More reliable virtual memory read/write

[AndrewFasano]

Our functions to read/write virtual memory sometimes fail. I believe this is due to paged-out memory and PANDA not having a way to resolve page faults. Designing and implementing an approach to fix this would be a very nice enhancement.

I wanted to make an issue for this to consolidate our discussion of the problem. I plan to post more in this thread later as I look into the failure more.

[AndrewFasano]

This blog post provides a good description of the problem and a potential solution: https://hvmi.github.io/blog/2020/12/14/pfinjection.html

[github-actions]

Stale issue message

[github-actions]

This issue has gone stale! If you believe it is still a problem, please comment on this issue or it will be closed in 30 days

[AndrewFasano]

#1103 seems to significantly reduce the frequency of failures in virtual memory read/write - once that's merged we can close this issue.

[AndrewFasano]

Seems like #1365 mostly solves this issue 🥳

It uses OSI to walk guest page tables to improve virtual memory accesses - we still can't handle paged out memory, but that's not nearly as common.