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 8E6323A4523; Tue, 28 Apr 2026 23:25:19 +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=1777418719; cv=none; b=eMYib1y9F/aahQOFny7vZx1Wc/0CKky30QXasNj9wyx5bRKYGlbunfO8lCN69KDAQOZYKMJUiOnH3+D5U46sfpdTfXjJqhA82K+LojQs5zDSewVnJ4eDLZwec4cJ9XMlSeHwVF6CoCZHbyhg1UknXyds1s2XpTRcM7OMksgWQfI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777418719; c=relaxed/simple; bh=yIQ1qb/5thBEPl1WW7+A4KzPierGynmKhGiUR/3Ml6c=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=XqEaT6JGDXqdgesbmVFh/YZ4cGvMSg4xdJY6F7CjQgcPvGD/2IxN1941YadEYrz8r/lTlmecLFgDxNem8UHXrUXEJQRn/FtRrNlQHy4EKMYMiuw26lj67/9ny5EHuf+0pQRnQiyvjkyri4taodfHRdPwiXOdA868SRac4LkNh+k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iqzkNOfj; 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="iqzkNOfj" Received: by smtp.kernel.org (Postfix) with ESMTPS id 540A2C2BCF7; Tue, 28 Apr 2026 23:25:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777418719; bh=yIQ1qb/5thBEPl1WW7+A4KzPierGynmKhGiUR/3Ml6c=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=iqzkNOfjetQv0OkOlMI4tZoTh+sRABN+hK+ANmOFw/Y0SQPFWkuEL1h8joP+JXUaw holJDjTe6B+rq4XlfKj3mAaSD488WXovSxw7VjFVbkk31MlIsZriCcQAUobgbbS5+4 U3vufYnU831eYzE7hnJgsAplr2Sf/lQetR74SIaW6TYCvLC9TnTHOVdX1yhvunNxmR sAZhmVuNPo8Ha+M+kQdBEXi3e+yI+rAc5yHBoH4kzECyKbbnVWSU33aaWelmlFVaur YvVc8MESc7z18FYFcuPypzKc/GC7Ywh8zipYDdvDfBE6GhtkEphZ+kVUEtljAgqH/I bH4JGvvE8VGtw== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B007FF8875; Tue, 28 Apr 2026 23:25:19 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Tue, 28 Apr 2026 16:25:20 -0700 Subject: [PATCH RFC v5 25/53] KVM: TDX: Make source page optional for KVM_TDX_INIT_MEM_REGION Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260428-gmem-inplace-conversion-v5-25-d8608ccfca22@google.com> References: <20260428-gmem-inplace-conversion-v5-0-d8608ccfca22@google.com> In-Reply-To: <20260428-gmem-inplace-conversion-v5-0-d8608ccfca22@google.com> To: aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, ira.weiny@intel.com, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Jason Gunthorpe , Vlastimil Babka Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1777418714; l=2077; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=ZUVil0lCIwc17luhnyQSnbr0drwWGJzhuW+VIyBKAEE=; b=7+JgXh5IsJ8zEo/B+5TkhpuCJ+LAfF3PUrxanugOqLUqBAxiPXjz3BKUNbVG/YL3JTPBaLNVM Arrpar2DOqaCNzQACmKnSm35p43EbE0LBLcBBsBuSJO2Q79UgEO9KPL X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com From: Ackerley Tng Update tdx_gmem_post_populate() to handle cases where a source page is not explicitly provided. Instead of returning -EOPNOTSUPP when src_page is NULL, default to using the page associated with the destination PFN. This change allows for in-place memory conversion where the data is already present in the target PFN, ensuring the TDX module has a valid source page reference for the TDH.MEM.PAGE.ADD operation. Signed-off-by: Ackerley Tng --- Documentation/virt/kvm/x86/intel-tdx.rst | 4 ++++ arch/x86/kvm/vmx/tdx.c | 8 ++++++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/Documentation/virt/kvm/x86/intel-tdx.rst b/Documentation/virt/kvm/x86/intel-tdx.rst index 6a222e9d09541..fbc0f179dc750 100644 --- a/Documentation/virt/kvm/x86/intel-tdx.rst +++ b/Documentation/virt/kvm/x86/intel-tdx.rst @@ -158,6 +158,10 @@ KVM_TDX_INIT_MEM_REGION Initialize @nr_pages TDX guest private memory starting from @gpa with userspace provided data from @source_addr. @source_addr must be PAGE_SIZE-aligned. +If memory attributes are tracked in guest_memfd, pass NULL for +@source_addr to initialize the memory region using memory contents +already populated in guest_memfd memory. + Note, before calling this sub command, memory attribute of the range [gpa, gpa + nr_pages] needs to be private. Userspace can use KVM_SET_MEMORY_ATTRIBUTES to set the attribute. diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 04ce321ebdf39..10373e606242a 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -3116,8 +3116,12 @@ static int tdx_gmem_post_populate(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, if (KVM_BUG_ON(kvm_tdx->page_add_src, kvm)) return -EIO; - if (!src_page) - return -EOPNOTSUPP; + if (!src_page) { + if (vm_memory_attributes) + return -EOPNOTSUPP; + + src_page = pfn_to_page(pfn); + } kvm_tdx->page_add_src = src_page; ret = kvm_tdp_mmu_map_private_pfn(arg->vcpu, gfn, pfn); -- 2.54.0.545.g6539524ca2-goog