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[REPOST,v19,1/2] virtio-crypto: Add virtio crypto device specification

Message ID 1505092362-10544-2-git-send-email-longpeng2@huawei.com (mailing list archive)
State New, archived
Headers show

Commit Message

Longpeng(Mike) Sept. 11, 2017, 1:12 a.m. UTC
From: Gonglei <arei.gonglei@huawei.com>

The virtio crypto device is a virtual crypto device (ie. hardware
crypto accelerator card). Currently, the virtio crypto device provides
the following crypto services: CIPHER, MAC, HASH, and AEAD.

In this patch, CIPHER, MAC, HASH, AEAD services are introduced.

VIRTIO-153

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
---
 acknowledgements.tex |    3 +
 content.tex          |    2 +
 virtio-crypto.tex    | 1479 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1484 insertions(+)
 create mode 100644 virtio-crypto.tex

Comments

Gonglei (Arei) Sept. 18, 2017, 12:13 p.m. UTC | #1
>

> > +

> > +The information required by AEAD session creation is stored in the

> virtio_crypto_aead_create_session_req

> > +structure, including the aead parameters stored in \field{para} and the

> cipher key in \field{key}.

> > +\field{input} stores the result of this operation.

> > +

> > +\drivernormative{\subparagraph}{Session operation: create session}{Device

> Types / Crypto Device / Device Operation / Control Virtqueue / Session

> operation / Session operation: create session}

> > +

> > +\begin{itemize*}

> > +\item The driver MUST set the control general header and the

> corresponding algorithm-specific structure.

> > +    See \ref{sec:Device Types / Crypto Device / Device Operation / Control

> Virtqueue}.

> > +\item The driver MUST set the \field{opcode} field based on service type:

> CIPHER, HASH, MAC, or AEAD.

> > +\item The driver MUST set the \field{queue_id} field to show used dataq.

> 

> I've failed to figure out the semantic behind queue_id. This could mean,

> that sessions and session_id's are queue scoped. But then we should be

> (IMHO) more explicit on this -- my guess is that session_id's aren't

> dataqueue scoped.

> 

> > +\end{itemize*}

> > +

> > +\devicenormative{\subparagraph}{Session operation: create session}{Device

> Types / Crypto Device / Device

> > +Operation / Control Virtqueue / Session operation / Session operation:

> create session}

> > +

> > +\begin{itemize*}

> > +\item The device MUST use the corresponding algorithm-specific structure

> according to the

> > +    \field{opcode} in the control general header.

> > +\item The device MUST set the \field{status} field to one of the following

> values of enum

> > +    VIRTIO_CRYPTO_STATUS after finish a session creation:

> > +\begin{itemize*}

> > +\item VIRTIO_CRYPTO_OK if a session is created successfully.

> > +\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is

> unsupported.

> > +\item VIRTIO_CRYPTO_NOSPC if no free session ID (only when the

> VIRTIO_CRYPTO_F_MUX_MODE

> > +    feature bit is negotiated).

> > +\item VIRTIO_CRYPTO_ERR if failure not mentioned above occurs.

> 

> I guess an invalid queue_id would be among these.

> 

> > +\end{itemize*}

> > +\item The device MUST set the \field{session_id} field to a unique session

> identifieronly

> s/identifieronly/identifier only

> > +    if the status is set to VIRTIO_CRYPTO_OK.

> > +\end{itemize*}

> > +

> > +\drivernormative{\subparagraph}{Session operation: destroy

> session}{Device Types / Crypto Device / Device

> > +Operation / Control Virtqueue / Session operation / Session operation:

> destroy session}

> > +

> > +\begin{itemize*}

> > +\item The driver MUST set the \field{opcode} field based on service type:

> CIPHER, HASH, MAC, or AEAD.

> > +\item The driver MUST set the \field{session_id} to a valid value assigned by

> the device

> > +    when the session was created.

> 

> Destroy does not need to specify queue_id. That means session_id's aren't

> queue scoped from namespace perspective. The question remains what is

> queue_id good for, and whether a session type op request should be

> rejected if the the session id originates from a session creation

> request specifying a different dataqueue (not the dataqueue containing

> the given request)?

> 


My original idea about the queue_id is using the queue_id to specify which
datequeue of the following data requests will be used. But after deep thinking,
I find that the queue_id is superfluous, and the current code in QEMU also
don't use the queue_id value as well. That's because the we can use session_id
to find the pervious session information and get the current dataqueue id
from the used virtqueue .

So maybe we should drop the queue_id this time.


> > +\end{itemize*}

> > +

> > +\devicenormative{\subparagraph}{Session operation: destroy

> session}{Device Types / Crypto Device / Device

> > +Operation / Control Virtqueue / Session operation / Session operation:

> destroy session}

> > +

> > +\begin{itemize*}

> > +\item The device MUST set the \field{status} field to one of the following

> values of enum VIRTIO_CRYPTO_STATUS.

> > +\begin{itemize*}

> > +\item VIRTIO_CRYPTO_OK if a session is created successfully.

> > +\item VIRTIO_CRYPTO_ERR if any failure occurs.

> > +\end{itemize*}

> > +\end{itemize*}

> > +

> > +\subsubsection{Data Virtqueue}\label{sec:Device Types / Crypto Device /

> Device Operation / Data Virtqueue}

> >

> 

> [..]

> 

> I've run through the rest. It some stuff seems very repetitive. I wonder if

> we can do better.

> 

> I also dislike this 5.7.7.5.3 Steps of Operation part. I also don't

> understand why is symmetric special in this respect (HASH, MAC and

> AEAD don't have a 'Steps of Operation' section.

> 

Hmm.. I just took a example as the symmetric is the most complicated operation. ;)

> I would like to try some things out with the reference implementation.

> Depending on how that goes I may or may not end up providing a detailed

> review for the rest before discussing what I've already addressed.

> 

Halil, Thank you for your work, pls go ahead :)

> Regards,

> Halil


Thanks,
-Gonglei
Halil Pasic Sept. 18, 2017, 1:08 p.m. UTC | #2
On 09/18/2017 02:13 PM, Gonglei (Arei) wrote:
>> Destroy does not need to specify queue_id. That means session_id's aren't
>> queue scoped from namespace perspective. The question remains what is
>> queue_id good for, and whether a session type op request should be
>> rejected if the the session id originates from a session creation
>> request specifying a different dataqueue (not the dataqueue containing
>> the given request)?
>>
> My original idea about the queue_id is using the queue_id to specify which
> datequeue of the following data requests will be used. But after deep thinking,
> I find that the queue_id is superfluous, and the current code in QEMU also
> don't use the queue_id value as well. That's because the we can use session_id
> to find the pervious session information and get the current dataqueue id
> from the used virtqueue .
> 
> So maybe we should drop the queue_id this time.
> 
> 

Sounds reasonable to me. We can make it reserved and ignored in
the specification. Linux uses it, but it's always set to 0 as we only
support one data-queue (if I'm not wrong). So reserved and must be zero
is an option too.

Halil
Gonglei (Arei) Sept. 18, 2017, 1:23 p.m. UTC | #3
> -----Original Message-----

> From: Halil Pasic [mailto:pasic@linux.vnet.ibm.com]

> Sent: Monday, September 18, 2017 9:08 PM

> Subject: Re: [Qemu-devel] [PATCH REPOST v19 1/2] virtio-crypto: Add virtio

> crypto device specification

> 

> 

> 

> On 09/18/2017 02:13 PM, Gonglei (Arei) wrote:

> >> Destroy does not need to specify queue_id. That means session_id's aren't

> >> queue scoped from namespace perspective. The question remains what is

> >> queue_id good for, and whether a session type op request should be

> >> rejected if the the session id originates from a session creation

> >> request specifying a different dataqueue (not the dataqueue containing

> >> the given request)?

> >>

> > My original idea about the queue_id is using the queue_id to specify which

> > datequeue of the following data requests will be used. But after deep

> thinking,

> > I find that the queue_id is superfluous, and the current code in QEMU also

> > don't use the queue_id value as well. That's because the we can use

> session_id

> > to find the pervious session information and get the current dataqueue id

> > from the used virtqueue .

> >

> > So maybe we should drop the queue_id this time.

> >

> >

> 

> Sounds reasonable to me. We can make it reserved and ignored in

> the specification. Linux uses it, but it's always set to 0 as we only

> support one data-queue (if I'm not wrong). So reserved and must be zero

> is an option too.

> 

Makes sense to keeping compatibility. 

Thanks,
-Gonglei
Xin Zeng Sept. 18, 2017, 2:51 p.m. UTC | #4
On Monday, September 18, 2017 9:24 PM, Gonglei (Arei) wrote:

< > On 09/18/2017 02:13 PM, Gonglei (Arei) wrote:
< > >> Destroy does not need to specify queue_id. That means session_id's aren't
< > >> queue scoped from namespace perspective. The question remains what is
< > >> queue_id good for, and whether a session type op request should be
< > >> rejected if the the session id originates from a session creation
< > >> request specifying a different dataqueue (not the dataqueue containing
< > >> the given request)?
< > >>
< > > My original idea about the queue_id is using the queue_id to specify which
< > > datequeue of the following data requests will be used. But after deep
< > thinking,
< > > I find that the queue_id is superfluous, and the current code in QEMU also
< > > don't use the queue_id value as well. That's because the we can use
< > session_id
< > > to find the pervious session information and get the current dataqueue id
< > > from the used virtqueue .
< > >
< > > So maybe we should drop the queue_id this time.
< > >
< > >
< >
< > Sounds reasonable to me. We can make it reserved and ignored in
< > the specification. Linux uses it, but it's always set to 0 as we only
< > support one data-queue (if I'm not wrong). So reserved and must be zero
< > is an option too.
< >
< Makes sense to keeping compatibility.
< 

If we always set it to 0, and backend device doesn't specify the queue
id when creating session, this works only when one data queue is
supported. But if we want to support multi data queues,
how does frontend driver know which queue it should use when 
sending requests to the virt queue? And furthermore, if the data queue 
id which can be used is determined by backend device, how does 
guest frontend driver know which queue can be used when operating
in stateless mode in case multi data queue is supported?
So from my point of view, session should only be associated with service
related information, but not associated with the transport layer information,
i.e. data queue id in this case. The data queue to be used should be chosen by
frontend driver. Frontend driver can use any valid data queue to send requests
to backend device, backend device need to extract the session information
from the request packet and retrieve the request's session info then handle it 
correspondingly.

< Thanks,
< -Gonglei
Halil Pasic Sept. 18, 2017, 4:32 p.m. UTC | #5
On 09/18/2017 04:51 PM, Zeng, Xin wrote:
> On Monday, September 18, 2017 9:24 PM, Gonglei (Arei) wrote:
> 
> < > On 09/18/2017 02:13 PM, Gonglei (Arei) wrote:
> < > >> Destroy does not need to specify queue_id. That means session_id's aren't
> < > >> queue scoped from namespace perspective. The question remains what is
> < > >> queue_id good for, and whether a session type op request should be
> < > >> rejected if the the session id originates from a session creation
> < > >> request specifying a different dataqueue (not the dataqueue containing
> < > >> the given request)?
> < > >>
> < > > My original idea about the queue_id is using the queue_id to specify which
> < > > datequeue of the following data requests will be used. But after deep
> < > thinking,
> < > > I find that the queue_id is superfluous, and the current code in QEMU also
> < > > don't use the queue_id value as well. That's because the we can use
> < > session_id
> < > > to find the pervious session information and get the current dataqueue id
> < > > from the used virtqueue .
> < > >
> < > > So maybe we should drop the queue_id this time.
> < > >
> < > >
> < >
> < > Sounds reasonable to me. We can make it reserved and ignored in
> < > the specification. Linux uses it, but it's always set to 0 as we only
> < > support one data-queue (if I'm not wrong). So reserved and must be zero
> < > is an option too.
> < >
> < Makes sense to keeping compatibility.
> < 
> 
> If we always set it to 0, and backend device doesn't specify the queue
> id when creating session, this works only when one data queue is
> supported. But if we want to support multi data queues,
> how does frontend driver know which queue it should use when 
> sending requests to the virt queue? And furthermore, if the data queue 
> id which can be used is determined by backend device, how does 
> guest frontend driver know which queue can be used when operating
> in stateless mode in case multi data queue is supported?

AFAIU you answered your own questions (questions above, answers below). Gonglei
has just stated that he intends to abandon the queue_id.

> So from my point of view, session should only be associated with service
> related information, but not associated with the transport layer information,
> i.e. data queue id in this case. The data queue to be used should be chosen by
> frontend driver. Frontend driver can use any valid data queue to send requests
> to backend device, backend device need to extract the session information
> from the request packet and retrieve the request's session info then handle it 
> correspondingly.

AFAIU that's what we have agreed, basically. I'm not sure about your wording
(for instance I would have said session identifier instead of session information),
but I think we think the same. In short conceptually all configured data queues
are equivalent in the sense that it does not matter on which queue a request is
placed -- modulo capacity.

Halil

> 
> < Thanks,
> < -Gonglei
>
Xin Zeng Sept. 19, 2017, 8:01 a.m. UTC | #6
on September 19, 2017 12:33 AM Halil Pasic Wrote:
< > < > >> Destroy does not need to specify queue_id. That means session_id's
< aren't
< > < > >> queue scoped from namespace perspective. The question remains what
< is
< > < > >> queue_id good for, and whether a session type op request should be
< > < > >> rejected if the the session id originates from a session creation
< > < > >> request specifying a different dataqueue (not the dataqueue containing
< > < > >> the given request)?
< > < > >>
< > < > > My original idea about the queue_id is using the queue_id to specify
< which
< > < > > datequeue of the following data requests will be used. But after deep
< > < > thinking,
< > < > > I find that the queue_id is superfluous, and the current code in QEMU
< also
< > < > > don't use the queue_id value as well. That's because the we can use
< > < > session_id
< > < > > to find the pervious session information and get the current dataqueue id
< > < > > from the used virtqueue .
< > < > >
< > < > > So maybe we should drop the queue_id this time.
< > < > >
< > < > >
< > < >
< > < > Sounds reasonable to me. We can make it reserved and ignored in
< > < > the specification. Linux uses it, but it's always set to 0 as we only
< > < > support one data-queue (if I'm not wrong). So reserved and must be zero
< > < > is an option too.
< > < >
< > < Makes sense to keeping compatibility.
< > <
< >
< > If we always set it to 0, and backend device doesn't specify the queue
< > id when creating session, this works only when one data queue is
< > supported. But if we want to support multi data queues,
< > how does frontend driver know which queue it should use when
< > sending requests to the virt queue? And furthermore, if the data queue
< > id which can be used is determined by backend device, how does
< > guest frontend driver know which queue can be used when operating
< > in stateless mode in case multi data queue is supported?
< 
< AFAIU you answered your own questions (questions above, answers below).
< Gonglei
< has just stated that he intends to abandon the queue_id.
< 
< > So from my point of view, session should only be associated with service
< > related information, but not associated with the transport layer information,
< > i.e. data queue id in this case. The data queue to be used should be chosen by
< > frontend driver. Frontend driver can use any valid data queue to send requests
< > to backend device, backend device need to extract the session information
< > from the request packet and retrieve the request's session info then handle it
< > correspondingly.
< 
< AFAIU that's what we have agreed, basically. I'm not sure about your wording
< (for instance I would have said session identifier instead of session information),
< but I think we think the same. In short conceptually all configured data queues
< are equivalent in the sense that it does not matter on which queue a request is
< placed -- modulo capacity.

Actually I agreed with your point to make queue_id reserved  in 
current implementation and ignored in the spec. I just want to clarify the 
usage of virt queues especially when multi data queue is supported.
Now it's clear, thanks.

Cheers
Xin

< 
< Halil
< 
< >
< > < Thanks,
< > < -Gonglei
< >n
< 
< 
< ---------------------------------------------------------------------
< To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org
< For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org
Longpeng(Mike) Sept. 26, 2017, 1:55 p.m. UTC | #7
Hi Halil,

On 2017/9/15 22:39, Halil Pasic wrote:

> 
> 
> On 09/11/2017 03:12 AM, Longpeng(Mike) wrote:
>> From: Gonglei <arei.gonglei@huawei.com>
>>
>> The virtio crypto device is a virtual crypto device (ie. hardware
>> crypto accelerator card). Currently, the virtio crypto device provides
>> the following crypto services: CIPHER, MAC, HASH, and AEAD.
>>
>> In this patch, CIPHER, MAC, HASH, AEAD services are introduced.
>>
>> VIRTIO-153
>>
>> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
>> Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
>> ---
>>  acknowledgements.tex |    3 +
>>  content.tex          |    2 +
>>  virtio-crypto.tex    | 1479 ++++++++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 1484 insertions(+)
>>  create mode 100644 virtio-crypto.tex
>>
>> diff --git a/acknowledgements.tex b/acknowledgements.tex
>> index 6c86d12..c4b6844 100644
>> --- a/acknowledgements.tex
>> +++ b/acknowledgements.tex
>> @@ -26,6 +26,8 @@ Sasha Levin,	Oracle	\newline
>>  Sergey Tverdyshev,	Thales e-Security	\newline
>>  Stefan Hajnoczi,	Red Hat	\newline
>>  Tom Lyon,	Samya Systems, Inc.	\newline
>> +Lei Gong,	Huawei	\newline
>> +Peng Long,	Huawei	\newline
>>  \end{oasistitlesection}
>>
>>  The following non-members have provided valuable feedback on this
>> @@ -43,4 +45,5 @@ Laura Novich, Red Hat	\newline
>>  Patrick Durusau,	Technical Advisory Board, OASIS	\newline
>>  Thomas Huth,	IBM	\newline
>>  Yan Vugenfirer, Red Hat / Daynix	\newline
>> +Halil Pasic,	IBM	\newline
>>  \end{oasistitlesection}
>> diff --git a/content.tex b/content.tex
>> index d989d98..7710f8c 100644
>> --- a/content.tex
>> +++ b/content.tex
>> @@ -5641,6 +5641,8 @@ descriptor for the \field{sense_len}, \field{residual},
>>  \field{status_qualifier}, \field{status}, \field{response} and
>>  \field{sense} fields.
>>
>> +\input{virtio-crypto.tex}
>> +
>>  \chapter{Reserved Feature Bits}\label{sec:Reserved Feature Bits}
>>
>>  Currently there are three device-independent feature bits defined:
>> diff --git a/virtio-crypto.tex b/virtio-crypto.tex
>> new file mode 100644
>> index 0000000..1e75cbc
>> --- /dev/null
>> +++ b/virtio-crypto.tex
>> @@ -0,0 +1,1479 @@
>> +\section{Crypto Device}\label{sec:Device Types / Crypto Device}
>> +
>> +The virtio crypto device is a virtual cryptography device as well as a
>> +virtual cryptographic accelerator. The virtio crypto device provides the
>> +following crypto services: CIPHER, MAC, HASH, and AEAD. Virtio crypto
>> +devices have a single control queue and at least one data queue. Crypto
>> +operation requests are placed into a data queue, and serviced by the
>> +device. Some crypto operation requests are only valid in the context of a
>> +session. The role of the control queue is facilitating control operation
>> +requests. Sessions management is realized with control operation
>> +requests.
>> +
>> +\subsection{Device ID}\label{sec:Device Types / Crypto Device / Device ID}
>> +
>> +20
>> +
>> +\subsection{Virtqueues}\label{sec:Device Types / Crypto Device / Virtqueues}
>> +
>> +\begin{description}
>> +\item[0] dataq1
>> +\item[\ldots]
>> +\item[N-1] dataqN
>> +\item[N] controlq
>> +\end{description}
>> +
>> +N is set by \field{max_dataqueues}.
>> +
>> +\subsection{Feature bits}\label{sec:Device Types / Crypto Device / Feature bits}
>> +
>> +\begin{description}
>> +\item VIRTIO_CRYPTO_F_MUX_MODE (0) multiplexing mode is available.
>> +\item VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE (1) stateless mode is available for CIPHER service.
>> +\item VIRTIO_CRYPTO_F_HASH_STATELESS_MODE (2) stateless mode is available for HASH service.
>> +\item VIRTIO_CRYPTO_F_MAC_STATELESS_MODE (3) stateless mode is available for MAC service.
>> +\item VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE (4) stateless mode is available for AEAD service.
>> +\end{description}
>> +
>> +\subsubsection{Feature bit requirements}\label{sec:Device Types / Crypto Device / Feature bits}
>> +
>> +Some crypto feature bits require other crypto feature bits
>> +(see \ref{drivernormative:Basic Facilities of a Virtio Device / Feature Bits}):
>> +
>> +\begin{description}
>> +\item[VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE] Requires VIRTIO_CRYPTO_F_MUX_MODE.
>> +\item[VIRTIO_CRYPTO_F_HASH_STATELESS_MODE] Requires VIRTIO_CRYPTO_F_MUX_MODE.
>> +\item[VIRTIO_CRYPTO_F_MAC_STATELESS_MODE] Requires VIRTIO_CRYPTO_F_MUX_MODE.
>> +\item[VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE] Requires VIRTIO_CRYPTO_F_MUX_MODE.
>> +\end{description}
>> +
>> +\subsection{Supported crypto services}\label{sec:Device Types / Crypto Device / Supported crypto services}
>> +
>> +The following crypto services are defined:
>> +
>> +\begin{lstlisting}
>> +/* CIPHER service */
>> +#define VIRTIO_CRYPTO_SERVICE_CIPHER 0
>> +/* HASH service */
>> +#define VIRTIO_CRYPTO_SERVICE_HASH   1
>> +/* MAC (Message Authentication Codes) service */
>> +#define VIRTIO_CRYPTO_SERVICE_MAC    2
>> +/* AEAD (Authenticated Encryption with Associated Data) service */
>> +#define VIRTIO_CRYPTO_SERVICE_AEAD   3
>> +\end{lstlisting}
>> +
>> +The above constants designate bits used to indicate the which of crypto services are
>> +offered by the device as described in, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
>> +
>> +\subsubsection{CIPHER services}\label{sec:Device Types / Crypto Device / Supported crypto services / CIPHER services}
>> +
>> +The following CIPHER algorithms are defined:
>> +
>> +\begin{lstlisting}
>> +#define VIRTIO_CRYPTO_NO_CIPHER                 0
>> +#define VIRTIO_CRYPTO_CIPHER_ARC4               1
>> +#define VIRTIO_CRYPTO_CIPHER_AES_ECB            2
>> +#define VIRTIO_CRYPTO_CIPHER_AES_CBC            3
>> +#define VIRTIO_CRYPTO_CIPHER_AES_CTR            4
>> +#define VIRTIO_CRYPTO_CIPHER_DES_ECB            5
>> +#define VIRTIO_CRYPTO_CIPHER_DES_CBC            6
>> +#define VIRTIO_CRYPTO_CIPHER_3DES_ECB           7
>> +#define VIRTIO_CRYPTO_CIPHER_3DES_CBC           8
>> +#define VIRTIO_CRYPTO_CIPHER_3DES_CTR           9
>> +#define VIRTIO_CRYPTO_CIPHER_KASUMI_F8          10
>> +#define VIRTIO_CRYPTO_CIPHER_SNOW3G_UEA2        11
>> +#define VIRTIO_CRYPTO_CIPHER_AES_F8             12
>> +#define VIRTIO_CRYPTO_CIPHER_AES_XTS            13
>> +#define VIRTIO_CRYPTO_CIPHER_ZUC_EEA3           14
>> +\end{lstlisting}
>> +
>> +The above constants have two usages:
>> +\begin{enumerate}
>> +\item As bit numbers, used to tell the driver which CIPHER algorithms
>> +are supported by the device, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
>> +\item As values, used to tell the device which CIPHER algorithm
>> +a crypto request from the driver requires, see \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}.
>> +\end{enumerate}
>> +
>> +\subsubsection{HASH services}\label{sec:Device Types / Crypto Device / Supported crypto services / HASH services}
>> +
>> +The following HASH algorithms are defined:
>> +
>> +\begin{lstlisting}
>> +#define VIRTIO_CRYPTO_NO_HASH            0
>> +#define VIRTIO_CRYPTO_HASH_MD5           1
>> +#define VIRTIO_CRYPTO_HASH_SHA1          2
>> +#define VIRTIO_CRYPTO_HASH_SHA_224       3
>> +#define VIRTIO_CRYPTO_HASH_SHA_256       4
>> +#define VIRTIO_CRYPTO_HASH_SHA_384       5
>> +#define VIRTIO_CRYPTO_HASH_SHA_512       6
>> +#define VIRTIO_CRYPTO_HASH_SHA3_224      7
>> +#define VIRTIO_CRYPTO_HASH_SHA3_256      8
>> +#define VIRTIO_CRYPTO_HASH_SHA3_384      9
>> +#define VIRTIO_CRYPTO_HASH_SHA3_512      10
>> +#define VIRTIO_CRYPTO_HASH_SHA3_SHAKE128      11
>> +#define VIRTIO_CRYPTO_HASH_SHA3_SHAKE256      12
>> +\end{lstlisting}
>> +
>> +The above constants have two usages:
>> +\begin{enumerate}
>> +\item As bit numbers, used to tell the driver which HASH algorithms
>> +are supported by the device, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
>> +\item As values, used to tell the device which HASH algorithm
>> +a crypto request from the driver requires, see \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}.
>> +\end{enumerate}
>> +
>> +\subsubsection{MAC services}\label{sec:Device Types / Crypto Device / Supported crypto services / MAC services}
>> +
>> +The following MAC algorithms are defined:
>> +
>> +\begin{lstlisting}
>> +#define VIRTIO_CRYPTO_NO_MAC                       0
>> +#define VIRTIO_CRYPTO_MAC_HMAC_MD5                 1
>> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA1                2
>> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA_224             3
>> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA_256             4
>> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA_384             5
>> +#define VIRTIO_CRYPTO_MAC_HMAC_SHA_512             6
>> +#define VIRTIO_CRYPTO_MAC_CMAC_3DES                25
>> +#define VIRTIO_CRYPTO_MAC_CMAC_AES                 26
>> +#define VIRTIO_CRYPTO_MAC_KASUMI_F9                27
>> +#define VIRTIO_CRYPTO_MAC_SNOW3G_UIA2              28
>> +#define VIRTIO_CRYPTO_MAC_GMAC_AES                 41
>> +#define VIRTIO_CRYPTO_MAC_GMAC_TWOFISH             42
>> +#define VIRTIO_CRYPTO_MAC_CBCMAC_AES               49
>> +#define VIRTIO_CRYPTO_MAC_CBCMAC_KASUMI_F9         50
>> +#define VIRTIO_CRYPTO_MAC_XCBC_AES                 53
>> +#define VIRTIO_CRYPTO_MAC_ZUC_EIA3                 54
>> +\end{lstlisting}
>> +
>> +The above constants have two usages:
>> +\begin{enumerate}
>> +\item As bit numbers, used to tell the driver which MAC algorithms
>> +are supported by the device, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
>> +\item As values, used to tell the device which MAC algorithm
>> +a crypto request from the driver requires, see \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}.
> 
> Cosmetic comment: instead of 'used to tell the device which MAC algorithm
> a crypto request form the driver requires' I would prefer  'used to designate
> the algorithm in (MAC type) crypto operation requests'.
> 


OK, yours is more decent. :)

> I think, your version is good enough (won't be misunderstood)  it is just
> that request requires sound a bit weird to me. I'm not sure my version is
> better though.
> 
>> +\end{enumerate}
>> +
>> +\subsubsection{AEAD services}\label{sec:Device Types / Crypto Device / Supported crypto services / AEAD services}
>> +
>> +The following AEAD algorithms are defined:
>> +
>> +\begin{lstlisting}
>> +#define VIRTIO_CRYPTO_NO_AEAD     0
>> +#define VIRTIO_CRYPTO_AEAD_GCM    1
>> +#define VIRTIO_CRYPTO_AEAD_CCM    2
>> +#define VIRTIO_CRYPTO_AEAD_CHACHA20_POLY1305  3
>> +\end{lstlisting}
>> +
>> +The above constants have two usages:
>> +\begin{enumerate}
>> +\item As bit numbers, used to tell the driver which AEAD algorithms
>> +are supported by the device, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
>> +\item As values, used to tell the device what AEAD algorithm
>> +a crypto request from the driver requires, see \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}.
> 
> More or less same as above (and we have some more similar occurrences below).
> 

OK.

>> +\end{enumerate}
>> +
>> +\subsection{Device configuration layout}\label{sec:Device Types / Crypto Device / Device configuration layout}
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_config {
>> +    le32 status;
>> +    le32 max_dataqueues;
>> +    le32 crypto_services;
>> +    /* Detailed algorithms mask */
>> +    le32 cipher_algo_l;
>> +    le32 cipher_algo_h;
>> +    le32 hash_algo;
>> +    le32 mac_algo_l;
>> +    le32 mac_algo_h;
>> +    le32 aead_algo;
>> +    /* Maximum length of cipher key in bytes */
>> +    le32 max_cipher_key_len;
>> +    /* Maximum length of authenticated key in bytes */
>> +    le32 max_auth_key_len;
>> +    le32 reserved;
>> +    /* Maximum size of each crypto request's content in bytes */
>> +    le64 max_size;
>> +};
>> +\end{lstlisting}
>> +
>> +\begin{description}
>> +\item[\field{status}] is used to show whether the device is ready to work or
>> +    not, it can be either zero or have one or more flags. Only one read-only
>> +	bit (for the driver) is currently defined for the \field{status} field: VIRTIO_CRYPTO_S_HW_READY:
> 
> Cosmetic comment: maybe 'Currently, only one \field(status) bit is defined:
> IRTIO_CRYPTO_S_HW_READY set indicates that the device is ready to process
> requests, this bit is read-only for the driver
> 

OK.

> While trying to reword this, I started thinking about whether read-only
> makes sense for individual bits. I think it does not (I think we can't
> do something like compare and swap to make this work). Does read
> only even make sense for configuration space? I mean it is not random
> access AFAIK (see 4.3 Virtio Over Channel I/O)?
> 
> I'm confused abut the config space in general. I've expected that after
> a certain stage it can be only changed by the device, but I didn't
> manage to find a corresponding statement in the spec.
> 

I'm not sure whether I understand you correctly.

For the virtio-crypto device, the fields in the configure space are all fixed
after the initialization, so maybe make them read-only is acceptable.

>> +\begin{lstlisting}
>> +#define VIRTIO_CRYPTO_S_HW_READY  (1 << 0)
>> +\end{lstlisting}
>> +
>> +\item[\field{max_dataqueues}] is the maximum number of data virtqueues exposed by
>> +    the device. The driver MAY use only one data queue,
>> +    or it can use more to achieve better performance.
> 
> s/exposed/ that can be configured/
> 

> This is the wording virtio-net uses (if I'm not mistaken). Exposed can be
> misleading.
> 

OK.

>> +
>> +\item[\field{crypto_services}] crypto service offered, see \ref{sec:Device Types / Crypto Device / Supported crypto services}.
>> +
>> +\item[\field{cipher_algo_l}] CIPHER algorithms bits 0-31, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / CIPHER services}.
>> +
>> +\item[\field{cipher_algo_h}] CIPHER algorithms bits 32-63, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / CIPHER services}.
>> +
>> +\item[\field{hash_algo}] HASH algorithms bits, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / HASH services}.
>> +
>> +\item[\field{mac_algo_l}] MAC algorithms bits 0-31, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / MAC services}.
>> +
>> +\item[\field{mac_algo_h}] MAC algorithms bits 32-63, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / MAC services}.
>> +
>> +\item[\field{aead_algo}] AEAD algorithms bits, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / AEAD services}.
>> +
>> +\item[\field{max_cipher_key_len}] is the maximum length of cipher key supported by the device.
>> +
>> +\item[\field{max_auth_key_len}] is the maximum length of authenticated key supported by the device.
>> +
>> +\item[\field{reserved}] is reserved for future use.
>> +
>> +\item[\field{max_size}] is the maximum size of each crypto request's content supported by the device
>> +\end{description}
>> +
>> +\begin{note}
>> +Unless explicitly stated otherwise all lengths and sizes are in bytes.
>> +\end{note}
>> +
>> +\devicenormative{\subsubsection}{Device configuration layout}{Device Types / Crypto Device / Device configuration layout}
>> +
>> +\begin{itemize*}
>> +\item The device MUST set \field{max_dataqueues} to between 1 and 65535 inclusive.
>> +\item The device MUST set the \field{status} flag based on the status of the crypto
> s/flag/flags ?
>> +    accelerator, Non-valid flags MUST NOT be set.
> What does this mean? It is a device requirement so it can't be about the driver.
> What does the device have to do if it encounters an unknown flag?


How about: The device MUST set the \field{status} with valid flags, undefined
flags MUST NOT be set ?

The existing crypto device in QEMU only sets VIRTIO_CRYPTO_S_HW_READY and other
bits are zero, it's impossible to encounters an undefined flag.

> 
>> +\item The device MUST accept and handle requests after \field{status} is set to VIRTIO_CRYPTO_S_HW_READY.
>> +\item The device MUST set \field{crypto_services} based on the crypto services the device offers.
>> +\item The device MUST set detailed algorithms masks for each service advertised by \field{crypto_services}.
>> +    The device MUST NOT set the not defined algorithms bits.
>> +\item The device MUST set \field{max_size} to show the maximum size of crypto request the device supports.
>> +\item The device MUST set \field{max_cipher_key_len} to show the maximum length of cipher key if the
>> +    device supports CIPHER service.
>> +\item The device MUST set \field{max_auth_key_len} to show the maximum length of authenticated key if
>> +    the device supports MAC service.
>> +\end{itemize*}
>> +
>> +\drivernormative{\subsubsection}{Device configuration layout}{Device Types / Crypto Device / Device configuration layout}
>> +
>> +\begin{itemize*}
>> +\item The driver MUST read the ready \field{status} from the bottom bit of status to check whether the
>> +    crypto accelerator is ready or not, and the driver MUST reread it after device reset.
> 
> You use 'ready' instead of VIRTIO_CRYPTO_S_HW_READY here and in the next point.
> s/ MUST read the ready \field{status}/ MUST read the \field{status}/ ?
> s/crypto accelerator is ready or not/VIRTIO_CRYPTO_S_HW_READY is set/ ?
> 

Uh, this is much better, thanks :)

>> +\item The driver MUST NOT transmit any requests to the device if the ready \field{status} is not set.
> s/if the ready \field{status}/VIRTIO_CRYPTO_S_HW_READY/ ?

OK.

>> +\item The driver MUST read \field{max_dataqueues} field to discover the number of data queues the device supports.> +\item The driver MUST read \field{crypto_services} field to discover which services the device is able to offer.
>> +\item The driver SHOULD ignore the not defined algorithms bits.
>> +\item The driver MUST read the detailed algorithms fields based on \field{crypto_services} field.
>> +\item The driver SHOULD read \field{max_size} to discover the maximum size of crypto request the device supports.
>> +\item The driver SHOULD read \field{max_cipher_key_len} to discover the maximum length of cipher key
>> +    the device supports.
>> +\item The driver SHOULD read \field{max_auth_key_len} to discover the maximum length of authenticated
>> +    key the device supports.
>> +\end{itemize*}
>> +
>> +\subsection{Device Initialization}\label{sec:Device Types / Crypto Device / Device Initialization}
>> +
>> +\drivernormative{\subsubsection}{Device Initialization}{Device Types / Crypto Device / Device Initialization}
>> +
>> +\begin{itemize*}
>> +\item The driver MUST identify and initialize all virtqueues.
> s/initialize/configure/ ?
> 

OK.

> I wonder, do we really want to mandate configuring all virtqueues even
> if some are going to be unused? If yes why?
> 

IMHO the virtio-net does, please see:
	\Device Types\Network Device\Device Initialization

In my opinion, this can makes everything as simple as possible. We need to
consider some complex situations if the vqs are configured as required, e.g,
what should the driver to do if initialize the vq failure.

>> +\item The driver MUST read the supported crypto services from bits of \field{crypto_services}.
>> +\item The driver MUST read the supported algorithms based on \field{crypto_services} field.
>> +\end{itemize*}
>> +
>> +\subsection{Device Operation}\label{sec:Device Types / Crypto Device / Device Operation}
>> +
>> +Requests can be transmitted by placing them in the controlq or dataq.
> 
> How about: The operation of a virtio crypto device is driven by requests
> placed on the virtqueues.
> 
> I don't like 'can be transmitted' and 'or' in your sentence. I can't put
> my finger on it.
> 

OK.

>> +Requests consist of a queue-type specific header specifying among
>> +others the operation, and an operation specific payload.
> 
> Maybe put 'specifying among others the operation' in parenthesis or
> between comas (I'm no good with grammar -- someone competent help!).
> 

OK.

>> +The payload is generally composed of operation parameters, output data, and input data.
>> +Operation parameters are algorithm-specific parameters, output data is the
> 
> Start a new sentence at the comma.

OK.

> 
>> +data that should be utilized in operations, and input data is equal to
>> +"operation result + result data".
>> +
>> +The device can support both session mode (See \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}) and stateless mode.
> 
> How about if VIRTIO_CRYPTO_F_MUX_MODE is negotioated the device
> may support both session mode ... and stateless mode operation requests.
> 

Uh, yours is pretty good :)

>> +In stateless mode all operation parameters are supplied as a part
>> +of each request, while in session mode, some or all operation parameters
>> +are managed within the session. Stateless mode is guarded by
>> +feature bits 0-4 on a service level. If stateless mode is negotiated
>> +for a service, the service is available both in session and
>> +stateless mode; otherwise it's only available in session mode.
>> +
>> +The device can set the operation status as follows:
> 
> This is the first time you mention operation status. The only status
> we have defined is the config layout status. Can we introduce the
> operation status later? Alternatively before we intreudce the op status
> code we could tell something about how requests serviced, and of course
> introduce the op status field as the part of (each?) request.
> 

OK, I'll introduce them later in the next version.

>> +
>> +\begin{lstlisting}
>> +enum VIRTIO_CRYPTO_STATUS {
>> +    VIRTIO_CRYPTO_OK = 0,
>> +    VIRTIO_CRYPTO_ERR = 1,
>> +    VIRTIO_CRYPTO_BADMSG = 2,
>> +    VIRTIO_CRYPTO_NOTSUPP = 3,
>> +    VIRTIO_CRYPTO_INVSESS = 4,
>> +    VIRTIO_CRYPTO_NOSPC = 5,
>> +    VIRTIO_CRYPTO_MAX
>> +};
>> +\end{lstlisting}
>> +
> 
> [..]
> 
> I will continue reviewing right away but wanted to slit this up because
> the patch is huge.
> 
> My overall impression is pretty decent (up until this point) even
> with my suggestions ignored. If this weren't a standard I wouldn't probably
> bother with most of the comments (a la, it's good enough and can be improved
> upon later if deemed necessary), but since it's a standard it's more important
> to get things as good as possible already in the first version.


Yea, thank for your patience and comments, they're very useful. :)

> 
> Regards,
> Halil
> 
> 
> .
>
Longpeng(Mike) Sept. 27, 2017, 1:50 a.m. UTC | #8
Hi Halil,

On 2017/9/15 23:59, Halil Pasic wrote:

> 
> 
> On 09/11/2017 03:12 AM, Longpeng(Mike) wrote:
>> From: Gonglei <arei.gonglei@huawei.com>
>>
>> The virtio crypto device is a virtual crypto device (ie. hardware
>> crypto accelerator card). Currently, the virtio crypto device provides
>> the following crypto services: CIPHER, MAC, HASH, and AEAD.
>>
>> In this patch, CIPHER, MAC, HASH, AEAD services are introduced.
>>
>> VIRTIO-153
>>
>> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
>> Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
>> ---
> [..]
> 
> 
>> +\subsubsection{Control Virtqueue}\label{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue}
>> +
>> +The driver uses the control virtqueue to send control commands to the
>> +device, such as session operations (See \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}).
>> +
>> +The header for controlq is of the following form:
>> +\begin{lstlisting}
>> +#define VIRTIO_CRYPTO_OPCODE(service, op)   (((service) << 8) | (op))
>> +
>> +struct virtio_crypto_ctrl_header {
>> +#define VIRTIO_CRYPTO_CIPHER_CREATE_SESSION \
>> +       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x02)
>> +#define VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION \
>> +       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x03)
>> +#define VIRTIO_CRYPTO_HASH_CREATE_SESSION \
>> +       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_HASH, 0x02)
>> +#define VIRTIO_CRYPTO_HASH_DESTROY_SESSION \
>> +       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_HASH, 0x03)
>> +#define VIRTIO_CRYPTO_MAC_CREATE_SESSION \
>> +       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_MAC, 0x02)
>> +#define VIRTIO_CRYPTO_MAC_DESTROY_SESSION \
>> +       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_MAC, 0x03)
>> +#define VIRTIO_CRYPTO_AEAD_CREATE_SESSION \
>> +       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x02)
>> +#define VIRTIO_CRYPTO_AEAD_DESTROY_SESSION \
>> +       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x03)
>> +    le32 opcode;
>> +    /* algo should be service-specific algorithms */
>> +    le32 algo;
>> +    le32 flag;
>> +    /* data virtqueue id */
>> +    le32 queue_id;
>> +};
>> +\end{lstlisting}
>> +
>> +The format of the controlq request depends on the VIRTIO_CRYPTO_F_MUX_MODE feature bit:
>> +
>> +\begin{itemize*}
>> +\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is NOT negotiated the controlq request is
>> +    a fixed-size structure of form:
>> +\begin{lstlisting}
>> +struct virtio_crypto_op_ctrl_req {
>> +    struct virtio_crypto_ctrl_header header;
>> +
>> +    union {
>> +        struct virtio_crypto_sym_create_session_req   sym_create_session;
>> +        struct virtio_crypto_hash_create_session_req  hash_create_session;
>> +        struct virtio_crypto_mac_create_session_req   mac_create_session;
>> +        struct virtio_crypto_aead_create_session_req  aead_create_session;
>> +        struct virtio_crypto_destroy_session_req      destroy_session;
>> +    } u;
>> +};
>> +\end{lstlisting}
>> +The header is the general header, and the union is of the algorithm-specific type or the
>> +virtio_crypto_destroy_session_req structure, which is set by the driver. All the properties
>> +in the union are shown as follows.
>> +
>> +\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated the controlq request is composed
>> +    of two parts, the additional paramenters are preceded by the general header.
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_op_ctrl_req_mux {
>> +    struct virtio_crypto_ctrl_header header;
>> +
>> +    /* additional paramenter */
>> +    u8 additional_para[addl_para_len];
>> +};
>> +\end{lstlisting}
>> +
>> +The additional paramenters are stored in a virtio_crypto_destroy_session_req structure or
>> +in a algorithm-specific structure:
>> +\begin{itemize*}
>> +\item struct virtio_crypto_sym_create_session_req
>> +\item struct virtio_crypto_hash_create_session_req
>> +\item struct virtio_crypto_mac_create_session_req
>> +\item struct virtio_crypto_aead_create_session_req
>> +\end{itemize*}
>> +All of the structures above are shown as follows.
>> +\end{itemize*}
>> +
>> +\paragraph{Session operation}\label{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}
>> +
>> +The session is a
>> +handle which describes the cryptographic parameters to be applied to
>> +a number of buffers.
>> +
>> +The following structure stores the result of session creation set by the device:
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_session_input {
>> +    /* Device-writable part */
>> +    le64 session_id;
>> +    le32 status;
>> +    le32 padding;
>> +};
>> +\end{lstlisting}
>> +
>> +A request to destroy a session includes the following information:
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_destroy_session_req {
>> +    /* Device-readable part */
>> +    le64  session_id;
>> +    /* Device-writable part */
>> +    le32  status;
>> +    le32  padding;
>> +};
>> +\end{lstlisting}
>> +
>> +\subparagraph{Session operation: HASH session}\label{sec:Device Types / Crypto Device / Device
>> +Operation / Control Virtqueue / Session operation / Session operation: HASH session}
>> +
>> +HASH session requests are as follows:
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_hash_session_para {
>> +    /* See VIRTIO_CRYPTO_HASH_* above */
>> +    le32 algo;
>> +    /* hash result length */
>> +    le32 hash_result_len;
>> +};
>> +struct virtio_crypto_hash_create_session_req {
>> +    /* Device-readable part */
>> +    struct virtio_crypto_hash_session_para para;
>> +    /* Device-writable part */
>> +    struct virtio_crypto_session_input input;
>> +};
>> +\end{lstlisting}
>> +
>> +The information required by HASH session creation is stored in the virtio_crypto_hash_create_session_req
>> +structure, including the hash parameters stored in \field{para}. \field{input} stores the result of this operation.
>> +
>> +\subparagraph{Session operation: MAC session}\label{sec:Device Types / Crypto Device / Device
>> +Operation / Control Virtqueue / Session operation / Session operation: MAC session}
>> +
>> +MAC session requests are as follows:
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_mac_session_para {
>> +    /* See VIRTIO_CRYPTO_MAC_* above */
>> +    le32 algo;
>> +    /* hash result length */
>> +    le32 hash_result_len;
>> +    /* length of authenticated key */
>> +    le32 auth_key_len;
>> +    le32 padding;
>> +};
>> +
>> +struct virtio_crypto_mac_create_session_req {
>> +    /* Device-readable part */
>> +    struct virtio_crypto_mac_session_para para;
>> +    /* The authenticated key */
>> +    u8 auth_key[auth_key_len];
>> +
>> +    /* Device-writable part */
>> +    struct virtio_crypto_session_input input;
>> +};
>> +\end{lstlisting}
>> +
>> +The information required by MAC session creation is stored in the virtio_crypto_mac_create_session_req
>> +structure, including the mac parameters stored in \field{para} and the authenticated key in \field{auth_key}.
>> +\field{input} stores the result of this operation.
>> +
>> +\subparagraph{Session operation: Symmetric algorithms session}\label{sec:Device Types / Crypto Device / Device
>> +Operation / Control Virtqueue / Session operation / Session operation: Symmetric algorithms session}
>> +
>> +The request of symmetric session includes two parts, CIPHER algorithms and chain
>> +algorithms (chaining CIPHER and HASH/MAC).
>> +
>> +CIPHER session requests are as follows:
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_cipher_session_para {
>> +    /* See VIRTIO_CRYPTO_CIPHER* above */
>> +    le32 algo;
>> +    /* length of key */
>> +    le32 keylen;
>> +#define VIRTIO_CRYPTO_OP_ENCRYPT  1
>> +#define VIRTIO_CRYPTO_OP_DECRYPT  2
>> +    /* encryption or decryption */
>> +    le32 op;
>> +    le32 padding;
>> +};
>> +
>> +struct virtio_crypto_cipher_session_req {
>> +    /* Device-readable part */
>> +    struct virtio_crypto_cipher_session_para para;
>> +    /* The cipher key */
>> +    u8 cipher_key[keylen];
>> +
>> +    /* Device-writable part */
>> +    struct virtio_crypto_session_input input;that
>> +};
>> +\end{lstlisting}
>> +
>> +Algorithm chaining requests are as follows:
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_alg_chain_session_para {
>> +#define VIRTIO_CRYPTO_SYM_ALG_CHAIN_ORDER_HASH_THEN_CIPHER  1
>> +#define VIRTIO_CRYPTO_SYM_ALG_CHAIN_ORDER_CIPHER_THEN_HASH  2
>> +    le32 alg_chain_order;
>> +/* Plain hash */
>> +#define VIRTIO_CRYPTO_SYM_HASH_MODE_PLAIN    1
>> +/* Authenticated hash (mac) */
>> +#define VIRTIO_CRYPTO_SYM_HASH_MODE_AUTH     2
>> +/* Nested hash */
>> +#define VIRTIO_CRYPTO_SYM_HASH_MODE_NESTED   3
>> +    le32 hash_mode;
>> +    struct virtio_crypto_cipher_session_para cipher_param;
>> +    union {
>> +        struct virtio_crypto_hash_session_para hash_param;
>> +        struct virtio_crypto_mac_session_para mac_param;
>> +    } u;
>> +    /* length of the additional authenticated data (AAD) in bytes */
>> +    le32 aad_len;
>> +    le32 padding;
>> +};
>> +
>> +struct virtio_crypto_alg_chain_session_req {
>> +    /* Device-readable part */
>> +    struct virtio_crypto_alg_chain_session_para para;
>> +    /* The cipher key */
>> +    u8 cipher_key[keylen];
>> +    /* The authenticated key */
>> +    u8 auth_key[auth_key_len];
>> +
>> +    /* Device-writable part */
>> +    struct virtio_crypto_session_input input;
>> +};
>> +\end{lstlisting}
>> +
>> +Symmetric algorithm requests are as follows:
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_sym_create_session_req {
>> +    union {
>> +        struct virtio_crypto_cipher_session_req cipher;
>> +        struct virtio_crypto_alg_chain_session_req chain;
>> +    } u;
>> +
>> +    /* Device-readable part */
>> +
>> +/* No operation */
>> +#define VIRTIO_CRYPTO_SYM_OP_NONE  0
>> +/* Cipher only operation on the data */
>> +#define VIRTIO_CRYPTO_SYM_OP_CIPHER  1
>> +/* Chain any cipher with any hash or mac operation. The order
>> +   depends on the value of alg_chain_order param */
>> +#define VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING  2
>> +    le32 op_type;
>> +    le32 padding;
>> +};
>> +\end{lstlisting}
>> +
>> +The information required by symmetric algorithms session creation is stored in the
>> +virtio_crypto_sym_create_session_req structure, including the symmetric operation
>> +type in \field{op_type} and the cipher parameters stored in \field{cipher} or the
>> +algorithm chaining paramenters in \field{chain}.
>> +
>> +The driver can set the \field{op_type} field in struct virtio_crypto_sym_create_session_req
>> +as follows: VIRTIO_CRYPTO_SYM_OP_NONE: no operation; VIRTIO_CRYPTO_SYM_OP_CIPHER: Cipher only
>> +operation on the data; VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING: Chain any cipher with any hash
>> +or mac operation.
>> +
>> +\subparagraph{Session operation: AEAD session}\label{sec:Device Types / Crypto Device / Device
>> +Operation / Control Virtqueue / Session operation / Session operation: AEAD session}
>> +
>> +AEAD session requests are as follows:
>> +
>> +\begin{lstlisting}
>> +struct virtio_crypto_aead_session_para {
>> +    /* See VIRTIO_CRYPTO_AEAD_* above */
>> +    le32 algo;
>> +    /* length of key */
>> +    le32 key_len;
>> +    /* Authentication tag length */
>> +    le32 tag_len;
>> +    /* The length of the additional authenticated data (AAD) in bytes */
>> +    le32 aad_len;
>> +    /* encryption or decryption, See above VIRTIO_CRYPTO_OP_* */
>> +    le32 op;
>> +    le32 padding;
>> +};
>> +
>> +struct virtio_crypto_aead_create_session_req {
>> +    /* Device-readable part */
>> +    struct virtio_crypto_aead_session_para para;
>> +    u8 key[key_len];
>> +
>> +    /* Device-writeable part */
>> +    struct virtio_crypto_session_input input;
>> +};
>> +\end{lstlisting}
>> +
>> +The information required by AEAD session creation is stored in the virtio_crypto_aead_create_session_req
>> +structure, including the aead parameters stored in \field{para} and the cipher key in \field{key}.
>> +\field{input} stores the result of this operation.
>> +
>> +\drivernormative{\subparagraph}{Session operation: create session}{Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation / Session operation: create session}
>> +
>> +\begin{itemize*}
>> +\item The driver MUST set the control general header and the corresponding algorithm-specific structure.
>> +    See \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue}.
>> +\item The driver MUST set the \field{opcode} field based on service type: CIPHER, HASH, MAC, or AEAD.
>> +\item The driver MUST set the \field{queue_id} field to show used dataq.
> 
> I've failed to figure out the semantic behind queue_id. This could mean,
> that sessions and session_id's are queue scoped. But then we should be
> (IMHO) more explicit on this -- my guess is that session_id's aren't
> dataqueue scoped.
> 
>> +\end{itemize*}
>> +
>> +\devicenormative{\subparagraph}{Session operation: create session}{Device Types / Crypto Device / Device
>> +Operation / Control Virtqueue / Session operation / Session operation: create session}
>> +
>> +\begin{itemize*}
>> +\item The device MUST use the corresponding algorithm-specific structure according to the
>> +    \field{opcode} in the control general header.
>> +\item The device MUST set the \field{status} field to one of the following values of enum
>> +    VIRTIO_CRYPTO_STATUS after finish a session creation:
>> +\begin{itemize*}
>> +\item VIRTIO_CRYPTO_OK if a session is created successfully.
>> +\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is unsupported.
>> +\item VIRTIO_CRYPTO_NOSPC if no free session ID (only when the VIRTIO_CRYPTO_F_MUX_MODE
>> +    feature bit is negotiated).
>> +\item VIRTIO_CRYPTO_ERR if failure not mentioned above occurs.
> 
> I guess an invalid queue_id would be among these.
> 
>> +\end{itemize*}
>> +\item The device MUST set the \field{session_id} field to a unique session identifieronly
> s/identifieronly/identifier only
>> +    if the status is set to VIRTIO_CRYPTO_OK.
>> +\end{itemize*}
>> +
>> +\drivernormative{\subparagraph}{Session operation: destroy session}{Device Types / Crypto Device / Device
>> +Operation / Control Virtqueue / Session operation / Session operation: destroy session}
>> +
>> +\begin{itemize*}
>> +\item The driver MUST set the \field{opcode} field based on service type: CIPHER, HASH, MAC, or AEAD.
>> +\item The driver MUST set the \field{session_id} to a valid value assigned by the device
>> +    when the session was created.
> 
> Destroy does not need to specify queue_id. That means session_id's aren't
> queue scoped from namespace perspective. The question remains what is
> queue_id good for, and whether a session type op request should be
> rejected if the the session id originates from a session creation
> request specifying a different dataqueue (not the dataqueue containing
> the given request)? 
> 

Gonglei and you have reached consensus, so we will make it reserved and must be
zero in the next version.

>> +\end{itemize*}
>> +
>> +\devicenormative{\subparagraph}{Session operation: destroy session}{Device Types / Crypto Device / Device
>> +Operation / Control Virtqueue / Session operation / Session operation: destroy session}
>> +
>> +\begin{itemize*}
>> +\item The device MUST set the \field{status} field to one of the following values of enum VIRTIO_CRYPTO_STATUS.
>> +\begin{itemize*}
>> +\item VIRTIO_CRYPTO_OK if a session is created successfully.
>> +\item VIRTIO_CRYPTO_ERR if any failure occurs.
>> +\end{itemize*}
>> +\end{itemize*}
>> +
>> +\subsubsection{Data Virtqueue}\label{sec:Device Types / Crypto Device / Device Operation / Data Virtqueue}
>>
> 
> [..]
> 
> I've run through the rest. It some stuff seems very repetitive. I wonder if
> we can do better.
> 

> I also dislike this 5.7.7.5.3 Steps of Operation part. I also don't
> understand why is symmetric special in this respect (HASH, MAC and
> AEAD don't have a 'Steps of Operation' section.
> 

I have a offline discussion with Gonglei about it, we prefer to drop the
5.7.7.5.3 Steps of Operation part.

> I would like to try some things out with the reference implementation.
> Depending on how that goes I may or may not end up providing a detailed
> review for the rest before discussing what I've already addressed.
> 
> Regards,
> Halil
> 
> 
> .
>
diff mbox

Patch

diff --git a/acknowledgements.tex b/acknowledgements.tex
index 6c86d12..c4b6844 100644
--- a/acknowledgements.tex
+++ b/acknowledgements.tex
@@ -26,6 +26,8 @@  Sasha Levin,	Oracle	\newline
 Sergey Tverdyshev,	Thales e-Security	\newline
 Stefan Hajnoczi,	Red Hat	\newline
 Tom Lyon,	Samya Systems, Inc.	\newline
+Lei Gong,	Huawei	\newline
+Peng Long,	Huawei	\newline
 \end{oasistitlesection}
 
 The following non-members have provided valuable feedback on this
@@ -43,4 +45,5 @@  Laura Novich, Red Hat	\newline
 Patrick Durusau,	Technical Advisory Board, OASIS	\newline
 Thomas Huth,	IBM	\newline
 Yan Vugenfirer, Red Hat / Daynix	\newline
+Halil Pasic,	IBM	\newline
 \end{oasistitlesection}
diff --git a/content.tex b/content.tex
index d989d98..7710f8c 100644
--- a/content.tex
+++ b/content.tex
@@ -5641,6 +5641,8 @@  descriptor for the \field{sense_len}, \field{residual},
 \field{status_qualifier}, \field{status}, \field{response} and
 \field{sense} fields.
 
+\input{virtio-crypto.tex}
+
 \chapter{Reserved Feature Bits}\label{sec:Reserved Feature Bits}
 
 Currently there are three device-independent feature bits defined:
diff --git a/virtio-crypto.tex b/virtio-crypto.tex
new file mode 100644
index 0000000..1e75cbc
--- /dev/null
+++ b/virtio-crypto.tex
@@ -0,0 +1,1479 @@ 
+\section{Crypto Device}\label{sec:Device Types / Crypto Device}
+
+The virtio crypto device is a virtual cryptography device as well as a
+virtual cryptographic accelerator. The virtio crypto device provides the
+following crypto services: CIPHER, MAC, HASH, and AEAD. Virtio crypto
+devices have a single control queue and at least one data queue. Crypto
+operation requests are placed into a data queue, and serviced by the
+device. Some crypto operation requests are only valid in the context of a
+session. The role of the control queue is facilitating control operation
+requests. Sessions management is realized with control operation
+requests.
+
+\subsection{Device ID}\label{sec:Device Types / Crypto Device / Device ID}
+
+20
+
+\subsection{Virtqueues}\label{sec:Device Types / Crypto Device / Virtqueues}
+
+\begin{description}
+\item[0] dataq1
+\item[\ldots]
+\item[N-1] dataqN
+\item[N] controlq
+\end{description}
+
+N is set by \field{max_dataqueues}.
+
+\subsection{Feature bits}\label{sec:Device Types / Crypto Device / Feature bits}
+
+\begin{description}
+\item VIRTIO_CRYPTO_F_MUX_MODE (0) multiplexing mode is available.
+\item VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE (1) stateless mode is available for CIPHER service.
+\item VIRTIO_CRYPTO_F_HASH_STATELESS_MODE (2) stateless mode is available for HASH service.
+\item VIRTIO_CRYPTO_F_MAC_STATELESS_MODE (3) stateless mode is available for MAC service.
+\item VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE (4) stateless mode is available for AEAD service.
+\end{description}
+
+\subsubsection{Feature bit requirements}\label{sec:Device Types / Crypto Device / Feature bits}
+
+Some crypto feature bits require other crypto feature bits
+(see \ref{drivernormative:Basic Facilities of a Virtio Device / Feature Bits}):
+
+\begin{description}
+\item[VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE] Requires VIRTIO_CRYPTO_F_MUX_MODE.
+\item[VIRTIO_CRYPTO_F_HASH_STATELESS_MODE] Requires VIRTIO_CRYPTO_F_MUX_MODE.
+\item[VIRTIO_CRYPTO_F_MAC_STATELESS_MODE] Requires VIRTIO_CRYPTO_F_MUX_MODE.
+\item[VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE] Requires VIRTIO_CRYPTO_F_MUX_MODE.
+\end{description}
+
+\subsection{Supported crypto services}\label{sec:Device Types / Crypto Device / Supported crypto services}
+
+The following crypto services are defined:
+
+\begin{lstlisting}
+/* CIPHER service */
+#define VIRTIO_CRYPTO_SERVICE_CIPHER 0
+/* HASH service */
+#define VIRTIO_CRYPTO_SERVICE_HASH   1
+/* MAC (Message Authentication Codes) service */
+#define VIRTIO_CRYPTO_SERVICE_MAC    2
+/* AEAD (Authenticated Encryption with Associated Data) service */
+#define VIRTIO_CRYPTO_SERVICE_AEAD   3
+\end{lstlisting}
+
+The above constants designate bits used to indicate the which of crypto services are
+offered by the device as described in, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
+
+\subsubsection{CIPHER services}\label{sec:Device Types / Crypto Device / Supported crypto services / CIPHER services}
+
+The following CIPHER algorithms are defined:
+
+\begin{lstlisting}
+#define VIRTIO_CRYPTO_NO_CIPHER                 0
+#define VIRTIO_CRYPTO_CIPHER_ARC4               1
+#define VIRTIO_CRYPTO_CIPHER_AES_ECB            2
+#define VIRTIO_CRYPTO_CIPHER_AES_CBC            3
+#define VIRTIO_CRYPTO_CIPHER_AES_CTR            4
+#define VIRTIO_CRYPTO_CIPHER_DES_ECB            5
+#define VIRTIO_CRYPTO_CIPHER_DES_CBC            6
+#define VIRTIO_CRYPTO_CIPHER_3DES_ECB           7
+#define VIRTIO_CRYPTO_CIPHER_3DES_CBC           8
+#define VIRTIO_CRYPTO_CIPHER_3DES_CTR           9
+#define VIRTIO_CRYPTO_CIPHER_KASUMI_F8          10
+#define VIRTIO_CRYPTO_CIPHER_SNOW3G_UEA2        11
+#define VIRTIO_CRYPTO_CIPHER_AES_F8             12
+#define VIRTIO_CRYPTO_CIPHER_AES_XTS            13
+#define VIRTIO_CRYPTO_CIPHER_ZUC_EEA3           14
+\end{lstlisting}
+
+The above constants have two usages:
+\begin{enumerate}
+\item As bit numbers, used to tell the driver which CIPHER algorithms
+are supported by the device, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
+\item As values, used to tell the device which CIPHER algorithm
+a crypto request from the driver requires, see \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}.
+\end{enumerate}
+
+\subsubsection{HASH services}\label{sec:Device Types / Crypto Device / Supported crypto services / HASH services}
+
+The following HASH algorithms are defined:
+
+\begin{lstlisting}
+#define VIRTIO_CRYPTO_NO_HASH            0
+#define VIRTIO_CRYPTO_HASH_MD5           1
+#define VIRTIO_CRYPTO_HASH_SHA1          2
+#define VIRTIO_CRYPTO_HASH_SHA_224       3
+#define VIRTIO_CRYPTO_HASH_SHA_256       4
+#define VIRTIO_CRYPTO_HASH_SHA_384       5
+#define VIRTIO_CRYPTO_HASH_SHA_512       6
+#define VIRTIO_CRYPTO_HASH_SHA3_224      7
+#define VIRTIO_CRYPTO_HASH_SHA3_256      8
+#define VIRTIO_CRYPTO_HASH_SHA3_384      9
+#define VIRTIO_CRYPTO_HASH_SHA3_512      10
+#define VIRTIO_CRYPTO_HASH_SHA3_SHAKE128      11
+#define VIRTIO_CRYPTO_HASH_SHA3_SHAKE256      12
+\end{lstlisting}
+
+The above constants have two usages:
+\begin{enumerate}
+\item As bit numbers, used to tell the driver which HASH algorithms
+are supported by the device, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
+\item As values, used to tell the device which HASH algorithm
+a crypto request from the driver requires, see \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}.
+\end{enumerate}
+
+\subsubsection{MAC services}\label{sec:Device Types / Crypto Device / Supported crypto services / MAC services}
+
+The following MAC algorithms are defined:
+
+\begin{lstlisting}
+#define VIRTIO_CRYPTO_NO_MAC                       0
+#define VIRTIO_CRYPTO_MAC_HMAC_MD5                 1
+#define VIRTIO_CRYPTO_MAC_HMAC_SHA1                2
+#define VIRTIO_CRYPTO_MAC_HMAC_SHA_224             3
+#define VIRTIO_CRYPTO_MAC_HMAC_SHA_256             4
+#define VIRTIO_CRYPTO_MAC_HMAC_SHA_384             5
+#define VIRTIO_CRYPTO_MAC_HMAC_SHA_512             6
+#define VIRTIO_CRYPTO_MAC_CMAC_3DES                25
+#define VIRTIO_CRYPTO_MAC_CMAC_AES                 26
+#define VIRTIO_CRYPTO_MAC_KASUMI_F9                27
+#define VIRTIO_CRYPTO_MAC_SNOW3G_UIA2              28
+#define VIRTIO_CRYPTO_MAC_GMAC_AES                 41
+#define VIRTIO_CRYPTO_MAC_GMAC_TWOFISH             42
+#define VIRTIO_CRYPTO_MAC_CBCMAC_AES               49
+#define VIRTIO_CRYPTO_MAC_CBCMAC_KASUMI_F9         50
+#define VIRTIO_CRYPTO_MAC_XCBC_AES                 53
+#define VIRTIO_CRYPTO_MAC_ZUC_EIA3                 54
+\end{lstlisting}
+
+The above constants have two usages:
+\begin{enumerate}
+\item As bit numbers, used to tell the driver which MAC algorithms
+are supported by the device, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
+\item As values, used to tell the device which MAC algorithm
+a crypto request from the driver requires, see \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}.
+\end{enumerate}
+
+\subsubsection{AEAD services}\label{sec:Device Types / Crypto Device / Supported crypto services / AEAD services}
+
+The following AEAD algorithms are defined:
+
+\begin{lstlisting}
+#define VIRTIO_CRYPTO_NO_AEAD     0
+#define VIRTIO_CRYPTO_AEAD_GCM    1
+#define VIRTIO_CRYPTO_AEAD_CCM    2
+#define VIRTIO_CRYPTO_AEAD_CHACHA20_POLY1305  3
+\end{lstlisting}
+
+The above constants have two usages:
+\begin{enumerate}
+\item As bit numbers, used to tell the driver which AEAD algorithms
+are supported by the device, see \ref{sec:Device Types / Crypto Device / Device configuration layout}.
+\item As values, used to tell the device what AEAD algorithm
+a crypto request from the driver requires, see \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}.
+\end{enumerate}
+
+\subsection{Device configuration layout}\label{sec:Device Types / Crypto Device / Device configuration layout}
+
+\begin{lstlisting}
+struct virtio_crypto_config {
+    le32 status;
+    le32 max_dataqueues;
+    le32 crypto_services;
+    /* Detailed algorithms mask */
+    le32 cipher_algo_l;
+    le32 cipher_algo_h;
+    le32 hash_algo;
+    le32 mac_algo_l;
+    le32 mac_algo_h;
+    le32 aead_algo;
+    /* Maximum length of cipher key in bytes */
+    le32 max_cipher_key_len;
+    /* Maximum length of authenticated key in bytes */
+    le32 max_auth_key_len;
+    le32 reserved;
+    /* Maximum size of each crypto request's content in bytes */
+    le64 max_size;
+};
+\end{lstlisting}
+
+\begin{description}
+\item[\field{status}] is used to show whether the device is ready to work or
+    not, it can be either zero or have one or more flags. Only one read-only
+	bit (for the driver) is currently defined for the \field{status} field: VIRTIO_CRYPTO_S_HW_READY:
+\begin{lstlisting}
+#define VIRTIO_CRYPTO_S_HW_READY  (1 << 0)
+\end{lstlisting}
+
+\item[\field{max_dataqueues}] is the maximum number of data virtqueues exposed by
+    the device. The driver MAY use only one data queue,
+    or it can use more to achieve better performance.
+
+\item[\field{crypto_services}] crypto service offered, see \ref{sec:Device Types / Crypto Device / Supported crypto services}.
+
+\item[\field{cipher_algo_l}] CIPHER algorithms bits 0-31, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / CIPHER services}.
+
+\item[\field{cipher_algo_h}] CIPHER algorithms bits 32-63, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / CIPHER services}.
+
+\item[\field{hash_algo}] HASH algorithms bits, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / HASH services}.
+
+\item[\field{mac_algo_l}] MAC algorithms bits 0-31, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / MAC services}.
+
+\item[\field{mac_algo_h}] MAC algorithms bits 32-63, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / MAC services}.
+
+\item[\field{aead_algo}] AEAD algorithms bits, see \ref{sec:Device Types / Crypto Device / Supported crypto services  / AEAD services}.
+
+\item[\field{max_cipher_key_len}] is the maximum length of cipher key supported by the device.
+
+\item[\field{max_auth_key_len}] is the maximum length of authenticated key supported by the device.
+
+\item[\field{reserved}] is reserved for future use.
+
+\item[\field{max_size}] is the maximum size of each crypto request's content supported by the device
+\end{description}
+
+\begin{note}
+Unless explicitly stated otherwise all lengths and sizes are in bytes.
+\end{note}
+
+\devicenormative{\subsubsection}{Device configuration layout}{Device Types / Crypto Device / Device configuration layout}
+
+\begin{itemize*}
+\item The device MUST set \field{max_dataqueues} to between 1 and 65535 inclusive.
+\item The device MUST set the \field{status} flag based on the status of the crypto
+    accelerator, Non-valid flags MUST NOT be set.
+\item The device MUST accept and handle requests after \field{status} is set to VIRTIO_CRYPTO_S_HW_READY.
+\item The device MUST set \field{crypto_services} based on the crypto services the device offers.
+\item The device MUST set detailed algorithms masks for each service advertised by \field{crypto_services}.
+    The device MUST NOT set the not defined algorithms bits.
+\item The device MUST set \field{max_size} to show the maximum size of crypto request the device supports.
+\item The device MUST set \field{max_cipher_key_len} to show the maximum length of cipher key if the
+    device supports CIPHER service.
+\item The device MUST set \field{max_auth_key_len} to show the maximum length of authenticated key if
+    the device supports MAC service.
+\end{itemize*}
+
+\drivernormative{\subsubsection}{Device configuration layout}{Device Types / Crypto Device / Device configuration layout}
+
+\begin{itemize*}
+\item The driver MUST read the ready \field{status} from the bottom bit of status to check whether the
+    crypto accelerator is ready or not, and the driver MUST reread it after device reset.
+\item The driver MUST NOT transmit any requests to the device if the ready \field{status} is not set.
+\item The driver MUST read \field{max_dataqueues} field to discover the number of data queues the device supports.
+\item The driver MUST read \field{crypto_services} field to discover which services the device is able to offer.
+\item The driver SHOULD ignore the not defined algorithms bits.
+\item The driver MUST read the detailed algorithms fields based on \field{crypto_services} field.
+\item The driver SHOULD read \field{max_size} to discover the maximum size of crypto request the device supports.
+\item The driver SHOULD read \field{max_cipher_key_len} to discover the maximum length of cipher key
+    the device supports.
+\item The driver SHOULD read \field{max_auth_key_len} to discover the maximum length of authenticated
+    key the device supports.
+\end{itemize*}
+
+\subsection{Device Initialization}\label{sec:Device Types / Crypto Device / Device Initialization}
+
+\drivernormative{\subsubsection}{Device Initialization}{Device Types / Crypto Device / Device Initialization}
+
+\begin{itemize*}
+\item The driver MUST identify and initialize all virtqueues.
+\item The driver MUST read the supported crypto services from bits of \field{crypto_services}.
+\item The driver MUST read the supported algorithms based on \field{crypto_services} field.
+\end{itemize*}
+
+\subsection{Device Operation}\label{sec:Device Types / Crypto Device / Device Operation}
+
+Requests can be transmitted by placing them in the controlq or dataq.
+Requests consist of a queue-type specific header specifying among
+others the operation, and an operation specific payload.
+The payload is generally composed of operation parameters, output data, and input data.
+Operation parameters are algorithm-specific parameters, output data is the
+data that should be utilized in operations, and input data is equal to
+"operation result + result data".
+
+The device can support both session mode (See \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}) and stateless mode.
+In stateless mode all operation parameters are supplied as a part
+of each request, while in session mode, some or all operation parameters
+are managed within the session. Stateless mode is guarded by
+feature bits 0-4 on a service level. If stateless mode is negotiated
+for a service, the service is available both in session and
+stateless mode; otherwise it's only available in session mode.
+
+The device can set the operation status as follows:
+
+\begin{lstlisting}
+enum VIRTIO_CRYPTO_STATUS {
+    VIRTIO_CRYPTO_OK = 0,
+    VIRTIO_CRYPTO_ERR = 1,
+    VIRTIO_CRYPTO_BADMSG = 2,
+    VIRTIO_CRYPTO_NOTSUPP = 3,
+    VIRTIO_CRYPTO_INVSESS = 4,
+    VIRTIO_CRYPTO_NOSPC = 5,
+    VIRTIO_CRYPTO_MAX
+};
+\end{lstlisting}
+
+\begin{itemize*}
+\item VIRTIO_CRYPTO_OK: success.
+\item VIRTIO_CRYPTO_BADMSG: authentication failed (only when AEAD decryption).
+\item VIRTIO_CRYPTO_NOTSUPP: operation or algorithm is unsupported.
+\item VIRTIO_CRYPTO_INVSESS: invalid session ID when executing crypto operations.
+\item VIRTIO_CRYPTO_NOSPC: no free session ID (only when the VIRTIO_CRYPTO_F_MUX_MODE
+    feature bit is negotiated).
+\item VIRTIO_CRYPTO_ERR: any failure not mentioned above occurs.
+\end{itemize*}
+
+\subsubsection{Control Virtqueue}\label{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue}
+
+The driver uses the control virtqueue to send control commands to the
+device, such as session operations (See \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}).
+
+The header for controlq is of the following form:
+\begin{lstlisting}
+#define VIRTIO_CRYPTO_OPCODE(service, op)   (((service) << 8) | (op))
+
+struct virtio_crypto_ctrl_header {
+#define VIRTIO_CRYPTO_CIPHER_CREATE_SESSION \
+       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x02)
+#define VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION \
+       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x03)
+#define VIRTIO_CRYPTO_HASH_CREATE_SESSION \
+       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_HASH, 0x02)
+#define VIRTIO_CRYPTO_HASH_DESTROY_SESSION \
+       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_HASH, 0x03)
+#define VIRTIO_CRYPTO_MAC_CREATE_SESSION \
+       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_MAC, 0x02)
+#define VIRTIO_CRYPTO_MAC_DESTROY_SESSION \
+       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_MAC, 0x03)
+#define VIRTIO_CRYPTO_AEAD_CREATE_SESSION \
+       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x02)
+#define VIRTIO_CRYPTO_AEAD_DESTROY_SESSION \
+       VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x03)
+    le32 opcode;
+    /* algo should be service-specific algorithms */
+    le32 algo;
+    le32 flag;
+    /* data virtqueue id */
+    le32 queue_id;
+};
+\end{lstlisting}
+
+The format of the controlq request depends on the VIRTIO_CRYPTO_F_MUX_MODE feature bit:
+
+\begin{itemize*}
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is NOT negotiated the controlq request is
+    a fixed-size structure of form:
+\begin{lstlisting}
+struct virtio_crypto_op_ctrl_req {
+    struct virtio_crypto_ctrl_header header;
+
+    union {
+        struct virtio_crypto_sym_create_session_req   sym_create_session;
+        struct virtio_crypto_hash_create_session_req  hash_create_session;
+        struct virtio_crypto_mac_create_session_req   mac_create_session;
+        struct virtio_crypto_aead_create_session_req  aead_create_session;
+        struct virtio_crypto_destroy_session_req      destroy_session;
+    } u;
+};
+\end{lstlisting}
+The header is the general header, and the union is of the algorithm-specific type or the
+virtio_crypto_destroy_session_req structure, which is set by the driver. All the properties
+in the union are shown as follows.
+
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated the controlq request is composed
+    of two parts, the additional paramenters are preceded by the general header.
+
+\begin{lstlisting}
+struct virtio_crypto_op_ctrl_req_mux {
+    struct virtio_crypto_ctrl_header header;
+
+    /* additional paramenter */
+    u8 additional_para[addl_para_len];
+};
+\end{lstlisting}
+
+The additional paramenters are stored in a virtio_crypto_destroy_session_req structure or
+in a algorithm-specific structure:
+\begin{itemize*}
+\item struct virtio_crypto_sym_create_session_req
+\item struct virtio_crypto_hash_create_session_req
+\item struct virtio_crypto_mac_create_session_req
+\item struct virtio_crypto_aead_create_session_req
+\end{itemize*}
+All of the structures above are shown as follows.
+\end{itemize*}
+
+\paragraph{Session operation}\label{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation}
+
+The session is a
+handle which describes the cryptographic parameters to be applied to
+a number of buffers.
+
+The following structure stores the result of session creation set by the device:
+
+\begin{lstlisting}
+struct virtio_crypto_session_input {
+    /* Device-writable part */
+    le64 session_id;
+    le32 status;
+    le32 padding;
+};
+\end{lstlisting}
+
+A request to destroy a session includes the following information:
+
+\begin{lstlisting}
+struct virtio_crypto_destroy_session_req {
+    /* Device-readable part */
+    le64  session_id;
+    /* Device-writable part */
+    le32  status;
+    le32  padding;
+};
+\end{lstlisting}
+
+\subparagraph{Session operation: HASH session}\label{sec:Device Types / Crypto Device / Device
+Operation / Control Virtqueue / Session operation / Session operation: HASH session}
+
+HASH session requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_hash_session_para {
+    /* See VIRTIO_CRYPTO_HASH_* above */
+    le32 algo;
+    /* hash result length */
+    le32 hash_result_len;
+};
+struct virtio_crypto_hash_create_session_req {
+    /* Device-readable part */
+    struct virtio_crypto_hash_session_para para;
+    /* Device-writable part */
+    struct virtio_crypto_session_input input;
+};
+\end{lstlisting}
+
+The information required by HASH session creation is stored in the virtio_crypto_hash_create_session_req
+structure, including the hash parameters stored in \field{para}. \field{input} stores the result of this operation.
+
+\subparagraph{Session operation: MAC session}\label{sec:Device Types / Crypto Device / Device
+Operation / Control Virtqueue / Session operation / Session operation: MAC session}
+
+MAC session requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_mac_session_para {
+    /* See VIRTIO_CRYPTO_MAC_* above */
+    le32 algo;
+    /* hash result length */
+    le32 hash_result_len;
+    /* length of authenticated key */
+    le32 auth_key_len;
+    le32 padding;
+};
+
+struct virtio_crypto_mac_create_session_req {
+    /* Device-readable part */
+    struct virtio_crypto_mac_session_para para;
+    /* The authenticated key */
+    u8 auth_key[auth_key_len];
+
+    /* Device-writable part */
+    struct virtio_crypto_session_input input;
+};
+\end{lstlisting}
+
+The information required by MAC session creation is stored in the virtio_crypto_mac_create_session_req
+structure, including the mac parameters stored in \field{para} and the authenticated key in \field{auth_key}.
+\field{input} stores the result of this operation.
+
+\subparagraph{Session operation: Symmetric algorithms session}\label{sec:Device Types / Crypto Device / Device
+Operation / Control Virtqueue / Session operation / Session operation: Symmetric algorithms session}
+
+The request of symmetric session includes two parts, CIPHER algorithms and chain
+algorithms (chaining CIPHER and HASH/MAC).
+
+CIPHER session requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_cipher_session_para {
+    /* See VIRTIO_CRYPTO_CIPHER* above */
+    le32 algo;
+    /* length of key */
+    le32 keylen;
+#define VIRTIO_CRYPTO_OP_ENCRYPT  1
+#define VIRTIO_CRYPTO_OP_DECRYPT  2
+    /* encryption or decryption */
+    le32 op;
+    le32 padding;
+};
+
+struct virtio_crypto_cipher_session_req {
+    /* Device-readable part */
+    struct virtio_crypto_cipher_session_para para;
+    /* The cipher key */
+    u8 cipher_key[keylen];
+
+    /* Device-writable part */
+    struct virtio_crypto_session_input input;
+};
+\end{lstlisting}
+
+Algorithm chaining requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_alg_chain_session_para {
+#define VIRTIO_CRYPTO_SYM_ALG_CHAIN_ORDER_HASH_THEN_CIPHER  1
+#define VIRTIO_CRYPTO_SYM_ALG_CHAIN_ORDER_CIPHER_THEN_HASH  2
+    le32 alg_chain_order;
+/* Plain hash */
+#define VIRTIO_CRYPTO_SYM_HASH_MODE_PLAIN    1
+/* Authenticated hash (mac) */
+#define VIRTIO_CRYPTO_SYM_HASH_MODE_AUTH     2
+/* Nested hash */
+#define VIRTIO_CRYPTO_SYM_HASH_MODE_NESTED   3
+    le32 hash_mode;
+    struct virtio_crypto_cipher_session_para cipher_param;
+    union {
+        struct virtio_crypto_hash_session_para hash_param;
+        struct virtio_crypto_mac_session_para mac_param;
+    } u;
+    /* length of the additional authenticated data (AAD) in bytes */
+    le32 aad_len;
+    le32 padding;
+};
+
+struct virtio_crypto_alg_chain_session_req {
+    /* Device-readable part */
+    struct virtio_crypto_alg_chain_session_para para;
+    /* The cipher key */
+    u8 cipher_key[keylen];
+    /* The authenticated key */
+    u8 auth_key[auth_key_len];
+
+    /* Device-writable part */
+    struct virtio_crypto_session_input input;
+};
+\end{lstlisting}
+
+Symmetric algorithm requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_sym_create_session_req {
+    union {
+        struct virtio_crypto_cipher_session_req cipher;
+        struct virtio_crypto_alg_chain_session_req chain;
+    } u;
+
+    /* Device-readable part */
+
+/* No operation */
+#define VIRTIO_CRYPTO_SYM_OP_NONE  0
+/* Cipher only operation on the data */
+#define VIRTIO_CRYPTO_SYM_OP_CIPHER  1
+/* Chain any cipher with any hash or mac operation. The order
+   depends on the value of alg_chain_order param */
+#define VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING  2
+    le32 op_type;
+    le32 padding;
+};
+\end{lstlisting}
+
+The information required by symmetric algorithms session creation is stored in the
+virtio_crypto_sym_create_session_req structure, including the symmetric operation
+type in \field{op_type} and the cipher parameters stored in \field{cipher} or the
+algorithm chaining paramenters in \field{chain}.
+
+The driver can set the \field{op_type} field in struct virtio_crypto_sym_create_session_req
+as follows: VIRTIO_CRYPTO_SYM_OP_NONE: no operation; VIRTIO_CRYPTO_SYM_OP_CIPHER: Cipher only
+operation on the data; VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING: Chain any cipher with any hash
+or mac operation.
+
+\subparagraph{Session operation: AEAD session}\label{sec:Device Types / Crypto Device / Device
+Operation / Control Virtqueue / Session operation / Session operation: AEAD session}
+
+AEAD session requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_aead_session_para {
+    /* See VIRTIO_CRYPTO_AEAD_* above */
+    le32 algo;
+    /* length of key */
+    le32 key_len;
+    /* Authentication tag length */
+    le32 tag_len;
+    /* The length of the additional authenticated data (AAD) in bytes */
+    le32 aad_len;
+    /* encryption or decryption, See above VIRTIO_CRYPTO_OP_* */
+    le32 op;
+    le32 padding;
+};
+
+struct virtio_crypto_aead_create_session_req {
+    /* Device-readable part */
+    struct virtio_crypto_aead_session_para para;
+    u8 key[key_len];
+
+    /* Device-writeable part */
+    struct virtio_crypto_session_input input;
+};
+\end{lstlisting}
+
+The information required by AEAD session creation is stored in the virtio_crypto_aead_create_session_req
+structure, including the aead parameters stored in \field{para} and the cipher key in \field{key}.
+\field{input} stores the result of this operation.
+
+\drivernormative{\subparagraph}{Session operation: create session}{Device Types / Crypto Device / Device Operation / Control Virtqueue / Session operation / Session operation: create session}
+
+\begin{itemize*}
+\item The driver MUST set the control general header and the corresponding algorithm-specific structure.
+    See \ref{sec:Device Types / Crypto Device / Device Operation / Control Virtqueue}.
+\item The driver MUST set the \field{opcode} field based on service type: CIPHER, HASH, MAC, or AEAD.
+\item The driver MUST set the \field{queue_id} field to show used dataq.
+\end{itemize*}
+
+\devicenormative{\subparagraph}{Session operation: create session}{Device Types / Crypto Device / Device
+Operation / Control Virtqueue / Session operation / Session operation: create session}
+
+\begin{itemize*}
+\item The device MUST use the corresponding algorithm-specific structure according to the
+    \field{opcode} in the control general header.
+\item The device MUST set the \field{status} field to one of the following values of enum
+    VIRTIO_CRYPTO_STATUS after finish a session creation:
+\begin{itemize*}
+\item VIRTIO_CRYPTO_OK if a session is created successfully.
+\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is unsupported.
+\item VIRTIO_CRYPTO_NOSPC if no free session ID (only when the VIRTIO_CRYPTO_F_MUX_MODE
+    feature bit is negotiated).
+\item VIRTIO_CRYPTO_ERR if failure not mentioned above occurs.
+\end{itemize*}
+\item The device MUST set the \field{session_id} field to a unique session identifieronly
+    if the status is set to VIRTIO_CRYPTO_OK.
+\end{itemize*}
+
+\drivernormative{\subparagraph}{Session operation: destroy session}{Device Types / Crypto Device / Device
+Operation / Control Virtqueue / Session operation / Session operation: destroy session}
+
+\begin{itemize*}
+\item The driver MUST set the \field{opcode} field based on service type: CIPHER, HASH, MAC, or AEAD.
+\item The driver MUST set the \field{session_id} to a valid value assigned by the device
+    when the session was created.
+\end{itemize*}
+
+\devicenormative{\subparagraph}{Session operation: destroy session}{Device Types / Crypto Device / Device
+Operation / Control Virtqueue / Session operation / Session operation: destroy session}
+
+\begin{itemize*}
+\item The device MUST set the \field{status} field to one of the following values of enum VIRTIO_CRYPTO_STATUS.
+\begin{itemize*}
+\item VIRTIO_CRYPTO_OK if a session is created successfully.
+\item VIRTIO_CRYPTO_ERR if any failure occurs.
+\end{itemize*}
+\end{itemize*}
+
+\subsubsection{Data Virtqueue}\label{sec:Device Types / Crypto Device / Device Operation / Data Virtqueue}
+
+The driver uses the data virtqueues to transmit crypto operation requests to the device,
+and completes the crypto operations.
+
+The header for dataq is as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_op_header {
+#define VIRTIO_CRYPTO_CIPHER_ENCRYPT \
+    VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x00)
+#define VIRTIO_CRYPTO_CIPHER_DECRYPT \
+    VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_CIPHER, 0x01)
+#define VIRTIO_CRYPTO_HASH \
+    VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_HASH, 0x00)
+#define VIRTIO_CRYPTO_MAC \
+    VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_MAC, 0x00)
+#define VIRTIO_CRYPTO_AEAD_ENCRYPT \
+    VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x00)
+#define VIRTIO_CRYPTO_AEAD_DECRYPT \
+    VIRTIO_CRYPTO_OPCODE(VIRTIO_CRYPTO_SERVICE_AEAD, 0x01)
+    le32 opcode;
+    /* algo should be service-specific algorithms */
+    le32 algo;
+    le64 session_id;
+#define VIRTIO_CRYPTO_FLAG_SESSION_MODE 1
+    /* control flag to control the request */
+    le32 flag;
+    le32 padding;
+};
+\end{lstlisting}
+
+The format of the dataq request depends on the VIRTIO_CRYPTO_F_MUX_MODE feature bit:
+
+\begin{itemize*}
+\item If VIRTIO_CRYPTO_F_MUX_MODE feature bit is NOT negotiated the dataq request is
+    a fixed-size structure of form:
+
+\begin{lstlisting}
+struct virtio_crypto_op_data_req {
+    struct virtio_crypto_op_header header;
+
+    union {
+        struct virtio_crypto_sym_data_req   sym_req;
+        struct virtio_crypto_hash_data_req  hash_req;
+        struct virtio_crypto_mac_data_req   mac_req;
+        struct virtio_crypto_aead_data_req  aead_req;
+    } u;
+};
+\end{lstlisting}
+
+The header is the general header, and the union is of the algorithm-specific type,
+which is set by the driver. All the properties in the union are shown as follows.
+
+\item If VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated the dataq requests is
+    composed of two parts, the additional paramenters are preceded by the general header:
+
+\begin{lstlisting}
+struct virtio_crypto_op_data_req_mux {
+    struct virtio_crypto_op_header header;
+
+    /* additional paramenter of the operation */
+    u8 additional_para[addl_para_len];
+};
+\end{lstlisting}
+
+The additional paramenters are stored in a algorithm-specific structure:
+\begin{itemize*}
+\item struct virtio_crypto_sym_data_req
+\item struct virtio_crypto_hash_data_req
+\item struct virtio_crypto_mac_data_req
+\item struct virtio_crypto_aead_data_req
+\item struct virtio_crypto_sym_data_req_stateless
+\item struct virtio_crypto_hash_data_req_stateless
+\item struct virtio_crypto_mac_data_req_stateless
+\item struct virtio_crypto_aead_data_req_stateless
+\end{itemize*}
+All of the structures above are shown as follows.
+\end{itemize*}
+
+There is a unified input header for all crypto services, is defined as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_inhdr {
+    u8 status;
+};
+\end{lstlisting}
+
+\subsubsection{HASH Service Operation}\label{sec:Device Types / Crypto Device / Device Operation / HASH Service Operation}
+
+Session mode HASH service requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_hash_para {
+    /* length of source data */
+    le32 src_data_len;
+    /* hash result length */
+    le32 hash_result_len;
+};
+
+struct virtio_crypto_hash_data_req {
+    /* Device-readable part */
+    struct virtio_crypto_hash_para para;
+    /* Source data */
+    u8 src_data[src_data_len];
+
+    /* Device-writable part */
+    /* Hash result data */
+    u8 hash_result[hash_result_len];
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+
+Each data request uses virtio_crypto_hash_data_req structure to store information
+used to run the HASH operations.
+
+The information includes the hash parameters stored in \field{para}, output data
+and input data. The output data here includes the source data and the input data
+includes the hash result data used to save the results of the HASH operations.
+\field{inhdr} stores the status of executing the HASH operations.
+
+Stateless mode HASH service requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_hash_para_statelesss {
+    struct {
+        /* See VIRTIO_CRYPTO_HASH_* above */
+        le32 algo;
+    } sess_para;
+
+    /* length of source data */
+    le32 src_data_len;
+    /* hash result length */
+    le32 hash_result_len;
+    le32 reserved;
+};
+struct virtio_crypto_hash_data_req_stateless {
+    /* Device-readable part */
+    struct virtio_crypto_hash_para_stateless para;
+    /* Source data */
+    u8 src_data[src_data_len];
+
+    /* Device-writable part */
+    /* Hash result data */
+    u8 hash_result[hash_result_len];
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+
+\drivernormative{\paragraph}{HASH Service Operation}{Device Types / Crypto Device / Device Operation / HASH Service Operation}
+
+\begin{itemize*}
+\item If the driver uses the session mode, then the driver MUST set \field{session_id}
+    in struct virtio_crypto_op_header to a valid value assigned by the device when the
+	session was created.
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated, the driver MUST use
+    struct virtio_crypto_op_data_req_mux to wrap crypto requests. Otherwise, the driver
+	MUST use struct virtio_crypto_op_data_req.
+\item If the VIRTIO_CRYPTO_F_HASH_STATELESS_MODE feature bit is negotiated, 1) if the
+    driver uses the stateless mode, then the driver MUST set the \field{flag} field in
+	struct virtio_crypto_op_header to VIRTIO_CRYPTO_FLAG_STATELESS_MODE and MUST set the
+	fields in struct virtio_crypto_hash_para_stateless.sess_para, 2) if the driver uses
+	the session mode, then the driver MUST set the \field{flag} field in struct
+	virtio_crypto_op_header to VIRTIO_CRYPTO_FLAG_SESSION_MODE.
+\item The driver MUST set \field{opcode} in struct virtio_crypto_op_header to VIRTIO_CRYPTO_HASH.
+\end{itemize*}
+
+\devicenormative{\paragraph}{HASH Service Operation}{Device Types / Crypto Device / Device Operation / HASH Service Operation}
+
+\begin{itemize*}
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated, the device MUST parse
+    the struct virtio_crypto_op_data_req_mux for crypto requests. Otherwise, the device
+	MUST parse the struct virtio_crypto_op_data_req.
+\item The device MUST use the corresponding algorithm-specific structure according to
+    the \field{opcode} in the data general header.
+\item If the VIRTIO_CRYPTO_F_HASH_STATELESS_MODE feature bit is negotiated, the device
+    MUST parse \field{flag} field in struct virtio_crypto_op_header in order to decide
+	which mode the driver uses.
+\item The device MUST copy the results of HASH operations in the hash_result[] if HASH
+    operations success.
+\item The device MUST set \field{status} in struct virtio_crypto_inhdr to one of the
+    following values of enum VIRTIO_CRYPTO_STATUS:
+\begin{itemize*}
+\item VIRTIO_CRYPTO_OK if the operation success.
+\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is unsupported.
+\item VIRTIO_CRYPTO_INVSESS if the session ID invalid when in session mode.
+\item VIRTIO_CRYPTO_ERR if any failure not mentioned above occurs.
+\end{itemize*}
+\end{itemize*}
+
+\subsubsection{MAC Service Operation}\label{sec:Device Types / Crypto Device / Device Operation / MAC Service Operation}
+
+Session mode MAC service requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_mac_para {
+    struct virtio_crypto_hash_para hash;
+};
+
+struct virtio_crypto_mac_data_req {
+    /* Device-readable part */
+    struct virtio_crypto_mac_para para;
+    /* Source data */
+    u8 src_data[src_data_len];
+
+    /* Device-writable part */
+    /* Hash result data */
+    u8 hash_result[hash_result_len];
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+
+Each request uses the virtio_crypto_mac_data_req structure to store information
+used to run the MAC operations.
+
+The information includes the hash parameters stored in \field{para}, output data
+and input data. The output data here includes the source data and the input data
+includes the hash result data used to save the results of the MAC operations.
+\field{inhdr} stores the status of executing the MAC operations.
+
+Stateless mode MAC service requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_mac_para_stateless {
+    struct {
+        /* See VIRTIO_CRYPTO_MAC_* above */
+        le32 algo;
+        /* length of authenticated key */
+        le32 auth_key_len;
+    } sess_para;
+
+    /* length of source data */
+    le32 src_data_len;
+    /* hash result length */
+    le32 hash_result_len;
+};
+
+struct virtio_crypto_mac_data_req_stateless {
+    /* Device-readable part */
+    struct virtio_crypto_mac_para_stateless para;
+    /* The authenticated key */
+    u8 auth_key[auth_key_len];
+    /* Source data */
+    u8 src_data[src_data_len];
+
+    /* Device-writable part */
+    /* Hash result data */
+    u8 hash_result[hash_result_len];
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+
+\drivernormative{\paragraph}{MAC Service Operation}{Device Types / Crypto Device / Device Operation / MAC Service Operation}
+
+\begin{itemize*}
+\item If the driver uses the session mode, then the driver MUST set \field{session_id}
+    in struct virtio_crypto_op_header to a valid value assigned by the device when the
+	session was created.
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated, the driver MUST use
+    struct virtio_crypto_op_data_req_mux to wrap crypto requests. Otherwise, the
+	driver MUST use struct virtio_crypto_op_data_req.
+\item If the VIRTIO_CRYPTO_F_MAC_STATELESS_MODE feature bit is negotiated, 1) if the
+    driver uses the stateless mode, then the driver MUST set the \field{flag} field
+	in struct virtio_crypto_op_header to VIRTIO_CRYPTO_FLAG_STATELESS_MODE and MUST
+	set the fields in struct virtio_crypto_mac_para_stateless.sess_para, 2) if the
+	driver uses the session mode, then the driver MUST set the \field{flag} field in
+	struct virtio_crypto_op_header to VIRTIO_CRYPTO_FLAG_SESSION_MODE.
+\item The driver MUST set \field{opcode} in struct virtio_crypto_op_header to VIRTIO_CRYPTO_MAC.
+\end{itemize*}
+
+\devicenormative{\paragraph}{MAC Service Operation}{Device Types / Crypto Device / Device Operation / MAC Service Operation}
+
+\begin{itemize*}
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated, the device MUST parse
+    the struct virtio_crypto_op_data_req_mux for crypto requests. Otherwise, the device
+	MUST parse the struct virtio_crypto_op_data_req.
+\item If the VIRTIO_CRYPTO_F_MAC_STATELESS_MODE feature bit is negotiated, the device
+    MUST parse \field{flag} field in struct virtio_crypto_op_header in order to decide
+	which mode the driver uses.
+\item The device MUST copy the results of MAC operations in the hash_result[] if HASH
+    operations success.
+\item The device MUST set \field{status} in struct virtio_crypto_inhdr to one of the
+    following values of enum VIRTIO_CRYPTO_STATUS:
+\begin{itemize*}
+\item VIRTIO_CRYPTO_OK if the operation success.
+\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is unsupported.
+\item VIRTIO_CRYPTO_INVSESS if the session ID invalid when in session mode.
+\item VIRTIO_CRYPTO_ERR if any failure not mentioned above occurs.
+\end{itemize*}
+\end{itemize*}
+
+\subsubsection{Symmetric algorithms Operation}\label{sec:Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation}
+
+Session mode CIPHER service requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_cipher_para {
+    /*
+     * Byte Length of valid IV/Counter data pointed to by the below iv data.
+     *
+     * For block ciphers in CBC or F8 mode, or for Kasumi in F8 mode, or for
+     *   SNOW3G in UEA2 mode, this is the length of the IV (which
+     *   must be the same as the block length of the cipher).
+     * For block ciphers in CTR mode, this is the length of the counter
+     *   (which must be the same as the block length of the cipher).
+     */
+    le32 iv_len;
+    /* length of source data */
+    le32 src_data_len;
+    /* length of destination data */
+    le32 dst_data_len;
+    le32 padding;
+};
+
+struct virtio_crypto_cipher_data_req {
+    /* Device-readable part */
+    struct virtio_crypto_cipher_para para;
+    /*
+     * Initialization Vector or Counter data.
+     *
+     * For block ciphers in CBC or F8 mode, or for Kasumi in F8 mode, or for
+     *   SNOW3G in UEA2 mode, this is the Initialization Vector (IV)
+     *   value.
+     * For block ciphers in CTR mode, this is the counter.
+     * For AES-XTS, this is the 128bit tweak, i, from IEEE Std 1619-2007.
+     *
+     * The IV/Counter will be updated after every partial cryptographic
+     * operation.
+     */
+    u8 iv[iv_len];
+    /* Source data */
+    u8 src_data[src_data_len];
+
+    /* Device-writable part */
+    /* Destination data */
+    u8 dst_data[dst_data_len];
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+
+Session mode requests of algorithm chaining are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_alg_chain_data_para {
+    le32 iv_len;
+    /* Length of source data */
+    le32 src_data_len;
+    /* Length of destination data */
+    le32 dst_data_len;
+    /* Starting point for cipher processing in source data */
+    le32 cipher_start_src_offset;
+    /* Length of the source data that the cipher will be computed on */
+    le32 len_to_cipher;
+    /* Starting point for hash processing in source data */
+    le32 hash_start_src_offset;
+    /* Length of the source data that the hash will be computed on */
+    le32 len_to_hash;
+    /* Length of the additional auth data */
+    le32 aad_len;
+    /* Length of the hash result */
+    le32 hash_result_len;
+    le32 reserved;
+};
+
+struct virtio_crypto_alg_chain_data_req {
+    /* Device-readable part */
+    struct virtio_crypto_alg_chain_data_para para;
+    /* Initialization Vector or Counter data */
+    u8 iv[iv_len];
+    /* Source data */
+    u8 src_data[src_data_len];
+    /* Additional authenticated data if exists */
+    u8 aad[aad_len];
+
+    /* Device-writable part */
+    /* Destination data */
+    u8 dst_data[dst_data_len];
+    /* Hash result data */
+    u8 hash_result[hash_result_len];
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+
+Session mode requests of symmetric algorithm are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_sym_data_req {
+    union {
+        struct virtio_crypto_cipher_data_req cipher;
+        struct virtio_crypto_alg_chain_data_req chain;
+    } u;
+
+    /* Device-readable part */
+
+    /* See above VIRTIO_CRYPTO_SYM_OP_* */
+    le32 op_type;
+    le32 padding;
+};
+\end{lstlisting}
+
+Each request uses the virtio_crypto_sym_data_req structure to store information
+used to run the CIPHER operations.
+
+The information includes the cipher parameters stored in \field{para}, output data
+and input data. In the first virtio_crypto_cipher_para structure, \field{iv_len}
+specifies the length of the initialization vector or counter, \field{src_data_len}
+specifies the length of the source data, and \field{dst_data_len} specifies the length
+of the destination data. For plain CIPHER operations, the output data here includes
+the IV/Counter data and source data, and the input data includes the destination data
+used to save the results of the CIPHER operations.
+
+For algorithms chain, the output data here includes the IV/Counter data, source data
+and additional authenticated data if exists. The input data includes both destination
+data and hash result data used to store the results of the HASH/MAC operations.
+\field{inhdr} stores the status of executing the crypto operations.
+
+Stateless mode CIPHER service requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_cipher_para_stateless {
+    struct {
+        /* See VIRTIO_CRYPTO_CIPHER* above */
+        le32 algo;
+        /* length of key */
+        le32 keylen;
+
+        /* See VIRTIO_CRYPTO_OP_* above */
+        le32 op;
+    } sess_para;
+
+    /*
+     * Byte Length of valid IV/Counter data pointed to by the below iv data.
+     */
+    le32 iv_len;
+    /* length of source data */
+    le32 src_data_len;
+    /* length of destination data */
+    le32 dst_data_len;
+};
+
+struct virtio_crypto_cipher_data_req_stateless {
+    /* Device-readable part */
+    struct virtio_crypto_cipher_para_stateless para;
+    /* The cipher key */
+    u8 cipher_key[keylen];
+
+    /* Initialization Vector or Counter data. */
+    u8 iv[iv_len];
+    /* Source data */
+    u8 src_data[src_data_len];
+
+    /* Device-writable part */
+    /* Destination data */
+    u8 dst_data[dst_data_len];
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+
+Stateless mode requests of algorithm chaining are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_alg_chain_data_para_stateless {
+    struct {
+        /* See VIRTIO_CRYPTO_SYM_ALG_CHAIN_ORDER_* above */
+        le32 alg_chain_order;
+        /* length of the additional authenticated data in bytes */
+        le32 aad_len;
+
+        struct {
+            /* See VIRTIO_CRYPTO_CIPHER* above */
+            le32 algo;
+            /* length of key */
+            le32 keylen;
+            /* See VIRTIO_CRYPTO_OP_* above */
+            le32 op;
+        } cipher;
+
+        struct {
+            /* See VIRTIO_CRYPTO_HASH_* or VIRTIO_CRYPTO_MAC_* above */
+            le32 algo;
+            /* length of authenticated key */
+            le32 auth_key_len;
+            /* See VIRTIO_CRYPTO_SYM_HASH_MODE_* above */
+            le32 hash_mode;
+        } hash;
+    } sess_para;
+
+    le32 iv_len;
+    /* Length of source data */
+    le32 src_data_len;
+    /* Length of destination data */
+    le32 dst_data_len;
+    /* Starting point for cipher processing in source data */
+    le32 cipher_start_src_offset;
+    /* Length of the source data that the cipher will be computed on */
+    le32 len_to_cipher;
+    /* Starting point for hash processing in source data */
+    le32 hash_start_src_offset;
+    /* Length of the source data that the hash will be computed on */
+    le32 len_to_hash;
+    /* Length of the additional auth data */
+    le32 aad_len;
+    /* Length of the hash result */
+    le32 hash_result_len;
+    le32 reserved;
+};
+
+struct virtio_crypto_alg_chain_data_req_stateless {
+    /* Device-readable part */
+    struct virtio_crypto_alg_chain_data_para_stateless para;
+    /* The cipher key */
+    u8 cipher_key[keylen];
+    /* The auth key */
+    u8 auth_key[auth_key_len];
+    /* Initialization Vector or Counter data */
+    u8 iv[iv_len];
+    /* Additional authenticated data if exists */
+    u8 aad[aad_len];
+    /* Source data */
+    u8 src_data[src_data_len];
+
+    /* Device-writable part */
+    /* Destination data */
+    u8 dst_data[dst_data_len];
+    /* Hash result data */
+    u8 hash_result[hash_result_len];
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+     *    header + key + auth_key + iv + srd_data + aad + dst_data + hash_result
+Stateless mode requests of symmetric algorithm are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_sym_data_req_stateless {
+    union {
+        struct virtio_crypto_cipher_data_req_stateless cipher;
+        struct virtio_crypto_alg_chain_data_req_stateless chain;
+    } u;
+
+    /* Device-readable part */
+
+    /* See above VIRTIO_CRYPTO_SYM_OP_* */
+    le32 op_type;
+    /* Data virtqueue id */
+    uint32_t queue_id;
+};
+\end{lstlisting}
+
+\drivernormative{\paragraph}{Symmetric algorithms Operation}{Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation}
+
+\begin{itemize*}
+\item If the driver uses the session mode, then the driver MUST set \field{session_id}
+    in struct virtio_crypto_op_header to a valid value assigned by the device when the
+	session was created.
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated, the driver MUST use
+    struct virtio_crypto_op_data_req_mux to wrap crypto requests. Otherwise, the driver
+	MUST use struct virtio_crypto_op_data_req.
+\item If the VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE feature bit is negotiated, 1) if the
+    driver uses the stateless mode, then the driver MUST set the \field{flag} field in
+	struct virtio_crypto_op_header to VIRTIO_CRYPTO_FLAG_STATELESS_MODE and MUST set the
+	fields in struct virtio_crypto_cipher_para_stateless.sess_para or struct
+	virtio_crypto_alg_chain_data_para_stateless.sess_para, 2) if the driver uses the
+	session mode, then the driver MUST set the \field{flag} field in struct
+	virtio_crypto_op_header to VIRTIO_CRYPTO_FLAG_SESSION_MODE.
+\item The driver MUST set the \field{opcode} field in struct virtio_crypto_op_header
+    to VIRTIO_CRYPTO_CIPHER_ENCRYPT or VIRTIO_CRYPTO_CIPHER_DECRYPT.
+\item The driver MUST specify the fields of struct virtio_crypto_cipher_data_req in
+    struct virtio_crypto_sym_data_req if the request is based on VIRTIO_CRYPTO_SYM_OP_CIPHER.
+\item The driver MUST specify the fields of both struct virtio_crypto_cipher_data_req
+    and struct virtio_crypto_mac_data_req in struct virtio_crypto_sym_data_req if the request
+	is of the VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING type and in the VIRTIO_CRYPTO_SYM_HASH_MODE_AUTH mode.
+\end{itemize*}
+
+\devicenormative{\paragraph}{Symmetric algorithms Operation}{Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation}
+
+\begin{itemize*}
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated, the device MUST parse
+    the struct virtio_crypto_op_data_req_mux for crypto requests. Otherwise, the device
+	MUST parse the struct virtio_crypto_op_data_req.
+\item If the VIRTIO_CRYPTO_F_CIPHER_STATELESS_MODE feature bit is negotiated, the device
+    MUST parse \field{flag} field in struct virtio_crypto_op_header in order to decide
+	which mode the driver uses.
+\item The device MUST parse the virtio_crypto_sym_data_req based on the \field{opcode}
+    field in general header.
+\item The device SHOULD only parse fields of struct virtio_crypto_cipher_data_req in
+    struct virtio_crypto_sym_data_req if the request is VIRTIO_CRYPTO_SYM_OP_CIPHER type.
+\item The device MUST parse fields of both struct virtio_crypto_cipher_data_req and
+    struct virtio_crypto_mac_data_req in struct virtio_crypto_sym_data_req if the request
+	is of the VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING operation type and in the
+	VIRTIO_CRYPTO_SYM_HASH_MODE_AUTH mode.
+\item The device MUST copy the result of cryptographic operation in the dst_data[] in
+    both plain CIPHER mode and algorithms chain mode.
+\item The device MUST check the \field{para}.\field{add_len} is bigger than 0 before
+    parse the additional authenticated data in plain algorithms chain mode.
+\item The device MUST copy the result of HASH/MAC operation in the hash_result[] is
+    of the VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING type.
+\item The device MUST set the \field{status} field in struct virtio_crypto_inhdr to
+    one of the following values of enum VIRTIO_CRYPTO_STATUS:
+\begin{itemize*}
+\item VIRTIO_CRYPTO_OK if the operation success.
+\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is unsupported.
+\item VIRTIO_CRYPTO_INVSESS if the session ID invalid when in session mode.
+\item VIRTIO_CRYPTO_ERR if failure not mentioned above occurs.
+\end{itemize*}
+\end{itemize*}
+
+\paragraph{Steps of Operation}\label{sec:Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation / Steps of Operation}
+
+The following is a example of the flow of work between the driver and the device if the VIRTIO_CRYPTO_F_MUX_MODE feature bit is NOT negotiated.
+
+\subparagraph{Step1: Create session}\label{sec:Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation / Steps of Operation / Step1: Create session on session mode}
+
+\begin{enumerate}
+\item The driver specifies information in struct virtio_crypto_op_ctrl_req, including
+    the algorithm name, key, keylen etc;
+\item The driver adds the request of session creation into the controlq's Vring Descriptor Table;
+\item The driver kicks the device;
+\item The device receives the request from controlq;
+\item The device parses information about the request, and determines the information
+    concerning the crypto accelerator;
+\item The device packs information based on the APIs of the crypto accelerator;
+\item The device invokes the session creation APIs of the crypto accelerator to create a session;
+\item The device returns the session id to the driver.
+\end{enumerate}
+
+\subparagraph{Step2: Execute cryptographic operation}\label{sec:Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation / Steps of Operation / Step2: Execute cryptographic operation}
+
+\begin{enumerate}
+\item The driver specifies information in struct virtio_crypto_op_data_req, including
+    struct virtio_crypto_op_header and struct virtio_crypto_sym_data_req,
+	see \ref{sec:Device Types / Crypto Device / Device Operation / Symmetric algorithms Operation};
+\item The driver adds the request for cryptographic operation into the dataq's Vring Descriptor Table;
+\item The driver kicks the device (Or the device actively polls the dataq's Vring Descriptor Table);
+\item The device receives the request from dataq;
+\item The device parses information about the request, and determines the identification
+    information for the crypto accelerator. For example, converting guest physical
+	addresses to host physical addresses;
+\item The device packs identification information based on the API of the crypto accelerator;
+\item The device invokes the cryptographic APIs of the crypto accelerator;
+\item The crypto accelerator executes the cryptographic operation implicitly;
+\item The device receives the cryptographic results from the crypto accelerator (synchronous or asynchronous);
+\item The device sets the \field{status} in struct virtio_crypto_inhdr;
+\item The device updates and flushes the Used Ring to return the cryptographic results to the driver;
+\item The device notifies the driver (Or the driver actively polls the dataq's Used Ring);
+\item The driver saves the cryptographic results.
+\end{enumerate}
+
+\subsubsection{AEAD Service Operation}\label{sec:Device Types / Crypto Device / Device Operation / AEAD Service Operation}
+
+Session mode requests of symmetric algorithm are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_aead_para {
+    /*
+     * Byte Length of valid IV data.
+     *
+     * For GCM mode, this is either 12 (for 96-bit IVs) or 16, in which
+     *   case iv points to J0.
+     * For CCM mode, this is the length of the nonce, which can be in the
+     *   range 7 to 13 inclusive.
+     */
+    le32 iv_len;
+    /* length of additional auth data */
+    le32 aad_len;
+    /* length of source data */
+    le32 src_data_len;
+    /* length of dst data, this should be at least src_data_len + tag_len */
+    le32 dst_data_len;
+    /* Authentication tag length */
+    le32 tag_len;
+    le32 reserved;
+};
+
+struct virtio_crypto_aead_data_req {
+    /* Device-readable part */
+    struct virtio_crypto_aead_para para;
+    /*
+     * Initialization Vector data.
+     *
+     * For GCM mode, this is either the IV (if the length is 96 bits) or J0
+     *   (for other sizes), where J0 is as defined by NIST SP800-38D.
+     *   Regardless of the IV length, a full 16 bytes needs to be allocated.
+     * For CCM mode, the first byte is reserved, and the nonce should be
+     *   written starting at &iv[1] (to allow space for the implementation
+     *   to write in the flags in the first byte).  Note that a full 16 bytes
+     *   should be allocated, even though the iv_len field will have
+     *   a value less than this.
+     *
+     * The IV will be updated after every partial cryptographic operation.
+     */
+    u8 iv[iv_len];
+    /* Source data */
+    u8 src_data[src_data_len];
+    /* Additional authenticated data if exists */
+    u8 aad[aad_len];
+
+    /* Device-writable part */
+    /* Pointer to output data */
+    u8 dst_data[dst_data_len];
+
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+
+Each data request uses virtio_crypto_aead_data_req structure to store information
+used to run the AEAD operations.
+
+The information includes the hash parameters stored in \field{para}, output data
+and input data. In the first virtio_crypto_aead_para structure, \field{iv_len}
+specifies the length of the initialization vector. \field{tag_len} specifies the
+length of the authentication tag; \field{aad_len} specifies the length of additional
+authentication data, \field{src_data_len} specifies the length of the source data;
+\field{dst_data_len} specifies the length of the destination data, which is at least
+\field{src_data_len} + \field{tag_len}.
+
+The output data here includes the IV/Counter data, source data and additional
+authenticated data if exists. The input data includes both destination data used
+to save the results of the AEAD operations. \field{inhdr} stores the status of
+executing the AEAD operations.
+
+Stateless mode AEAD service requests are as follows:
+
+\begin{lstlisting}
+struct virtio_crypto_aead_para_stateless {
+    struct {
+        /* See VIRTIO_CRYPTO_AEAD_* above */
+        le32 algo;
+        /* length of key */
+        le32 key_len;
+        /* encrypt or decrypt, See above VIRTIO_CRYPTO_OP_* */
+        le32 op;
+    } sess_para;
+
+    /* Byte Length of valid IV data. */
+    le32 iv_len;
+    /* Authentication tag length */
+    le32 tag_len;
+    /* length of additional auth data */
+    le32 aad_len;
+    /* length of source data */
+    le32 src_data_len;
+    /* length of dst data, this should be at least src_data_len + tag_len */
+    le32 dst_data_len;
+};
+
+struct virtio_crypto_aead_data_req_stateless {
+    /* Device-readable part */
+    struct virtio_crypto_aead_para_stateless para;
+    /* The cipher key */
+    u8 key[key_len];
+    /* Initialization Vector data. */
+    u8 iv[iv_len];
+    /* Source data */
+    u8 src_data[src_data_len];
+    /* Additional authenticated data if exists */
+    u8 aad[aad_len];
+
+    /* Device-writable part */
+    /* Pointer to output data */
+    u8 dst_data[dst_data_len];
+
+    struct virtio_crypto_inhdr inhdr;
+};
+\end{lstlisting}
+
+\drivernormative{\paragraph}{AEAD Service Operation}{Device Types / Crypto Device / Device Operation / AEAD Service Operation}
+
+\begin{itemize*}
+\item If the driver uses the session mode, then the driver MUST set
+    \field{session_id} in struct virtio_crypto_op_header to a valid value assigned
+	by the device when the session was created.
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated, the driver MUST
+    use struct virtio_crypto_op_data_req_mux to wrap crypto requests. Otherwise,
+	the driver MUST use struct virtio_crypto_op_data_req.
+\item If the VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE feature bit is negotiated, 1) if
+    the driver uses the stateless mode, then the driver MUST set the \field{flag}
+	field in struct virtio_crypto_op_header to VIRTIO_CRYPTO_FLAG_STATELESS_MODE
+	and MUST set the fields in struct virtio_crypto_aead_para_stateless.sess_para,
+	2) if the driver uses the session mode, then the driver MUST set the \field{flag}
+	field in struct virtio_crypto_op_header to VIRTIO_CRYPTO_FLAG_SESSION_MODE.
+\item The driver MUST set the \field{opcode} field in struct virtio_crypto_op_header
+    to VIRTIO_CRYPTO_AEAD_ENCRYPT or VIRTIO_CRYPTO_AEAD_DECRYPT.
+\end{itemize*}
+
+\devicenormative{\paragraph}{AEAD Service Operation}{Device Types / Crypto Device / Device Operation / AEAD Service Operation}
+
+\begin{itemize*}
+\item If the VIRTIO_CRYPTO_F_MUX_MODE feature bit is negotiated, the device MUST
+    parse the struct virtio_crypto_op_data_req_mux for crypto requests. Otherwise,
+	the device MUST parse the struct virtio_crypto_op_data_req.
+\item If the VIRTIO_CRYPTO_F_AEAD_STATELESS_MODE feature bit is negotiated, the
+    device MUST parse the virtio_crypto_aead_data_req based on the \field{opcode}
+	field in general header.
+\item The device MUST copy the result of cryptographic operation in the dst_data[].
+\item The device MUST copy the authentication tag in the dst_data[] offset the cipher result.
+\item The device MUST set the \field{status} field in struct virtio_crypto_inhdr to
+    one of the following values of enum VIRTIO_CRYPTO_STATUS:
+\item When the \field{opcode} field is VIRTIO_CRYPTO_AEAD_DECRYPT, the device MUST
+    verify and return the verification result to the driver.
+\begin{itemize*}
+\item VIRTIO_CRYPTO_OK if the operation success.
+\item VIRTIO_CRYPTO_NOTSUPP if the requested algorithm or operation is unsupported.
+\item VIRTIO_CRYPTO_BADMSG if the verification result is incorrect.
+\item VIRTIO_CRYPTO_INVSESS if the session ID invalid when in session mode.
+\item VIRTIO_CRYPTO_ERR if any failure not mentioned above occurs.
+\end{itemize*}
+\end{itemize*}