From patchwork Mon Jul 1 09:54:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 13717736 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 83837C2BD09 for ; Mon, 1 Jul 2024 09:57:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Y+O3IrY7Te0iO3aBTIrZPtbZAqhQnCeNrg4axMiQcXU=; b=SpQLIu6jnp/JNKpCQE4Pgk0yAT 78UpvbsioNI8OgpApCszBg9utFYjkgHoNDovDUZPXfZ57qrUMPR9JWTHCEZ2HH7A1J2Mv5EvXNyKp iKJYEqWuflJfY5EJdhAbbtntIsMyfDP8zEGHvfRR6BrTFiSzYdODUnmytg+oIjAYSnY3Rl+LN54Zb /hlYxzq4WN7uOqwyGatm8m1mFTF8CPMWgby916BRWH5fC72CDjqmK20Z26bFhSiX5ckUcIPl22Gp1 RCwavu4BF74OXnTC9BHnphDUNPchl1Y72KqXBMlHD+Ym8I8YM2XC3ZuYI1LndtYOw/1GObThq3F9y 6SsWxKKw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sODmH-00000002Wrc-2N5E; Mon, 01 Jul 2024 09:56:53 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sODlF-00000002WDO-1qDD for linux-arm-kernel@lists.infradead.org; Mon, 01 Jul 2024 09:55:51 +0000 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 ED68F339; Mon, 1 Jul 2024 02:56:13 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.44.170]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 70C593F762; Mon, 1 Jul 2024 02:55:44 -0700 (PDT) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Suzuki K Poulose , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , 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 , Steven Price Subject: [PATCH v4 09/15] arm64: Enable memory encrypt for Realms Date: Mon, 1 Jul 2024 10:54:59 +0100 Message-Id: <20240701095505.165383-10-steven.price@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240701095505.165383-1-steven.price@arm.com> References: <20240701095505.165383-1-steven.price@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240701_025549_707190_DDEAA751 X-CRM114-Status: GOOD ( 23.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Suzuki K Poulose Use the memory encryption APIs to trigger a RSI call to request a transition between protected memory and shared memory (or vice versa) and updating the kernel's linear map of modified pages to flip the top bit of the IPA. This requires that block mappings are not used in the direct map for realm guests. Signed-off-by: Suzuki K Poulose Co-developed-by: Steven Price Signed-off-by: Steven Price --- Changes since v3: * Provide pgprot_{de,en}crypted() macros * Rename __set_memory_encrypted() to __set_memory_enc_dec() since it both encrypts and decrypts. Changes since v2: * Fix location of set_memory_{en,de}crypted() and export them. * Break-before-make when changing the top bit of the IPA for transitioning to/from shared. --- arch/arm64/Kconfig | 3 ++ arch/arm64/include/asm/mem_encrypt.h | 17 +++++++ arch/arm64/include/asm/pgtable.h | 5 ++ arch/arm64/include/asm/set_memory.h | 3 ++ arch/arm64/kernel/rsi.c | 12 +++++ arch/arm64/mm/pageattr.c | 68 ++++++++++++++++++++++++++-- 6 files changed, 105 insertions(+), 3 deletions(-) create mode 100644 arch/arm64/include/asm/mem_encrypt.h diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 5d91259ee7b5..0f1480caeeec 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -20,6 +20,7 @@ config ARM64 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE select ARCH_HAS_CACHE_LINE_SIZE + select ARCH_HAS_CC_PLATFORM select ARCH_HAS_CURRENT_STACK_POINTER select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEBUG_VM_PGTABLE @@ -41,6 +42,8 @@ config ARM64 select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SET_DIRECT_MAP select ARCH_HAS_SET_MEMORY + select ARCH_HAS_MEM_ENCRYPT + select ARCH_HAS_FORCE_DMA_UNENCRYPTED select ARCH_STACKWALK select ARCH_HAS_STRICT_KERNEL_RWX select ARCH_HAS_STRICT_MODULE_RWX diff --git a/arch/arm64/include/asm/mem_encrypt.h b/arch/arm64/include/asm/mem_encrypt.h new file mode 100644 index 000000000000..e47265cd180a --- /dev/null +++ b/arch/arm64/include/asm/mem_encrypt.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2023 ARM Ltd. + */ + +#ifndef __ASM_MEM_ENCRYPT_H +#define __ASM_MEM_ENCRYPT_H + +#include + +/* All DMA must be to non-secure memory for now */ +static inline bool force_dma_unencrypted(struct device *dev) +{ + return is_realm_world(); +} + +#endif diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 11d614d83317..f5d5f416d47d 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -636,6 +636,11 @@ static inline void set_pud_at(struct mm_struct *mm, unsigned long addr, #define pgprot_nx(prot) \ __pgprot_modify(prot, PTE_MAYBE_GP, PTE_PXN) +#define pgprot_decrypted(prot) \ + __pgprot_modify(prot, PROT_NS_SHARED, PROT_NS_SHARED) +#define pgprot_encrypted(prot) \ + __pgprot_modify(prot, PROT_NS_SHARED, 0) + /* * Mark the prot value as uncacheable and unbufferable. */ diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h index 0f740b781187..3b6619c04677 100644 --- a/arch/arm64/include/asm/set_memory.h +++ b/arch/arm64/include/asm/set_memory.h @@ -14,4 +14,7 @@ int set_direct_map_invalid_noflush(struct page *page); int set_direct_map_default_noflush(struct page *page); bool kernel_page_present(struct page *page); +int set_memory_encrypted(unsigned long addr, int numpages); +int set_memory_decrypted(unsigned long addr, int numpages); + #endif /* _ASM_ARM64_SET_MEMORY_H */ diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c index 918db258cd4a..ef6415a1a86c 100644 --- a/arch/arm64/kernel/rsi.c +++ b/arch/arm64/kernel/rsi.c @@ -7,6 +7,7 @@ #include #include #include +#include #include @@ -20,6 +21,17 @@ unsigned int phys_mask_shift = CONFIG_ARM64_PA_BITS; DEFINE_STATIC_KEY_FALSE_RO(rsi_present); EXPORT_SYMBOL(rsi_present); +bool cc_platform_has(enum cc_attr attr) +{ + switch (attr) { + case CC_ATTR_MEM_ENCRYPT: + return is_realm_world(); + default: + return false; + } +} +EXPORT_SYMBOL_GPL(cc_platform_has); + static bool rsi_version_matches(void) { unsigned long ver_lower, ver_higher; diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 547a9e0b46c2..458124d5454a 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -5,10 +5,12 @@ #include #include #include +#include #include #include #include +#include #include #include #include @@ -23,14 +25,16 @@ bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED bool can_set_direct_map(void) { /* - * rodata_full and DEBUG_PAGEALLOC require linear map to be - * mapped at page granularity, so that it is possible to + * rodata_full, DEBUG_PAGEALLOC and a Realm guest all require linear + * map to be mapped at page granularity, so that it is possible to * protect/unprotect single pages. * * KFENCE pool requires page-granular mapping if initialized late. + * + * Realms need to make pages shared/protected at page granularity. */ return rodata_full || debug_pagealloc_enabled() || - arm64_kfence_can_set_direct_map(); + arm64_kfence_can_set_direct_map() || is_realm_world(); } static int change_page_range(pte_t *ptep, unsigned long addr, void *data) @@ -198,6 +202,64 @@ int set_direct_map_default_noflush(struct page *page) PAGE_SIZE, change_page_range, &data); } +static int __set_memory_enc_dec(unsigned long addr, + int numpages, + bool encrypt) +{ + unsigned long set_prot = 0, clear_prot = 0; + phys_addr_t start, end; + int ret; + + if (!is_realm_world()) + return 0; + + if (!__is_lm_address(addr)) + return -EINVAL; + + start = __virt_to_phys(addr); + end = start + numpages * PAGE_SIZE; + + /* + * Break the mapping before we make any changes to avoid stale TLB + * entries or Synchronous External Aborts caused by RIPAS_EMPTY + */ + ret = __change_memory_common(addr, PAGE_SIZE * numpages, + __pgprot(0), + __pgprot(PTE_VALID)); + + if (ret) + return ret; + + if (encrypt) { + clear_prot = PROT_NS_SHARED; + ret = rsi_set_memory_range_protected(start, end); + } else { + set_prot = PROT_NS_SHARED; + ret = rsi_set_memory_range_shared(start, end); + } + + if (ret) + return ret; + + set_prot |= PTE_VALID; + + return __change_memory_common(addr, PAGE_SIZE * numpages, + __pgprot(set_prot), + __pgprot(clear_prot)); +} + +int set_memory_encrypted(unsigned long addr, int numpages) +{ + return __set_memory_enc_dec(addr, numpages, true); +} +EXPORT_SYMBOL_GPL(set_memory_encrypted); + +int set_memory_decrypted(unsigned long addr, int numpages) +{ + return __set_memory_enc_dec(addr, numpages, false); +} +EXPORT_SYMBOL_GPL(set_memory_decrypted); + #ifdef CONFIG_DEBUG_PAGEALLOC void __kernel_map_pages(struct page *page, int numpages, int enable) {