This might seem like a too easy theory, but if you l9ok 8nto the article posted by jedisct1 there is the somewhat unrestricted access of the L1 Cache and well with multiple mentions of Rowhammer, could it just be rowhammering from whatever the L1 Cache accesses?
The mysterious case of the Linux Page Table Isolation patches
261–264 of 264 posts
Re: The mysterious case of the Linux Page Table Isolation patches
#262Re: The mysterious case of the Linux Page Table Isolation patches
#263Earlier quoted context omitted.
In this specific scenario what's the mitigation for cloud customers? Or even cloud providers? A customer can't migrate all of their infrastructure before a packaged exploit can be distributed. A provider can't dedicate hardware for every single customer. Let's be realistic here.
This is the classic case of the frog being boiled. Or the pig getting lazy... At every step along the way, there's been a choice of "Well, we could own the hardware and incur overhead costs, or we could trust someone else and pay our share of lower overhead. It'll mean giving up some control, but it'll save us a few bucks." Or maybe it goes like "Well, we could develop with practices that result in more robust code,…
The three little pigs taught me "Don't bother putting in the hard work; because when the shit hits the fan, someone else will happily bail you out".
Re: The mysterious case of the Linux Page Table Isolation patches
#264Earlier quoted context omitted.
Every draw call will need to transition to kernel space to send data over the PCIe bus to the GPU. Modern games execute something on the order of 1000+ draws per frame, so assuming 60fps that's going to be at least 60,000*2 context switches into the kernel and back per second, more if you're doing high refresh rates. How big the impact I will be, I don't know - but I wouldn't be surprised if it was a couple percent (…
I was also worried about network I/O too, which could be an absolute pain for games where you care about latency.
Network IO is negligible in game. The source engine for instance is hard limited to using 30 kB/s of bandwidth.