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 4D3EB13B293 for ; Mon, 5 Jan 2026 15:50:43 +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=1767628243; cv=none; b=M8yf8z/F6TpveQfvQ2dkMZ2PLDumQVcDdSO7jNa+Qy823oKq2A29dpoppzf8d/G+cJ83kEO3Y5kiUlbpPyPFjukM1Bc2tiOlqLZGg3m3+qVi+umtkScg9Yc0gIhS88CEE7EONnG0HZsnsbORdCOg1/cKAiGCVZNw+9mIKnmPyiw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767628243; c=relaxed/simple; bh=qoVYpen1ot9+zckdKOrRl6patLQCwhmwP11TPG1QGCc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=An+zVot1MlbRAcnuQ6CS3XGlvLuJ4kp3mz2eX8lfUHFcRtvrUDbHejwLzfF1xM20u+tbidEEdtsSaIprSOgn8u3eQt0RAf5BWr3gnbCviS5y+BD3U2U7tEeDnVGWJaF0vRR++in6+2+rbrpJmuTMY8fdgzuzhukFeGwzY9xosag= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=o37UXH+d; 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="o37UXH+d" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58034C2BC86; Mon, 5 Jan 2026 15:50:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767628242; bh=qoVYpen1ot9+zckdKOrRl6patLQCwhmwP11TPG1QGCc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o37UXH+d2UdpG3NYHzvxp1n7iRvDGlDwM740z0eYCdJJ3rKQlbWsoYvNkxUoC4k57 2PBilLB6dRXoAgJ1YCh8rUo+ZOhfPApI8vpP0n0ld6zoVbV3BzwA2XMpTzUUOO5AsA GcdOdiwjuRJmxQs8M2AcNoeQno9Fc8ex7jDG0IoCSab9bBqBBVeGbVM08F+rvGSNdW JEEkPYqiavWtVLw5ewdcJrOFqHo13lfKVAKp0O1+XuxHhpH8e2II+G2n5jk7i3X4G+ q636v6YpY3ifvbEsN7ZhcwrIl5x0j5Qz0lMFd5IpEVKw5f5nqr4B8/ivvcA8gKKPie zd8uRf5R2crew== 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 17/30] KVM: arm64: Generalise kvm_pgtable_stage2_set_owner() Date: Mon, 5 Jan 2026 15:49:25 +0000 Message-ID: <20260105154939.11041-18-will@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260105154939.11041-1-will@kernel.org> References: <20260105154939.11041-1-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 62 bits in the page tables, as long as we don't set the 'valid' or KVM_INVALID_PTE_LOCKED bits. Let's do that and reduce the owner field to 4 bits to free up more annotation space for future work. Signed-off-by: Will Deacon --- arch/arm64/include/asm/kvm_pgtable.h | 21 +++++++++++++-------- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 14 ++++++++++++-- arch/arm64/kvm/hyp/pgtable.c | 17 ++++++----------- 3 files changed, 31 insertions(+), 21 deletions(-) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 9ce55442b621..ddbe0e506e4c 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -97,14 +97,17 @@ typedef u64 kvm_pte_t; KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | \ KVM_PTE_LEAF_ATTR_HI_S2_XN) -#define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2) -#define KVM_MAX_OWNER_ID 3 +/* pKVM invalid pte encodings */ +#define KVM_INVALID_PTE_OWNER_MASK GENMASK(4, 1) +#define KVM_INVALID_PTE_EXTRA_MASK GENMASK(62, 5) +#define KVM_INVALID_PTE_ANNOT_MASK (KVM_INVALID_PTE_OWNER_MASK | \ + KVM_INVALID_PTE_EXTRA_MASK) /* * Used to indicate a pte for which a 'break-before-make' sequence is in * progress. */ -#define KVM_INVALID_PTE_LOCKED BIT(10) +#define KVM_INVALID_PTE_LOCKED BIT(63) static inline bool kvm_pte_valid(kvm_pte_t pte) { @@ -657,14 +660,16 @@ 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. + * @annotation: A 62-bit value that will be stored in the page tables. + * @annotation[0] and @annotation[63] must be 0. + * @annotation[62:1] is stored in the page tables. * * 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 +678,8 @@ 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, 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 0336143cbb24..6c32bdc689ed 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -539,15 +539,25 @@ 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; + if (!FIELD_FIT(KVM_INVALID_PTE_OWNER_MASK, owner_id)) + return -EINVAL; + if (!range_is_memory(addr, addr + size)) return -EPERM; - 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, annotation); if (ret) return ret; diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 9abc0a6cf448..749ee5863601 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; @@ -946,7 +941,7 @@ 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 +1095,16 @@ 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, 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, }; struct kvm_pgtable_walker walker = { .cb = stage2_map_walker, @@ -1118,7 +1113,7 @@ 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; ret = kvm_pgtable_walk(pgt, addr, size, &walker); -- 2.52.0.351.gbe84eed79e-goog