Introduce akcipher service for virtio-crypto

[zhenwei pi]

v7 - v8:
- The changes of QEMU crypto has been reviewed & merged by Daniel,
  remove this part from this series. Thanks to Daniel!
- virtio_crypto.h is updated by e4082063e47e
  ("linux-headers: Update to v5.18-rc6"), remove from this series.
- Minor fixes reviewed by Gonglei. Thanks to Gonglei!

v6 -> v7:
- Fix serval build errors for some specific platforms/configurations.
- Use '%zu' instead of '%lu' for size_t parameters.
- AkCipher-gcrypt: avoid setting wrong error messages when parsing RSA
  keys.
- AkCipher-benchmark: process constant amount of sign/verify instead
 of running sign/verify for a constant duration.

v5 -> v6:
- Fix build errors and codestyles.
- Add parameter 'Error **errp' for qcrypto_akcipher_rsakey_parse.
- Report more detailed errors.
- Fix buffer length check and return values of akcipher-nettle, allows caller to
 pass a buffer with larger size than actual needed.

A million thanks to Daniel!

v4 -> v5:
- Move QCryptoAkCipher into akcipherpriv.h, and modify the related comments.
- Rename asn1_decoder.c to der.c.
- Code style fix: use 'cleanup' & 'error' lables.
- Allow autoptr type to auto-free.
- Add test cases for rsakey to handle DER error.
- Other minor fixes.

v3 -> v4:
- Coding style fix: Akcipher -> AkCipher, struct XXX -> XXX, Rsa -> RSA,
XXX-alg -> XXX-algo.
- Change version info in qapi/crypto.json, from 7.0 -> 7.1.
- Remove ecdsa from qapi/crypto.json, it would be introduced with the 
implemetion later.
- Use QCryptoHashAlgothrim instead of QCryptoRSAHashAlgorithm(removed) in 
qapi/crypto.json.
- Rename arguments of qcrypto_akcipher_XXX to keep aligned with 
qcrypto_cipher_XXX(dec/enc/sign/vefiry -> in/out/in2), and add 
qcrypto_akcipher_max_XXX APIs.
- Add new API: qcrypto_akcipher_supports.
- Change the return value of qcrypto_akcipher_enc/dec/sign, these functions 
return the actual length of result.
- Separate ASN.1 source code and test case clean.
- Disable RSA raw encoding for akcipher-nettle.
- Separate RSA key parser into rsakey.{hc}, and implememts it with 
builtin-asn1-decoder and nettle respectivly.
- Implement RSA(pkcs1 and raw encoding) algorithm by gcrypt. This has higher 
priority than nettle.
- For some akcipher operations(eg, decryption of pkcs1pad(rsa)), the length of 
returned result maybe less than the dst buffer size, return the actual length 
of result instead of the buffer length to the guest side. (in function 
virtio_crypto_akcipher_input_data_helper)
- Other minor changes.

Thanks to Daniel!

Eric pointed out this missing part of use case, send it here again.

In our plan, the feature is designed for HTTPS offloading case and other 
applications which use kernel RSA/ecdsa by keyctl syscall. The full picture 
shows bellow:


                 Nginx/openssl[1] ... Apps
Guest   -----------------------------------------
                  virtio-crypto driver[2]
-------------------------------------------------
                  virtio-crypto backend[3]
Host    -----------------------------------------
                 /          |          \
             builtin[4]   vhost     keyctl[5] ...


[1] User applications can offload RSA calculation to kernel by keyctl syscall. 
There is no keyctl engine in openssl currently, we developed a engine and tried 
to contribute it to openssl upstream, but openssl 1.x does not accept new 
feature. Link:
   https://github.com/openssl/openssl/pull/16689

This branch is available and maintained by Lei <helei.sig11@bytedance.com>
   https://github.com/TousakaRin/openssl/tree/OpenSSL_1_1_1-kctl_engine

We tested nginx(change config file only) with openssl keyctl engine, it works 
fine.

[2] virtio-crypto driver is used to communicate with host side, send requests 
to host side to do asymmetric calculation.
   https://lkml.org/lkml/2022/3/1/1425

[3] virtio-crypto backend handles requests from guest side, and forwards 
request to crypto backend driver of QEMU.

[4] Currently RSA is supported only in builtin driver. This driver is supposed 
to test the full feature without other software(Ex vhost process) and hardware 
dependence. ecdsa is introduced into qapi type without implementation, this may 
be implemented in Q3-2022 or later. If ecdsa type definition should be added 
with the implementation together, I'll remove this in next version.

[5] keyctl backend is in development, we will post this feature in Q2-2022. 
keyctl backend can use hardware acceleration(Ex, Intel QAT).

Setup the full environment, tested with Intel QAT on host side, the QPS of 
HTTPS increase to ~200% in a guest.

VS PCI passthrough: the most important benefit of this solution makes the VM 
migratable.

v2 -> v3:
- Introduce akcipher types to qapi
- Add test/benchmark suite for akcipher class
- Seperate 'virtio_crypto: Support virtio crypto asym operation' into:
 - crypto: Introduce akcipher crypto class
 - virtio-crypto: Introduce RSA algorithm

v1 -> v2:
- Update virtio_crypto.h from v2 version of related kernel patch.

v1:
- Support akcipher for virtio-crypto.
- Introduce akcipher class.
- Introduce ASN1 decoder into QEMU.
- Implement RSA backend by nettle/hogweed.

Zhenwei Pi (1):
  crypto: Introduce RSA algorithm

 backends/cryptodev-builtin.c      | 274 +++++++++++++++++++++----
 backends/cryptodev-vhost-user.c   |  34 +++-
 backends/cryptodev.c              |  32 ++-
 hw/virtio/virtio-crypto.c         | 323 ++++++++++++++++++++++++------
 include/hw/virtio/virtio-crypto.h |   5 +-
 include/sysemu/cryptodev.h        |  83 ++++++--
 6 files changed, 607 insertions(+), 144 deletions(-)

-- 
2.20.1