GitLab

Constructors and casting inlines are in arch-dep
code header.

Nasty casting bug. (I should create separate
types for gpa, hpa, hva, gva...).

Wasn't setting paging entry var when
allocating memory for a paging structure.

Updated tests.

Originally, destroying the ept structures also
freed the mapped host physical memory. This is
leading to bad double free errors. Instead, I
will report a potential memory leak if an ept
pte is present.

Users of the ept should unmap any host phys
memory before destroying the ept (will shift
over ept unmap range from arch-indep to
arch-dep next).

Updated arch test04 to use vmx_free_ept, now
that it doesn't try to free mapped host phys
mem.

Added pgd_pfn to asm/pgtables.h.

I needed to mask off the flags in the lower part
of the pte ...

For paging mem allocation.

Need to load vmcs in order to modify it.

Was falling through fail labels.

Can't set stack pointer until vmcs is loaded.

Pushing in case of crash ...

Each step in the deallocation requires resolving
a guest physical address to a host virtual
address, unmapping the paging structure in the
lcd's ept, and freeing the host physical memory.

This was tricky. Unfortunately, since guest physical
addresses are wrapped in the paging entries, we can't
use some of the linux macros / routines (e.g.,
pud_offset). This would allow us to benefit from pud-
and pmd-folding, making the code more portable. Perhaps
we'll think of something later...

The code will only work on a linux with 4 paging levels
(pgd, pud, pmd, page table). lcd_mm_gva_walk is the
main routine that traverses the hierarchy. Each subroutine
translates a paging structures guest physical to host
virtual address, and gets the correct entry.

A simple watermark is used (rather than a bitmap) for
allocating guest physical memory.

Guest physical unmapping code.

Guest virtual tear down to be implemented soon.

Changed to use macro accessor in lcd_arch. I think
this is less confusing and less bug prone. So,
to access lcd's utcb, do:

struct lcd_utcb *utcb;
utcb = LCD_ARCH_GET_UTCB(vcpu);

(Code before relied on free ept to free memory. But
this could be confusing and hard to debug in the future...)