From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CAE303BFE2B; Mon, 6 Jul 2026 06:05:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783317961; cv=none; b=JOv19GydvV+mTlpgM+VERFlGlumTtwG3u+bEoPAGomj7QRJdZtmZaCYs1tMcbnl8bB2toA+KUSIHt0Fi3hi9qMInbMYT54DuvW8p5p18ngS2uvv63ES6Q9hW57UPktjDNsuYOiAGXJrJT/A9IkPBpdY5xuQ5Nzbp/moZEu6FVaA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783317961; c=relaxed/simple; bh=aHZizbhEAfqrPA0yo/xctJ8q0zfUR7Ra2y+sLtJarAU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IwPODfCPVQdr6FVA5g0na+8pcwhf4vChkmPbwBtyAS3rObSY6LgYrzMzk7P0hF9V/fIK1Rhtdd7xSnlirU9KbhIn1XqVGWKCXj6/1x+2yRcgRw1lNZUUzfLSw2lENLSPHVkBz/YAQ8L90HrV1Bih+hXQr5zK6Stv6wIG5cVkl8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V3zjjBqd; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="V3zjjBqd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 425311F000E9; Mon, 6 Jul 2026 06:05:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783317959; bh=W0GTpGojCkTLTigXJjUWY8A7Bx3gwP5wr1YCstPCEu8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=V3zjjBqdcv8eoKzWoxHaUZNJXnhzGnVJ6LDlGEJ0g/uoEjoFlGJF93F7LnFvAzwV1 ZBoUn5L0SHty3yrfyEXpodJLyNpLg9ibW1FD6o19jfXV6Mg8PkyG3vA4bDbyRbWl7k aYfp4Y3Gd4HMjFmfHABdZ2ib3xuZGeb219FrxQF6xeTtaBTK5EUv5SlOjZD9KwMrdm 9O++XOLGiT8/DkGqOnnMoCJugcTTEiJOuSWAxMqrv/PSfrYbEIBaMAxPoEvPCJZL/j YbdPph+0mAX3ay04g4PWU7ERX+vPDrchXGh8sqfvzNb3hUlOly9QrJ01d/pvD89OWm weNWhxvBWxVkw== From: "Aneesh Kumar K.V (Arm)" To: linux-coco@lists.linux.dev, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev Cc: "Aneesh Kumar K.V (Arm)" , Catalin Marinas , Jason Gunthorpe , Marc Zyngier , Marek Szyprowski , Robin Murphy , Steven Price , Suzuki K Poulose , Thomas Gleixner , Will Deacon Subject: [PATCH v5 10/10] arm64: realm: Expose the CCA shared granule size through mem_encrypt ops Date: Mon, 6 Jul 2026 11:34:32 +0530 Message-ID: <20260706060432.1375570-11-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260706060432.1375570-1-aneesh.kumar@kernel.org> References: <20260706060432.1375570-1-aneesh.kumar@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit CCA guests must align shared/private memory transitions to the size reported by the host for IPA state changes. This size can be larger than PAGE_SIZE, so allowing a guest to convert only a PAGE_SIZE-sized subrange can leave the remaining part of that host-sized range in the wrong state. Cache the RHI-reported IPA sate change alignment during Realm initialization and expose it through a new arm64 mem_encrypt callback. Use PAGE_SIZE as the default shared granule size when no backend callback is registered. Validate both the address and byte size passed to set_memory_encrypted() and set_memory_decrypted() against mem_cc_shared_granule_size() before calling into the backend. This prevents callers from converting only part of a host-managed page. Signed-off-by: Aneesh Kumar K.V (Arm) --- arch/arm64/include/asm/mem_encrypt.h | 4 ++++ arch/arm64/kernel/rsi.c | 13 ++++++++++- arch/arm64/mm/mem_encrypt.c | 32 ++++++++++++++++++++++++---- 3 files changed, 44 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/mem_encrypt.h b/arch/arm64/include/asm/mem_encrypt.h index f6325f30e844..5018581fed87 100644 --- a/arch/arm64/include/asm/mem_encrypt.h +++ b/arch/arm64/include/asm/mem_encrypt.h @@ -9,6 +9,7 @@ struct device; struct arm64_mem_crypt_ops { int (*encrypt)(unsigned long addr, int numpages); int (*decrypt)(unsigned long addr, int numpages); + size_t (*cc_shared_granule_size)(void); }; int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops); @@ -17,6 +18,9 @@ int set_memory_encrypted(unsigned long addr, int numpages); int set_memory_decrypted(unsigned long addr, int numpages); int __set_memory_enc_dec(unsigned long addr, int numpages, bool encrypt); +#define mem_cc_shared_granule_size mem_cc_shared_granule_size +size_t mem_cc_shared_granule_size(void); + static inline bool force_dma_unencrypted(struct device *dev) { return is_realm_world(); diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c index f52f240bb44c..54fb929067c9 100644 --- a/arch/arm64/kernel/rsi.c +++ b/arch/arm64/kernel/rsi.c @@ -20,6 +20,7 @@ static struct realm_config config; static struct kobject *cca_kobj; +static unsigned long ipa_state_change_granule_size; unsigned long prot_ns_shared; EXPORT_SYMBOL(prot_ns_shared); @@ -168,9 +169,17 @@ static int realm_set_memory_decrypted(unsigned long addr, int numpages) return ret; } +static size_t realm_cc_shared_granule_size(void) +{ + if (is_realm_world()) + return ipa_state_change_granule_size; + return PAGE_SIZE; +} + static const struct arm64_mem_crypt_ops realm_crypt_ops = { .encrypt = realm_set_memory_encrypted, .decrypt = realm_set_memory_decrypted, + .cc_shared_granule_size = realm_cc_shared_granule_size, }; static int realm_register_memory_enc_ops(void) @@ -180,7 +189,7 @@ static int realm_register_memory_enc_ops(void) /* we need an aligned struct for rsi_host_call. slab is not yet ready */ static struct rsi_host_call hostconf_call __initdata; -static unsigned long __maybe_unused __init get_ipa_state_change_alignment(void) +static unsigned long __init get_ipa_state_change_alignment(void) { long ret; unsigned long shared_granule_size; @@ -230,6 +239,8 @@ void __init arm64_rsi_init(void) return; if (WARN_ON(rsi_get_realm_config(lm_alias(&config)))) return; + + ipa_state_change_granule_size = get_ipa_state_change_alignment(); prot_ns_shared = __phys_to_pte_val(BIT(config.ipa_bits - 1)); if (arm64_ioremap_prot_hook_register(realm_ioremap_hook)) diff --git a/arch/arm64/mm/mem_encrypt.c b/arch/arm64/mm/mem_encrypt.c index ee3c0ab04384..69783c6a3c08 100644 --- a/arch/arm64/mm/mem_encrypt.c +++ b/arch/arm64/mm/mem_encrypt.c @@ -17,8 +17,7 @@ #include #include #include - -#include +#include static const struct arm64_mem_crypt_ops *crypt_ops; @@ -33,18 +32,43 @@ int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops) int set_memory_encrypted(unsigned long addr, int numpages) { - if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr))) + unsigned long size = (unsigned long)numpages << PAGE_SHIFT; + + if (likely(!crypt_ops)) return 0; + if (WARN_ON(!IS_ALIGNED(addr, mem_cc_shared_granule_size()))) + return -EINVAL; + + if (WARN_ON(!IS_ALIGNED(size, mem_cc_shared_granule_size()))) + return -EINVAL; + return crypt_ops->encrypt(addr, numpages); } EXPORT_SYMBOL_GPL(set_memory_encrypted); int set_memory_decrypted(unsigned long addr, int numpages) { - if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr))) + unsigned long size = (unsigned long)numpages << PAGE_SHIFT; + + if (likely(!crypt_ops)) return 0; + if (WARN_ON(!IS_ALIGNED(addr, mem_cc_shared_granule_size()))) + return -EINVAL; + + if (WARN_ON(!IS_ALIGNED(size, mem_cc_shared_granule_size()))) + return -EINVAL; + return crypt_ops->decrypt(addr, numpages); } EXPORT_SYMBOL_GPL(set_memory_decrypted); + +size_t mem_cc_shared_granule_size(void) +{ + if (likely(!crypt_ops) || !crypt_ops->cc_shared_granule_size) + return PAGE_SIZE; + + return crypt_ops->cc_shared_granule_size(); +} +EXPORT_SYMBOL_GPL(mem_cc_shared_granule_size); -- 2.43.0