On 01/27/2011 10:33 AM, Nadav Har'El wrote:
In VMX, before we bring down a CPU we must VMCLEAR all VMCSs loaded on it
because (at least in theory) the processor might not have written all of its
content back to memory. Since a patch from June 26, 2008, this is done using
a per-cpu "vcpus_on_cpu" linked list of vcpus loaded on each CPU.
The problem is that with nested VMX, we no longer have the concept of a
vcpu being loaded on a cpu: A vcpu has multiple VMCSs (one for L1, others for
each L2), and each of those may be have been last loaded on a different cpu.
This trivial patch changes the code to keep on vcpus_on_cpu only L1 VMCSs.
This fixes crashes on L1 shutdown caused by incorrectly maintaing the linked
lists.
It is not a complete solution, though. It doesn't flush the inactive L1 or L2
VMCSs loaded on a CPU which is being shutdown. Doing this correctly will
probably require replacing the vcpu linked list by a link list of "saved_vcms"
objects (VMCS, cpu and launched), and it is left as a TODO.
It looks like the right thing is a structure that represents the common
things between 02 and 02 vmcses:
- pointer to memory
- cpu
- linked list entries for vcpus_on_vcpu (to be renamed vmcses_on_cpu)
You could then use vcpu_clear() in the previous patch.
--
error compiling committee.c: too many arguments to function
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
