From patchwork Thu Jan 12 19:18:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13098649 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 67F6BC63797 for ; Thu, 12 Jan 2023 19:27:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240117AbjALT11 (ORCPT ); Thu, 12 Jan 2023 14:27:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239901AbjALT0v (ORCPT ); Thu, 12 Jan 2023 14:26:51 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05E26FEF for ; Thu, 12 Jan 2023 11:20:52 -0800 (PST) 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 39FFE62086 for ; Thu, 12 Jan 2023 19:20:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 967E5C433F1; Thu, 12 Jan 2023 19:20:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673551251; bh=TlJtz0XtzrPZ/3Di6kzUruT+R+5mVn0pMDj2qb6ZKGA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YuHa7UD5pXrW2xwtt0YnnzdndpVjsuOXNqghnpThOds32PI8kxo1Mb1FCuhUEbsNA ElyPjJq7xxLRciBSxb4/mSPxEIZm8BfD805RnpWTeq/DSK5f9AEIWSSEcrlzSf4Ufn /4CxnzUBquPRRbZK2/Ca1Nc3EswiiZpb0Wip36yS7AGcpUxIC/8yJEWMJNGcTojh5i K+bcJ4tRp/1tQQpqFqFW19uBysaCtZ00G0sOcGx5fAESEmO4Fx4nATpo/oKTN3OxYr rLGEI7Wcb30UvWfAqBN3RxUMhw4n7n1oQshEoNan8ofcckeO8yBbcO7PhgR39+t2Gt EA1Mlzjd5HgKw== 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 1pG373-001IWu-5w; Thu, 12 Jan 2023 19:19:45 +0000 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 , Jintack Lim , Russell King , James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu Subject: [PATCH v7 23/68] KVM: arm64: nv: Respect virtual CPTR_EL2.{TFP,FPEN} settings Date: Thu, 12 Jan 2023 19:18:42 +0000 Message-Id: <20230112191927.1814989-24-maz@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230112191927.1814989-1-maz@kernel.org> References: <20230112191927.1814989-1-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, jintack@cs.columbia.edu, rmk+kernel@armlinux.org.uk, 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 | 8 ++++++-- 3 files changed, 43 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index ea73377693af..d90de6666259 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 @@ -333,6 +334,30 @@ 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 ea73b47b99ac..2aefe35409c9 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -97,11 +97,19 @@ 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; } @@ -263,7 +271,7 @@ 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 e0bcaf000251..f458c2439271 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -174,8 +174,12 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) sve_guest = vcpu_has_sve(vcpu); esr_ec = kvm_vcpu_trap_get_class(vcpu); - /* Don't handle SVE traps for non-SVE vcpus here: */ - if (!sve_guest && esr_ec != ESR_ELx_EC_FP_ASIMD) + /* + * Don't handle SVE traps for non-SVE vcpus here. This + * includes NV guests for the time being. + */ + if (!sve_guest && (esr_ec != ESR_ELx_EC_FP_ASIMD || + guest_hyp_fpsimd_traps_enabled(vcpu))) return false; /* Valid trap. Switch the context: */