From patchwork Thu Jan 12 19:18:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13098704 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 2295CC54EBE for ; Thu, 12 Jan 2023 19:30:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240478AbjALTaa (ORCPT ); Thu, 12 Jan 2023 14:30:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240602AbjALT2i (ORCPT ); Thu, 12 Jan 2023 14:28:38 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61392C01 for ; Thu, 12 Jan 2023 11:23:00 -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 sin.source.kernel.org (Postfix) with ESMTPS id CF059CE1FAD for ; Thu, 12 Jan 2023 19:22:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E84AC433EF; Thu, 12 Jan 2023 19:22:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673551377; bh=ZdF0Vi6WI55UG43SPoot4i4lR4nOp/RpjK2vQ6Aryck=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KF50l1xQOMFczylBkxG1rKwv/SSrw+tmP260usTgw86os2aA0OOZiaz5O6rOr+LN7 C0fjIDmB/HSoU4U/pbcV4uMHe+rOqX4KQ8JovOZhlxEK/OeLZMMsR9BU52xS4Jj8rI e+FUC2JMToobDxODTb6taw401yvw9sTTsTauCOE471nABLhfX2IgN6WpJUSEYWCfyo PjMG7VA5MI5Wp/RVD/t0YlpqwZ2fr0ps8Ke4uC176RH0ME/BlT5LZcNk/tIYwwCS4N QlgHhNOsWlpK6chtcx8mJk2/ZeFaT2sJdmBytF8fiaqkUcZbwOaDX0N10qWc8HatDX yVLe9nvLtGn5g== 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-EP; 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 24/68] KVM: arm64: nv: Respect the virtual HCR_EL2.NV bit setting Date: Thu, 12 Jan 2023 19:18:43 +0000 Message-Id: <20230112191927.1814989-25-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 HCR_EL2.NV bit to the virtual EL2 if they are not coming from the virtual EL2 and the virtual HCR_EL2.NV bit is set. In addition to EL2 register accesses, setting NV bit will also make EL12 register accesses trap to EL2. To emulate this for the virtual EL2, forword traps due to EL12 register accessses to the virtual EL2 if the virtual HCR_EL2.NV bit is set. Same thing is done for SMCs issued by a guest and trapped by the virtual EL2. This is for recursive nested virtualization. Signed-off-by: Jintack Lim [Moved code to emulate-nested.c] Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_arm.h | 1 + arch/arm64/include/asm/kvm_nested.h | 3 +++ arch/arm64/kvm/emulate-nested.c | 27 +++++++++++++++++++++++++++ arch/arm64/kvm/handle_exit.c | 7 +++++++ arch/arm64/kvm/sys_regs.c | 21 +++++++++++++++++++++ 5 files changed, 59 insertions(+) diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index d86c0050b69d..3f98c115d029 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -20,6 +20,7 @@ #define HCR_AMVOFFEN (UL(1) << 51) #define HCR_FIEN (UL(1) << 47) #define HCR_FWB (UL(1) << 46) +#define HCR_NV (UL(1) << 42) #define HCR_API (UL(1) << 41) #define HCR_APK (UL(1) << 40) #define HCR_TEA (UL(1) << 37) diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index f7bb1f0d0954..befd2501d5ba 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -59,4 +59,7 @@ static inline u64 translate_ttbr0_el2_to_ttbr0_el1(u64 ttbr0) return ttbr0 & ~GENMASK_ULL(63, 48); } +extern bool forward_traps(struct kvm_vcpu *vcpu, u64 control_bit); +extern bool forward_nv_traps(struct kvm_vcpu *vcpu); + #endif /* __ARM64_KVM_NESTED_H */ diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c index b96662029fb1..75cf6f15accc 100644 --- a/arch/arm64/kvm/emulate-nested.c +++ b/arch/arm64/kvm/emulate-nested.c @@ -14,6 +14,26 @@ #include "trace.h" +bool forward_traps(struct kvm_vcpu *vcpu, u64 control_bit) +{ + bool control_bit_set; + + if (!vcpu_has_nv(vcpu)) + return false; + + control_bit_set = __vcpu_sys_reg(vcpu, HCR_EL2) & control_bit; + if (!vcpu_is_el2(vcpu) && control_bit_set) { + kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu)); + return true; + } + return false; +} + +bool forward_nv_traps(struct kvm_vcpu *vcpu) +{ + return forward_traps(vcpu, HCR_NV); +} + static u64 kvm_check_illegal_exception_return(struct kvm_vcpu *vcpu, u64 spsr) { u64 mode = spsr & PSR_MODE_MASK; @@ -52,6 +72,13 @@ void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu) u64 spsr, elr, mode; bool direct_eret; + /* + * Forward this trap to the virtual EL2 if the virtual + * HCR_EL2.NV bit is set and this is coming from !EL2. + */ + if (forward_nv_traps(vcpu)) + return; + /* * Going through the whole put/load motions is a waste of time * if this is a VHE guest hypervisor returning to its own diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 2aefe35409c9..cfc50d67a6bc 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -65,6 +65,13 @@ static int handle_smc(struct kvm_vcpu *vcpu) { int ret; + /* + * Forward this trapped smc instruction to the virtual EL2 if + * the guest has asked for it. + */ + if (forward_traps(vcpu, HCR_TSC)) + return 1; + /* * "If an SMC instruction executed at Non-secure EL1 is * trapped to EL2 because HCR_EL2.TSC is 1, the exception is a diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 27fb2d8f29ca..934341a1df2e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -263,10 +263,19 @@ static u32 get_ccsidr(u32 csselr) return ccsidr; } +static bool el12_reg(struct sys_reg_params *p) +{ + /* All *_EL12 registers have Op1=5. */ + return (p->Op1 == 5); +} + static bool access_rw(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { + if (el12_reg(p) && forward_nv_traps(vcpu)) + return false; + if (p->is_write) vcpu_write_sys_reg(vcpu, p->regval, r->reg); else @@ -335,6 +344,9 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu, bool was_enabled = vcpu_has_cache_enabled(vcpu); u64 val, mask, shift; + if (el12_reg(p) && forward_nv_traps(vcpu)) + return false; + /* We don't expect TRVM on the host */ BUG_ON(!vcpu_is_el2(vcpu) && !p->is_write); @@ -1734,6 +1746,9 @@ static bool access_elr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { + if (el12_reg(p) && forward_nv_traps(vcpu)) + return false; + if (p->is_write) vcpu_write_sys_reg(vcpu, p->regval, ELR_EL1); else @@ -1746,6 +1761,9 @@ static bool access_spsr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { + if (el12_reg(p) && forward_nv_traps(vcpu)) + return false; + if (p->is_write) __vcpu_sys_reg(vcpu, SPSR_EL1) = p->regval; else @@ -1758,6 +1776,9 @@ static bool access_spsr_el2(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { + if (el12_reg(p) && forward_nv_traps(vcpu)) + return false; + if (p->is_write) vcpu_write_sys_reg(vcpu, p->regval, SPSR_EL2); else