From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (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 4D9981419A4 for ; Mon, 31 Aug 2026 06:22:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788157322; cv=none; b=g7Reo/vXYj/Lc0h52hon8FtwdfCGPKjuBwwiHF5Dc8igsq3uV+VnAquWGlO8cxgSe7MeBNSGPD3lFVX8jedCGu6PW8H6lt22zB4JxGlhzY0gjoc6towi+hG5UFBxtsumEE0Nn9dRVPNTm0eu8GxMBbAyQaFlDCl/0LLARTjSAos= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788157322; c=relaxed/simple; bh=WqBC9k9dQo1Fkp8FeGnmJpcacq5DVytNnWXm1742Lso=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=UujsxdEWGxeRPxpyeXaWHJ9chfN10QoO2H+h446BAAGfRiuGnBrkVQpcKH89XD/wyTm2O8+wQtPhIWkOxHpD1dhsAh//j1kP/dFChZCJCPWZZOiyvQPo2s9Vp87Shezo2O9XV7Qz0Hw40IbUizgSUU8vVAxAGyGs4l0hPTdoIBU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=Kn1YWkQ+; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=CTXoUPlF; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="Kn1YWkQ+"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="CTXoUPlF" Received: from pps.filterd (m0279867.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 67V52QaS3678801 for ; Mon, 31 Aug 2026 06:22:00 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= wcg0Ez9nJOyV/8LnbrobWqWP9ec96FQgJeXfFdTZe98=; b=Kn1YWkQ+vhRQHjuO SVI5IsM2hTE6k/B7tdf0xyH4PlNsXgYl0N7x5vnWCEca9O8XKKg3jahYZUWkPR0n +qeSVd8FRmIHiewURxfvjSJx+uB64pJtZrLrdWPHjCg9DpizkuocQjaFcrVAYkdA WDc0L3w92gEM5Q6XgPxrcAVACH75rTknrsWOyWoifZj6aMGpw+/JdPW8KpmmqdTR 2DNyt5eb9xVa2A/rliKmaFuK9WT9pS/5fEYovg4utjnON5Xd8G3nJx79Paor08QO Y4IZqDQaCcKxlz8U8G4vQ1MSFmarnUr5FdbXlPv8RgNsz599hGjCmB4+7NR8x6nI mTa+6g== Received: from mail-pj1-f70.google.com (mail-pj1-f70.google.com [209.85.216.70]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4gcv8h14qv-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Mon, 31 Aug 2026 06:22:00 +0000 (GMT) Received: by mail-pj1-f70.google.com with SMTP id 98e67ed59e1d1-38e475f83a2so5482953a91.1 for ; Sun, 30 Aug 2026 23:22:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1788157320; x=1788762120; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:content-language :references:cc:to:from:subject:user-agent:mime-version:date :message-id:from:to:cc:subject:date:message-id:reply-to:content-type; bh=wcg0Ez9nJOyV/8LnbrobWqWP9ec96FQgJeXfFdTZe98=; b=CTXoUPlFxDy5AjZY6a2DZj94A/vhfWRpXd7rGiup+u4Tc0zbU9uNwhexOwweSvyxPw 2Zso9xODn7Yp80lPj8bZMMYTew5Q10i5omdUpQRrXlAtNQqSMlAAdR+Swko4rG3RennM tjZBgjEvcxAzZ3u8+Sq6H7FF7K5Ll4nCZji9S7FuIHyj06qvOGeV/kR1tbP5p90g8TZ/ yx8aHBQGLq7SibJMxdi3CQPcBVKNWQVZRD3TWxvevGN0lmgoAoPPLXJ3V1B112u+IraR g46S8pzPTWVJvzmDM0bmrpcPR1QHEcgun1gjSGmGbyxNLPrFP3pQ0WHt94tGON4JuLeP 4Iew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788157320; x=1788762120; h=content-transfer-encoding:content-type:in-reply-to:content-language :references:cc:to:from:subject:user-agent:mime-version:date :message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=wcg0Ez9nJOyV/8LnbrobWqWP9ec96FQgJeXfFdTZe98=; b=qQXb/pxgnS3+EO3VMDC2kQMExrenT8TvJU4t03iLETMjrfhVxU4qhtXR8z+5V3JHQr 3+4tQ4HXmqqlPE+rRNYmWHx3+HmTem+PV1D5z+XfzJ/JfbppIHkMCEBDWND15blckc4a QM17B00Vi2nJEkvR4vP7UMH580xhobclv/54VNx1OKPP/CBP0Dlr46+1WHtJgOPOeUa4 SH6efKklTF4uu7jwAw2n4cNv8o5bi9ilGavQ2sM+tlaeNuIjFghyRiTADIWTUNURKD17 j1QmRkKQjSmrQJVJvGkAsm1KwnX3BfBKNwjxus4/AGYKkD1gqJtzJZePZ1IpZ0T//3vZ hgZA== X-Forwarded-Encrypted: i=1; AKwUvBzIgFEc9W/FnEH9ZGKLc04CU6Gp8+OuFtrV/v+9H6FmZ8IdrzfhL6JFaYKFRahdgd5iHZTuFNPphhqx0f0=@vger.kernel.org X-Gm-Message-State: AFuF++kOHQH/UP0kOyBC7JvansjOklzYuxbf/O2uReAjrqKxVVtQQjPp 8UhRDTNIwOr0juut3e4EKf4R9lK5/tq3bL1VDQZt/JvlORpSmJq5WJ4J5r0jZw7USB8SvgzgBAD CjRnMsrTyGAes09qRU3vdQD+L77XyqTg2U/s8cUlk2r+3xiXBf2865OLPx4V2cnDVa7M= X-Gm-Gg: AYBFou3gI30W9rPBNp7yJEGFInPg54+OqJ6jd/ImNDnr58oD5Yypwz/ALRqvZWdwr65 89c8emZ6H4OWdRnQkNKbF/OCXkNvCdmJ4yytwBzNIUtRtZrgeue1u+0noXHAVccKv5EZN0yYzjd scLqzZBv+MFSahQgr6xzq585JFGrUZHDaOd8RQ3ptk09mVTWHbmYlMbmoQfS8r0N0o2wl++leWN jmvVi3Ah0f1muididhlj+xZzweO5b37wG1zk7/RYZ5GqJ+R2L3xQofoE1jo18DnVI+klDZYIQYx WfV1JRidHU031uX9+3uqeacxgjrKXEpr/nJk3HBvcyyV+3Vv5973mnT57d8zAha4yn1jr4Wg3fP EePY4t0mu57c/kRYeKiYvMNW/zbrqBIYAzo9dfj98J2Do34+CtxVs5A5FVQ== X-Received: by 2002:a17:90b:4d0c:b0:37f:c97a:939f with SMTP id 98e67ed59e1d1-396d0dd5069mr33909577a91.7.1788157319623; Sun, 30 Aug 2026 23:21:59 -0700 (PDT) X-Received: by 2002:a17:90b:4d0c:b0:37f:c97a:939f with SMTP id 98e67ed59e1d1-396d0dd5069mr33909493a91.7.1788157319060; Sun, 30 Aug 2026 23:21:59 -0700 (PDT) Received: from [10.110.79.126] (i-global254.qualcomm.com. [199.106.103.254]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-142e0d38207sm25010026c88.5.2026.08.30.23.21.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 30 Aug 2026 23:21:58 -0700 (PDT) Message-ID: Date: Mon, 31 Aug 2026 14:21:50 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 00/11] FBE virtualization: inline encryption for virtio-blk guests From: Linlin Zhang To: Eric Biggers Cc: axboe@kernel.dk, mst@redhat.com, jasowangio@gmail.com, James.Bottomley@hansenpartnership.com, martin.petersen@oracle.com, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, linux-block@vger.kernel.org, linux-crypto@vger.kernel.org, linux-scsi@vger.kernel.org, virtualization@lists.linux.dev, devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, neeraj.soni@oss.qualcomm.com, gaurav.kashyap@oss.qualcomm.com, mani@kernel.org, andersson@kernel.org, konradybcio@kernel.org, bvanassche@acm.org, alim.akhtar@samsung.com, avri.altman@sandisk.com, stefanha@redhat.com, pbonzini@redhat.com, eperezma@redhat.com, xuanzhuo@linux.alibaba.com, linux-kernel@vger.kernel.org References: <20260827160806.1295313-1-linlin.zhang@oss.qualcomm.com> <20260827184219.GB2137493@google.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Authority-Analysis: v=2.4 cv=DY0nbPtW c=1 sm=1 tr=0 ts=6a951d88 cx=c_pps a=0uOsjrqzRL749jD1oC5vDA==:117 a=JYp8KDb2vCoCEuGobkYCKw==:17 a=IkcTkHD0fZMA:10 a=Sv0fKeRqtYgA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=eoimf2acIAo5FJnRuUoq:22 a=EUspDBNiAAAA:8 a=_h6NAR8LnRz2utxSRfIA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=mQ_c8vxmzFEMiUWkPHU9:22 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODMxMDA1MyBTYWx0ZWRfX9L3ujWS5U9A4 vDKe6GRUp6nfl05SrRWu7zigBK9it82+LR//WrXmR9RggCKiQM+ZMg9zrtn4QY8tNE6HSido7x5 wJmEJytdPTC65ADA1NrJ12qgM+8/+wrL6xyAMyAg3JzrIWrPxDB+zXmEEjU38zZmNYHuva3Qd7l y33KAJAGSvV1j5Tw54dOb3NkCmmj5G1rFUXXajawMLdBj+ukZTCjnvD7DYixxSGVlTQKgXKp0O4 EfaAC1YIePxPRh0JhqLnKU82pk5MdzDpzzGRS2uY2a8w4iVbPcCg/s5qSex8wmMsHONLqRHM51g oM54ieqOAM59JSxX/dA3ZKk6RzHLwCTuClAPCY4At4C4BvyggTD8Wx7BWR6xyQkOKx+7b84+H0t pfpT3B/TBshfjAVqkQ7cD8njeY8uug/Xs4FEE+Te/T9xIE1/EkyzVQGQqCxkx57XKP0XzLvEN0K 4OSf6GJh4J+Yp01RbVg== X-Proofpoint-ORIG-GUID: LhO96_RtiC02lbvBXo2i3MehqPCgVbR6 X-Proofpoint-Spam-Info: AW1haW4tMjYwODMxMDA1MyBTYWx0ZWRfX24v/miu1hWX4 epKhv18fb7LOTgAWjyzM4b/519FPre2FKCWAKeizdVZYmJ3IGLxX6M377YtGa5gx9gMJvNdaoD/ LLFDmIy54Pe3mxAzJZzTWiytovsOPMM= X-Proofpoint-GUID: LhO96_RtiC02lbvBXo2i3MehqPCgVbR6 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-31_02,2026-08-27_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 adultscore=0 clxscore=1015 priorityscore=1501 spamscore=0 suspectscore=0 malwarescore=0 bulkscore=0 lowpriorityscore=0 impostorscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608310053 On 8/28/2026 11:37 PM, Linlin Zhang wrote: > > > On 8/28/2026 2:42 AM, Eric Biggers wrote: >> On Thu, Aug 27, 2026 at 09:07:09AM -0700, Linlin Zhang wrote: >>> From: linlzhan >>> >>> Current virtio-blk does not provide a mechanism for a guest to >>> program hardware keys or submit encrypted I/O using pre-programmed >>> keyslots. It drops the crypto context when issuing a bio request >>> to the virtio-blk queue, preventing inline-encryption-based FBE >>> on virtio block devices. >>> >>> This series enables File-Based Encryption in guest VMs on Qualcomm >>> GVM platforms where the ICE inline encryption hardware is shared >>> between the host and guests. In this environment the guest kernel >>> has no access to the ICE hardware directly; it supplies a virtual >>> keyslot index and data unit number with each encrypted I/O request >>> via VIRTIO_BLK_F_INLINE_ENCRYPTION, and the host must translate the >>> virtual slot to a physical ICE keyslot and submit the bio — without >>> transferring raw key material across the VM boundary. >> >> This seems to be designed incorrectly by not making virtio-blk itself >> support key programming and eviction. That complicates things >> significantly by then having to handle the key programming and eviction >> out-of-band using Qualcomm-specific SCM calls. It also means that >> adding other implementations of this would be very difficult. >> >> There are some claims that not transmitting keys across the VM boundary >> is desirable. But that doesn't seem meaningful, given that all the I/O >> is transmitted across that boundary in plaintext anyway, and also it >> seems that hardware-wrapped keys will be supported too. >> >> Please make virtio-blk support the key programming, eviction, and >> HW-wrapped key management operations that are needed for this to work. >> >> - Eric > > Thanks for your comments! > > Not making virtio-blk itself support key programming and eviction is > something done deliberately. Based on that HW-wrapped key management > operations are also handled in the out-of-band path. > > There are bellow 2 approaches I investigated to let virtio-blk programming > the key. > > 1. virtio_blk implements blk_crypto_ll_ops interfaces, including program > key and evict key interfaces.(Same to 'the virtio-blk interface standardized > blk_crypto_ll_ops requests' mentioned by Stefan in the virtio SPEC thread) > > The guest's block crypto profile manages the keyslot in virtual slot > format in this scenario. > > - block crypto key and virt_slot index it passed to the hypervisor's > (EL2) device emulation (QEMU, using QEMU in the following) which > runs in userspace of the host. Besides of transferring the virtual > slot to the physical slot, a programming block crypto key UAPI need > be added. Follow current blk-crypto design, it may be like > BLKCRYPTOGENERATEKEY. I thought this results in a security risk that > allows userspace process a key into a key slot. > > - For key eviction, it's similar to above key programming handling, also > need a key eviction in blk IOCTLs, but leads to the security risk > that allow userspace client to evict a key in a key slot. > > virt_slot, DUN and DUSize is appended to virtblk request during crypto > I/O. > > 2. virtio_blk implements blk_crypto_ll_ops interfaces, excluding program > key and evict key interfaces. > > The guest's block crypto profile doesn't manage keyslot for the guest, > the host's block crypto profile manages keyslot for both the guest and > the host. The trigger of key programming operation is moved from the > guest to the host. > > - The whole block crypto key (key size, key bytes, blk_crypto_config) > and DUN are appended to the virtblk request during IO, a little > high payload. > > The backend parses the crypto message in the virtio queue and > construct a block crypto key and DUN for the bio_crypto_ctx > set to the BIO. So that the IO flow in the host can program > the key. > > The question is that the blk-crypto-profile distinguishs the > block crypto key via the key's address. But the host has > different key addresses for the programming and eviction key > operations of the same block crypto key from GVM, because the > key is re-constructed in the host for the key program and > eviction operations. > > To fix it, the approach I thought is maintaining a new key > hash table in the backend, and comparing the block crypto key > content and DUN parsed from virtio queue with that in the key > hash table. > My major concern is that this need keep the keys synchronization > b/w this new hash table and the blk-crypto-profile's hash table > carefully, avoiding that key is still present in the > blk-crypto-profile's hash table, but removed in backend hash > table. Another point is that the whole block crypto key and > DUN are appended into virtio block request per crypto I/O. > > - For key eviction, adding a key eviction in blk IOCTLs allows > userspace client to evict a key in a key slot. I thought this > is a security concern. Correction. The key eviction operation is also moved from the Guest's blk_crypto_profile to the Host's blk_crypto_profile. As a result, the entire block crypto key (including the key size, key material, and blk_crypto_config) is appended to the virtblk request. The backend parses the supplied blk_crypto_key, looks it up in its key hash table, and can then invoke blk_crypto_evict_key() to evict the corresponding key from the ICE keyslot. Unlike Approach 1, Approach 2 does not allow the guest to specify the keyslot to be evicted through the block ioctl interface. I'm appreciated if you can share your insights and thoughts about these 3 approaches. > > > This option doesn't need map virt_slot to physical one. > > > Taking all the above into account, I made a compromise to implement > blk_crypto_ll_ops interfaces in a out-of-band path, which lets the virtio > blk only need focus on the data path. I agree that it is complex than > the second option mentioned in the above, but small payload (only > virt_slot, DUN, DUSize) in the virtio block request and no security > risk of key eviction from userspace. > > > I would like to hear your thoughts about the above and am appreciated > if you could share your insights about the design of inline > encryption in virtio block. > > Regards, > Linlin > > >