AMD's Future Chips & SoC's: News, Info & Rumours.

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https://www.phoronix.com/scan.php?page=news_item&px=Linux-Tip-Git-Disable-x86-PTI

Update: Linus Torvalds has now ended up pulling the latest PTI fixes that also include the change to disable page table isolation for now on all AMD CPUs. The commit is in mainline for Linux 4.15 along with a few basic fixes and ensuring PAGE_TABLE_ISOLATION is enabled by default.

Kernel developer Thomas Gleixner wrote in the pull request of disabling KPTI on AMD hardware, "Not necessarily a fix, but if AMD is so confident that they are not affected, then we should not burden users with the overhead."
Click to expand...
 

Heh. Linus is being brutal here. On one hand, he is not taking the "defensive coding" approach to this fix; that is hardly a good call IMO, but he has way more experience on these topics, so I won't argue there. And on the other hand, he is saying: "AMD, if you are affected, you will be the laughing stock for ages".

I really hope AMD makes really sure they're not affected by this.

Cheers!
 

https://meltdownattack.com/meltdown.pdf
6.4 Limitations on ARM and AMD
We also tried to reproduce the Meltdown bug on several
ARM and AMD CPUs. However, we did not manage
to successfully leak kernel memory with the attack described
in Section 5, neither on ARM nor on AMD. The
reasons for this can be manifold. First of all, our implementation
might simply be too slow and a more optimized
version might succeed. For instance, a more shallow
out-of-order execution pipeline could tip the race
condition towards against the data leakage. Similarly,
if the processor lacks certain features, e.g., no re-order
buffer, our current implementation might not be able to
leak data. However, for both ARM and AMD, the toy
example as described in Section 3 works reliably, indicating
that out-of-order execution generally occurs and
instructions past illegal memory accesses are also performed.
Click to expand...
 
qi6i1IA.png
 


AMD has confirmed their CPUs are unaffected.
 
You guys are protecting AMD like furious body guards, .I just don't get it, is just another company like any other.
Initial reports on Wednesday said that the flaw, which could allow hackers to steal confidential information like passwords, only affected Intel’s chips(LIE) sent the company’s stock price plunging 7% while competitor Advanced Micro Devices shares jumped 6%. Reports that a software fix would slow the performance of affected PCs contributed to the strong reaction.

IT WAS A LIE, Everyone is affected, Intel Says Major Security Bug Also Affects Competitors ARM and AMD. But in a mid-afternoon statement, Intel (INTC, -1.39%) said the early reports were wrong. And mobile chip designer ARM Holdings said its chips were also affected and that it was working with Intel and AMD (AMD, +5.89%) on a fix. That helped Intel shares claw back some of the drop and the stock closed down only 3%, while AMD ended with a 5% gain.

Now ARM, which is owned by SoftBank Group, said in a statement: “ARM have been working with Intel and AMD to devise mitigation for a new method identified by security researchers that can exploit certain high-end processors, including ours…Software mitigation measures have already been shared with our partners. ARM takes all security threats seriously and we encourage individual users to ensure their software is up-to-date and always practice good security hygiene.”AMD said its chips were affected by some but not all of a series of related security exploits uncovered by researchers. AMD has already developed a simple software fix for its chips that will not impact PC performance, an AMD spokesman said."

Intel Says Major Security Bug Also Affects Competitors ARM and AMD and Intel already begun distributing software fixes to eliminate the issue and denied that the patches would noticeably hamper the performance of affected systems. “Contrary to some reports, any performance impacts are workload-dependent, and, for the average computer user, should not be significant and will be mitigated over time,” Intel said.
 


To be fair, there are TWO separate classes of issues. AMD is believed to be immune to the first (which is the more immediate problem), but *everyone* is affected by the second.

But yeah, the spin cycle is clearly anti-Intel right now.
 


Believed by whom? The researches that discovered the flaw claim this " Currently, we have only verified Meltdown on Intel processors. At the moment, it is unclear whether ARM and AMD processors are also affected by Meltdown."

http://www.tomshardware.co.uk/forum/id-3609004/cpu-security-vulnerabilities-information.html
 


What is comes down to is that a Meltdown was tested on Intel CPU's successfully, and unsuccessfully on AMD or ARM processors, so only Intel has had to apply a patch to fix the Meltdown vulnerability. This is also what sparked all the attention on day one of the story, because of potential performance decreases associated with high system calls from the patch Intel had to apply. The fixes for Spectre were mitigated through OS updates, and thought to cause minimal performance loss.
6.4 Limitations on ARM and AMD
We also tried to reproduce the Meltdown bug on several
ARM and AMD CPUs. However, we did not manage
to successfully leak kernel memory with the attack described
in Section 5, neither on ARM nor on AMD.
Click to expand...
All this information and more is readily available in this thread. Read the papers on each form of attack, and the subsequent post form a timeline of events as they appeared.
http://www.tomshardware.com/forum/id-3609004/cpu-security-vulnerabilities-information.html

Edit: Just to be clear the patch Intel applied, and the OS software mitigation are band aids to help reduce the likely hood of a successful attack, and do not prevent it completely! Only hardware design changes will fix this.
 


Ryzen 3 Mobile APUs: January 9th
Ryzen Desktop APUs: February 12th
Second Generation Ryzen Desktop Processors: April.
Ryzen Pro Mobile APUs: Q2 2018
Second Generation Threadripper Processors: 2H 2018
Second Generation Ryzen Pro Desktop Processors: 2H 2018

Edit: April for Zen+
 


True. It is hilarious that Zen+ was renamed to Zen2, Zen++ was renamed to Zen3, and now Zen is renamed to Zen+. So now there are two different Zen+ on the Internet. Now when searching for "Zen+" in the Internet we can find older slides about the original Zen+ (aka Zen2) and the new slides about the new Zen+ (aka Zen). Older slides as this

Zen-8.jpg


Where that 'Zen+' (aka Zen2) will confound some people.

All this is much more hilarious than when 14nm+ was renamed to 12nm. Anandtech covering of the CES presentation even makes jokes about how the 7nm+ node used for Zen3 could be relabeled

Finally, AMD expects to implement Zen 3 by 2020. Just to be clear, if AMD did launch in Q4 of 2020 that would still be within AMD’s target window. Zen 3 will be built on an improved 7nm process called 7nm+. It is our understanding that the 12nm process is essentially a 14+ process for GloFo, so the 7+ process might be renamed at a later date perhaps. But if the Zen 2 design is complete, I would expect more of AMD’s microarchitectural engineers to be on the Zen 3 design now.
Click to expand...

Any bet that 7nm+ will be relabeled as "5nm"?

REFERENCES:
https://en.wikipedia.org/w/index.php?title=Zen_2&oldid=776589059
https://wccftech.com/amd-zen-ryzen-naples-processors-four-years-roadmap/
https://cpugrade.com/articles/amd-zen-core-complexes-and-configurations/
https://www.anandtech.com/show/12233/amd-tech-day-at-ces-2018-roadmap-revealed-with-ryzen-apus-zen-on-12nm-vega-on-7nm
 
Juanrga, that's the perfect example of why we all shouldn't go too crazy of product names before they are released. We never know exactly what is going to happen with anything till it's released. All we really have to go on is what we are told. But part of the fun is making guesses or assumptions about future expectations with the information we given or find.
 


No, not really. It only confused you.

Additionally, given what they've said about the changes, Zen+ seems more fitting to the iteration.

So, they did introduce minor changes and they've made a hard distinction on Zen+ and Zen2.
 


Yes indeed it does make perfect sense, an it also sets our expectations.

 


Agree. I never imagined that they would use "Zen+" twice.



I know perfectly that "Zen+" in older slides mean Zen2 and "Zen+" in newest slides means Zen. No confusion on my side. And, during months, I have been advising people to not use "Zen+" for Pinnacle Ridge because it would give confusion with the old usage of "Zen+". So what are you talking here?

And what changes? What minor changes?
 
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