From nobody Wed Dec 17 16:11:39 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D1BBE34E768; Wed, 17 Dec 2025 10:13:33 +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=1765966415; cv=none; b=kHT0A42pvAPcGPnUru4B5EsCqtj4tO+jt8MwJf6RJ9BWRWhbJSNhDCa8oTVVSLslmEzfG3MDW2DSCWhagltT8Dk7H6wHOO2X3v6br5jFu96xEcgnQqorgiuhN1M38R+xFo9ttkYeakfhve/tIAXkfRdbLIPGbQyOW2y50n39M0g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765966415; c=relaxed/simple; bh=nIpKTWELtOnqA0N3t1I/B/zDz1c8WpFZIpVSBgNSgCg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cXCcNuxE2Lag3CjbEpkmyNo+yq/L03p41SVogqnHNOUkFMSpj7eDC3iCNEGLiXEcUBnWL3R0yHqtYTUCrCwcvhSzcDcdOet8q91hnG7VslelYoTxLR2/TEDCbqbjkK8f9+prO+NBQC51LEkgest/43g/DA0Sik/HjpBgcBQO730= 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 452D7168F; Wed, 17 Dec 2025 02:13:26 -0800 (PST) Received: from e122027.arm.com (unknown [10.57.45.201]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3CD993F73B; Wed, 17 Dec 2025 02:13:29 -0800 (PST) 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 v12 22/46] arm64: RMI: Create the realm descriptor Date: Wed, 17 Dec 2025 10:10:59 +0000 Message-ID: <20251217101125.91098-23-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251217101125.91098-1-steven.price@arm.com> References: <20251217101125.91098-1-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 --- New patch for v12 --- arch/arm64/kvm/rmi.c | 117 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 115 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c index b51e68e56d56..18edc7eeb5fa 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -500,6 +500,106 @@ static void realm_unmap_shared_range(struct kvm *kvm, start, end); } =20 +/* Calculate the number of s2 root rtts needed */ +static int realm_num_root_rtts(struct realm *realm) +{ + unsigned int ipa_bits =3D realm->ia_bits; + unsigned int levels =3D 4 - get_start_level(realm); + unsigned int sl_ipa_bits =3D levels * (RMM_PAGE_SHIFT - 3) + + RMM_PAGE_SHIFT; + + if (sl_ipa_bits >=3D ipa_bits) + return 1; + + return 1 << (ipa_bits - sl_ipa_bits); +} + +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; + int rtt_num_start; + + realm->ia_bits =3D VTCR_EL2_IPA(kvm->arch.mmu.vtcr); + rtt_num_start =3D realm_num_root_rtts(realm); + + if (WARN_ON(realm->rd || !realm->params)) + return -EEXIST; + + if (pgd_size / RMM_PAGE_SIZE < rtt_num_start) + return -EINVAL; + + rd =3D (void *)__get_free_page(GFP_KERNEL); + if (!rd) + return -ENOMEM; + + rd_phys =3D virt_to_phys(rd); + if (rmi_granule_delegate(rd_phys)) { + r =3D -ENXIO; + goto free_rd; + } + + for (i =3D 0; i < pgd_size; i +=3D RMM_PAGE_SIZE) { + phys_addr_t pgd_phys =3D kvm->arch.mmu.pgd_phys + i; + + if (rmi_granule_delegate(pgd_phys)) { + 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 rtt_num_start; + params->rtt_base =3D kvm->arch.mmu.pgd_phys; + params->vmid =3D realm->vmid; + + 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: + while (i > 0) { + i -=3D RMM_PAGE_SIZE; + + phys_addr_t pgd_phys =3D kvm->arch.mmu.pgd_phys + i; + + if (WARN_ON(rmi_granule_undelegate(pgd_phys))) { + /* Leak the pages if they cannot be returned */ + kvm->arch.mmu.pgt =3D NULL; + break; + } + } + if (WARN_ON(rmi_granule_undelegate(rd_phys))) { + /* Leak the page if it isn't returned */ + return r; + } +free_rd: + free_page((unsigned long)rd); + return r; +} + static int realm_unmap_private_page(struct realm *realm, unsigned long ipa, unsigned long *next_addr) @@ -803,8 +903,21 @@ 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