Il 05/02/2014 17:30, Vincent KHERBACHE ha scritto:
Hi all,
I'm trying to get the dirty bitmap of a specific VM, using
KVM_GET_DIRTY_LOG ioctl.
For this purpose, I should be able to get the file descriptor of an
existing VM by doing something like :
kvm_fd = open("/dev/kvm")
...
b = ioctl(KVM_GET_DIRTY_LOG, vm_fd)
I also can see, from the API documentation
(https://www.kernel.org/doc/Documentation/virtual/kvm/api.txt), that
there is the following restriction concerning VM ioctls :
"Only run VM ioctls from the same process (address space) that was used
to create the VM."
Is there a way to get the fd of a running VM (created from an other
process), or maybe a better/easier manner to get the dirty bitmap ?
You can get ask the other process to retrieve the dirty bitmap and place
it in a shared memory segment.
However, note that KVM_GET_DIRTY_LOG retrieves _and clears_ the dirty
bitmap. So if the "owner" of the running VM is already using the dirty
bitmap, calling KVM_GET_DIRTY_LOG will likely break that usage.
Paolo
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
