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 4749AC44501 for ; Wed, 15 Jul 2026 14:30:50 +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=Ngwd/f+btwbmeHukreOfJy5lzE5vtF3ygmACKePfIbY=; b=UL8O8ClKvxDyDLZeYUT1+FIfO5 DIuMkMrtX3JUtiTFMBwN5cFRhQe0ScUKWeSfHLgHB4+2dv4hktRTlwB5XJKOws+EzVraS4yaBX2Gj Xy9DX8flzysIJ4puGk/MEIuNLeW3MrmTdafuGoHzAYVbTf7ipjN7JsXcA93PHClM7bSmjDJX5hkiV /iy1K6i7bqxg8CC46N1WBJkZK2yfMAD2F+QO3foYX3ystQ2uNVB1V2u5OqnUe46tpaDE8fOrEhBNy /fC4YcS1i/NNrZeu/2EiZ1DnZd7arKv3B0+BE3mpoOd0sw1t4nJgvbxiToWgKdG+me9zFr78B94n7 l3HFAHZw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wk0dI-0000000F9Ie-0Vhy; Wed, 15 Jul 2026 14:30:44 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wk0d6-0000000F97R-1tux for linux-arm-kernel@lists.infradead.org; Wed, 15 Jul 2026 14:30:39 +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 5F05C1576; Wed, 15 Jul 2026 07:30:27 -0700 (PDT) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.25.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6E2E53F7B4; Wed, 15 Jul 2026 07:30:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784125831; bh=xB20vi2nNALS9GBzmutQDk9WbDugbz1wVrS9SO+qgWw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HiPsrwLhRBVIxGq/u5Mm62zS4lNbScLifEZPvmFVJCAmHxi6g35GAiV46G4aCXQ7S bCYrCSUVXcK3lLT2xgAoSz3RGUlIpQ4YpsfWZKFou4FSR9fZ9ClMcdJeMyBpEsp4Tu 7hw1FdoZT8tW+gcR/FG4q01DgIzRY83Ynui99I5E= 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 , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve , WeiLin.Chang@arm.com, Lorenzo Pieralisi Subject: [PATCH v15 20/37] KVM: arm64: CCA: Allow populating initial contents Date: Wed, 15 Jul 2026 15:28:22 +0100 Message-ID: <20260715142841.80544-21-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260715142841.80544-1-steven.price@arm.com> References: <20260715142841.80544-1-steven.price@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260715_073032_590280_6327EA91 X-CRM114-Status: GOOD ( 19.90 ) 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 The VMM needs to populate the realm with some data before starting (e.g. a kernel and initrd). This is measured by the RMM and used as part of the attestation later on. Signed-off-by: Steven Price --- Changes since v14: * Holding of locks slots_lock and config_lock have been moved up the callstack with lockdesp assertions placed in the lower functions. * Add overflow check into kvm_arm_rmi_populate(). Changes since v13: * Rename realm_create_protected_data_page() to realm_data_map_init(). Changes since v12: * The ioctl now updates the structure with the amount populated rather than returning this through the ioctl return code. * Use the new RMM v2.0 range based RMI calls. * Adapt to upstream changes in kvm_gmem_populate(). Changes since v11: * The multiplex CAP is gone and there's a new ioctl which makes use of the generic kvm_gmem_populate() functionality. Changes since v7: * Improve the error codes. * Other minor changes from review. Changes since v6: * Handle host potentially having a larger page size than the RMM granule. * Drop historic "par" (protected address range) from populate_par_region() - it doesn't exist within the current architecture. * Add a cond_resched() call in kvm_populate_realm(). Changes since v5: * Refactor to use PFNs rather than tracking struct page in realm_create_protected_data_page(). * Pull changes from a later patch (in the v5 series) for accessing pages from a guest memfd. * Do the populate in chunks to avoid holding locks for too long and triggering RCU stall warnings. --- arch/arm64/include/asm/kvm_rmi.h | 4 ++ arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/arm.c | 13 ++++ arch/arm64/kvm/rmi.c | 119 +++++++++++++++++++++++++++++++ 4 files changed, 137 insertions(+) diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h index 5cb99c187202..fd0c57594a22 100644 --- a/arch/arm64/include/asm/kvm_rmi.h +++ b/arch/arm64/include/asm/kvm_rmi.h @@ -105,6 +105,10 @@ int kvm_rec_enter(struct kvm_vcpu *vcpu); int kvm_rec_pre_enter(struct kvm_vcpu *vcpu); int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_status); +struct kvm_arm_rmi_populate; + +int kvm_arm_rmi_populate(struct kvm *kvm, + struct kvm_arm_rmi_populate *arg); void kvm_realm_unmap_range(struct kvm *kvm, unsigned long ipa, unsigned long size, diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 189e8ad78b22..83b95e836b4d 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -37,6 +37,7 @@ menuconfig KVM select SCHED_INFO select GUEST_PERF_EVENTS if PERF_EVENTS select KVM_GUEST_MEMFD + select HAVE_KVM_ARCH_GMEM_POPULATE select ARM_RMM help Support hosting virtualized guest machines. diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index df33322b8fea..1558bb12b1b1 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2153,6 +2153,19 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) return -EFAULT; return kvm_vm_ioctl_get_reg_writable_masks(kvm, &range); } + case KVM_ARM_RMI_POPULATE: { + struct kvm_arm_rmi_populate req; + int ret; + + if (!kvm_is_realm(kvm)) + return -ENXIO; + if (copy_from_user(&req, argp, sizeof(req))) + return -EFAULT; + ret = kvm_arm_rmi_populate(kvm, &req); + if (copy_to_user(argp, &req, sizeof(req))) + return -EFAULT; + return ret; + } default: return -EINVAL; } diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c index 53b5b18f2275..e2b4c64e982d 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -590,6 +590,76 @@ void kvm_realm_unmap_range(struct kvm *kvm, unsigned long start, realm_unmap_private_range(kvm, start, end, may_block); } +static int realm_data_map_init(struct kvm *kvm, unsigned long ipa, + kvm_pfn_t dst_pfn, kvm_pfn_t src_pfn, + unsigned long flags) +{ + struct realm *realm = &kvm->arch.realm; + phys_addr_t rd = virt_to_phys(realm->rd); + phys_addr_t dst_phys, src_phys; + int ret; + + lockdep_assert_held(&kvm->slots_lock); + lockdep_assert_held(&kvm->arch.config_lock); + + dst_phys = __pfn_to_phys(dst_pfn); + src_phys = __pfn_to_phys(src_pfn); + + if (rmi_delegate_page(dst_phys)) + return -ENXIO; + +retry: + ret = rmi_rtt_data_map_init(rd, dst_phys, ipa, src_phys, flags); + if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) { + /* Create missing RTTs and retry */ + int level = RMI_RETURN_INDEX(ret); + + KVM_BUG_ON(level >= KVM_PGTABLE_LAST_LEVEL, kvm); + + ret = realm_create_rtt_levels(realm, ipa, level, + level + 1, NULL); + if (!ret) + goto retry; + } + + if (ret && WARN_ON(rmi_undelegate_page(dst_phys))) { + /* Leak the page if the undelegate fails */ + get_page(pfn_to_page(dst_pfn)); + } + + return ret <= 0 ? ret : -ENXIO; +} + +static int populate_region_cb(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, + struct page *src_page, void *opaque) +{ + unsigned long data_flags = *(unsigned long *)opaque; + phys_addr_t ipa = gfn_to_gpa(gfn); + + return realm_data_map_init(kvm, ipa, pfn, page_to_pfn(src_page), + data_flags); +} + +static long populate_region(struct kvm *kvm, + gfn_t base_gfn, + unsigned long pages, + u64 uaddr, + unsigned long data_flags) +{ + long ret = 0; + + lockdep_assert_held(&kvm->slots_lock); + lockdep_assert_held(&kvm->arch.config_lock); + + if (!uaddr) + return -EINVAL; + + ret = kvm_gmem_populate(kvm, base_gfn, u64_to_user_ptr(uaddr), pages, + false, populate_region_cb, &data_flags); + + return ret; +} + enum ripas_action { RIPAS_INIT, RIPAS_SET, @@ -705,6 +775,55 @@ static int realm_ensure_created(struct kvm *kvm) return realm_create_rd(kvm); } +int kvm_arm_rmi_populate(struct kvm *kvm, + struct kvm_arm_rmi_populate *args) +{ + unsigned long data_flags = 0; + unsigned long ipa_start = args->base; + unsigned long ipa_end = ipa_start + args->size; + long pages_populated; + int ret; + + if (args->reserved || + (args->flags & ~KVM_ARM_RMI_POPULATE_FLAGS_MEASURE) || + args->base + args->size < args->base || + !IS_ALIGNED(ipa_start, PAGE_SIZE) || + !IS_ALIGNED(ipa_end, PAGE_SIZE) || + !IS_ALIGNED(args->source_uaddr, PAGE_SIZE)) + return -EINVAL; + + if (args->flags & KVM_ARM_RMI_POPULATE_FLAGS_MEASURE) + data_flags |= RMI_MEASURE_CONTENT; + + mutex_lock(&kvm->slots_lock); + mutex_lock(&kvm->arch.config_lock); + + ret = realm_ensure_created(kvm); + if (ret) + goto out_unlock; + + if (args->size == 0) + goto out_unlock; + + pages_populated = populate_region(kvm, gpa_to_gfn(ipa_start), + args->size >> PAGE_SHIFT, + args->source_uaddr, data_flags); + + if (pages_populated < 0) { + ret = pages_populated; + goto out_unlock; + } + + args->size -= pages_populated << PAGE_SHIFT; + args->source_uaddr += pages_populated << PAGE_SHIFT; + args->base += pages_populated << PAGE_SHIFT; + +out_unlock: + mutex_unlock(&kvm->arch.config_lock); + mutex_unlock(&kvm->slots_lock); + return ret; +} + static void kvm_complete_ripas_change(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; -- 2.43.0