Re: [PATCH] KVM: nVMX: nested VPID emulation

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2015-09-15 12:14, Wanpeng Li wrote:
> On 9/14/15 10:54 PM, Jan Kiszka wrote:
>> Last but not least: the guest can now easily exhaust the host's pool of
>> vpid by simply spawning plenty of VCPUs for L2, no? Is this acceptable
>> or should there be some limit?
> 
> I reuse the value of vpid02 while vpid12 changed w/ one invvpid in v2,
> and the scenario which you pointed out can be avoid.

I cannot yet follow why there is no chance for L1 to consume all vpids
that the host manages in that single, global bitmap by simply spawning a
lot of nested VCPUs for some L2. What is enforcing L1 to call nested
vmclear - apparently the only way, besides destructing nested VCPUs, to
release such vpids again?

Jan

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