Messages in this thread | | | Date | Mon, 15 May 2023 17:25:55 +0100 | Subject | Re: [PATCH v6 01/21] net/tcp: Prepare tcp_md5sig_pool for TCP-AO | From | Dmitry Safonov <> |
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On 5/15/23 05:48, Herbert Xu wrote: > On Fri, May 12, 2023 at 09:22:51PM +0100, Dmitry Safonov wrote: >> TCP-AO, similarly to TCP-MD5, needs to allocate tfms on a slow-path, >> which is setsockopt() and use crypto ahash requests on fast paths, >> which are RX/TX softirqs. Also, it needs a temporary/scratch buffer >> for preparing the hash. >> >> Rework tcp_md5sig_pool in order to support other hashing algorithms >> than MD5. It will make it possible to share pre-allocated crypto_ahash >> descriptors and scratch area between all TCP hash users. >> >> Internally tcp_sigpool preferences crypto_clone_ahash() API over >> pre-allocating per-CPU crypto requests. Kudos to Herbert, who provided >> this new crypto API [1]. Currently, there's still per-CPU crypto request >> allocation fallback, that is needed for ciphers, that yet don't support >> cloning (TCP-AO requires cmac(aes128) in RFC5925). >> >> I was a little concerned over GFP_ATOMIC allocations of ahash and >> crypto_request in RX/TX (see tcp_sigpool_start()), so I benchmarked both >> "backends" with different algorithms, using patched version of iperf3[2]. >> On my laptop with i7-7600U @ 2.80GHz: >> >> clone-tfm per-CPU-requests >> TCP-MD5 2.25 Gbits/sec 2.30 Gbits/sec >> TCP-AO(hmac(sha1)) 2.53 Gbits/sec 2.54 Gbits/sec >> TCP-AO(hmac(sha512)) 1.67 Gbits/sec 1.64 Gbits/sec >> TCP-AO(hmac(sha384)) 1.77 Gbits/sec 1.80 Gbits/sec >> TCP-AO(hmac(sha224)) 1.29 Gbits/sec 1.30 Gbits/sec >> TCP-AO(hmac(sha3-512)) 481 Mbits/sec 480 Mbits/sec >> TCP-AO(hmac(md5)) 2.07 Gbits/sec 2.12 Gbits/sec >> TCP-AO(hmac(rmd160)) 1.01 Gbits/sec 995 Mbits/sec >> TCP-AO(cmac(aes128)) [not supporetd yet] 2.11 Gbits/sec >> >> So, it seems that my concerns don't have strong grounds and per-CPU >> crypto_request allocation can be dropped/removed from tcp_sigpool once >> ciphers get crypto_clone_ahash() support. > > This support is now in the upstream kernel. Please let me know > if you run into any issues using it.
Hi Herbert, thanks for your patches. Could you point me to the repo that has ciphers clone-tfm support? I've looked in Torvald's/master, your cryptodev-2.6.git and in linux-next, but I can't see anywhere in cmac_create() something of inst->alg.base.clone_tfm = cmac_clone_tfm kind.
As I wrote two paragraphs above, it's required for TCP-AO to provide cmac(aes128) support. Let me know if you have cmac clone-tfm somewhere or if you're cooking it. On the cover-letter for this patch set, it's in TODO.
Thanks, Dmitry
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