, following a similar logic to that of the VHE implementation: - the SVE state is switched on trap from EL1 to EL2 - no further changes to ZCR_EL2 occur as long as the guest isn't preempted or exit to userspace - on vcpu_put(), ZCR_EL2 is reset to its default value, and ZCR_EL1 restored to the default guest value Signed-off-by: Marc Zyngier --- arch/arm64/kvm/fpsimd.c | 15 ++++++++-- arch/arm64/kvm/hyp/include/hyp/switch.h | 37 +++++++++---------------- arch/arm64/kvm/hyp/nvhe/switch.c | 4 +-- 3 files changed, 28 insertions(+), 28 deletions(-) diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index b5f95abd23f5..cc6cdea69596 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -121,11 +121,22 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) local_irq_save(flags); if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { - if (guest_has_sve) + if (guest_has_sve) { __vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR); + /* Restore the VL that was saved when bound to the CPU */ + if (!has_vhe()) { + u64 zcr; + + kvm_call_hyp(__kvm_reset_sve_vq); + zcr = vcpu_sve_vq(vcpu) - 1; + if (read_sysreg_el1(SYS_ZCR) != zcr) + write_sysreg_el1(zcr, SYS_ZCR); + } + } + fpsimd_save_and_flush_cpu_state(); - } else if (host_has_sve) { + } else if (has_vhe() && host_has_sve) { /* * The FPSIMD/SVE state in the CPU has not been touched, and we * have SVE (and VHE): CPACR_EL1 (alias CPTR_EL2) has been diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index d34dc220a1ce..777b9bfa4478 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -218,25 +218,19 @@ static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu) /* Check for an FPSIMD/SVE trap and handle as appropriate */ static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu) { - bool vhe, sve_guest, sve_host; + bool sve_guest, sve_host; u8 esr_ec; + u64 reg; if (!system_supports_fpsimd()) return false; - /* - * Currently system_supports_sve() currently implies has_vhe(), - * so the check is redundant. However, has_vhe() can be determined - * statically and helps the compiler remove dead code. - */ - if (has_vhe() && system_supports_sve()) { + if (system_supports_sve()) { sve_guest = vcpu_has_sve(vcpu); sve_host = vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE; - vhe = true; } else { sve_guest = false; sve_host = false; - vhe = has_vhe(); } esr_ec = kvm_vcpu_trap_get_class(vcpu); @@ -245,31 +239,26 @@ static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu) return false; /* Don't handle SVE traps for non-SVE vcpus here: */ - if (!sve_guest) - if (esr_ec != ESR_ELx_EC_FP_ASIMD) - return false; + if (!sve_guest && esr_ec != ESR_ELx_EC_FP_ASIMD) + return false; /* Valid trap. Switch the context: */ - - if (vhe) { - u64 reg = read_sysreg(cpacr_el1) | CPACR_EL1_FPEN; - + if (has_vhe()) { + reg = CPACR_EL1_FPEN; if (sve_guest) reg |= CPACR_EL1_ZEN; - write_sysreg(reg, cpacr_el1); + sysreg_clear_set(cpacr_el1, 0, reg); } else { - write_sysreg(read_sysreg(cptr_el2) & ~(u64)CPTR_EL2_TFP, - cptr_el2); - } + reg = CPTR_EL2_TFP; + if (sve_guest) + reg |= CPTR_EL2_TZ; + sysreg_clear_set(cptr_el2, reg, 0); + } isb(); if (vcpu->arch.flags & KVM_ARM64_FP_HOST) { - /* - * In the SVE case, VHE is assumed: it is enforced by - * Kconfig and kvm_arch_init(). - */ if (sve_host) __hyp_sve_save_host(vcpu); else diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index f3d0e9eca56c..ef47abcef63f 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -41,9 +41,9 @@ static void __activate_traps(struct kvm_vcpu *vcpu) __activate_traps_common(vcpu); val = CPTR_EL2_DEFAULT; - val |= CPTR_EL2_TTA | CPTR_EL2_TZ | CPTR_EL2_TAM; + val |= CPTR_EL2_TTA | CPTR_EL2_TAM; if (!update_fp_enabled(vcpu)) { - val |= CPTR_EL2_TFP; + val |= CPTR_EL2_TFP | CPTR_EL2_TZ; __activate_traps_fpsimd32(vcpu); }