Map VM's memory?

Map VM's memory?

[Jun Koi]

Hi,

Could anybody tell me how to map memory of VMs in KVM (mapping done
from hypervisor)?
I am reading the source, but still cannot figure it out.

Another question: can KVM provide strong isolation between VMs? That
means if there is a security bug in a VM kernel, can it affect other
VMs? (It seems not to me, could anybody confirm this?)

Thanks,
Jun

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Re: Map VM's memory?

[Avi Kivity]

Jun Koi wrote:
> Hi,
>
> Could anybody tell me how to map memory of VMs in KVM (mapping done
> from hypervisor)?
> I am reading the source, but still cannot figure it out.
>
>   

In the kernel, see struct kvm->memslots[x].phys_mem[y].  You need to 
kmap()/kunmap() it before use.

In userspace, just mmap() /dev/kvm, the file offset is the physical 
memory address.


> Another question: can KVM provide strong isolation between VMs? That
> means if there is a security bug in a VM kernel, can it affect other
> VMs? (It seems not to me, could anybody confirm this?)
>
>   

Barring any bugs, kvm fully isolates guests.  Guest kernel activity 
(malicious or erronous) should not affect other guests except through 
defined interfaces (e.g. networking).

-- 
error compiling committee.c: too many arguments to function


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