From patchwork Mon May 15 17:30:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13241969 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53CC8C7EE25 for ; Mon, 15 May 2023 17:50:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244885AbjEORue (ORCPT ); Mon, 15 May 2023 13:50:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244772AbjEORuD (ORCPT ); Mon, 15 May 2023 13:50:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F0881CA41 for ; Mon, 15 May 2023 10:48:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8528F62F14 for ; Mon, 15 May 2023 17:47:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6311C433D2; Mon, 15 May 2023 17:47:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684172877; bh=ZeZTZEc+uxxgSGrsGWLlzL6+q+gUyk2CGotXFTZBYko=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i5Bvx7M/GrylslNBAcUGR0ZdjYbyqqglTUgfNsxeYwektGo9mNVYD+arxk3EJXsIS Aa9+62UA2SocLHjUNxf9uCPVVw3Sdz9VHcgAxnTATOwhQrvCeYWXCJ1wg3HrQT59d6 VF+3OxoxNMhYNHN6o52kNKYcwQMPKH7J05G9tpPb1BCFh+I9q53WD4PyXkG3FwrQAP CwMSQVsSiK12Ar4k9k+LmtUcie+6asD0MnDa+o+EBdfKD3txjWMRsoKWyuBjRVyfqj VkJrzhsMrIiUUmKWfZRwv3UXn6gNq9Q23MpP5sed1VM6G1EMly1BIm69DYRhHimJ8p rfsY0gqdO97Lg== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pyc2j-00FJAF-5H; Mon, 15 May 2023 18:31:29 +0100 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Alexandru Elisei , Andre Przywara , Chase Conklin , Christoffer Dall , Ganapatrao Kulkarni , Darren Hart , Jintack Lim , Russell King , Miguel Luis , James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu Subject: [PATCH v10 22/59] KVM: arm64: nv: Respect virtual CPTR_EL2.{TFP,FPEN} settings Date: Mon, 15 May 2023 18:30:26 +0100 Message-Id: <20230515173103.1017669-23-maz@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230515173103.1017669-1-maz@kernel.org> References: <20230515173103.1017669-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, alexandru.elisei@arm.com, andre.przywara@arm.com, chase.conklin@arm.com, christoffer.dall@arm.com, gankulkarni@os.amperecomputing.com, darren@os.amperecomputing.com, jintack@cs.columbia.edu, rmk+kernel@armlinux.org.uk, miguel.luis@oracle.com, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.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 From: Jintack Lim Forward traps due to FP/ASIMD register accesses to the virtual EL2 if virtual CPTR_EL2.TFP is set (with HCR_EL2.E2H == 0) or CPTR_EL2.FPEN is configure to do so (with HCR_EL2.E2h == 1). Signed-off-by: Jintack Lim Signed-off-by: Christoffer Dall [maz: account for HCR_EL2.E2H when testing for TFP/FPEN, with all the hard work actually being done by Chase Conklin] Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_emulate.h | 25 +++++++++++++++++++++++++ arch/arm64/kvm/handle_exit.c | 16 ++++++++++++---- arch/arm64/kvm/hyp/include/hyp/switch.h | 4 ++++ 3 files changed, 41 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 1ff0a224c32b..c64980d33c8b 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -11,6 +11,7 @@ #ifndef __ARM64_KVM_EMULATE_H__ #define __ARM64_KVM_EMULATE_H__ +#include #include #include @@ -335,6 +336,30 @@ 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) +{ + u64 val; + + if (!vcpu_has_nv(vcpu)) + return false; + + val = vcpu_read_sys_reg(vcpu, CPTR_EL2); + + if (!vcpu_el2_e2h_is_set(vcpu)) + return (val & CPTR_EL2_TFP); + + switch (FIELD_GET(CPACR_ELx_FPEN, val)) { + case 0b00: + case 0b10: + return true; + case 0b01: + return vcpu_el2_tge_is_set(vcpu) && !vcpu_is_el2(vcpu); + case 0b11: + default: /* GCC is dumb */ + return false; + } +} + static __always_inline u64 kvm_vcpu_get_esr(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 5811a791cf01..c4dc144726ee 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -87,11 +87,19 @@ static int handle_smc(struct kvm_vcpu *vcpu) } /* - * 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) +static int kvm_handle_fpasimd(struct kvm_vcpu *vcpu) { + if (guest_hyp_fpsimd_traps_enabled(vcpu)) + return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu)); + + /* This is the case when the system doesn't support FP/ASIMD. */ kvm_inject_undefined(vcpu); return 1; } @@ -253,7 +261,7 @@ 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/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index c6d62357e736..0a344184f26c 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -172,6 +172,10 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) if (!system_supports_fpsimd()) return false; + /* Forward traps to the guest hypervisor as required */ + if (guest_hyp_fpsimd_traps_enabled(vcpu)) + return false; + sve_guest = vcpu_has_sve(vcpu); esr_ec = kvm_vcpu_trap_get_class(vcpu);