From: Jan Kiszka <jan.kiszka@siemens.com>
To: Wanpeng Li <wanpeng.li@hotmail.com>, Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: nVMX: nested VPID emulation
Date: Tue, 15 Sep 2015 19:32:45 +0200 [thread overview]
Message-ID: <55F8563D.3050905@siemens.com> (raw)
In-Reply-To: <BLU436-SMTP11466E2B935C6296917ADBA805C0@phx.gbl>
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
--
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2015-09-15 17:32 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-14 12:52 [PATCH] KVM: nVMX: nested VPID emulation Wanpeng Li
2015-09-14 14:54 ` Jan Kiszka
2015-09-15 10:14 ` Wanpeng Li
2015-09-15 17:32 ` Jan Kiszka [this message]
2015-09-16 2:36 ` Wanpeng Li
2015-09-16 5:20 ` Jan Kiszka
2015-09-16 6:10 ` Wanpeng Li
2015-09-14 16:08 ` Bandan Das
2015-09-15 10:18 ` Wanpeng Li
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