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Intel deprecates SGX on Core series processors

edc.intel.com

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Re: Intel deprecates SGX on Core series processors

#101

Post by tryfinally »

WithinReason wrote: post #76
janwas wrote: post #67

Earlier quoted context omitted.

That's a bold claim. What are your sources? The two latest things I worked on, JPEG XL and quicksort, see a 1.4 and 1.6x speedup from AVX-512. That's on SKX and includes the much-maligned throttling. On a system level, I doubt moving those to GPU is helpful.

If you're processing a lot of data, you're better off moving it to the GPU. If you're processing only a little data, the speed-up doesn't matter. I wonder how wide is the Goldilocks Zone where AVX512 makes a practical difference?

Assuming AVX-512 actually works well (haven't had the opportunity to use it myself), it could be very useful in high-end gamedev. Data-oriented programming is popular there, which makes it much easier to optimize data transformations w/ SIMD. Good compilers can even do some auto-vectorization (it's a nice boost with no additional programmer effort but you can't rely on it much). GPUs tend to be already fully loaded by the intensive rendering workload, so there is a large incentive to squeeze as much as you can out of the CPU.

Re: Intel deprecates SGX on Core series processors

#102

Post by espadrine »

phire wrote: post #98
eightysixfour wrote: post #59

Earlier quoted context omitted.

It is gone now, but IIRC Microsoft was working on a blockchain for inter-enterprise settlement that ran in the secure enclave. It had extremely high throughput and all of the parties could “trust” that the code running was the same, so they were all following the same rules. Neat concept, they killed it before ever sharing source code.

I have seen a deployed altcoin built on SGX. Can't remember the name or if it was even successful. In my opinion, it's a huge risk. With a regular blockchain, the fact that someone might maliciously be running the wrong code is baked into the design, and the security model has to handle it. With SGX, you are relying on Intel's security model to make sure everyone is running the same code. If SGX is ever broken (which…

> I have seen a deployed altcoin built on SGX.

That may be MobileCoin[0].

Before that, from the same inspiration, Signal built SVR[1], a recovery system for the address book that uses SGX to ensure the servers cannot decrypt the backup.

I wonder how they will react to this deprecation.

[0]: https://developers.mobilecoin.com/overview/security/secure-e...

[1]: https://signal.org/blog/secure-value-recovery/#deus-sgx-mach...

Re: Intel deprecates SGX on Core series processors

#103

Post by paconbork »

phire wrote: post #98
eightysixfour wrote: post #59

Earlier quoted context omitted.

It is gone now, but IIRC Microsoft was working on a blockchain for inter-enterprise settlement that ran in the secure enclave. It had extremely high throughput and all of the parties could “trust” that the code running was the same, so they were all following the same rules. Neat concept, they killed it before ever sharing source code.

I have seen a deployed altcoin built on SGX. Can't remember the name or if it was even successful. In my opinion, it's a huge risk. With a regular blockchain, the fact that someone might maliciously be running the wrong code is baked into the design, and the security model has to handle it. With SGX, you are relying on Intel's security model to make sure everyone is running the same code. If SGX is ever broken (which…

Are you thinking of Secret Network? If I remember correctly, they use SGX for transaction privacy (transactions are encrypted with a key that is only known to enclaves). An SGX break I think would just make it a generic proof of stake network but maybe the way they ended up doing smart contracts is different?

Re: Intel deprecates SGX on Core series processors

#104

Post by paconbork »

justinclift wrote: post #87
eightysixfour wrote: post #59

Earlier quoted context omitted.

It is gone now, but IIRC Microsoft was working on a blockchain for inter-enterprise settlement that ran in the secure enclave. It had extremely high throughput and all of the parties could “trust” that the code running was the same, so they were all following the same rules. Neat concept, they killed it before ever sharing source code.

> all of the parties could “trust” that the code running was the same Doesn't that trust fall apart when the SGX has known hacks? eg bad actors can do their thing

Yeah, the Foreshadow attack leaked signing keys, so you could attest to a modified program running outside an enclave. I think other attacks didn't get that far though

Re: Intel deprecates SGX on Core series processors

#105

Post by the8472 »

adrian_b wrote: post #86
femto wrote: post #56

Also the note at the bottom of that page: that they are doing away with AVX-512. A bit sad for those who need to squeeze maximum performance out of a CPU. (I gather it lives on in Xeon and Zen 4.)

AVX-512 is not supported on the CPUs with "Hybrid Technology", i.e. the current Alder Lake and Raptor Lake, which will be launched towards the end of 2022, to replace Alder Lake. What will happen when the Gracemont small cores will be replaced at the end of 2023, is not known yet. It is still possible that the successor of Gracemont will have AVX-512, in which case the Intel processors with "Hybrid Technology" will a…

It seems silly to do that just due to asymmetric processors. The small cores could simply not support the instructions and the OS could then handle the fault by moving the task to a big core. Perhaps this could be signaled via a different CPU feature flag to avoid libraries using AVX512 instructions sporadically (e.g. in memcopy) and only use it in long-running loops. Or maybe give the OS a way to determine whether the CPU flags should be shown to a specific process or not. Or applications could install a SIGILL handler and deal with it in userspace.

Re: Intel deprecates SGX on Core series processors

#106

Post by ClumsyPilot »

NavinF wrote: post #58
femto wrote: post #56

Also the note at the bottom of that page: that they are doing away with AVX-512. A bit sad for those who need to squeeze maximum performance out of a CPU. (I gather it lives on in Xeon and Zen 4.)

Meh, the few workloads that benefit from AVX-512 would be better off on a GPU. Also note that it wasn’t well received 2 years ago. Example: https://news.ycombinator.com/item?id=23809335

'few workloads that benefit from AVX-512 would be better off on a GPU.'

Have you seen the state of GPU software development? GPUs are very expensive in cloud, are poorly supported in containers and virtual machines If you want to use GPU compute, some stuff is Nvidia-only, some stuff is glitching and crashy, it's probably not avaliable in your language of choice, etc.

It is literally impossible for me to add GPU compute to any of our corporate workloads, but I can tap into AVX easilly in my language of choice.

Re: Intel deprecates SGX on Core series processors

#107

Post by pclmulqdq »

ClumsyPilot wrote: post #106
NavinF wrote: post #58

Earlier quoted context omitted.

Meh, the few workloads that benefit from AVX-512 would be better off on a GPU. Also note that it wasn’t well received 2 years ago. Example: https://news.ycombinator.com/item?id=23809335

'few workloads that benefit from AVX-512 would be better off on a GPU.' Have you seen the state of GPU software development? GPUs are very expensive in cloud, are poorly supported in containers and virtual machines If you want to use GPU compute, some stuff is Nvidia-only, some stuff is glitching and crashy, it's probably not avaliable in your language of choice, etc. It is literally impossible for me to add GPU comp…

Pretty much all cloud CPUs are planned to continue supporting AVX-512. It's only the client side where they are axing it.

Re: Intel deprecates SGX on Core series processors

#108

Post by adgjlsfhk1 »

the8472 wrote: post #105
adrian_b wrote: post #86

Earlier quoted context omitted.

AVX-512 is not supported on the CPUs with "Hybrid Technology", i.e. the current Alder Lake and Raptor Lake, which will be launched towards the end of 2022, to replace Alder Lake. What will happen when the Gracemont small cores will be replaced at the end of 2023, is not known yet. It is still possible that the successor of Gracemont will have AVX-512, in which case the Intel processors with "Hybrid Technology" will a…

It seems silly to do that just due to asymmetric processors. The small cores could simply not support the instructions and the OS could then handle the fault by moving the task to a big core. Perhaps this could be signaled via a different CPU feature flag to avoid libraries using AVX512 instructions sporadically (e.g. in memcopy) and only use it in long-running loops. Or maybe give the OS a way to determine whether t…

even easier would be to have avx 512 be micro coded for the small cores. most of avx512 can be emulated pretty easily.

Re: Intel deprecates SGX on Core series processors

#109

Post by mort96 »

eightysixfour wrote: post #59
Uptrenda wrote: post #49

Many moons ago, I wrote a prototype on Azure's 'confidential computing' VMs that demonstrated how a computer could 'prove' to another that it was running certain code using 'attestations.' I thought it was cool as hell, and honestly thought that if such a technology held up you could build many interesting things with it. Potentially, it would have had many use-cases in the DeFi industry, privacy-preserving computati…

It is gone now, but IIRC Microsoft was working on a blockchain for inter-enterprise settlement that ran in the secure enclave. It had extremely high throughput and all of the parties could “trust” that the code running was the same, so they were all following the same rules. Neat concept, they killed it before ever sharing source code.

How did that solution do? How did it solve the 51% attack problem without being bundled with a cryptocurrency?

...Or are you just using the word "blockchain" to literally mean a Merkle tree, so that the "innovation" was equivalent to storing settlements in git?

Re: Intel deprecates SGX on Core series processors

#110

Post by adgjlsfhk1 »

WithinReason wrote: post #76
janwas wrote: post #67

Earlier quoted context omitted.

That's a bold claim. What are your sources? The two latest things I worked on, JPEG XL and quicksort, see a 1.4 and 1.6x speedup from AVX-512. That's on SKX and includes the much-maligned throttling. On a system level, I doubt moving those to GPU is helpful.

If you're processing a lot of data, you're better off moving it to the GPU. If you're processing only a little data, the speed-up doesn't matter. I wonder how wide is the Goldilocks Zone where AVX512 makes a practical difference?

gpus generally aren't worth it for moderately cheap O(n) operations. avx 512 is really nice because if you match the memory speed, you beat GPU (since the cost of GPU will also be memory speed constrained).
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