From patchwork Tue Feb 11 17:48:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11376231 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 14A2A14B4 for ; Tue, 11 Feb 2020 17:52:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDA6E206CC for ; Tue, 11 Feb 2020 17:52:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581443544; bh=e288yNviCD4w55sXsGvgxFgNRKWiZoGCOqW7St9mC1M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ur4PzymiTOR5HDhKWfikC/KFudsK8oG0op7S8qmYdtv6OIpSGi9AGqvMvJ7V7MJRl /45kagjie8bfS8sUJ+6hZpMhfmtMSJfTSh2ilXsWr2iyH0jervZOkdCkGVEut3yaCG 71RRfsyrrbIgE4cZz/yG6fMbZPLbFk6op0+RlpAw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730523AbgBKRwX (ORCPT ); Tue, 11 Feb 2020 12:52:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:55240 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730518AbgBKRwW (ORCPT ); Tue, 11 Feb 2020 12:52:22 -0500 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 566F421569; Tue, 11 Feb 2020 17:52:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581443541; bh=e288yNviCD4w55sXsGvgxFgNRKWiZoGCOqW7St9mC1M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p8P6ra8cseEoZYcvUkZ6uwV5TiQbgxng7M8AvvVdwpvZj33vypHDBShimcgc8jacX 0GGvOHSWI1RDUp2/IjncfudT3s5UD/gubRmcyLBkbjh0NB5ARMzBP1KL8YMAKReg0h f3t7qK6lT4P0Y/dfDmHC6HFGwKZbUfzIdlXTCvj4= 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:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j1Zfv-004O7k-6j; Tue, 11 Feb 2020 17:50:19 +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 , Dave Martin , Jintack Lim , Alexandru Elisei , James Morse , Julien Thierry , Suzuki K Poulose Subject: [PATCH v2 44/94] KVM: arm64: nv: Trap and emulate AT instructions from virtual EL2 Date: Tue, 11 Feb 2020 17:48:48 +0000 Message-Id: <20200211174938.27809-45-maz@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200211174938.27809-1-maz@kernel.org> References: <20200211174938.27809-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 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, Dave.Martin@arm.com, jintack@cs.columbia.edu, alexandru.elisei@arm.com, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Jintack Lim When supporting nested virtualization a guest hypervisor executing AT instructions must be trapped and emulated by the host hypervisor, because untrapped AT instructions operating on S1E1 will use the wrong translation regieme (the one used to emulate virtual EL2 in EL1 instead of virtual EL1) and AT instructions operating on S12 will not work from EL1. This patch does several things. 1. List and define all AT system instructions to emulate and document the emulation design. 2. Implement AT instruction handling logic in EL2. This will be used to emulate AT instructions executed in the virtual EL2. AT instruction emulation works by loading the proper processor context, which depends on the trapped instruction and the virtual HCR_EL2, to the EL1 virtual memory control registers and executing AT instructions. Note that ctxt->hw_sys_regs is expected to have the proper processor context before calling the handling function(__kvm_at_insn) implemented in this patch. 4. Emulate AT S1E[01] instructions by issuing the same instructions in EL2. We set the physical EL1 registers, NV and NV1 bits as described in the AT instruction emulation overview. 5. Emulate AT A12E[01] instructions in two steps: First, do the stage-1 translation by reusing the existing AT emulation functions. Second, do the stage-2 translation by walking the guest hypervisor's stage-2 page table in software. Record the translation result to PAR_EL1. 6. Emulate AT S1E2 instructions by issuing the corresponding S1E1 instructions in EL2. We set the physical EL1 registers and the HCR_EL2 register as described in the AT instruction emulation overview. 7. Forward system instruction traps to the virtual EL2 if the corresponding virtual AT bit is set in the virtual HCR_EL2. [ Much logic above has been reworked by Marc Zyngier ] Signed-off-by: Jintack Lim Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm64/include/asm/kvm_arm.h | 2 + arch/arm64/include/asm/kvm_asm.h | 2 + arch/arm64/include/asm/sysreg.h | 17 +++ arch/arm64/kvm/hyp/Makefile | 1 + arch/arm64/kvm/hyp/at.c | 231 +++++++++++++++++++++++++++++++ arch/arm64/kvm/hyp/switch.c | 13 +- arch/arm64/kvm/sys_regs.c | 201 ++++++++++++++++++++++++++- 7 files changed, 463 insertions(+), 4 deletions(-) create mode 100644 arch/arm64/kvm/hyp/at.c diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 95dfef820cf1..2e5be806a5c9 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -13,6 +13,7 @@ /* Hyp Configuration Register (HCR) bits */ #define HCR_FWB (UL(1) << 46) +#define HCR_AT (UL(1) << 44) #define HCR_NV1 (UL(1) << 43) #define HCR_NV (UL(1) << 42) #define HCR_API (UL(1) << 41) @@ -107,6 +108,7 @@ #define VTCR_EL2_TG0_16K TCR_TG0_16K #define VTCR_EL2_TG0_64K TCR_TG0_64K #define VTCR_EL2_SH0_MASK TCR_SH0_MASK +#define VTCR_EL2_SH0_SHIFT TCR_SH0_SHIFT #define VTCR_EL2_SH0_INNER TCR_SH0_INNER #define VTCR_EL2_ORGN0_MASK TCR_ORGN0_MASK #define VTCR_EL2_ORGN0_WBWA TCR_ORGN0_WBWA diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 80f5633d9559..8acbe64572a2 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -64,6 +64,8 @@ extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu); extern void __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu); extern void __kvm_timer_set_cntvoff(u32 cntvoff_low, u32 cntvoff_high); +extern void __kvm_at_s1e01(struct kvm_vcpu *vcpu, u32 op, u64 vaddr); +extern void __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr); extern int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index a167219e42f4..f0bb76c7d04d 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -532,6 +532,23 @@ #define SYS_SP_EL2 sys_reg(3, 6, 4, 1, 0) +/* AT instructions */ +#define AT_Op0 1 +#define AT_CRn 7 + +#define OP_AT_S1E1R sys_insn(AT_Op0, 0, AT_CRn, 8, 0) +#define OP_AT_S1E1W sys_insn(AT_Op0, 0, AT_CRn, 8, 1) +#define OP_AT_S1E0R sys_insn(AT_Op0, 0, AT_CRn, 8, 2) +#define OP_AT_S1E0W sys_insn(AT_Op0, 0, AT_CRn, 8, 3) +#define OP_AT_S1E1RP sys_insn(AT_Op0, 0, AT_CRn, 9, 0) +#define OP_AT_S1E1WP sys_insn(AT_Op0, 0, AT_CRn, 9, 1) +#define OP_AT_S1E2R sys_insn(AT_Op0, 4, AT_CRn, 8, 0) +#define OP_AT_S1E2W sys_insn(AT_Op0, 4, AT_CRn, 8, 1) +#define OP_AT_S12E1R sys_insn(AT_Op0, 4, AT_CRn, 8, 4) +#define OP_AT_S12E1W sys_insn(AT_Op0, 4, AT_CRn, 8, 5) +#define OP_AT_S12E0R sys_insn(AT_Op0, 4, AT_CRn, 8, 6) +#define OP_AT_S12E0W sys_insn(AT_Op0, 4, AT_CRn, 8, 7) + /* Common SCTLR_ELx flags. */ #define SCTLR_ELx_DSSBS (BIT(44)) #define SCTLR_ELx_ENIA (BIT(31)) diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile index ea710f674cb6..f7af51647079 100644 --- a/arch/arm64/kvm/hyp/Makefile +++ b/arch/arm64/kvm/hyp/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_KVM_ARM_HOST) += entry.o obj-$(CONFIG_KVM_ARM_HOST) += switch.o obj-$(CONFIG_KVM_ARM_HOST) += fpsimd.o obj-$(CONFIG_KVM_ARM_HOST) += tlb.o +obj-$(CONFIG_KVM_ARM_HOST) += at.o obj-$(CONFIG_KVM_ARM_HOST) += hyp-entry.o # KVM code is run at a different exception code with a different map, so diff --git a/arch/arm64/kvm/hyp/at.c b/arch/arm64/kvm/hyp/at.c new file mode 100644 index 000000000000..9fdb87fa3597 --- /dev/null +++ b/arch/arm64/kvm/hyp/at.c @@ -0,0 +1,231 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017 - Linaro Ltd + * Author: Jintack Lim + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include +#include + +struct mmu_config { + u64 ttbr0; + u64 ttbr1; + u64 tcr; + u64 sctlr; + u64 vttbr; + u64 vtcr; + u64 hcr; +}; + +static void __mmu_config_save(struct mmu_config *config) +{ + config->ttbr0 = read_sysreg_el1(SYS_TTBR0); + config->ttbr1 = read_sysreg_el1(SYS_TTBR1); + config->tcr = read_sysreg_el1(SYS_TCR); + config->sctlr = read_sysreg_el1(SYS_SCTLR); + config->vttbr = read_sysreg(vttbr_el2); + config->vtcr = read_sysreg(vtcr_el2); + config->hcr = read_sysreg(hcr_el2); +} + +static void __mmu_config_restore(struct mmu_config *config) +{ + write_sysreg_el1(config->ttbr0, SYS_TTBR0); + write_sysreg_el1(config->ttbr1, SYS_TTBR1); + write_sysreg_el1(config->tcr, SYS_TCR); + write_sysreg_el1(config->sctlr, SYS_SCTLR); + write_sysreg(config->vttbr, vttbr_el2); + write_sysreg(config->vtcr, vtcr_el2); + write_sysreg(config->hcr, hcr_el2); + + isb(); +} + +void __kvm_at_s1e01(struct kvm_vcpu *vcpu, u32 op, u64 vaddr) +{ + struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt; + struct mmu_config config; + struct kvm_s2_mmu *mmu; + + spin_lock(&vcpu->kvm->mmu_lock); + + /* + * If HCR_EL2.{E2H,TGE} == {1,1}, the MMU context is already + * the right one (as we trapped from vEL2). + */ + if (vcpu_el2_e2h_is_set(vcpu) && vcpu_el2_tge_is_set(vcpu)) + goto skip_mmu_switch; + + /* + * FIXME: Obtaining the S2 MMU for a guest guest is horribly + * racy, and we may not find it (evicted by another vcpu, for + * example). + */ + mmu = lookup_s2_mmu(vcpu->kvm, + vcpu_read_sys_reg(vcpu, VTTBR_EL2), + vcpu_read_sys_reg(vcpu, HCR_EL2)); + + if (WARN_ON(!mmu)) + goto out; + + /* We've trapped, so everything is live on the CPU. */ + __mmu_config_save(&config); + + write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], SYS_TTBR0); + write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], SYS_TTBR1); + write_sysreg_el1(ctxt->sys_regs[TCR_EL1], SYS_TCR); + write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1], SYS_SCTLR); + write_sysreg(kvm_get_vttbr(mmu), vttbr_el2); + /* + * REVISIT: do we need anything from the guest's VTCR_EL2? If + * looks like keeping the hosts configuration is the right + * thing to do at this stage (and we could avoid save/restore + * it. Keep the host's version for now. + */ + write_sysreg((config.hcr & ~HCR_TGE) | HCR_VM, hcr_el2); + + isb(); + +skip_mmu_switch: + + switch (op) { + case OP_AT_S1E1R: + case OP_AT_S1E1RP: + asm volatile("at s1e1r, %0" : : "r" (vaddr)); + break; + case OP_AT_S1E1W: + case OP_AT_S1E1WP: + asm volatile("at s1e1w, %0" : : "r" (vaddr)); + break; + case OP_AT_S1E0R: + asm volatile("at s1e0r, %0" : : "r" (vaddr)); + break; + case OP_AT_S1E0W: + asm volatile("at s1e0w, %0" : : "r" (vaddr)); + break; + default: + WARN_ON_ONCE(1); + break; + } + + isb(); + + ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1); + + /* + * Failed? let's leave the building now. + * + * FIXME: how about a failed translation because the shadow S2 + * wasn't populated? We may need to perform a SW PTW, + * populating our shadow S2 and retry the instruction. + */ + if (ctxt->sys_regs[PAR_EL1] & 1) + goto nopan; + + /* No PAN? No problem. */ + if (!(*vcpu_cpsr(vcpu) & PSR_PAN_BIT)) + goto nopan; + + /* + * For PAN-involved AT operations, perform the same + * translation, using EL0 this time. + */ + switch (op) { + case OP_AT_S1E1RP: + asm volatile("at s1e0r, %0" : : "r" (vaddr)); + break; + case OP_AT_S1E1WP: + asm volatile("at s1e0w, %0" : : "r" (vaddr)); + break; + default: + goto nopan; + } + + /* + * If the EL0 translation has succeeded, we need to pretend + * the AT operation has failed, as the PAN setting forbids + * such a translation. + * + * FIXME: we hardcode a Level-3 permission fault. We really + * should return the real fault level. + */ + if (!(read_sysreg(par_el1) & 1)) + ctxt->sys_regs[PAR_EL1] = 0x1f; + +nopan: + if (!(vcpu_el2_e2h_is_set(vcpu) && vcpu_el2_tge_is_set(vcpu))) + __mmu_config_restore(&config); + +out: + spin_unlock(&vcpu->kvm->mmu_lock); +} + +void __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr) +{ + struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt; + struct mmu_config config; + struct kvm_s2_mmu *mmu; + u64 val; + + spin_lock(&vcpu->kvm->mmu_lock); + + mmu = &vcpu->kvm->arch.mmu; + + /* We've trapped, so everything is live on the CPU. */ + __mmu_config_save(&config); + + if (vcpu_el2_e2h_is_set(vcpu)) { + write_sysreg_el1(ctxt->sys_regs[TTBR0_EL2], SYS_TTBR0); + write_sysreg_el1(ctxt->sys_regs[TTBR1_EL2], SYS_TTBR1); + write_sysreg_el1(ctxt->sys_regs[TCR_EL2], SYS_TCR); + write_sysreg_el1(ctxt->sys_regs[SCTLR_EL2], SYS_SCTLR); + + val = config.hcr; + } else { + write_sysreg_el1(ctxt->sys_regs[TTBR0_EL2], SYS_TTBR0); + write_sysreg_el1(translate_tcr(ctxt->sys_regs[TCR_EL2]), + SYS_TCR); + write_sysreg_el1(translate_sctlr(ctxt->sys_regs[SCTLR_EL2]), + SYS_SCTLR); + + val = config.hcr | HCR_NV | HCR_NV1; + } + + write_sysreg(kvm_get_vttbr(mmu), vttbr_el2); + /* FIXME: write S2 MMU VTCR_EL2? */ + write_sysreg((val & ~HCR_TGE) | HCR_VM, hcr_el2); + + isb(); + + switch (op) { + case OP_AT_S1E2R: + asm volatile("at s1e1r, %0" : : "r" (vaddr)); + break; + case OP_AT_S1E2W: + asm volatile("at s1e1w, %0" : : "r" (vaddr)); + break; + default: + WARN_ON_ONCE(1); + break; + } + + isb(); + + /* FIXME: handle failed translation due to shadow S2 */ + ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1); + + __mmu_config_restore(&config); + spin_unlock(&vcpu->kvm->mmu_lock); +} diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 08f12c96c458..61686b8a992e 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -157,9 +157,10 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu) if (!vcpu_el2_e2h_is_set(vcpu)) { /* * For a guest hypervisor on v8.0, trap and emulate - * the EL1 virtual memory control register accesses. + * the EL1 virtual memory control register accesses + * as well as the AT S1 operations. */ - hcr |= HCR_TVM | HCR_TRVM | HCR_NV1; + hcr |= HCR_TVM | HCR_TRVM | HCR_AT | HCR_NV1; } else { /* * For a guest hypervisor on v8.1 (VHE), allow to @@ -182,6 +183,14 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu) hcr &= ~HCR_TVM; hcr |= vhcr_el2 & (HCR_TVM | HCR_TRVM); + + /* + * If we're using the EL1 translation regime + * (TGE clear, then ensure that AT S1 ops are + * trapped too. + */ + if (!vcpu_el2_tge_is_set(vcpu)) + hcr |= HCR_AT; } } diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 026395d16c9f..1ff2e16b1f57 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1678,6 +1678,10 @@ static bool access_sp_el1(struct kvm_vcpu *vcpu, return true; } +static bool forward_at_traps(struct kvm_vcpu *vcpu) +{ + return forward_traps(vcpu, HCR_AT); +} static bool access_elr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, @@ -2089,12 +2093,205 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_SP_EL2), NULL, reset_unknown, SP_EL2 }, }; -#define SYS_INSN_TO_DESC(insn, access_fn, forward_fn) \ - { SYS_DESC((insn)), (access_fn), NULL, 0, 0, NULL, NULL, (forward_fn) } +static bool handle_s1e01(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + int sys_encoding = sys_insn(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2); + + __kvm_at_s1e01(vcpu, sys_encoding, p->regval); + + return true; +} + +static bool handle_s1e2(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + int sys_encoding = sys_insn(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2); + + __kvm_at_s1e2(vcpu, sys_encoding, p->regval); + + return true; +} + +static u64 setup_par_aborted(u32 esr) +{ + u64 par = 0; + + /* S [9]: fault in the stage 2 translation */ + par |= (1 << 9); + /* FST [6:1]: Fault status code */ + par |= (esr << 1); + /* F [0]: translation is aborted */ + par |= 1; + + return par; +} + +static u64 setup_par_completed(struct kvm_vcpu *vcpu, struct kvm_s2_trans *out) +{ + u64 par, vtcr_sh0; + + /* F [0]: Translation is completed successfully */ + par = 0; + /* ATTR [63:56] */ + par |= out->upper_attr; + /* PA [47:12] */ + par |= out->output & GENMASK_ULL(11, 0); + /* RES1 [11] */ + par |= (1UL << 11); + /* SH [8:7]: Shareability attribute */ + vtcr_sh0 = vcpu_read_sys_reg(vcpu, VTCR_EL2) & VTCR_EL2_SH0_MASK; + par |= (vtcr_sh0 >> VTCR_EL2_SH0_SHIFT) << 7; + + return par; +} + +static bool handle_s12(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r, bool write) +{ + u64 par, va; + u32 esr; + phys_addr_t ipa; + struct kvm_s2_trans out; + int ret; + + /* Do the stage-1 translation */ + handle_s1e01(vcpu, p, r); + par = vcpu_read_sys_reg(vcpu, PAR_EL1); + if (par & 1) { + /* The stage-1 translation aborted */ + return true; + } + + /* Do the stage-2 translation */ + va = p->regval; + ipa = (par & GENMASK_ULL(47, 12)) | (va & GENMASK_ULL(11, 0)); + out.esr = 0; + ret = kvm_walk_nested_s2(vcpu, ipa, &out); + if (ret < 0) + return false; + + /* Check if the stage-2 PTW is aborted */ + if (out.esr) { + esr = out.esr; + goto s2_trans_abort; + } + + /* Check the access permission */ + if ((!write && !out.readable) || (write && !out.writable)) { + esr = ESR_ELx_FSC_PERM; + esr |= out.level & 0x3; + goto s2_trans_abort; + } + + vcpu_write_sys_reg(vcpu, setup_par_completed(vcpu, &out), PAR_EL1); + return true; + +s2_trans_abort: + vcpu_write_sys_reg(vcpu, setup_par_aborted(esr), PAR_EL1); + return true; +} + +static bool handle_s12r(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + return handle_s12(vcpu, p, r, false); +} + +static bool handle_s12w(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + return handle_s12(vcpu, p, r, true); +} + +/* + * AT instruction emulation + * + * We emulate AT instructions executed in the virtual EL2. + * Basic strategy for the stage-1 translation emulation is to load proper + * context, which depends on the trapped instruction and the virtual HCR_EL2, + * to the EL1 virtual memory control registers and execute S1E[01] instructions + * in EL2. See below for more detail. + * + * For the stage-2 translation, which is necessary for S12E[01] emulation, + * we walk the guest hypervisor's stage-2 page table in software. + * + * The stage-1 translation emulations can be divided into two groups depending + * on the translation regime. + * + * 1. EL2 AT instructions: S1E2x + * +-----------------------------------------------------------------------+ + * | | Setting for the emulation | + * | Virtual HCR_EL2.E2H on trap |-----------------------------------------+ + * | | Phys EL1 regs | Phys NV, NV1 | Phys TGE | + * |-----------------------------------------------------------------------| + * | 0 | vEL2 | (1, 1) | 0 | + * | 1 | vEL2 | (0, 0) | 0 | + * +-----------------------------------------------------------------------+ + * + * We emulate the EL2 AT instructions by loading virtual EL2 context + * to the EL1 virtual memory control registers and executing corresponding + * EL1 AT instructions. + * + * We set physical NV and NV1 bits to use EL2 page table format for non-VHE + * guest hypervisor (i.e. HCR_EL2.E2H == 0). As a VHE guest hypervisor uses the + * EL1 page table format, we don't set those bits. + * + * We should clear physical TGE bit not to use the EL2 translation regime when + * the host uses the VHE feature. + * + * + * 2. EL0/EL1 AT instructions: S1E[01]x, S12E1x + * +----------------------------------------------------------------------+ + * | Virtual HCR_EL2 on trap | Setting for the emulation | + * |----------------------------------------------------------------------+ + * | (vE2H, vTGE) | (vNV, vNV1) | Phys EL1 regs | Phys NV, NV1 | Phys TGE | + * |----------------------------------------------------------------------| + * | (0, 0)* | (0, 0) | vEL1 | (0, 0) | 0 | + * | (0, 0) | (1, 1) | vEL1 | (1, 1) | 0 | + * | (1, 1) | (0, 0) | vEL2 | (0, 0) | 0 | + * | (1, 1) | (1, 1) | vEL2 | (1, 1) | 0 | + * +----------------------------------------------------------------------+ + * + * *For (0, 0) in the 'Virtual HCR_EL2 on trap' column, it actually means + * (1, 1). Keep them (0, 0) just for the readability. + * + * We set physical EL1 virtual memory control registers depending on + * (vE2H, vTGE) pair. When the pair is (0, 0) where AT instructions are + * supposed to use EL0/EL1 translation regime, we load the EL1 registers with + * the virtual EL1 registers (i.e. EL1 registers from the guest hypervisor's + * point of view). When the pair is (1, 1), however, AT instructions are defined + * to apply EL2 translation regime. To emulate this behavior, we load the EL1 + * registers with the virtual EL2 context. (i.e the shadow registers) + * + * We respect the virtual NV and NV1 bit for the emulation. When those bits are + * set, it means that a guest hypervisor would like to use EL2 page table format + * for the EL1 translation regime. We emulate this by setting the physical + * NV and NV1 bits. + */ + +#define SYS_INSN_TO_DESC(insn, access_fn, forward_fn) \ + { SYS_DESC(OP_##insn), (access_fn), NULL, 0, 0, \ + NULL, NULL, (forward_fn) } static struct sys_reg_desc sys_insn_descs[] = { { SYS_DESC(SYS_DC_ISW), access_dcsw }, + + SYS_INSN_TO_DESC(AT_S1E1R, handle_s1e01, forward_at_traps), + SYS_INSN_TO_DESC(AT_S1E1W, handle_s1e01, forward_at_traps), + SYS_INSN_TO_DESC(AT_S1E0R, handle_s1e01, forward_at_traps), + SYS_INSN_TO_DESC(AT_S1E0W, handle_s1e01, forward_at_traps), + SYS_INSN_TO_DESC(AT_S1E1RP, handle_s1e01, forward_at_traps), + SYS_INSN_TO_DESC(AT_S1E1WP, handle_s1e01, forward_at_traps), + { SYS_DESC(SYS_DC_CSW), access_dcsw }, { SYS_DESC(SYS_DC_CISW), access_dcsw }, + + SYS_INSN_TO_DESC(AT_S1E2R, handle_s1e2, forward_nv_traps), + SYS_INSN_TO_DESC(AT_S1E2W, handle_s1e2, forward_nv_traps), + SYS_INSN_TO_DESC(AT_S12E1R, handle_s12r, forward_nv_traps), + SYS_INSN_TO_DESC(AT_S12E1W, handle_s12w, forward_nv_traps), + SYS_INSN_TO_DESC(AT_S12E0R, handle_s12r, forward_nv_traps), + SYS_INSN_TO_DESC(AT_S12E0W, handle_s12w, forward_nv_traps), }; static bool trap_dbgidr(struct kvm_vcpu *vcpu,