From nobody Mon Apr 6 18:24:01 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 15C574014B4; Wed, 18 Mar 2026 15:56:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773849366; cv=none; b=SA9YaLHXYsGpCDoBpIMztnWDXtbnCDrw5f+lMTKblcDoEQxsysWe1vstjYHBMj3XAQUjYZ3mFgo3/ga/UeMgntCp2rvDwxtWmDeOxBK1giUP+mVeaUabltmKP3Wlgpgc6eF6TzDoeF5Aiu00JVisUwlDHoSmKXtSx3pteCav0j0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773849366; c=relaxed/simple; bh=yjgweW6eEEE4cN6YDy/gZC6DdktcoFGGf6CpIpDY3AE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KedAQfbjXaU2feBWBQknw95KSJgu1PTzNKAoroUrop7LDIsicJtlxhhF1EJJxYR1nTmJhCyGKkUHnp8Emq5SWgvpbIY3DDCJpcB8GMEig7M///ODpS/lD1nmbsmPTkTfDprGmMrUaVhs5dVsofLZoEtfN28oIxB1Ws92I8PmSCs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 3C41C2008; Wed, 18 Mar 2026 08:55:54 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.61.122]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 282033F73B; Wed, 18 Mar 2026 08:55:57 -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 , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve Subject: [PATCH v13 26/48] arm64: RMI: Create the realm descriptor Date: Wed, 18 Mar 2026 15:53:50 +0000 Message-ID: <20260318155413.793430-27-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260318155413.793430-1-steven.price@arm.com> References: <20260318155413.793430-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Creating a realm involves first creating a realm descriptor (RD). This involves passing the configuration information to the RMM. Do this as part of realm_ensure_created() so that the realm is created when it is first needed. Signed-off-by: Steven Price --- Changes since v12: * Since RMM page size is now equal to the host's page size various calculations are simplified. * Switch to using range based APIs to delegate/undelegate. * VMID handling is now handled entirely by the RMM. --- arch/arm64/kvm/rmi.c | 94 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 92 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c index 38349c7b34f4..d5fee203824b 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -649,6 +649,83 @@ static void realm_unmap_shared_range(struct kvm *kvm, start, end); } =20 +static int realm_create_rd(struct kvm *kvm) +{ + struct realm *realm =3D &kvm->arch.realm; + struct realm_params *params =3D realm->params; + void *rd =3D NULL; + phys_addr_t rd_phys, params_phys; + size_t pgd_size =3D kvm_pgtable_stage2_pgd_size(kvm->arch.mmu.vtcr); + int i, r; + + realm->ia_bits =3D VTCR_EL2_IPA(kvm->arch.mmu.vtcr); + + if (WARN_ON(realm->rd || !realm->params)) + return -EEXIST; + + rd =3D (void *)__get_free_page(GFP_KERNEL); + if (!rd) + return -ENOMEM; + + rd_phys =3D virt_to_phys(rd); + if (delegate_page(rd_phys)) { + r =3D -ENXIO; + goto free_rd; + } + + if (delegate_range(kvm->arch.mmu.pgd_phys, pgd_size)) { + r =3D -ENXIO; + goto out_undelegate_tables; + } + + params->s2sz =3D VTCR_EL2_IPA(kvm->arch.mmu.vtcr); + params->rtt_level_start =3D get_start_level(realm); + params->rtt_num_start =3D pgd_size / PAGE_SIZE; + params->rtt_base =3D kvm->arch.mmu.pgd_phys; + + if (kvm->arch.arm_pmu) { + params->pmu_num_ctrs =3D kvm->arch.nr_pmu_counters; + params->flags |=3D RMI_REALM_PARAM_FLAG_PMU; + } + + if (kvm_lpa2_is_enabled()) + params->flags |=3D RMI_REALM_PARAM_FLAG_LPA2; + + params_phys =3D virt_to_phys(params); + + if (rmi_realm_create(rd_phys, params_phys)) { + r =3D -ENXIO; + goto out_undelegate_tables; + } + + if (WARN_ON(rmi_rec_aux_count(rd_phys, &realm->num_aux))) { + WARN_ON(rmi_realm_destroy(rd_phys)); + r =3D -ENXIO; + goto out_undelegate_tables; + } + + realm->rd =3D rd; + WRITE_ONCE(realm->state, REALM_STATE_NEW); + /* The realm is up, free the parameters. */ + free_page((unsigned long)realm->params); + realm->params =3D NULL; + + return 0; + +out_undelegate_tables: + if (WARN_ON(undelegate_range(kvm->arch.mmu.pgd_phys, i))) { + /* Leak the pages if they cannot be returned */ + kvm->arch.mmu.pgt =3D NULL; + } + if (WARN_ON(undelegate_page(rd_phys))) { + /* Leak the page if it isn't returned */ + return r; + } +free_rd: + free_page((unsigned long)rd); + return r; +} + static void realm_unmap_private_range(struct kvm *kvm, unsigned long start, unsigned long end, @@ -893,8 +970,21 @@ static int realm_init_ipa_state(struct kvm *kvm, =20 static int realm_ensure_created(struct kvm *kvm) { - /* Provided in later patch */ - return -ENXIO; + int ret; + + switch (kvm_realm_state(kvm)) { + case REALM_STATE_NONE: + break; + case REALM_STATE_NEW: + return 0; + case REALM_STATE_DEAD: + return -ENXIO; + default: + return -EBUSY; + } + + ret =3D realm_create_rd(kvm); + return ret; } =20 static int set_ripas_of_protected_regions(struct kvm *kvm) --=20 2.43.0