[Qemu-devel] 答复: [RFC v1] virtio-crypto specification

[Lingli Deng]

Hi Varun,

Thanks for the bridging. 

Hi Gonglei and virtio-crypto guys, 

As Varun said, dpacc is working on enabling the portability of data plane VNFs 
(leveraging software/hardware accelerators in the host) across hardware 
platforms, and virtio extensions for such accelerator had been recognized as a 
promising solution. In particular, we are interested in the use-case of a 
smallcell GW VNF, where hardware/host accelerators are used for crypto 
offloading. As part of the OPNFV initiative, we are targeting at adding 
features to the open-source platform, which would used as a reference 
implementation for NFV deployment.

However, we are not member of OASIS, and is not familiar with its organization 
or procedure. So we start with the gap analysis and the PoC implementation, 
without knowing that there is actually an OASIS thread taking place in parallel.

I understand it may not the the only application scenario for virtio-crypto 
spec you are doing, but assume it could be an interesting one in operators' NFV 
deployment.

I believe we should definitely encourage this discussion and try to work 
together. 
I suppose we can start with an exchange of what we expect in our usecase and 
PoC with what you would provide with the specified virtual device.

Please advise how we can start collaboration.

Regards,
Lingli
+86 13810597148

-----邮件原件-----
发件人: Varun Sethi [mailto:address@hidden 
发送时间: 2015年11月25日 20:41
收件人: Gonglei (Arei); address@hidden; address@hidden
抄送: Hanweidong (Randy); address@hidden; Claudio Fontana; Huangpeng (Peter); 
Lauri Leukkunen; Jani Kokkonen; Denis Crasta; Arun Pathak; Lingli Deng; Caraman 
Mike
主题: RE: [RFC v1] virtio-crypto specification

Hi Gonglei,
Please find my comments inline.

Regards
Varun

> -----Original Message-----
> From: Gonglei (Arei) [mailto:address@hidden
> Sent: Wednesday, November 25, 2015 1:14 PM
> To: Sethi Varun-B16395 <address@hidden>; 
> address@hidden open.org; address@hidden
> Cc: Hanweidong (Randy) <address@hidden>; address@hidden; 
> Claudio Fontana <address@hidden>; Huangpeng (Peter) 
> <address@hidden>; Lauri Leukkunen 
> <address@hidden>; Jani Kokkonen 
> <address@hidden>; Crasta Denis-B22176 
> <address@hidden>; Pathak Arun-B33046 
> <address@hidden>
> Subject: RE: [RFC v1] virtio-crypto specification
> 
> Hello Varun,
> 
> 
> > -----Original Message-----
> > From: Varun Sethi [mailto:address@hidden
> > Sent: Wednesday, November 25, 2015 3:08 AM
> > Subject: RE: [RFC v1] virtio-crypto specification
> >
> > Hi Gonglei,
> > We have been working on the virtio-ipsec  look-aside accelerator 
> > device specification at the OPNFV DPACC forum. The virtio-ipsec 
> > device is aimed at providing the protocol offload capabilities 
> > (offered by security hardware
> > accelerator) to the VM. The device supports a control queue and 
> > encap/decap queue pair per guest vcpu (multi queue support). Based 
> > on the feature bits, a notification queue can also be supported.
> > Following document gives the details for the virtio-ipsec device:
> > https://wiki.opnfv.org/_media/dpacc/freescale-ipsec-virtual-accelera
> > tor-rev-
> 3.
> > docx
> >
> > Currently we are focusing on userspace virtio-ipsec backend emulation.
> > We are working on a POC  for vhost-user IPSec backend emulation and 
> > guest VM kernel virtio-ipsec driver.
> >
> > Following document provides guest API details to utilize the 
> > virtio-ipsec look aside accelerator.
> > https://wiki.opnfv.org/_media/dpacc/freescale-ipsec-virtual-accelera
> > to
> > r-gapi-r
> > ev02.pdf
> >
> 
> Actually, our virtio-crypto device isn't limited on NFV scenario, but 
> all encrypt & decrypt scenarios which need to use para-virtualization 
> of accelerator hardwares.
> 
[Varun]  Agreed, but we can work towards a generic specification.

> > We can look at collaborating for the virtio-crypto device definition.
> >
> 
> Welcome to join us :)
> 
[Varun] Thanks, it would be nice if we can leverage the work done as a part of 
the virtio-ipsec device specification. I have also added Lingli to the mail 
chain. Lingli is leading the OPNFV  DPACC effort. Please let us know if we can 
have a discussion on this.


> Regards,
> -Gonglei
> 
> > Regards
> > Varun
> >
> > -----Original Message-----
> > From: address@hidden
> > [mailto:address@hidden On 
> > Behalf Of Gonglei (Arei)
> > Sent: Friday, November 20, 2015 8:58 AM
> > To: address@hidden; address@hidden
> > Cc: Hanweidong (Randy) <address@hidden>; address@hidden; 
> > Claudio Fontana <address@hidden>; Huangpeng (Peter) 
> > <address@hidden>; Lauri Leukkunen 
> > <address@hidden>; Gonglei (Arei) 
> > <address@hidden>; Jani Kokkonen <address@hidden>
> > Subject: [Qemu-devel] [RFC v1] virtio-crypto specification
> >
> > Hi guys,
> >
> > After initial discussion at this year's KVM forum, I post the RFC 
> > version of virtio-crypto device specification now.
> >
> > If you have any comments, please let me know, thanks.
> >
> > Regards,
> > -Gonglei
> >
> >
> > 1   Crypto Device
> >
> > The virtio crypto device is a virtual crypto device (ie. hardware 
> > crypto accelerator card). Encrypt and decrypt requests are placed in 
> > the data queue, and handled by the real hardware crypto accelerators 
> > finally. A second queue is the controlling queue, which is used to 
> > create/destroy session or some other advanced filtering features.
> >
> > 1.1 Device ID
> >
> >     65535 (experimental)
> >
> > 1.2 Virtqueues
> >
> > 0
> >     controlq
> > 1
> >     dataq
> >
> > 1.3 Feature bits
> >
> > VIRTIO_CRYPTO_F_REQ_SIZE_MAX (0)
> > Maximum size of any single request is in “size_max”.
> > VIRTIO_CRYPTO_F_SYM (1)
> > Device supports the symmetric cryptography API.
> > VIRTIO_CRYPTO_F_DH (2)
> > Device supports the Diffie Hellman API.
> > VIRTIO_CRYPTO_F_DSA (3)
> > Device supports the DSA API.
> > VIRTIO_CRYPTO_F_RSA (4)
> > Device supports the RSA API.
> > VIRTIO_CRYPTO_F_EC (5)
> > Device supports the Elliptic Curve API.
> > VIRTIO_CRYPTO_F_ECDH (6)
> > Device supports the Elliptic Curve Diffie Hellman API.
> > VIRTIO_CRYPTO_F_ECDSA (7)
> > Device supports the Elliptic Curve DSA API.
> > VIRTIO_CRYPTO_F _KEY (8)
> > Device supports the Key Generation API.
> > VIRTIO_CRYPTO_F_LN (9)
> > Device supports the Large Number API.
> > VIRTIO_CRYPTO_F_PRIME (10)
> > Device supports the prime number testing API.
> > VIRTIO_CRYPTO_F_DRGB (11)
> > Device supports the DRGB API.
> > VIRTIO_CRYPTO_F_NRGB (12)
> > Device supports the NRGB API.
> > VIRTIO_CRYPTO_F_RAND (13)
> > Device supports the random bit/number generation API.
> >
> > 1.4 Device configuration layout
> >
> > struct virtio_crypto_config {
> >     le32 size_max; /* Maximum size of any single request */ }
> >
> > 1.5 Device Initialization
> >
> > 1. The initialization routine should identify the data and control 
> > virtqueues.
> > 2. If the VIRTIO_CRYPTO_F_SYM feature bit is negotiated, identify 
> > the device supports the symmetric cryptography API, which as the 
> > same as other features.
> >
> > 1.6 Device Operation
> >
> > The controlq is used to control session operations, such as create or 
> > destroy.
> > Meanwhile, some other features or functions can also be handled by controlq.
> > The control request is preceded by a header:
> > struct virtio_crypto_ctx_outhdr {
> >     /* cipher algorithm type (ie. aes-cbc ) */
> >     __virtio32 alg;
> >     /* length of key */
> >     __virtio32 keylen;
> >     /* reserved */
> >     __virtio32 flags;
> >     /* control type  */
> >     uint8_t type;
> >     /* encrypt or decrypt */
> >     uint8_t op;
> >     /* mode of hash operation, including authenticated/plain/nested hash */
> >     uint8_t hash_mode;
> >     /* authenticate hash/cipher ordering  */
> >     uint8_t alg_chain_order;
> >     /* length of authenticated key */
> >     __virtio32 auth_key_len;
> >     /* hash algorithm type */
> >     __virtio32 hash_alg;
> > };
> > The encrypt/decrypt requests and the corresponding results are 
> > transmitted by placing them in dataq. The request itself is preceded 
> > by a
> header:
> > struct virtio_crypto_req_outhdr {
> >     /* algorithm type (ie. aes-128-cbc ) */
> >     __virtio32 mode;
> >     /* length of iv */
> >     __virtio32 ivlen;
> >     /* length of source data */
> >     __virtio32 len;
> >     /* length of auth data */
> >     __virtio32 auth_len;
> >     /* the backend session id */
> >     __virtio64 session_id;
> >     /* reserved */
> >     __virtio32 flags;
> > };
> >
> > Both ctx and data requests end by a status byte. The final status 
> > byte is written by the device: either VIRTIO_CRYPTO_S_OK for 
> > success, VIRTIO_BLK_S_IOERR for device or driver error or 
> > VIRTIO_BLK_S_UNSUPP for a request unsupported by device, 
> > VIRTIO_CRYPTO_S_BADMSG for verification failed when decrypt AEAD algorithms:
> >
> > #define VIRTIO_CRYPTO_S_OK    0
> > #define VIRTIO_CRYPTO_S_ERR    1
> > #define VIRTIO_CRYPTO_S_UNSUPP    2
> > #define VIRTIO_CRYPTO_S_BADMSG    3
> >
> > For symmetric cryptography, three types algorithms are supported:
> > enum {
> >     VIRTIO_CRYPTO_ABLKCIPHER,
> >     VIRTIO_CRYPTO_AEAD,
> >     VIRTIO_CRYPTO_HASH,
> > };
> > VIRTIO_CRYPTO_ABLKCIPHER: Asynchronous Block Cipher.
> > VIRTIO_CRYPTO_AEAD: Authenticated Encryption With Associated Data
> > (AEAD) Cipher.
> > VIRTIO_CRYPTO_HASH: Hash and MAC (Message Authentication Code) cipher.
> >
> > 1.6.1       Encryption Operation
> >
> > Bothe ctrlq and dataq virtqueue are bidirectional.
> > Step1: Create a session:
> > 1.  The front-end driver fill out the context message, include algorithm
> name,
> > key, keylen etc;
> > 2.  The front-end driver send a context message to the backend device by
> > controlq;
> > 3.  The backend driver create a session using the message transmitted by
> > controlq;
> > 4.  Return a session id to the driver.
> > Step 2: Execute the detail encryption operation:
> > 1.  The front-end driver fill out the encrypt requests;
> > 2.  Put the requests into dataq and kick the virtqueue;
> > 3.  The backend driver execute the encryption operation according the
> > requests’ arguments;
> > 4.  Return the encryption result to the front-end driver by dataq.
> > 5.  The front-end driver callback handle the result and over
> >
> > Note: the front-end driver needs to support both synchronous and 
> > asynchronous encryption. Even then the performance is poor in 
> > synchronous operation because frequent context switching and 
> > virtualization
> overhead.
> >
> > 1.6.2       Decryption Operation
> >
> > The decryption process is the same with encryption, except that AEAD 
> > algorithm needs to be verified before decryption, if the verify 
> > result is not correct, the device will directly return 
> > VIRTIO_CRYPTO_S_BADMSG (bad
> > message) to front-end driver.
> >