From patchwork Wed Aug 21 15:38:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 13771852 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 BE363C52D6F for ; Wed, 21 Aug 2024 15:53:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=EK5jmW1LTP0IsMlC3Yw8673KH9IgC3n6kq6H6lOUKDY=; b=YT6rbCTK1FYxRgV3uu8sQKeOCO c86W20bwvrsEtEeZIpU5HzZDSQUCCaYZzCn+H2fg7SKlMI+bqIEdffqaNbg6B+Pt8eGxMcV4ixnJX pWq1rHck9h6jlyeLvvMb+NoYnnSgTlTl8WsK0NwnAgDLSnnaX1NrPYHfngE9IAma6tzOuHnHHDwaN 8EsGLxRJ4IyZSYYhGImuSE+o/OtHeviw3A2gTBcAYEt7T38CGTo+iSahRR2p/Vj80YObF3QRDoIdV TMcNGpR0OTB/iaXLp+/g9wIU/2foKaKjeCuwK5GIRw9QMZhZJw3Z8CNnQDRXF/dJheNcXIcatGzW6 Vh+B52oA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sgndw-00000009bjx-2pcm; Wed, 21 Aug 2024 15:53:04 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sgnRW-00000009XHq-1mWM for linux-arm-kernel@lists.infradead.org; Wed, 21 Aug 2024 15:40:16 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1901FDA7; Wed, 21 Aug 2024 08:40:40 -0700 (PDT) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.37.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E53E53F73B; Wed, 21 Aug 2024 08:40:09 -0700 (PDT) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun Subject: [PATCH v4 18/43] arm64: RME: Handle realm enter/exit Date: Wed, 21 Aug 2024 16:38:19 +0100 Message-Id: <20240821153844.60084-19-steven.price@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240821153844.60084-1-steven.price@arm.com> References: <20240821153844.60084-1-steven.price@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240821_084014_589078_BA82437C X-CRM114-Status: GOOD ( 28.30 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Entering a realm is done using a SMC call to the RMM. On exit the exit-codes need to be handled slightly differently to the normal KVM path so define our own functions for realm enter/exit and hook them in if the guest is a realm guest. Signed-off-by: Steven Price --- Changes since v2: * realm_set_ipa_state() now provides an output parameter for the top_iap that was changed. Use this to signal the VMM with the correct range that has been transitioned. * Adapt to previous patch changes. --- arch/arm64/include/asm/kvm_rme.h | 3 + arch/arm64/kvm/Makefile | 2 +- arch/arm64/kvm/arm.c | 19 +++- arch/arm64/kvm/rme-exit.c | 181 +++++++++++++++++++++++++++++++ arch/arm64/kvm/rme.c | 11 ++ 5 files changed, 210 insertions(+), 6 deletions(-) create mode 100644 arch/arm64/kvm/rme-exit.c diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h index c064bfb080ad..0e44b20cfa48 100644 --- a/arch/arm64/include/asm/kvm_rme.h +++ b/arch/arm64/include/asm/kvm_rme.h @@ -96,6 +96,9 @@ void kvm_realm_destroy_rtts(struct kvm *kvm, u32 ia_bits); int kvm_create_rec(struct kvm_vcpu *vcpu); void kvm_destroy_rec(struct kvm_vcpu *vcpu); +int kvm_rec_enter(struct kvm_vcpu *vcpu); +int handle_rme_exit(struct kvm_vcpu *vcpu, int rec_run_status); + void kvm_realm_unmap_range(struct kvm *kvm, unsigned long ipa, u64 size, diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 5e79e5eee88d..9f893e86cac9 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -21,7 +21,7 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ vgic/vgic-mmio.o vgic/vgic-mmio-v2.o \ vgic/vgic-mmio-v3.o vgic/vgic-kvm-device.o \ vgic/vgic-its.o vgic/vgic-debug.o \ - rme.o + rme.o rme-exit.o kvm-$(CONFIG_HW_PERF_EVENTS) += pmu-emul.o pmu.o kvm-$(CONFIG_ARM64_PTR_AUTH) += pauth.o diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 568e9e6e5a4e..e8dabb996705 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1282,7 +1282,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) trace_kvm_entry(*vcpu_pc(vcpu)); guest_timing_enter_irqoff(); - ret = kvm_arm_vcpu_enter_exit(vcpu); + if (vcpu_is_rec(vcpu)) + ret = kvm_rec_enter(vcpu); + else + ret = kvm_arm_vcpu_enter_exit(vcpu); vcpu->mode = OUTSIDE_GUEST_MODE; vcpu->stat.exits++; @@ -1336,10 +1339,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) local_irq_enable(); - trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu)); - /* Exit types that need handling before we can be preempted */ - handle_exit_early(vcpu, ret); + if (!vcpu_is_rec(vcpu)) { + trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), + *vcpu_pc(vcpu)); + + handle_exit_early(vcpu, ret); + } preempt_enable(); @@ -1362,7 +1368,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) ret = ARM_EXCEPTION_IL; } - ret = handle_exit(vcpu, ret); + if (vcpu_is_rec(vcpu)) + ret = handle_rme_exit(vcpu, ret); + else + ret = handle_exit(vcpu, ret); } /* Tell userspace about in-kernel device output levels */ diff --git a/arch/arm64/kvm/rme-exit.c b/arch/arm64/kvm/rme-exit.c new file mode 100644 index 000000000000..f4e45d475798 --- /dev/null +++ b/arch/arm64/kvm/rme-exit.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2023 ARM Ltd. + */ + +#include +#include +#include + +#include +#include +#include +#include + +typedef int (*exit_handler_fn)(struct kvm_vcpu *vcpu); + +static int rec_exit_reason_notimpl(struct kvm_vcpu *vcpu) +{ + struct realm_rec *rec = &vcpu->arch.rec; + + pr_err("[vcpu %d] Unhandled exit reason from realm (ESR: %#llx)\n", + vcpu->vcpu_id, rec->run->exit.esr); + return -ENXIO; +} + +static int rec_exit_sync_dabt(struct kvm_vcpu *vcpu) +{ + return kvm_handle_guest_abort(vcpu); +} + +static int rec_exit_sync_iabt(struct kvm_vcpu *vcpu) +{ + struct realm_rec *rec = &vcpu->arch.rec; + + pr_err("[vcpu %d] Unhandled instruction abort (ESR: %#llx).\n", + vcpu->vcpu_id, rec->run->exit.esr); + return -ENXIO; +} + +static int rec_exit_sys_reg(struct kvm_vcpu *vcpu) +{ + struct realm_rec *rec = &vcpu->arch.rec; + unsigned long esr = kvm_vcpu_get_esr(vcpu); + int rt = kvm_vcpu_sys_get_rt(vcpu); + bool is_write = !(esr & 1); + int ret; + + if (is_write) + vcpu_set_reg(vcpu, rt, rec->run->exit.gprs[0]); + + ret = kvm_handle_sys_reg(vcpu); + + if (ret >= 0 && !is_write) + rec->run->enter.gprs[0] = vcpu_get_reg(vcpu, rt); + + return ret; +} + +static exit_handler_fn rec_exit_handlers[] = { + [0 ... ESR_ELx_EC_MAX] = rec_exit_reason_notimpl, + [ESR_ELx_EC_SYS64] = rec_exit_sys_reg, + [ESR_ELx_EC_DABT_LOW] = rec_exit_sync_dabt, + [ESR_ELx_EC_IABT_LOW] = rec_exit_sync_iabt +}; + +static int rec_exit_psci(struct kvm_vcpu *vcpu) +{ + struct realm_rec *rec = &vcpu->arch.rec; + int i; + int ret; + + for (i = 0; i < REC_RUN_GPRS; i++) + vcpu_set_reg(vcpu, i, rec->run->exit.gprs[i]); + + ret = kvm_smccc_call_handler(vcpu); + + for (i = 0; i < REC_RUN_GPRS; i++) + rec->run->enter.gprs[i] = vcpu_get_reg(vcpu, i); + + return ret; +} + +static int rec_exit_ripas_change(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + struct realm *realm = &kvm->arch.realm; + struct realm_rec *rec = &vcpu->arch.rec; + unsigned long base = rec->run->exit.ripas_base; + unsigned long top = rec->run->exit.ripas_top; + unsigned long ripas = rec->run->exit.ripas_value & 1; + unsigned long top_ipa; + int ret = -EINVAL; + + if (realm_is_addr_protected(realm, base) && + realm_is_addr_protected(realm, top - 1)) { + kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_cache, + kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu)); + write_lock(&kvm->mmu_lock); + ret = realm_set_ipa_state(vcpu, base, top, ripas, &top_ipa); + write_unlock(&kvm->mmu_lock); + } + + WARN(ret && ret != -ENOMEM, + "Unable to satisfy SET_IPAS for %#lx - %#lx, ripas: %#lx\n", + base, top, ripas); + + /* Exit to VMM to complete the change */ + kvm_prepare_memory_fault_exit(vcpu, base, top_ipa - base, false, false, + ripas == 1); + + return 0; +} + +static void update_arch_timer_irq_lines(struct kvm_vcpu *vcpu) +{ + struct realm_rec *rec = &vcpu->arch.rec; + + __vcpu_sys_reg(vcpu, CNTV_CTL_EL0) = rec->run->exit.cntv_ctl; + __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0) = rec->run->exit.cntv_cval; + __vcpu_sys_reg(vcpu, CNTP_CTL_EL0) = rec->run->exit.cntp_ctl; + __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0) = rec->run->exit.cntp_cval; + + kvm_realm_timers_update(vcpu); +} + +/* + * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on + * proper exit to userspace. + */ +int handle_rme_exit(struct kvm_vcpu *vcpu, int rec_run_ret) +{ + struct realm_rec *rec = &vcpu->arch.rec; + u8 esr_ec = ESR_ELx_EC(rec->run->exit.esr); + unsigned long status, index; + + status = RMI_RETURN_STATUS(rec_run_ret); + index = RMI_RETURN_INDEX(rec_run_ret); + + /* + * If a PSCI_SYSTEM_OFF request raced with a vcpu executing, we might + * see the following status code and index indicating an attempt to run + * a REC when the RD state is SYSTEM_OFF. In this case, we just need to + * return to user space which can deal with the system event or will try + * to run the KVM VCPU again, at which point we will no longer attempt + * to enter the Realm because we will have a sleep request pending on + * the VCPU as a result of KVM's PSCI handling. + */ + if (status == RMI_ERROR_REALM && index == 1) { + vcpu->run->exit_reason = KVM_EXIT_UNKNOWN; + return 0; + } + + if (rec_run_ret) + return -ENXIO; + + vcpu->arch.fault.esr_el2 = rec->run->exit.esr; + vcpu->arch.fault.far_el2 = rec->run->exit.far; + vcpu->arch.fault.hpfar_el2 = rec->run->exit.hpfar; + + update_arch_timer_irq_lines(vcpu); + + /* Reset the emulation flags for the next run of the REC */ + rec->run->enter.flags = 0; + + switch (rec->run->exit.exit_reason) { + case RMI_EXIT_SYNC: + return rec_exit_handlers[esr_ec](vcpu); + case RMI_EXIT_IRQ: + case RMI_EXIT_FIQ: + return 1; + case RMI_EXIT_PSCI: + return rec_exit_psci(vcpu); + case RMI_EXIT_RIPAS_CHANGE: + return rec_exit_ripas_change(vcpu); + } + + kvm_pr_unimpl("Unsupported exit reason: %u\n", + rec->run->exit.exit_reason); + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + return 0; +} diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c index 1fa9991d708b..fd4162af551d 100644 --- a/arch/arm64/kvm/rme.c +++ b/arch/arm64/kvm/rme.c @@ -899,6 +899,17 @@ void kvm_destroy_realm(struct kvm *kvm) kvm_free_stage2_pgd(&kvm->arch.mmu); } +int kvm_rec_enter(struct kvm_vcpu *vcpu) +{ + struct realm_rec *rec = &vcpu->arch.rec; + + if (kvm_realm_state(vcpu->kvm) != REALM_STATE_ACTIVE) + return -EINVAL; + + return rmi_rec_enter(virt_to_phys(rec->rec_page), + virt_to_phys(rec->run)); +} + static void free_rec_aux(struct page **aux_pages, unsigned int num_aux) {