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 25AED47143A; Fri, 4 Sep 2026 10:35:53 +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=1788518156; cv=none; b=Iexdq0BLogUJ3wa4S70iwdAgXwO55IZSUOWJX6/24xXwJSJLF7z+FnAJdTwHLDNFGxtSeWjFktcDzvA8udonY+lGvKxPzzKPi6Qip/VGMb4NcwfmidJh+dCY+YEGHaa3MtfFo+LdqQ3i11e/NL4CvV+uQFj/jet5yI0/y7Q2XJQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788518156; c=relaxed/simple; bh=nd6sf8naTpyYqcNuS3y+EeUYR4Zl5gEmukrd0lFeVSc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jP00SoZSDtNlRqU0JtMqx/RNrs8upjF/bevVg7NzEGgezgn+CFQTyUGGZegl1tBzjmm8Mx8SONQ2tf3DGgRoHkXVJ1lfe8I0k6P4++nxSui1seV8WlYIyUzvWCfG6RDOxU9t9NL3xhLgnsRcxUTcTSUfdT/h1UEGwvzV1ZUWi7c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ag3TqrjJ; 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="Ag3TqrjJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65AAD1F00A3E; Fri, 4 Sep 2026 10:35:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788518153; bh=u9I2WPocLUacIb6MXv6UW+BXVCGDKNGSQF8ffRh5uJE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Ag3TqrjJK6NyKSY5HFriLni2RYiMqOyiczi4SedYu9aoxcW7VAiIQmq3OgqnuN+lO t48NCzb9u4ItoAs2nwdCm3BWWbyM8Xvcw4b6JOsIo8nyL+wIOL70dofHXvFQelH2ac rn+fVTW4+VlGbZZYilrDNAqmBV+FoOb6MZh3IgTYfl8Q4U4ujL6wxVBM1KCNyVlsKS nK/KT/uyhGZUhQI6zI29x8SiDyrL1zQquaWzefOINBzcZVtLdxb6pPiclH0+ORPito iSkjUKubJh7FuCBbH0uEHgDigwKXqLbpesSLWU023N2AVQpJipCrJ3qgT24kYgyhoC RwplQVNBH5AaQ== 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 v6 9/9] arm64: realm: Expose the CCA shared granule size through mem_encrypt ops Date: Fri, 4 Sep 2026 16:04:52 +0530 Message-ID: <20260904103452.1197239-10-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260904103452.1197239-1-aneesh.kumar@kernel.org> References: <20260904103452.1197239-1-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/mm/mem_encrypt.c | 32 ++++++++++++++++++++++++---- drivers/firmware/arm_rmm/rsi.c | 13 ++++++++++- 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 ef8b8463e52b..890faeed0eb3 100644 --- a/arch/arm64/include/asm/mem_encrypt.h +++ b/arch/arm64/include/asm/mem_encrypt.h @@ -10,6 +10,7 @@ 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); @@ -18,6 +19,9 @@ 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() || is_protected_kvm_guest(); 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); diff --git a/drivers/firmware/arm_rmm/rsi.c b/drivers/firmware/arm_rmm/rsi.c index 2cd53f82432f..eeb797c6c2c7 100644 --- a/drivers/firmware/arm_rmm/rsi.c +++ b/drivers/firmware/arm_rmm/rsi.c @@ -19,6 +19,7 @@ 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); @@ -155,9 +156,17 @@ 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) @@ -167,7 +176,7 @@ 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; @@ -218,6 +227,8 @@ 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)) -- 2.43.0