[Qemu-devel] KVMonitor-like technology

[Qemu-devel] KVMonitor-like technology

[Mike Guidry]

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I have a project where I would like to inspect a QEMU Guest.  I came across
KVMonitor and really like some of the concepts.

I'd like to use shared memory/file backed memory to read guest memory
immediately using CR3 for Guest->Host memory address translation.

Has anyone has experience doing this?  I first changed qemu_try_memalign()
and realized that its for local memory allocations, usually.  I proceeded
to change other functions, and came across qemu_anon_ram_alloc() which
seemed to be where the larger (gigabyte) allocations were heading.  I
enabled prealloc and finally began getting the allocations I wanted...

I'm curious if anyone has any other suggestions than to use shm_open()
here.  I wanted to quickly hack this together and realized I cannot list
shared memory regions on OSX, so I dumped them to files.  My question is:
 I realize there is file-back for 'Large TLB,' although I didn't much
success converting that function for non-TLB based file systems.  I
considered doing mkramfs (with modified kernel for larger amounts, such as
larger shared memory is necessary), and putting the file system on top.  I
really haven't decided if I wanted to add another 'type' of backend, or to
quickly modify one of these.

 Am i missing some feature that may allow me to handle this quickly?  I
even considered using LD_PRELOAD to quickly hijack and enable all memory
under shared memory for reading guest VM memory from another process.  I
just have to ensure I have the CR3 context at all times of the particular
process I'd like to  read.

Thanks,
Mike

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