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 21A5A3233E8; Mon, 21 Sep 2026 14:49:28 +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=1790002170; cv=none; b=tk8uWAsDXrr6zd/8hk+1YNXiXhQywtMyOW9ihPIKZAzB3Wx4XTDZnKOgvtVcLemLX0BT6qPM60HdZ3aujv3MU7UcdiEgwpKgMocPlG5TAYheeSWc5w0RHi8NX6saymzSBxCmfYdnWAzZmwFSRDVWZzfaZbvh4yg0jo71h/uwPWQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790002170; c=relaxed/simple; bh=m2MH69T4bqEk5LFJZ7xmCp4truzSoJU2K5PjcpbIjYE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aJiPp015VaQ084selJaydGDyACISiOb990cMNT5vCPc2IWO+Fm72RlicMLwnoOLTu5MXjk4oshKUnVTm+1205kptHa0UL6tiIl+FtEB3GNTP5cHo1DIpGEaLTDwYrvZw5aF9aZOCOhkGgpzYXZJq/Ql/zUc0SXG6fQigCJVdGyo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=avX+lq+F; 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="avX+lq+F" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3AFFD1F0089A; Mon, 21 Sep 2026 14:49:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790002168; bh=AgD4D7h4EfSsMTxEOq8ADKWRNeWiq2+KsY/R5C+YQNM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=avX+lq+FEOvHDH2Ka+90xabX+/3XfcNlbMJOgo8hQbVT7KtytJirI2WAK3ZkdU+A2 dhOvEYZsoG4EK7R7gE/4hye/lvQQedFCROIZN1l6Ld90l61kqkUYnN03fFNFiaYeNw xYhBUCcKknnZvHXKI7GHaDux6pUgVHLc0uY4qpQE1aVbJbF6TcenTqDGPVxMhfNzEU A5n9MGaMcMz9ytuyWSYbK8Q+RhhbKuySFp6CYcloHxaLPeHMEykf8QuR+nfpaHndMC eMeu0po3UwytgA8nKwZWgmhH5E9118kfO7P0hK8BFGlTQZgTXiEdpTbbrdUfSBmXiV vdTOxKBQ5YG6g== 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)" , Andrew Morton , Catalin Marinas , christian.koenig@amd.com, Jason Gunthorpe , Joerg Roedel , Marc Zyngier , Marek Szyprowski , Robin Murphy , Steven Price , Sumit Semwal , Suzuki K Poulose , Thomas Gleixner , Will Deacon , dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-media@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v7 03/13] arm64: realm: Expose the CCA shared granule size through mem_encrypt ops Date: Mon, 21 Sep 2026 20:18:37 +0530 Message-ID: <20260921144847.501151-4-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260921144847.501151-1-aneesh.kumar@kernel.org> References: <20260921144847.501151-1-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 IPA state change alignment reported by the host. This alignment can be larger than PAGE_SIZE, so transitioning only a PAGE_SIZE-sized subrange may leave part of the host-managed granule in the wrong state. Cache the RHI-reported alignment during Realm initialization and expose it through the arm64 memory encryption operations. Implement arch_cc_shared_granule_size() so the common CoCo shared-memory allocator uses the same constraint. Use PAGE_SIZE when no suitable backend is registered. The common cc_make_shared() and cc_make_private() wrappers validate both the base and size against the architecture's shared granule size. Remove the PAGE_SIZE-only address checks from the lower-level arm64 transition hooks so that range validation remains in the common wrappers. Signed-off-by: Aneesh Kumar K.V (Arm) --- arch/arm64/include/asm/mem_encrypt.h | 1 + arch/arm64/mm/mem_encrypt.c | 13 +++++++++++-- drivers/firmware/arm_rmm/rsi.c | 13 ++++++++++++- 3 files changed, 24 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/mem_encrypt.h b/arch/arm64/include/asm/mem_encrypt.h index ef8b8463e52b..32064338c9b0 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 (*shared_granule_size)(void); }; int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops); diff --git a/arch/arm64/mm/mem_encrypt.c b/arch/arm64/mm/mem_encrypt.c index ee3c0ab04384..e6c059d20595 100644 --- a/arch/arm64/mm/mem_encrypt.c +++ b/arch/arm64/mm/mem_encrypt.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -33,7 +34,7 @@ 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))) + if (likely(!crypt_ops)) return 0; return crypt_ops->encrypt(addr, numpages); @@ -42,9 +43,17 @@ EXPORT_SYMBOL_GPL(set_memory_encrypted); int set_memory_decrypted(unsigned long addr, int numpages) { - if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr))) + if (likely(!crypt_ops)) return 0; return crypt_ops->decrypt(addr, numpages); } EXPORT_SYMBOL_GPL(set_memory_decrypted); + +size_t arch_cc_shared_granule_size(void) +{ + if (likely(!crypt_ops) || !crypt_ops->shared_granule_size) + return PAGE_SIZE; + + return crypt_ops->shared_granule_size(); +} diff --git a/drivers/firmware/arm_rmm/rsi.c b/drivers/firmware/arm_rmm/rsi.c index 883f6091ff95..b59099d1f318 100644 --- a/drivers/firmware/arm_rmm/rsi.c +++ b/drivers/firmware/arm_rmm/rsi.c @@ -18,6 +18,7 @@ #include static struct realm_config config; +static size_t ipa_state_change_alignment = PAGE_SIZE; unsigned long prot_ns_shared; EXPORT_SYMBOL(prot_ns_shared); @@ -154,9 +155,17 @@ static int realm_set_memory_decrypted(unsigned long addr, int numpages) return ret; } +static size_t realm_shared_granule_size(void) +{ + if (is_realm_world()) + return ipa_state_change_alignment; + return PAGE_SIZE; +} + static const struct arm64_mem_crypt_ops realm_crypt_ops = { .encrypt = realm_set_memory_encrypted, .decrypt = realm_set_memory_decrypted, + .shared_granule_size = realm_shared_granule_size, }; static int realm_register_memory_enc_ops(void) @@ -166,7 +175,7 @@ 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; @@ -217,6 +226,8 @@ void __init arm64_rsi_init(void) return; if (WARN_ON(rsi_get_realm_config(lm_alias(&config)))) return; + + ipa_state_change_alignment = 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