From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (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 EA81B3ACF1B; Mon, 28 Sep 2026 09:11:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790586702; cv=none; b=gt9Oqbua/hUA93frtwk37X93/2zxrDAEKfBrGVU07t8x9Sk94nTYc6C0pdl0vJ2OrvPGPHbXbZzdSYvnKxB5MU1QJRZtlQCPA06P9IVm2sAQuDrLKrsTPgjwAS4Sb/4L5YNhxr7W3fPwAzmfPxawapXP4f0HTbL9a4nxeLUBkJc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790586702; c=relaxed/simple; bh=GvJMxRCWJr2M3aM5fGBhG2o17KvUmU40LnQl6XvWZjk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=K2ujSGCDd3sNHjQjo/vlJX5q8i7JNMUBb1HW9/7JSGFxPUEsg/tfP/WCkUiYUv1qbCJd9vGihcD6FB++8LPr8yHyeo6YQh369S2r/Gbs90WpO3d92uFr94shPo41A8oFnHG1+l2dMAXfEN5GmaVhLB7ea8SramAXBL7NXMpmSy8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Vz3TWDvX; arc=none smtp.client-ip=198.175.65.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Vz3TWDvX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1790586701; x=1822122701; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=GvJMxRCWJr2M3aM5fGBhG2o17KvUmU40LnQl6XvWZjk=; b=Vz3TWDvXSZS42isrA86XqoPHCqVL1eW/Q+baf3epxwgGrBMkMOJHYSOE YO0Efp5T9rXB/GaH/uEHpV0s9TtEQXIt9AfA7kFmbX1PIlA+AssKmuw53 E0zjPo5V6Pd8ktErvxg5d2GXxn50KeecbllNjA+Rqrckt4ZCpaDN6rX2U 2HdFBmhnQ38hiDv/zroG33ArGG23OD5PBLBuP12fYUqIEDTA9mwUP8CVA POMVbzYuLKYAdwnfdhW+2A8Mw3KNt5z69nv5EWQFGPQ8TyL8UlIZUck2x 4l7HctGXrIvmhIgf0zLbgEpiPrkn2kZ8A0pbUjH5pcpoGtfFQkuDBQDg3 g==; X-CSE-ConnectionGUID: sZWUVyzsTJuqX8Ab5E/mHg== X-CSE-MsgGUID: sBIc1CsfR5ONLvrrbOdCUw== X-IronPort-AV: E=McAfee;i="6800,10657,11918"; a="90323417" X-IronPort-AV: E=Sophos;i="6.27,128,1787036400"; d="scan'208";a="90323417" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Sep 2026 02:11:41 -0700 X-CSE-ConnectionGUID: uFCqSsJPSSmGll/JFDjRzA== X-CSE-MsgGUID: vbYbCR9ERey02FV51wAg9w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,128,1787036400"; d="scan'208";a="278819313" Received: from yzhao56-desk.sh.intel.com ([10.239.47.61]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Sep 2026 02:11:35 -0700 From: Yan Zhao To: seanjc@google.com, pbonzini@redhat.com, dave.hansen@intel.com Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, rick.p.edgecombe@intel.com, kas@kernel.org, tabba@google.com, ackerleytng@google.com, michael.roth@amd.com, david@kernel.org, vannapurve@google.com, sagis@google.com, vbabka@suse.cz, thomas.lendacky@amd.com, nik.borisov@suse.com, pgonda@google.com, fan.du@intel.com, jun.miao@intel.com, francescolavra.fl@gmail.com, jgross@suse.com, xiaoyao.li@intel.com, kai.huang@intel.com, binbin.wu@linux.intel.com, chao.p.peng@intel.com, chao.gao@intel.com, farrah.chen@intel.com, yan.y.zhao@intel.com Subject: [PATCH v4 10/17] KVM: x86/mmu: Add a TDP MMU API to split huge pages for mirror roots Date: Mon, 28 Sep 2026 17:11:03 +0800 Message-ID: <20260928091103.15631-1-yan.y.zhao@intel.com> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20260928090729.15468-1-yan.y.zhao@intel.com> References: <20260928090729.15468-1-yan.y.zhao@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sean Christopherson Add an exported API to split huge pages in mirror roots for a given gfn range. TDX will use the API to split huge pages in preparation for partially zapping a private huge page, e.g., for converting a huge page from private to shared, or for splitting a huge page to match the guest's ACCEPT level. For all intents and purposes, no functional change intended. Signed-off-by: Sean Christopherson Signed-off-by: Yan Zhao --- v4: - new patch. --- arch/x86/kvm/mmu/tdp_mmu.c | 40 ++++++++++++++++++++++++++++---------- arch/x86/kvm/mmu/tdp_mmu.h | 2 ++ 2 files changed, 32 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 472419963a19..9c783accb9ed 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1616,6 +1616,26 @@ static int tdp_mmu_split_huge_pages_root(struct kvm *kvm, return 0; } +static int tdp_mmu_split_huge_pages(struct kvm *kvm, int as_id, + enum kvm_tdp_mmu_root_types type, + gfn_t start, gfn_t end, + int target_level, bool shared) +{ + struct kvm_mmu_page *root; + int r; + + kvm_lockdep_assert_mmu_lock_held(kvm, shared); + + __for_each_tdp_mmu_root_yield_safe(kvm, root, as_id, type) { + r = tdp_mmu_split_huge_pages_root(kvm, root, start, end, + target_level, shared); + if (r) { + kvm_tdp_mmu_put_root(kvm, root); + return r; + } + } + return 0; +} /* * Try to split all huge pages mapped by the TDP MMU down to the target level. @@ -1625,18 +1645,18 @@ void kvm_tdp_mmu_try_split_huge_pages(struct kvm *kvm, gfn_t start, gfn_t end, int target_level, bool shared) { - struct kvm_mmu_page *root; - int r = 0; + tdp_mmu_split_huge_pages(kvm, slot->as_id, KVM_VALID_ROOTS, start, end, + target_level, shared); +} - kvm_lockdep_assert_mmu_lock_held(kvm, shared); - for_each_valid_tdp_mmu_root_yield_safe(kvm, root, slot->as_id) { - r = tdp_mmu_split_huge_pages_root(kvm, root, start, end, target_level, shared); - if (r) { - kvm_tdp_mmu_put_root(kvm, root); - break; - } - } +int kvm_tdp_mmu_mirrors_split_huge_pages(struct kvm *kvm, gfn_t start, + gfn_t end, int target_level) +{ + /* The as_id for mirror roots can only be 0 */ + return tdp_mmu_split_huge_pages(kvm, 0, KVM_MIRROR_ROOTS, start, end, + target_level, false); } +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_tdp_mmu_mirrors_split_huge_pages); static bool tdp_mmu_need_write_protect(struct kvm *kvm, struct kvm_mmu_page *sp) { diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h index bd62977c9199..a6919de10ca2 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.h +++ b/arch/x86/kvm/mmu/tdp_mmu.h @@ -97,6 +97,8 @@ void kvm_tdp_mmu_try_split_huge_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, gfn_t start, gfn_t end, int target_level, bool shared); +int kvm_tdp_mmu_mirrors_split_huge_pages(struct kvm *kvm, gfn_t start, + gfn_t end, int target_level); static inline void kvm_tdp_mmu_walk_lockless_begin(void) { -- 2.43.2