CODEWITHSUNDEEP
memorymemory-managementlinux-kernelkvm
tamlok
tamlok

Reputation: 707

Is there an explict split between userspace and kernel in physical memory on Linux x86-64?

That is, given a physical address, can I tell whether this address is from userspace or not?

As far as I know, in virtual address space, the kernel will use the upper half and the userspace will use the lower half. But what about in physical address space?

What makes the problem complicated is that I want to check the guest physical address in KVM, which means that I can't call some kernel functions in the guest OS. So I want to know whether there is an explict split line?

Upvotes: 3

Views: 1070

Answers (1)

caf
caf

Reputation: 239011

No.

Almost any physical page frame can be mapped to a userspace virtual address or a kernel virtual address, or even both at the same time.

Upvotes: 7

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