From mboxrd@z Thu Jan 1 00:00:00 1970 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 DB03BC433F5 for ; Fri, 28 Jan 2022 12:19:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348416AbiA1MTh (ORCPT ); Fri, 28 Jan 2022 07:19:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348389AbiA1MTc (ORCPT ); Fri, 28 Jan 2022 07:19:32 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 349CEC06173B for ; Fri, 28 Jan 2022 04:19:32 -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 ams.source.kernel.org (Postfix) with ESMTPS id C790CB8256B for ; Fri, 28 Jan 2022 12:19:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3BACBC340E0; Fri, 28 Jan 2022 12:19:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643372369; bh=ib01pCIICDTcSj2/VQrOFepT0kjwR3U7S0YNvl+yzwU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dhk6HCVcpphde4TTYrsYhu5igTFQEuEd6CVV4UIbhfF5CFOhyBluZD46k0ghBS2wu LhUhUsfdOCmEyhhjD6o+1FBxyptoxoAz3fgp9EP208H0p7JQPF2iyz62uPLe5JWSYX vp8f1xvwRRBIjf0+MA116Xo1LOwYRU4gO8xWL05Lddc1GQ1rzq/5WID0T0+injRSez 2PaQMqBJDDQSgO14lap5hnBAeClfcaE+bjvZzbCdSHyLYAtX7UPhIo3podH3BVXJoa WezhuYGTTHycSSXU22VdIoKSl+NQ7atVO2LZMpPa3p9+mNhlkqAlXJ26SFuc6/4ILs QseFO5EucRqkg== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nDQDv-003njR-B0; Fri, 28 Jan 2022 12:19:27 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara , Christoffer Dall , Jintack Lim , Haibo Xu , Ganapatrao Kulkarni , Chase Conklin , "Russell King (Oracle)" , James Morse , Suzuki K Poulose , Alexandru Elisei , karl.heubaum@oracle.com, mihai.carabas@oracle.com, miguel.luis@oracle.com, kernel-team@android.com Subject: [PATCH v6 09/64] KVM: arm64: nv: Support virtual EL2 exceptions Date: Fri, 28 Jan 2022 12:18:17 +0000 Message-Id: <20220128121912.509006-10-maz@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220128121912.509006-1-maz@kernel.org> References: <20220128121912.509006-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, andre.przywara@arm.com, christoffer.dall@arm.com, jintack@cs.columbia.edu, haibo.xu@linaro.org, gankulkarni@os.amperecomputing.com, chase.conklin@arm.com, linux@armlinux.org.uk, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, karl.heubaum@oracle.com, mihai.carabas@oracle.com, miguel.luis@oracle.com, 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 From: Jintack Lim Support injecting exceptions and performing exception returns to and from virtual EL2. This must be done entirely in software except when taking an exception from vEL0 to vEL2 when the virtual HCR_EL2.{E2H,TGE} == {1,1} (a VHE guest hypervisor). Reviewed-by: Ganapatrao Kulkarni Signed-off-by: Jintack Lim Signed-off-by: Christoffer Dall [maz: switch to common exception injection framework, illegal exeption return handling] Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_arm.h | 17 +++ arch/arm64/include/asm/kvm_emulate.h | 10 ++ arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/Makefile | 2 +- arch/arm64/kvm/emulate-nested.c | 197 +++++++++++++++++++++++++++ arch/arm64/kvm/hyp/exception.c | 49 +++++-- arch/arm64/kvm/inject_fault.c | 68 +++++++-- arch/arm64/kvm/trace_arm.h | 59 ++++++++ 8 files changed, 382 insertions(+), 21 deletions(-) create mode 100644 arch/arm64/kvm/emulate-nested.c diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 01d47c5886dc..e6e3aae87a09 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -359,4 +359,21 @@ #define CPACR_EL1_TTA (1 << 28) #define CPACR_EL1_DEFAULT (CPACR_EL1_FPEN | CPACR_EL1_ZEN_EL1EN) +#define kvm_mode_names \ + { PSR_MODE_EL0t, "EL0t" }, \ + { PSR_MODE_EL1t, "EL1t" }, \ + { PSR_MODE_EL1h, "EL1h" }, \ + { PSR_MODE_EL2t, "EL2t" }, \ + { PSR_MODE_EL2h, "EL2h" }, \ + { PSR_MODE_EL3t, "EL3t" }, \ + { PSR_MODE_EL3h, "EL3h" }, \ + { PSR_AA32_MODE_USR, "32-bit USR" }, \ + { PSR_AA32_MODE_FIQ, "32-bit FIQ" }, \ + { PSR_AA32_MODE_IRQ, "32-bit IRQ" }, \ + { PSR_AA32_MODE_SVC, "32-bit SVC" }, \ + { PSR_AA32_MODE_ABT, "32-bit ABT" }, \ + { PSR_AA32_MODE_HYP, "32-bit HYP" }, \ + { PSR_AA32_MODE_UND, "32-bit UND" }, \ + { PSR_AA32_MODE_SYS, "32-bit SYS" } + #endif /* __ARM64_KVM_ARM_H__ */ diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index ea9a130c4b6a..cb9f123d26f3 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -33,6 +33,12 @@ enum exception_type { except_type_serror = 0x180, }; +#define kvm_exception_type_names \ + { except_type_sync, "SYNC" }, \ + { except_type_irq, "IRQ" }, \ + { except_type_fiq, "FIQ" }, \ + { except_type_serror, "SERROR" } + bool kvm_condition_valid32(const struct kvm_vcpu *vcpu); void kvm_skip_instr32(struct kvm_vcpu *vcpu); @@ -43,6 +49,10 @@ void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr); void kvm_vcpu_wfi(struct kvm_vcpu *vcpu); +void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu); +int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2); +int kvm_inject_nested_irq(struct kvm_vcpu *vcpu); + static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu) { return !(vcpu->arch.hcr_el2 & HCR_RW); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 15f690c27baf..8fffe2888403 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -467,6 +467,7 @@ struct kvm_vcpu_arch { #define KVM_ARM64_EXCEPT_AA64_ELx_SERR (3 << 9) #define KVM_ARM64_EXCEPT_AA64_EL1 (0 << 11) #define KVM_ARM64_EXCEPT_AA64_EL2 (1 << 11) +#define KVM_ARM64_EXCEPT_AA64_EL_MASK (1 << 11) #define KVM_ARM64_DEBUG_STATE_SAVE_SPE (1 << 12) /* Save SPE context if active */ #define KVM_ARM64_DEBUG_STATE_SAVE_TRBE (1 << 13) /* Save TRBE context if active */ diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 91861fd8b897..b67c4ebd72b1 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -14,7 +14,7 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ inject_fault.o va_layout.o handle_exit.o \ guest.o debug.o reset.o sys_regs.o \ vgic-sys-reg-v3.o fpsimd.o pmu.o pkvm.o \ - arch_timer.o trng.o\ + arch_timer.o trng.o emulate-nested.o \ vgic/vgic.o vgic/vgic-init.o \ vgic/vgic-irqfd.o vgic/vgic-v2.o \ vgic/vgic-v3.o vgic/vgic-v4.o \ diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c new file mode 100644 index 000000000000..f52cd4458947 --- /dev/null +++ b/arch/arm64/kvm/emulate-nested.c @@ -0,0 +1,197 @@ +/* + * Copyright (C) 2016 - Linaro and Columbia University + * Author: Jintack Lim + */ + +#include +#include + +#include +#include + +#include "hyp/include/hyp/adjust_pc.h" + +#include "trace.h" + +static u64 kvm_check_illegal_exception_return(struct kvm_vcpu *vcpu, u64 spsr) +{ + u64 mode = spsr & PSR_MODE_MASK; + + /* + * Possible causes for an Illegal Exception Return from EL2: + * - trying to return to EL3 + * - trying to return to a 32bit EL + * - trying to return to EL1 with HCR_EL2.TGE set + */ + if (mode == PSR_MODE_EL3t || mode == PSR_MODE_EL3h || + spsr & PSR_MODE32_BIT || + (vcpu_el2_tge_is_set(vcpu) && (mode == PSR_MODE_EL1t || + mode == PSR_MODE_EL1h))) { + /* + * The guest is playing with our nerves. Preserve EL, SP, + * masks, flags from the existing PSTATE, and set IL. + * The HW will then generate an Illegal State Exception + * immediately after ERET. + */ + spsr = *vcpu_cpsr(vcpu); + + spsr &= (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | + PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT | + PSR_MODE_MASK | PSR_MODE32_BIT); + spsr |= PSR_IL_BIT; + } + + return spsr; +} + +void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu) +{ + u64 spsr, elr, mode; + bool direct_eret; + + /* + * Going through the whole put/load motions is a waste of time + * if this is a VHE guest hypervisor returning to its own + * userspace, or the hypervisor performing a local exception + * return. No need to save/restore registers, no need to + * switch S2 MMU. Just do the canonical ERET. + */ + spsr = vcpu_read_sys_reg(vcpu, SPSR_EL2); + spsr = kvm_check_illegal_exception_return(vcpu, spsr); + + mode = spsr & (PSR_MODE_MASK | PSR_MODE32_BIT); + + direct_eret = (mode == PSR_MODE_EL0t && + vcpu_el2_e2h_is_set(vcpu) && + vcpu_el2_tge_is_set(vcpu)); + direct_eret |= (mode == PSR_MODE_EL2h || mode == PSR_MODE_EL2t); + + if (direct_eret) { + *vcpu_pc(vcpu) = vcpu_read_sys_reg(vcpu, ELR_EL2); + *vcpu_cpsr(vcpu) = spsr; + trace_kvm_nested_eret(vcpu, *vcpu_pc(vcpu), spsr); + return; + } + + preempt_disable(); + kvm_arch_vcpu_put(vcpu); + + elr = __vcpu_sys_reg(vcpu, ELR_EL2); + + trace_kvm_nested_eret(vcpu, elr, spsr); + + /* + * Note that the current exception level is always the virtual EL2, + * since we set HCR_EL2.NV bit only when entering the virtual EL2. + */ + *vcpu_pc(vcpu) = elr; + *vcpu_cpsr(vcpu) = spsr; + + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); +} + +static void kvm_inject_el2_exception(struct kvm_vcpu *vcpu, u64 esr_el2, + enum exception_type type) +{ + trace_kvm_inject_nested_exception(vcpu, esr_el2, type); + + switch (type) { + case except_type_sync: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_ELx_SYNC; + break; + case except_type_irq: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_ELx_IRQ; + break; + default: + WARN_ONCE(1, "Unsupported EL2 exception injection %d\n", type); + } + + vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL2 | + KVM_ARM64_PENDING_EXCEPTION); + + vcpu_write_sys_reg(vcpu, esr_el2, ESR_EL2); +} + +/* + * Emulate taking an exception to EL2. + * See ARM ARM J8.1.2 AArch64.TakeException() + */ +static int kvm_inject_nested(struct kvm_vcpu *vcpu, u64 esr_el2, + enum exception_type type) +{ + u64 pstate, mode; + bool direct_inject; + + if (!vcpu_has_nv(vcpu)) { + kvm_err("Unexpected call to %s for the non-nesting configuration\n", + __func__); + return -EINVAL; + } + + /* + * As for ERET, we can avoid doing too much on the injection path by + * checking that we either took the exception from a VHE host + * userspace or from vEL2. In these cases, there is no change in + * translation regime (or anything else), so let's do as little as + * possible. + */ + pstate = *vcpu_cpsr(vcpu); + mode = pstate & (PSR_MODE_MASK | PSR_MODE32_BIT); + + direct_inject = (mode == PSR_MODE_EL0t && + vcpu_el2_e2h_is_set(vcpu) && + vcpu_el2_tge_is_set(vcpu)); + direct_inject |= (mode == PSR_MODE_EL2h || mode == PSR_MODE_EL2t); + + if (direct_inject) { + kvm_inject_el2_exception(vcpu, esr_el2, type); + return 1; + } + + preempt_disable(); + kvm_arch_vcpu_put(vcpu); + + kvm_inject_el2_exception(vcpu, esr_el2, type); + + /* + * A hard requirement is that a switch between EL1 and EL2 + * contexts has to happen between a put/load, so that we can + * pick the correct timer and interrupt configuration, among + * other things. + * + * Make sure the exception actually took place before we load + * the new context. + */ + __kvm_adjust_pc(vcpu); + + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); + + return 1; +} + +int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2) +{ + return kvm_inject_nested(vcpu, esr_el2, except_type_sync); +} + +int kvm_inject_nested_irq(struct kvm_vcpu *vcpu) +{ + /* + * Do not inject an irq if the: + * - Current exception level is EL2, and + * - virtual HCR_EL2.TGE == 0 + * - virtual HCR_EL2.IMO == 0 + * + * See Table D1-17 "Physical interrupt target and masking when EL3 is + * not implemented and EL2 is implemented" in ARM DDI 0487C.a. + */ + + if (vcpu_is_el2(vcpu) && !vcpu_el2_tge_is_set(vcpu) && + !(__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_IMO)) + return 1; + + /* esr_el2 value doesn't matter for exits due to irqs. */ + return kvm_inject_nested(vcpu, 0, except_type_irq); +} diff --git a/arch/arm64/kvm/hyp/exception.c b/arch/arm64/kvm/hyp/exception.c index 0418399e0a20..93f9c6f97376 100644 --- a/arch/arm64/kvm/hyp/exception.c +++ b/arch/arm64/kvm/hyp/exception.c @@ -13,6 +13,7 @@ #include #include #include +#include #if !defined (__KVM_NVHE_HYPERVISOR__) && !defined (__KVM_VHE_HYPERVISOR__) #error Hypervisor code only! @@ -22,7 +23,9 @@ static inline u64 __vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg) { u64 val; - if (__vcpu_read_sys_reg_from_cpu(reg, &val)) + if (unlikely(vcpu_has_nv(vcpu))) + return vcpu_read_sys_reg(vcpu, reg); + else if (__vcpu_read_sys_reg_from_cpu(reg, &val)) return val; return __vcpu_sys_reg(vcpu, reg); @@ -30,14 +33,24 @@ static inline u64 __vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg) static inline void __vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) { - if (__vcpu_write_sys_reg_to_cpu(val, reg)) - return; - - __vcpu_sys_reg(vcpu, reg) = val; + if (unlikely(vcpu_has_nv(vcpu))) + vcpu_write_sys_reg(vcpu, val, reg); + else if (!__vcpu_write_sys_reg_to_cpu(val, reg)) + __vcpu_sys_reg(vcpu, reg) = val; } -static void __vcpu_write_spsr(struct kvm_vcpu *vcpu, u64 val) +static void __vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long target_mode, + u64 val) { + if (unlikely(vcpu_has_nv(vcpu))) { + if (target_mode == PSR_MODE_EL1h) + vcpu_write_sys_reg(vcpu, val, SPSR_EL1); + else + vcpu_write_sys_reg(vcpu, val, SPSR_EL2); + + return; + } + write_sysreg_el1(val, SYS_SPSR); } @@ -97,6 +110,11 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode, sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL1); __vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL1); break; + case PSR_MODE_EL2h: + vbar = __vcpu_read_sys_reg(vcpu, VBAR_EL2); + sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL2); + __vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL2); + break; default: /* Don't do that */ BUG(); @@ -149,7 +167,7 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode, new |= target_mode; *vcpu_cpsr(vcpu) = new; - __vcpu_write_spsr(vcpu, old); + __vcpu_write_spsr(vcpu, target_mode, old); } /* @@ -320,11 +338,22 @@ static void kvm_inject_exception(struct kvm_vcpu *vcpu) KVM_ARM64_EXCEPT_AA64_EL1): enter_exception64(vcpu, PSR_MODE_EL1h, except_type_sync); break; + + case (KVM_ARM64_EXCEPT_AA64_ELx_SYNC | + KVM_ARM64_EXCEPT_AA64_EL2): + enter_exception64(vcpu, PSR_MODE_EL2h, except_type_sync); + break; + + case (KVM_ARM64_EXCEPT_AA64_ELx_IRQ | + KVM_ARM64_EXCEPT_AA64_EL2): + enter_exception64(vcpu, PSR_MODE_EL2h, except_type_irq); + break; + default: /* - * Only EL1_SYNC makes sense so far, EL2_{SYNC,IRQ} - * will be implemented at some point. Everything - * else gets silently ignored. + * Only EL1_SYNC and EL2_{SYNC,IRQ} makes + * sense so far. Everything else gets silently + * ignored. */ break; } diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index b47df73e98d7..81ceee6998cc 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c @@ -12,19 +12,58 @@ #include #include +#include #include +static void pend_sync_exception(struct kvm_vcpu *vcpu) +{ + vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_ELx_SYNC | + KVM_ARM64_PENDING_EXCEPTION); + + /* If not nesting, EL1 is the only possible exception target */ + if (likely(!vcpu_has_nv(vcpu))) { + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL1; + return; + } + + /* + * With NV, we need to pick between EL1 and EL2. Note that we + * never deal with a nesting exception here, hence never + * changing context, and the exception itself can be delayed + * until the next entry. + */ + switch(*vcpu_cpsr(vcpu) & PSR_MODE_MASK) { + case PSR_MODE_EL2h: + case PSR_MODE_EL2t: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL2; + break; + case PSR_MODE_EL1h: + case PSR_MODE_EL1t: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL1; + break; + case PSR_MODE_EL0t: + if (vcpu_el2_tge_is_set(vcpu)) + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL2; + else + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL1; + break; + default: + BUG(); + } +} + +static bool match_target_el(struct kvm_vcpu *vcpu, unsigned long target) +{ + return (vcpu->arch.flags & KVM_ARM64_EXCEPT_AA64_EL_MASK) == target; +} + static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr) { unsigned long cpsr = *vcpu_cpsr(vcpu); bool is_aarch32 = vcpu_mode_is_32bit(vcpu); u32 esr = 0; - vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1 | - KVM_ARM64_EXCEPT_AA64_ELx_SYNC | - KVM_ARM64_PENDING_EXCEPTION); - - vcpu_write_sys_reg(vcpu, addr, FAR_EL1); + pend_sync_exception(vcpu); /* * Build an {i,d}abort, depending on the level and the @@ -45,16 +84,22 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr if (!is_iabt) esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT; - vcpu_write_sys_reg(vcpu, esr | ESR_ELx_FSC_EXTABT, ESR_EL1); + esr |= ESR_ELx_FSC_EXTABT; + + if (match_target_el(vcpu, KVM_ARM64_EXCEPT_AA64_EL1)) { + vcpu_write_sys_reg(vcpu, addr, FAR_EL1); + vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + } else { + vcpu_write_sys_reg(vcpu, addr, FAR_EL2); + vcpu_write_sys_reg(vcpu, esr, ESR_EL2); + } } static void inject_undef64(struct kvm_vcpu *vcpu) { u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); - vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1 | - KVM_ARM64_EXCEPT_AA64_ELx_SYNC | - KVM_ARM64_PENDING_EXCEPTION); + pend_sync_exception(vcpu); /* * Build an unknown exception, depending on the instruction @@ -63,7 +108,10 @@ static void inject_undef64(struct kvm_vcpu *vcpu) if (kvm_vcpu_trap_il_is32bit(vcpu)) esr |= ESR_ELx_IL; - vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + if (match_target_el(vcpu, KVM_ARM64_EXCEPT_AA64_EL1)) + vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + else + vcpu_write_sys_reg(vcpu, esr, ESR_EL2); } #define DFSR_FSC_EXTABT_LPAE 0x10 diff --git a/arch/arm64/kvm/trace_arm.h b/arch/arm64/kvm/trace_arm.h index 33e4e7dd2719..f3e46a976125 100644 --- a/arch/arm64/kvm/trace_arm.h +++ b/arch/arm64/kvm/trace_arm.h @@ -2,6 +2,7 @@ #if !defined(_TRACE_ARM_ARM64_KVM_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_ARM_ARM64_KVM_H +#include #include #include @@ -301,6 +302,64 @@ TRACE_EVENT(kvm_timer_emulate, __entry->timer_idx, __entry->should_fire) ); +TRACE_EVENT(kvm_nested_eret, + TP_PROTO(struct kvm_vcpu *vcpu, unsigned long elr_el2, + unsigned long spsr_el2), + TP_ARGS(vcpu, elr_el2, spsr_el2), + + TP_STRUCT__entry( + __field(struct kvm_vcpu *, vcpu) + __field(unsigned long, elr_el2) + __field(unsigned long, spsr_el2) + __field(unsigned long, target_mode) + __field(unsigned long, hcr_el2) + ), + + TP_fast_assign( + __entry->vcpu = vcpu; + __entry->elr_el2 = elr_el2; + __entry->spsr_el2 = spsr_el2; + __entry->target_mode = spsr_el2 & (PSR_MODE_MASK | PSR_MODE32_BIT); + __entry->hcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + ), + + TP_printk("elr_el2: 0x%lx spsr_el2: 0x%08lx (M: %s) hcr_el2: %lx", + __entry->elr_el2, __entry->spsr_el2, + __print_symbolic(__entry->target_mode, kvm_mode_names), + __entry->hcr_el2) +); + +TRACE_EVENT(kvm_inject_nested_exception, + TP_PROTO(struct kvm_vcpu *vcpu, u64 esr_el2, int type), + TP_ARGS(vcpu, esr_el2, type), + + TP_STRUCT__entry( + __field(struct kvm_vcpu *, vcpu) + __field(unsigned long, esr_el2) + __field(int, type) + __field(unsigned long, spsr_el2) + __field(unsigned long, pc) + __field(unsigned long, source_mode) + __field(unsigned long, hcr_el2) + ), + + TP_fast_assign( + __entry->vcpu = vcpu; + __entry->esr_el2 = esr_el2; + __entry->type = type; + __entry->spsr_el2 = *vcpu_cpsr(vcpu); + __entry->pc = *vcpu_pc(vcpu); + __entry->source_mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT); + __entry->hcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + ), + + TP_printk("%s: esr_el2 0x%lx elr_el2: 0x%lx spsr_el2: 0x%08lx (M: %s) hcr_el2: %lx", + __print_symbolic(__entry->type, kvm_exception_type_names), + __entry->esr_el2, __entry->pc, __entry->spsr_el2, + __print_symbolic(__entry->source_mode, kvm_mode_names), + __entry->hcr_el2) +); + #endif /* _TRACE_ARM_ARM64_KVM_H */ #undef TRACE_INCLUDE_PATH -- 2.30.2 From mboxrd@z Thu Jan 1 00:00:00 1970 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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4878BC433F5 for ; Fri, 28 Jan 2022 12:19:44 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id EF8A64B0B4; Fri, 28 Jan 2022 07:19:43 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id LceE8JmTzW2j; 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SAEximRunCond expanded to false Cc: kernel-team@android.com, Andre Przywara , Christoffer Dall , Chase Conklin , "Russell King \(Oracle\)" , mihai.carabas@oracle.com, Ganapatrao Kulkarni X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu From: Jintack Lim Support injecting exceptions and performing exception returns to and from virtual EL2. This must be done entirely in software except when taking an exception from vEL0 to vEL2 when the virtual HCR_EL2.{E2H,TGE} == {1,1} (a VHE guest hypervisor). Reviewed-by: Ganapatrao Kulkarni Signed-off-by: Jintack Lim Signed-off-by: Christoffer Dall [maz: switch to common exception injection framework, illegal exeption return handling] Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_arm.h | 17 +++ arch/arm64/include/asm/kvm_emulate.h | 10 ++ arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/Makefile | 2 +- arch/arm64/kvm/emulate-nested.c | 197 +++++++++++++++++++++++++++ arch/arm64/kvm/hyp/exception.c | 49 +++++-- arch/arm64/kvm/inject_fault.c | 68 +++++++-- arch/arm64/kvm/trace_arm.h | 59 ++++++++ 8 files changed, 382 insertions(+), 21 deletions(-) create mode 100644 arch/arm64/kvm/emulate-nested.c diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 01d47c5886dc..e6e3aae87a09 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -359,4 +359,21 @@ #define CPACR_EL1_TTA (1 << 28) #define CPACR_EL1_DEFAULT (CPACR_EL1_FPEN | CPACR_EL1_ZEN_EL1EN) +#define kvm_mode_names \ + { PSR_MODE_EL0t, "EL0t" }, \ + { PSR_MODE_EL1t, "EL1t" }, \ + { PSR_MODE_EL1h, "EL1h" }, \ + { PSR_MODE_EL2t, "EL2t" }, \ + { PSR_MODE_EL2h, "EL2h" }, \ + { PSR_MODE_EL3t, "EL3t" }, \ + { PSR_MODE_EL3h, "EL3h" }, \ + { PSR_AA32_MODE_USR, "32-bit USR" }, \ + { PSR_AA32_MODE_FIQ, "32-bit FIQ" }, \ + { PSR_AA32_MODE_IRQ, "32-bit IRQ" }, \ + { PSR_AA32_MODE_SVC, "32-bit SVC" }, \ + { PSR_AA32_MODE_ABT, "32-bit ABT" }, \ + { PSR_AA32_MODE_HYP, "32-bit HYP" }, \ + { PSR_AA32_MODE_UND, "32-bit UND" }, \ + { PSR_AA32_MODE_SYS, "32-bit SYS" } + #endif /* __ARM64_KVM_ARM_H__ */ diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index ea9a130c4b6a..cb9f123d26f3 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -33,6 +33,12 @@ enum exception_type { except_type_serror = 0x180, }; +#define kvm_exception_type_names \ + { except_type_sync, "SYNC" }, \ + { except_type_irq, "IRQ" }, \ + { except_type_fiq, "FIQ" }, \ + { except_type_serror, "SERROR" } + bool kvm_condition_valid32(const struct kvm_vcpu *vcpu); void kvm_skip_instr32(struct kvm_vcpu *vcpu); @@ -43,6 +49,10 @@ void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr); void kvm_vcpu_wfi(struct kvm_vcpu *vcpu); +void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu); +int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2); +int kvm_inject_nested_irq(struct kvm_vcpu *vcpu); + static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu) { return !(vcpu->arch.hcr_el2 & HCR_RW); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 15f690c27baf..8fffe2888403 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -467,6 +467,7 @@ struct kvm_vcpu_arch { #define KVM_ARM64_EXCEPT_AA64_ELx_SERR (3 << 9) #define KVM_ARM64_EXCEPT_AA64_EL1 (0 << 11) #define KVM_ARM64_EXCEPT_AA64_EL2 (1 << 11) +#define KVM_ARM64_EXCEPT_AA64_EL_MASK (1 << 11) #define KVM_ARM64_DEBUG_STATE_SAVE_SPE (1 << 12) /* Save SPE context if active */ #define KVM_ARM64_DEBUG_STATE_SAVE_TRBE (1 << 13) /* Save TRBE context if active */ diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 91861fd8b897..b67c4ebd72b1 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -14,7 +14,7 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ inject_fault.o va_layout.o handle_exit.o \ guest.o debug.o reset.o sys_regs.o \ vgic-sys-reg-v3.o fpsimd.o pmu.o pkvm.o \ - arch_timer.o trng.o\ + arch_timer.o trng.o emulate-nested.o \ vgic/vgic.o vgic/vgic-init.o \ vgic/vgic-irqfd.o vgic/vgic-v2.o \ vgic/vgic-v3.o vgic/vgic-v4.o \ diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c new file mode 100644 index 000000000000..f52cd4458947 --- /dev/null +++ b/arch/arm64/kvm/emulate-nested.c @@ -0,0 +1,197 @@ +/* + * Copyright (C) 2016 - Linaro and Columbia University + * Author: Jintack Lim + */ + +#include +#include + +#include +#include + +#include "hyp/include/hyp/adjust_pc.h" + +#include "trace.h" + +static u64 kvm_check_illegal_exception_return(struct kvm_vcpu *vcpu, u64 spsr) +{ + u64 mode = spsr & PSR_MODE_MASK; + + /* + * Possible causes for an Illegal Exception Return from EL2: + * - trying to return to EL3 + * - trying to return to a 32bit EL + * - trying to return to EL1 with HCR_EL2.TGE set + */ + if (mode == PSR_MODE_EL3t || mode == PSR_MODE_EL3h || + spsr & PSR_MODE32_BIT || + (vcpu_el2_tge_is_set(vcpu) && (mode == PSR_MODE_EL1t || + mode == PSR_MODE_EL1h))) { + /* + * The guest is playing with our nerves. Preserve EL, SP, + * masks, flags from the existing PSTATE, and set IL. + * The HW will then generate an Illegal State Exception + * immediately after ERET. + */ + spsr = *vcpu_cpsr(vcpu); + + spsr &= (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | + PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT | + PSR_MODE_MASK | PSR_MODE32_BIT); + spsr |= PSR_IL_BIT; + } + + return spsr; +} + +void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu) +{ + u64 spsr, elr, mode; + bool direct_eret; + + /* + * Going through the whole put/load motions is a waste of time + * if this is a VHE guest hypervisor returning to its own + * userspace, or the hypervisor performing a local exception + * return. No need to save/restore registers, no need to + * switch S2 MMU. Just do the canonical ERET. + */ + spsr = vcpu_read_sys_reg(vcpu, SPSR_EL2); + spsr = kvm_check_illegal_exception_return(vcpu, spsr); + + mode = spsr & (PSR_MODE_MASK | PSR_MODE32_BIT); + + direct_eret = (mode == PSR_MODE_EL0t && + vcpu_el2_e2h_is_set(vcpu) && + vcpu_el2_tge_is_set(vcpu)); + direct_eret |= (mode == PSR_MODE_EL2h || mode == PSR_MODE_EL2t); + + if (direct_eret) { + *vcpu_pc(vcpu) = vcpu_read_sys_reg(vcpu, ELR_EL2); + *vcpu_cpsr(vcpu) = spsr; + trace_kvm_nested_eret(vcpu, *vcpu_pc(vcpu), spsr); + return; + } + + preempt_disable(); + kvm_arch_vcpu_put(vcpu); + + elr = __vcpu_sys_reg(vcpu, ELR_EL2); + + trace_kvm_nested_eret(vcpu, elr, spsr); + + /* + * Note that the current exception level is always the virtual EL2, + * since we set HCR_EL2.NV bit only when entering the virtual EL2. + */ + *vcpu_pc(vcpu) = elr; + *vcpu_cpsr(vcpu) = spsr; + + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); +} + +static void kvm_inject_el2_exception(struct kvm_vcpu *vcpu, u64 esr_el2, + enum exception_type type) +{ + trace_kvm_inject_nested_exception(vcpu, esr_el2, type); + + switch (type) { + case except_type_sync: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_ELx_SYNC; + break; + case except_type_irq: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_ELx_IRQ; + break; + default: + WARN_ONCE(1, "Unsupported EL2 exception injection %d\n", type); + } + + vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL2 | + KVM_ARM64_PENDING_EXCEPTION); + + vcpu_write_sys_reg(vcpu, esr_el2, ESR_EL2); +} + +/* + * Emulate taking an exception to EL2. + * See ARM ARM J8.1.2 AArch64.TakeException() + */ +static int kvm_inject_nested(struct kvm_vcpu *vcpu, u64 esr_el2, + enum exception_type type) +{ + u64 pstate, mode; + bool direct_inject; + + if (!vcpu_has_nv(vcpu)) { + kvm_err("Unexpected call to %s for the non-nesting configuration\n", + __func__); + return -EINVAL; + } + + /* + * As for ERET, we can avoid doing too much on the injection path by + * checking that we either took the exception from a VHE host + * userspace or from vEL2. In these cases, there is no change in + * translation regime (or anything else), so let's do as little as + * possible. + */ + pstate = *vcpu_cpsr(vcpu); + mode = pstate & (PSR_MODE_MASK | PSR_MODE32_BIT); + + direct_inject = (mode == PSR_MODE_EL0t && + vcpu_el2_e2h_is_set(vcpu) && + vcpu_el2_tge_is_set(vcpu)); + direct_inject |= (mode == PSR_MODE_EL2h || mode == PSR_MODE_EL2t); + + if (direct_inject) { + kvm_inject_el2_exception(vcpu, esr_el2, type); + return 1; + } + + preempt_disable(); + kvm_arch_vcpu_put(vcpu); + + kvm_inject_el2_exception(vcpu, esr_el2, type); + + /* + * A hard requirement is that a switch between EL1 and EL2 + * contexts has to happen between a put/load, so that we can + * pick the correct timer and interrupt configuration, among + * other things. + * + * Make sure the exception actually took place before we load + * the new context. + */ + __kvm_adjust_pc(vcpu); + + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); + + return 1; +} + +int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2) +{ + return kvm_inject_nested(vcpu, esr_el2, except_type_sync); +} + +int kvm_inject_nested_irq(struct kvm_vcpu *vcpu) +{ + /* + * Do not inject an irq if the: + * - Current exception level is EL2, and + * - virtual HCR_EL2.TGE == 0 + * - virtual HCR_EL2.IMO == 0 + * + * See Table D1-17 "Physical interrupt target and masking when EL3 is + * not implemented and EL2 is implemented" in ARM DDI 0487C.a. + */ + + if (vcpu_is_el2(vcpu) && !vcpu_el2_tge_is_set(vcpu) && + !(__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_IMO)) + return 1; + + /* esr_el2 value doesn't matter for exits due to irqs. */ + return kvm_inject_nested(vcpu, 0, except_type_irq); +} diff --git a/arch/arm64/kvm/hyp/exception.c b/arch/arm64/kvm/hyp/exception.c index 0418399e0a20..93f9c6f97376 100644 --- a/arch/arm64/kvm/hyp/exception.c +++ b/arch/arm64/kvm/hyp/exception.c @@ -13,6 +13,7 @@ #include #include #include +#include #if !defined (__KVM_NVHE_HYPERVISOR__) && !defined (__KVM_VHE_HYPERVISOR__) #error Hypervisor code only! @@ -22,7 +23,9 @@ static inline u64 __vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg) { u64 val; - if (__vcpu_read_sys_reg_from_cpu(reg, &val)) + if (unlikely(vcpu_has_nv(vcpu))) + return vcpu_read_sys_reg(vcpu, reg); + else if (__vcpu_read_sys_reg_from_cpu(reg, &val)) return val; return __vcpu_sys_reg(vcpu, reg); @@ -30,14 +33,24 @@ static inline u64 __vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg) static inline void __vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) { - if (__vcpu_write_sys_reg_to_cpu(val, reg)) - return; - - __vcpu_sys_reg(vcpu, reg) = val; + if (unlikely(vcpu_has_nv(vcpu))) + vcpu_write_sys_reg(vcpu, val, reg); + else if (!__vcpu_write_sys_reg_to_cpu(val, reg)) + __vcpu_sys_reg(vcpu, reg) = val; } -static void __vcpu_write_spsr(struct kvm_vcpu *vcpu, u64 val) +static void __vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long target_mode, + u64 val) { + if (unlikely(vcpu_has_nv(vcpu))) { + if (target_mode == PSR_MODE_EL1h) + vcpu_write_sys_reg(vcpu, val, SPSR_EL1); + else + vcpu_write_sys_reg(vcpu, val, SPSR_EL2); + + return; + } + write_sysreg_el1(val, SYS_SPSR); } @@ -97,6 +110,11 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode, sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL1); __vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL1); break; + case PSR_MODE_EL2h: + vbar = __vcpu_read_sys_reg(vcpu, VBAR_EL2); + sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL2); + __vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL2); + break; default: /* Don't do that */ BUG(); @@ -149,7 +167,7 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode, new |= target_mode; *vcpu_cpsr(vcpu) = new; - __vcpu_write_spsr(vcpu, old); + __vcpu_write_spsr(vcpu, target_mode, old); } /* @@ -320,11 +338,22 @@ static void kvm_inject_exception(struct kvm_vcpu *vcpu) KVM_ARM64_EXCEPT_AA64_EL1): enter_exception64(vcpu, PSR_MODE_EL1h, except_type_sync); break; + + case (KVM_ARM64_EXCEPT_AA64_ELx_SYNC | + KVM_ARM64_EXCEPT_AA64_EL2): + enter_exception64(vcpu, PSR_MODE_EL2h, except_type_sync); + break; + + case (KVM_ARM64_EXCEPT_AA64_ELx_IRQ | + KVM_ARM64_EXCEPT_AA64_EL2): + enter_exception64(vcpu, PSR_MODE_EL2h, except_type_irq); + break; + default: /* - * Only EL1_SYNC makes sense so far, EL2_{SYNC,IRQ} - * will be implemented at some point. Everything - * else gets silently ignored. + * Only EL1_SYNC and EL2_{SYNC,IRQ} makes + * sense so far. Everything else gets silently + * ignored. */ break; } diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index b47df73e98d7..81ceee6998cc 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c @@ -12,19 +12,58 @@ #include #include +#include #include +static void pend_sync_exception(struct kvm_vcpu *vcpu) +{ + vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_ELx_SYNC | + KVM_ARM64_PENDING_EXCEPTION); + + /* If not nesting, EL1 is the only possible exception target */ + if (likely(!vcpu_has_nv(vcpu))) { + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL1; + return; + } + + /* + * With NV, we need to pick between EL1 and EL2. Note that we + * never deal with a nesting exception here, hence never + * changing context, and the exception itself can be delayed + * until the next entry. + */ + switch(*vcpu_cpsr(vcpu) & PSR_MODE_MASK) { + case PSR_MODE_EL2h: + case PSR_MODE_EL2t: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL2; + break; + case PSR_MODE_EL1h: + case PSR_MODE_EL1t: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL1; + break; + case PSR_MODE_EL0t: + if (vcpu_el2_tge_is_set(vcpu)) + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL2; + else + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL1; + break; + default: + BUG(); + } +} + +static bool match_target_el(struct kvm_vcpu *vcpu, unsigned long target) +{ + return (vcpu->arch.flags & KVM_ARM64_EXCEPT_AA64_EL_MASK) == target; +} + static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr) { unsigned long cpsr = *vcpu_cpsr(vcpu); bool is_aarch32 = vcpu_mode_is_32bit(vcpu); u32 esr = 0; - vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1 | - KVM_ARM64_EXCEPT_AA64_ELx_SYNC | - KVM_ARM64_PENDING_EXCEPTION); - - vcpu_write_sys_reg(vcpu, addr, FAR_EL1); + pend_sync_exception(vcpu); /* * Build an {i,d}abort, depending on the level and the @@ -45,16 +84,22 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr if (!is_iabt) esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT; - vcpu_write_sys_reg(vcpu, esr | ESR_ELx_FSC_EXTABT, ESR_EL1); + esr |= ESR_ELx_FSC_EXTABT; + + if (match_target_el(vcpu, KVM_ARM64_EXCEPT_AA64_EL1)) { + vcpu_write_sys_reg(vcpu, addr, FAR_EL1); + vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + } else { + vcpu_write_sys_reg(vcpu, addr, FAR_EL2); + vcpu_write_sys_reg(vcpu, esr, ESR_EL2); + } } static void inject_undef64(struct kvm_vcpu *vcpu) { u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); - vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1 | - KVM_ARM64_EXCEPT_AA64_ELx_SYNC | - KVM_ARM64_PENDING_EXCEPTION); + pend_sync_exception(vcpu); /* * Build an unknown exception, depending on the instruction @@ -63,7 +108,10 @@ static void inject_undef64(struct kvm_vcpu *vcpu) if (kvm_vcpu_trap_il_is32bit(vcpu)) esr |= ESR_ELx_IL; - vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + if (match_target_el(vcpu, KVM_ARM64_EXCEPT_AA64_EL1)) + vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + else + vcpu_write_sys_reg(vcpu, esr, ESR_EL2); } #define DFSR_FSC_EXTABT_LPAE 0x10 diff --git a/arch/arm64/kvm/trace_arm.h b/arch/arm64/kvm/trace_arm.h index 33e4e7dd2719..f3e46a976125 100644 --- a/arch/arm64/kvm/trace_arm.h +++ b/arch/arm64/kvm/trace_arm.h @@ -2,6 +2,7 @@ #if !defined(_TRACE_ARM_ARM64_KVM_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_ARM_ARM64_KVM_H +#include #include #include @@ -301,6 +302,64 @@ TRACE_EVENT(kvm_timer_emulate, __entry->timer_idx, __entry->should_fire) ); +TRACE_EVENT(kvm_nested_eret, + TP_PROTO(struct kvm_vcpu *vcpu, unsigned long elr_el2, + unsigned long spsr_el2), + TP_ARGS(vcpu, elr_el2, spsr_el2), + + TP_STRUCT__entry( + __field(struct kvm_vcpu *, vcpu) + __field(unsigned long, elr_el2) + __field(unsigned long, spsr_el2) + __field(unsigned long, target_mode) + __field(unsigned long, hcr_el2) + ), + + TP_fast_assign( + __entry->vcpu = vcpu; + __entry->elr_el2 = elr_el2; + __entry->spsr_el2 = spsr_el2; + __entry->target_mode = spsr_el2 & (PSR_MODE_MASK | PSR_MODE32_BIT); + __entry->hcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + ), + + TP_printk("elr_el2: 0x%lx spsr_el2: 0x%08lx (M: %s) hcr_el2: %lx", + __entry->elr_el2, __entry->spsr_el2, + __print_symbolic(__entry->target_mode, kvm_mode_names), + __entry->hcr_el2) +); + +TRACE_EVENT(kvm_inject_nested_exception, + TP_PROTO(struct kvm_vcpu *vcpu, u64 esr_el2, int type), + TP_ARGS(vcpu, esr_el2, type), + + TP_STRUCT__entry( + __field(struct kvm_vcpu *, vcpu) + __field(unsigned long, esr_el2) + __field(int, type) + __field(unsigned long, spsr_el2) + __field(unsigned long, pc) + __field(unsigned long, source_mode) + __field(unsigned long, hcr_el2) + ), + + TP_fast_assign( + __entry->vcpu = vcpu; + __entry->esr_el2 = esr_el2; + __entry->type = type; + __entry->spsr_el2 = *vcpu_cpsr(vcpu); + __entry->pc = *vcpu_pc(vcpu); + __entry->source_mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT); + __entry->hcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + ), + + TP_printk("%s: esr_el2 0x%lx elr_el2: 0x%lx spsr_el2: 0x%08lx (M: %s) hcr_el2: %lx", + __print_symbolic(__entry->type, kvm_exception_type_names), + __entry->esr_el2, __entry->pc, __entry->spsr_el2, + __print_symbolic(__entry->source_mode, kvm_mode_names), + __entry->hcr_el2) +); + #endif /* _TRACE_ARM_ARM64_KVM_H */ #undef TRACE_INCLUDE_PATH -- 2.30.2 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 45D01C433F5 for ; Fri, 28 Jan 2022 12:25:46 +0000 (UTC) DKIM-Signature: v=1; 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Fri, 28 Jan 2022 12:19:27 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara , Christoffer Dall , Jintack Lim , Haibo Xu , Ganapatrao Kulkarni , Chase Conklin , "Russell King (Oracle)" , James Morse , Suzuki K Poulose , Alexandru Elisei , karl.heubaum@oracle.com, mihai.carabas@oracle.com, miguel.luis@oracle.com, kernel-team@android.com Subject: [PATCH v6 09/64] KVM: arm64: nv: Support virtual EL2 exceptions Date: Fri, 28 Jan 2022 12:18:17 +0000 Message-Id: <20220128121912.509006-10-maz@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220128121912.509006-1-maz@kernel.org> References: <20220128121912.509006-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, andre.przywara@arm.com, christoffer.dall@arm.com, jintack@cs.columbia.edu, haibo.xu@linaro.org, gankulkarni@os.amperecomputing.com, chase.conklin@arm.com, linux@armlinux.org.uk, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, karl.heubaum@oracle.com, mihai.carabas@oracle.com, miguel.luis@oracle.com, 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220128_041930_381119_AA42FD80 X-CRM114-Status: GOOD ( 32.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Jintack Lim Support injecting exceptions and performing exception returns to and from virtual EL2. This must be done entirely in software except when taking an exception from vEL0 to vEL2 when the virtual HCR_EL2.{E2H,TGE} == {1,1} (a VHE guest hypervisor). Reviewed-by: Ganapatrao Kulkarni Signed-off-by: Jintack Lim Signed-off-by: Christoffer Dall [maz: switch to common exception injection framework, illegal exeption return handling] Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_arm.h | 17 +++ arch/arm64/include/asm/kvm_emulate.h | 10 ++ arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/Makefile | 2 +- arch/arm64/kvm/emulate-nested.c | 197 +++++++++++++++++++++++++++ arch/arm64/kvm/hyp/exception.c | 49 +++++-- arch/arm64/kvm/inject_fault.c | 68 +++++++-- arch/arm64/kvm/trace_arm.h | 59 ++++++++ 8 files changed, 382 insertions(+), 21 deletions(-) create mode 100644 arch/arm64/kvm/emulate-nested.c diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 01d47c5886dc..e6e3aae87a09 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -359,4 +359,21 @@ #define CPACR_EL1_TTA (1 << 28) #define CPACR_EL1_DEFAULT (CPACR_EL1_FPEN | CPACR_EL1_ZEN_EL1EN) +#define kvm_mode_names \ + { PSR_MODE_EL0t, "EL0t" }, \ + { PSR_MODE_EL1t, "EL1t" }, \ + { PSR_MODE_EL1h, "EL1h" }, \ + { PSR_MODE_EL2t, "EL2t" }, \ + { PSR_MODE_EL2h, "EL2h" }, \ + { PSR_MODE_EL3t, "EL3t" }, \ + { PSR_MODE_EL3h, "EL3h" }, \ + { PSR_AA32_MODE_USR, "32-bit USR" }, \ + { PSR_AA32_MODE_FIQ, "32-bit FIQ" }, \ + { PSR_AA32_MODE_IRQ, "32-bit IRQ" }, \ + { PSR_AA32_MODE_SVC, "32-bit SVC" }, \ + { PSR_AA32_MODE_ABT, "32-bit ABT" }, \ + { PSR_AA32_MODE_HYP, "32-bit HYP" }, \ + { PSR_AA32_MODE_UND, "32-bit UND" }, \ + { PSR_AA32_MODE_SYS, "32-bit SYS" } + #endif /* __ARM64_KVM_ARM_H__ */ diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index ea9a130c4b6a..cb9f123d26f3 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -33,6 +33,12 @@ enum exception_type { except_type_serror = 0x180, }; +#define kvm_exception_type_names \ + { except_type_sync, "SYNC" }, \ + { except_type_irq, "IRQ" }, \ + { except_type_fiq, "FIQ" }, \ + { except_type_serror, "SERROR" } + bool kvm_condition_valid32(const struct kvm_vcpu *vcpu); void kvm_skip_instr32(struct kvm_vcpu *vcpu); @@ -43,6 +49,10 @@ void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr); void kvm_vcpu_wfi(struct kvm_vcpu *vcpu); +void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu); +int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2); +int kvm_inject_nested_irq(struct kvm_vcpu *vcpu); + static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu) { return !(vcpu->arch.hcr_el2 & HCR_RW); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 15f690c27baf..8fffe2888403 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -467,6 +467,7 @@ struct kvm_vcpu_arch { #define KVM_ARM64_EXCEPT_AA64_ELx_SERR (3 << 9) #define KVM_ARM64_EXCEPT_AA64_EL1 (0 << 11) #define KVM_ARM64_EXCEPT_AA64_EL2 (1 << 11) +#define KVM_ARM64_EXCEPT_AA64_EL_MASK (1 << 11) #define KVM_ARM64_DEBUG_STATE_SAVE_SPE (1 << 12) /* Save SPE context if active */ #define KVM_ARM64_DEBUG_STATE_SAVE_TRBE (1 << 13) /* Save TRBE context if active */ diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 91861fd8b897..b67c4ebd72b1 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -14,7 +14,7 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ inject_fault.o va_layout.o handle_exit.o \ guest.o debug.o reset.o sys_regs.o \ vgic-sys-reg-v3.o fpsimd.o pmu.o pkvm.o \ - arch_timer.o trng.o\ + arch_timer.o trng.o emulate-nested.o \ vgic/vgic.o vgic/vgic-init.o \ vgic/vgic-irqfd.o vgic/vgic-v2.o \ vgic/vgic-v3.o vgic/vgic-v4.o \ diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c new file mode 100644 index 000000000000..f52cd4458947 --- /dev/null +++ b/arch/arm64/kvm/emulate-nested.c @@ -0,0 +1,197 @@ +/* + * Copyright (C) 2016 - Linaro and Columbia University + * Author: Jintack Lim + */ + +#include +#include + +#include +#include + +#include "hyp/include/hyp/adjust_pc.h" + +#include "trace.h" + +static u64 kvm_check_illegal_exception_return(struct kvm_vcpu *vcpu, u64 spsr) +{ + u64 mode = spsr & PSR_MODE_MASK; + + /* + * Possible causes for an Illegal Exception Return from EL2: + * - trying to return to EL3 + * - trying to return to a 32bit EL + * - trying to return to EL1 with HCR_EL2.TGE set + */ + if (mode == PSR_MODE_EL3t || mode == PSR_MODE_EL3h || + spsr & PSR_MODE32_BIT || + (vcpu_el2_tge_is_set(vcpu) && (mode == PSR_MODE_EL1t || + mode == PSR_MODE_EL1h))) { + /* + * The guest is playing with our nerves. Preserve EL, SP, + * masks, flags from the existing PSTATE, and set IL. + * The HW will then generate an Illegal State Exception + * immediately after ERET. + */ + spsr = *vcpu_cpsr(vcpu); + + spsr &= (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | + PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT | + PSR_MODE_MASK | PSR_MODE32_BIT); + spsr |= PSR_IL_BIT; + } + + return spsr; +} + +void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu) +{ + u64 spsr, elr, mode; + bool direct_eret; + + /* + * Going through the whole put/load motions is a waste of time + * if this is a VHE guest hypervisor returning to its own + * userspace, or the hypervisor performing a local exception + * return. No need to save/restore registers, no need to + * switch S2 MMU. Just do the canonical ERET. + */ + spsr = vcpu_read_sys_reg(vcpu, SPSR_EL2); + spsr = kvm_check_illegal_exception_return(vcpu, spsr); + + mode = spsr & (PSR_MODE_MASK | PSR_MODE32_BIT); + + direct_eret = (mode == PSR_MODE_EL0t && + vcpu_el2_e2h_is_set(vcpu) && + vcpu_el2_tge_is_set(vcpu)); + direct_eret |= (mode == PSR_MODE_EL2h || mode == PSR_MODE_EL2t); + + if (direct_eret) { + *vcpu_pc(vcpu) = vcpu_read_sys_reg(vcpu, ELR_EL2); + *vcpu_cpsr(vcpu) = spsr; + trace_kvm_nested_eret(vcpu, *vcpu_pc(vcpu), spsr); + return; + } + + preempt_disable(); + kvm_arch_vcpu_put(vcpu); + + elr = __vcpu_sys_reg(vcpu, ELR_EL2); + + trace_kvm_nested_eret(vcpu, elr, spsr); + + /* + * Note that the current exception level is always the virtual EL2, + * since we set HCR_EL2.NV bit only when entering the virtual EL2. + */ + *vcpu_pc(vcpu) = elr; + *vcpu_cpsr(vcpu) = spsr; + + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); +} + +static void kvm_inject_el2_exception(struct kvm_vcpu *vcpu, u64 esr_el2, + enum exception_type type) +{ + trace_kvm_inject_nested_exception(vcpu, esr_el2, type); + + switch (type) { + case except_type_sync: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_ELx_SYNC; + break; + case except_type_irq: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_ELx_IRQ; + break; + default: + WARN_ONCE(1, "Unsupported EL2 exception injection %d\n", type); + } + + vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL2 | + KVM_ARM64_PENDING_EXCEPTION); + + vcpu_write_sys_reg(vcpu, esr_el2, ESR_EL2); +} + +/* + * Emulate taking an exception to EL2. + * See ARM ARM J8.1.2 AArch64.TakeException() + */ +static int kvm_inject_nested(struct kvm_vcpu *vcpu, u64 esr_el2, + enum exception_type type) +{ + u64 pstate, mode; + bool direct_inject; + + if (!vcpu_has_nv(vcpu)) { + kvm_err("Unexpected call to %s for the non-nesting configuration\n", + __func__); + return -EINVAL; + } + + /* + * As for ERET, we can avoid doing too much on the injection path by + * checking that we either took the exception from a VHE host + * userspace or from vEL2. In these cases, there is no change in + * translation regime (or anything else), so let's do as little as + * possible. + */ + pstate = *vcpu_cpsr(vcpu); + mode = pstate & (PSR_MODE_MASK | PSR_MODE32_BIT); + + direct_inject = (mode == PSR_MODE_EL0t && + vcpu_el2_e2h_is_set(vcpu) && + vcpu_el2_tge_is_set(vcpu)); + direct_inject |= (mode == PSR_MODE_EL2h || mode == PSR_MODE_EL2t); + + if (direct_inject) { + kvm_inject_el2_exception(vcpu, esr_el2, type); + return 1; + } + + preempt_disable(); + kvm_arch_vcpu_put(vcpu); + + kvm_inject_el2_exception(vcpu, esr_el2, type); + + /* + * A hard requirement is that a switch between EL1 and EL2 + * contexts has to happen between a put/load, so that we can + * pick the correct timer and interrupt configuration, among + * other things. + * + * Make sure the exception actually took place before we load + * the new context. + */ + __kvm_adjust_pc(vcpu); + + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); + + return 1; +} + +int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2) +{ + return kvm_inject_nested(vcpu, esr_el2, except_type_sync); +} + +int kvm_inject_nested_irq(struct kvm_vcpu *vcpu) +{ + /* + * Do not inject an irq if the: + * - Current exception level is EL2, and + * - virtual HCR_EL2.TGE == 0 + * - virtual HCR_EL2.IMO == 0 + * + * See Table D1-17 "Physical interrupt target and masking when EL3 is + * not implemented and EL2 is implemented" in ARM DDI 0487C.a. + */ + + if (vcpu_is_el2(vcpu) && !vcpu_el2_tge_is_set(vcpu) && + !(__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_IMO)) + return 1; + + /* esr_el2 value doesn't matter for exits due to irqs. */ + return kvm_inject_nested(vcpu, 0, except_type_irq); +} diff --git a/arch/arm64/kvm/hyp/exception.c b/arch/arm64/kvm/hyp/exception.c index 0418399e0a20..93f9c6f97376 100644 --- a/arch/arm64/kvm/hyp/exception.c +++ b/arch/arm64/kvm/hyp/exception.c @@ -13,6 +13,7 @@ #include #include #include +#include #if !defined (__KVM_NVHE_HYPERVISOR__) && !defined (__KVM_VHE_HYPERVISOR__) #error Hypervisor code only! @@ -22,7 +23,9 @@ static inline u64 __vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg) { u64 val; - if (__vcpu_read_sys_reg_from_cpu(reg, &val)) + if (unlikely(vcpu_has_nv(vcpu))) + return vcpu_read_sys_reg(vcpu, reg); + else if (__vcpu_read_sys_reg_from_cpu(reg, &val)) return val; return __vcpu_sys_reg(vcpu, reg); @@ -30,14 +33,24 @@ static inline u64 __vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg) static inline void __vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) { - if (__vcpu_write_sys_reg_to_cpu(val, reg)) - return; - - __vcpu_sys_reg(vcpu, reg) = val; + if (unlikely(vcpu_has_nv(vcpu))) + vcpu_write_sys_reg(vcpu, val, reg); + else if (!__vcpu_write_sys_reg_to_cpu(val, reg)) + __vcpu_sys_reg(vcpu, reg) = val; } -static void __vcpu_write_spsr(struct kvm_vcpu *vcpu, u64 val) +static void __vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long target_mode, + u64 val) { + if (unlikely(vcpu_has_nv(vcpu))) { + if (target_mode == PSR_MODE_EL1h) + vcpu_write_sys_reg(vcpu, val, SPSR_EL1); + else + vcpu_write_sys_reg(vcpu, val, SPSR_EL2); + + return; + } + write_sysreg_el1(val, SYS_SPSR); } @@ -97,6 +110,11 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode, sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL1); __vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL1); break; + case PSR_MODE_EL2h: + vbar = __vcpu_read_sys_reg(vcpu, VBAR_EL2); + sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL2); + __vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL2); + break; default: /* Don't do that */ BUG(); @@ -149,7 +167,7 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode, new |= target_mode; *vcpu_cpsr(vcpu) = new; - __vcpu_write_spsr(vcpu, old); + __vcpu_write_spsr(vcpu, target_mode, old); } /* @@ -320,11 +338,22 @@ static void kvm_inject_exception(struct kvm_vcpu *vcpu) KVM_ARM64_EXCEPT_AA64_EL1): enter_exception64(vcpu, PSR_MODE_EL1h, except_type_sync); break; + + case (KVM_ARM64_EXCEPT_AA64_ELx_SYNC | + KVM_ARM64_EXCEPT_AA64_EL2): + enter_exception64(vcpu, PSR_MODE_EL2h, except_type_sync); + break; + + case (KVM_ARM64_EXCEPT_AA64_ELx_IRQ | + KVM_ARM64_EXCEPT_AA64_EL2): + enter_exception64(vcpu, PSR_MODE_EL2h, except_type_irq); + break; + default: /* - * Only EL1_SYNC makes sense so far, EL2_{SYNC,IRQ} - * will be implemented at some point. Everything - * else gets silently ignored. + * Only EL1_SYNC and EL2_{SYNC,IRQ} makes + * sense so far. Everything else gets silently + * ignored. */ break; } diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index b47df73e98d7..81ceee6998cc 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c @@ -12,19 +12,58 @@ #include #include +#include #include +static void pend_sync_exception(struct kvm_vcpu *vcpu) +{ + vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_ELx_SYNC | + KVM_ARM64_PENDING_EXCEPTION); + + /* If not nesting, EL1 is the only possible exception target */ + if (likely(!vcpu_has_nv(vcpu))) { + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL1; + return; + } + + /* + * With NV, we need to pick between EL1 and EL2. Note that we + * never deal with a nesting exception here, hence never + * changing context, and the exception itself can be delayed + * until the next entry. + */ + switch(*vcpu_cpsr(vcpu) & PSR_MODE_MASK) { + case PSR_MODE_EL2h: + case PSR_MODE_EL2t: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL2; + break; + case PSR_MODE_EL1h: + case PSR_MODE_EL1t: + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL1; + break; + case PSR_MODE_EL0t: + if (vcpu_el2_tge_is_set(vcpu)) + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL2; + else + vcpu->arch.flags |= KVM_ARM64_EXCEPT_AA64_EL1; + break; + default: + BUG(); + } +} + +static bool match_target_el(struct kvm_vcpu *vcpu, unsigned long target) +{ + return (vcpu->arch.flags & KVM_ARM64_EXCEPT_AA64_EL_MASK) == target; +} + static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr) { unsigned long cpsr = *vcpu_cpsr(vcpu); bool is_aarch32 = vcpu_mode_is_32bit(vcpu); u32 esr = 0; - vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1 | - KVM_ARM64_EXCEPT_AA64_ELx_SYNC | - KVM_ARM64_PENDING_EXCEPTION); - - vcpu_write_sys_reg(vcpu, addr, FAR_EL1); + pend_sync_exception(vcpu); /* * Build an {i,d}abort, depending on the level and the @@ -45,16 +84,22 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr if (!is_iabt) esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT; - vcpu_write_sys_reg(vcpu, esr | ESR_ELx_FSC_EXTABT, ESR_EL1); + esr |= ESR_ELx_FSC_EXTABT; + + if (match_target_el(vcpu, KVM_ARM64_EXCEPT_AA64_EL1)) { + vcpu_write_sys_reg(vcpu, addr, FAR_EL1); + vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + } else { + vcpu_write_sys_reg(vcpu, addr, FAR_EL2); + vcpu_write_sys_reg(vcpu, esr, ESR_EL2); + } } static void inject_undef64(struct kvm_vcpu *vcpu) { u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); - vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1 | - KVM_ARM64_EXCEPT_AA64_ELx_SYNC | - KVM_ARM64_PENDING_EXCEPTION); + pend_sync_exception(vcpu); /* * Build an unknown exception, depending on the instruction @@ -63,7 +108,10 @@ static void inject_undef64(struct kvm_vcpu *vcpu) if (kvm_vcpu_trap_il_is32bit(vcpu)) esr |= ESR_ELx_IL; - vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + if (match_target_el(vcpu, KVM_ARM64_EXCEPT_AA64_EL1)) + vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + else + vcpu_write_sys_reg(vcpu, esr, ESR_EL2); } #define DFSR_FSC_EXTABT_LPAE 0x10 diff --git a/arch/arm64/kvm/trace_arm.h b/arch/arm64/kvm/trace_arm.h index 33e4e7dd2719..f3e46a976125 100644 --- a/arch/arm64/kvm/trace_arm.h +++ b/arch/arm64/kvm/trace_arm.h @@ -2,6 +2,7 @@ #if !defined(_TRACE_ARM_ARM64_KVM_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_ARM_ARM64_KVM_H +#include #include #include @@ -301,6 +302,64 @@ TRACE_EVENT(kvm_timer_emulate, __entry->timer_idx, __entry->should_fire) ); +TRACE_EVENT(kvm_nested_eret, + TP_PROTO(struct kvm_vcpu *vcpu, unsigned long elr_el2, + unsigned long spsr_el2), + TP_ARGS(vcpu, elr_el2, spsr_el2), + + TP_STRUCT__entry( + __field(struct kvm_vcpu *, vcpu) + __field(unsigned long, elr_el2) + __field(unsigned long, spsr_el2) + __field(unsigned long, target_mode) + __field(unsigned long, hcr_el2) + ), + + TP_fast_assign( + __entry->vcpu = vcpu; + __entry->elr_el2 = elr_el2; + __entry->spsr_el2 = spsr_el2; + __entry->target_mode = spsr_el2 & (PSR_MODE_MASK | PSR_MODE32_BIT); + __entry->hcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + ), + + TP_printk("elr_el2: 0x%lx spsr_el2: 0x%08lx (M: %s) hcr_el2: %lx", + __entry->elr_el2, __entry->spsr_el2, + __print_symbolic(__entry->target_mode, kvm_mode_names), + __entry->hcr_el2) +); + +TRACE_EVENT(kvm_inject_nested_exception, + TP_PROTO(struct kvm_vcpu *vcpu, u64 esr_el2, int type), + TP_ARGS(vcpu, esr_el2, type), + + TP_STRUCT__entry( + __field(struct kvm_vcpu *, vcpu) + __field(unsigned long, esr_el2) + __field(int, type) + __field(unsigned long, spsr_el2) + __field(unsigned long, pc) + __field(unsigned long, source_mode) + __field(unsigned long, hcr_el2) + ), + + TP_fast_assign( + __entry->vcpu = vcpu; + __entry->esr_el2 = esr_el2; + __entry->type = type; + __entry->spsr_el2 = *vcpu_cpsr(vcpu); + __entry->pc = *vcpu_pc(vcpu); + __entry->source_mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT); + __entry->hcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + ), + + TP_printk("%s: esr_el2 0x%lx elr_el2: 0x%lx spsr_el2: 0x%08lx (M: %s) hcr_el2: %lx", + __print_symbolic(__entry->type, kvm_exception_type_names), + __entry->esr_el2, __entry->pc, __entry->spsr_el2, + __print_symbolic(__entry->source_mode, kvm_mode_names), + __entry->hcr_el2) +); + #endif /* _TRACE_ARM_ARM64_KVM_H */ #undef TRACE_INCLUDE_PATH -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel