From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 22DE935E555 for ; Mon, 19 Jan 2026 12:47:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768826875; cv=none; b=Sz8wx81G1WIO81d7vtgkTwKZD8o87ef9lh4hH+fbxvQoggE5qDgxYp1O/vBl9+I9Q6/ylsZcK3b5VrfXOMn3z8b8HWGKNI2F9tK7EZzBJ1MdOLU33jnFmMo2JszDwSLRTZljvGsFw/MVTIAlZOh9bbrIu/u5jz8yU/QrOFE4Pww= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768826875; c=relaxed/simple; bh=sgOZZb6q9M08bmQiXhieF6pJuGs5khdAx8nj6Z9sywM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EuAZjb7kMjrQc63f7/WxpJaLwdhhqV+3nuNebJ5cZ3ZPv+MJ1XFzAyDChmvayjEGLIr2zlkJ+u6M51+1/8q61s8oTGYnY+k1rnHbIX//osXNzY11kzc6FTiW17x2Z2plJHFzpncZgQ8YGO1eWg19VLEG/J1FlpWrKLTVQjClbMc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PiV9LCg1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PiV9LCg1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E808C19423; Mon, 19 Jan 2026 12:47:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768826874; bh=sgOZZb6q9M08bmQiXhieF6pJuGs5khdAx8nj6Z9sywM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PiV9LCg1PexKXgWo5zFhwIAJn8FgGiFPP1bbum8QDaAbzLqNtQpEhKb3sJq+Y9Vy1 Uqp2cAW3WtuhdTtDUUpCnO7nyhbcwR7pFrZAMvHgpbbwxxPh8VAD4OYs3YEPmrS0aU W5flyyjOw/wPjOGqxynt+qfbED4SuFXGv44SuGE6kn0vlz6nZiKceATb3NlHZ6sgkQ ra2oH9REx+18RQ/o2adDaXdGt+VpSyw5hq2rjTRsPBBP4NSLrR0wo8cUBpWpEj3FBA b54Dsd4LWqHPUoBASacHZc7oeiHEAvdxOrq8MOzOEnZeuUYOr6RvrVe+U4VX999RIZ Dv+vs8ca6Wm+w== From: Will Deacon To: kvmarm@lists.linux.dev Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Quentin Perret , Fuad Tabba , Vincent Donnefort , Mostafa Saleh Subject: [PATCH v2 20/35] KVM: arm64: Generalise kvm_pgtable_stage2_set_owner() Date: Mon, 19 Jan 2026 12:46:13 +0000 Message-ID: <20260119124629.2563-21-will@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260119124629.2563-1-will@kernel.org> References: <20260119124629.2563-1-will@kernel.org> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit kvm_pgtable_stage2_set_owner() can be generalised into a way to store up to 59 bits in the page tables alongside a 4-bit 'type' identifier specific to the format of the 59-bit payload. Introduce kvm_pgtable_stage2_annotate() and move the existing invalid ptes (for locked ptes and donated pages) over to the new scheme. Signed-off-by: Will Deacon --- arch/arm64/include/asm/kvm_pgtable.h | 39 +++++++++++++++++++-------- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 16 +++++++++-- arch/arm64/kvm/hyp/pgtable.c | 33 ++++++++++++++--------- 3 files changed, 62 insertions(+), 26 deletions(-) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 9ce55442b621..4c41a8ed4a7c 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -98,13 +98,25 @@ typedef u64 kvm_pte_t; KVM_PTE_LEAF_ATTR_HI_S2_XN) #define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2) -#define KVM_MAX_OWNER_ID 3 -/* - * Used to indicate a pte for which a 'break-before-make' sequence is in - * progress. - */ -#define KVM_INVALID_PTE_LOCKED BIT(10) +/* pKVM invalid pte encodings */ +#define KVM_INVALID_PTE_TYPE_MASK GENMASK(63, 60) +#define KVM_INVALID_PTE_ANNOT_MASK ~(KVM_PTE_VALID | \ + KVM_INVALID_PTE_TYPE_MASK) + +enum kvm_invalid_pte_type { + /* + * Used to indicate a pte for which a 'break-before-make' + * sequence is in progress. + */ + KVM_INVALID_PTE_TYPE_LOCKED = 1, + + /* + * pKVM has unmapped the page from the host due to a change of + * ownership. + */ + KVM_HOST_INVALID_PTE_TYPE_DONATION, +}; static inline bool kvm_pte_valid(kvm_pte_t pte) { @@ -657,14 +669,18 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, void *mc, enum kvm_pgtable_walk_flags flags); /** - * kvm_pgtable_stage2_set_owner() - Unmap and annotate pages in the IPA space to - * track ownership. + * kvm_pgtable_stage2_annotate() - Unmap and annotate pages in the IPA space + * to track ownership (and more). * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Base intermediate physical address to annotate. * @size: Size of the annotated range. * @mc: Cache of pre-allocated and zeroed memory from which to allocate * page-table pages. - * @owner_id: Unique identifier for the owner of the page. + * @type: The type of the annotation, determining its meaning and format. + * @annotation: A 59-bit value that will be stored in the page tables. + * @annotation[0] and @annotation[63:60] must be 0. + * @annotation[59:1] is stored in the page tables, along + * with @type. * * By default, all page-tables are owned by identifier 0. This function can be * used to mark portions of the IPA space as owned by other entities. When a @@ -673,8 +689,9 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, * * Return: 0 on success, negative error code on failure. */ -int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, - void *mc, u8 owner_id); +int kvm_pgtable_stage2_annotate(struct kvm_pgtable *pgt, u64 addr, u64 size, + void *mc, enum kvm_invalid_pte_type type, + kvm_pte_t annotation); /** * kvm_pgtable_stage2_unmap() - Remove a mapping from a guest stage-2 page-table. diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 55df0c45b0f2..3f8a73461f90 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -546,10 +546,19 @@ static void __host_update_page_state(phys_addr_t addr, u64 size, enum pkvm_page_ set_host_state(page, state); } +static kvm_pte_t kvm_init_invalid_leaf_owner(u8 owner_id) +{ + return FIELD_PREP(KVM_INVALID_PTE_OWNER_MASK, owner_id); +} + int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id) { + kvm_pte_t annotation; int ret = -EINVAL; + if (!FIELD_FIT(KVM_INVALID_PTE_OWNER_MASK, owner_id)) + return -EINVAL; + if (!range_is_memory(addr, addr + size)) return -EPERM; @@ -561,8 +570,11 @@ int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id) break; case PKVM_ID_GUEST: case PKVM_ID_HYP: - ret = host_stage2_try(kvm_pgtable_stage2_set_owner, &host_mmu.pgt, - addr, size, &host_s2_pool, owner_id); + annotation = kvm_init_invalid_leaf_owner(owner_id); + ret = host_stage2_try(kvm_pgtable_stage2_annotate, &host_mmu.pgt, + addr, size, &host_s2_pool, + KVM_HOST_INVALID_PTE_TYPE_DONATION, + annotation); if (!ret) __host_update_page_state(addr, size, PKVM_NOPAGE); break; diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 9abc0a6cf448..38465f547c8c 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -114,11 +114,6 @@ static kvm_pte_t kvm_init_valid_leaf_pte(u64 pa, kvm_pte_t attr, s8 level) return pte; } -static kvm_pte_t kvm_init_invalid_leaf_owner(u8 owner_id) -{ - return FIELD_PREP(KVM_INVALID_PTE_OWNER_MASK, owner_id); -} - static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data, const struct kvm_pgtable_visit_ctx *ctx, enum kvm_pgtable_walk_flags visit) @@ -563,7 +558,7 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt) struct stage2_map_data { const u64 phys; kvm_pte_t attr; - u8 owner_id; + kvm_pte_t pte_annot; kvm_pte_t *anchor; kvm_pte_t *childp; @@ -780,7 +775,11 @@ static bool stage2_pte_is_counted(kvm_pte_t pte) static bool stage2_pte_is_locked(kvm_pte_t pte) { - return !kvm_pte_valid(pte) && (pte & KVM_INVALID_PTE_LOCKED); + if (kvm_pte_valid(pte)) + return false; + + return FIELD_GET(KVM_INVALID_PTE_TYPE_MASK, pte) == + KVM_INVALID_PTE_TYPE_LOCKED; } static bool stage2_try_set_pte(const struct kvm_pgtable_visit_ctx *ctx, kvm_pte_t new) @@ -811,6 +810,7 @@ static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx, struct kvm_s2_mmu *mmu) { struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + kvm_pte_t locked_pte; if (stage2_pte_is_locked(ctx->old)) { /* @@ -821,7 +821,9 @@ static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx, return false; } - if (!stage2_try_set_pte(ctx, KVM_INVALID_PTE_LOCKED)) + locked_pte = FIELD_PREP(KVM_INVALID_PTE_TYPE_MASK, + KVM_INVALID_PTE_TYPE_LOCKED); + if (!stage2_try_set_pte(ctx, locked_pte)) return false; if (!kvm_pgtable_walk_skip_bbm_tlbi(ctx)) { @@ -946,7 +948,7 @@ static int stage2_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx, if (!data->annotation) new = kvm_init_valid_leaf_pte(phys, data->attr, ctx->level); else - new = kvm_init_invalid_leaf_owner(data->owner_id); + new = data->pte_annot; /* * Skip updating the PTE if we are trying to recreate the exact @@ -1100,16 +1102,18 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, return ret; } -int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, - void *mc, u8 owner_id) +int kvm_pgtable_stage2_annotate(struct kvm_pgtable *pgt, u64 addr, u64 size, + void *mc, enum kvm_invalid_pte_type type, + kvm_pte_t pte_annot) { int ret; struct stage2_map_data map_data = { .mmu = pgt->mmu, .memcache = mc, - .owner_id = owner_id, .force_pte = true, .annotation = true, + .pte_annot = pte_annot | + FIELD_PREP(KVM_INVALID_PTE_TYPE_MASK, type), }; struct kvm_pgtable_walker walker = { .cb = stage2_map_walker, @@ -1118,7 +1122,10 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, .arg = &map_data, }; - if (owner_id > KVM_MAX_OWNER_ID) + if (pte_annot & ~KVM_INVALID_PTE_ANNOT_MASK) + return -EINVAL; + + if (!type || type == KVM_INVALID_PTE_TYPE_LOCKED) return -EINVAL; ret = kvm_pgtable_walk(pgt, addr, size, &walker); -- 2.52.0.457.g6b5491de43-goog