From: Paolo Bonzini <pbonzini@redhat.com>
To: Arthur Chunqi Li <yzt356@gmail.com>
Cc: kvm <kvm@vger.kernel.org>
Subject: Re: How to get to know vcpu status from outside
Date: Tue, 17 Dec 2013 12:21:31 +0100 [thread overview]
Message-ID: <52B033BB.6070401@redhat.com> (raw)
In-Reply-To: <CABpY8M+eq9UMtNtDDckw9gQNjiNkxcrAAZNNPM7ZfQ_9vwuk0Q@mail.gmail.com>
Il 17/12/2013 07:11, Arthur Chunqi Li ha scritto:
> Hi Paolo,
>
> Since VCPU is managed the same as a process in kernel, how can I know
> the status (running, sleeping etc.) of a vcpu in kernel? Is there a
> variant in struct kvm_vcpu or something else indicate this?
waitqueue_active(&vcpu->wq) means that the VCPU is sleeping in the
kernel (i.e. in a halted state).
vcpu->mode == IN_GUEST_MODE means that the VCPU is running.
Anything else means that the host is running some kind of "glue" code
(either kernel or userspace).
> Besides, if vcpu1 is running on pcpu1, and a kernel thread running on
> pcpu0. Can the kernel thread send a message to force vcpu1 trap to
> VMM? How can I do this?
Yes, with kvm_vcpu_kick. KVM tracks internally which pcpu will run the
vcpu in vcpu->cpu, and kvm_vcpu_kick sends either a wakeup (if the vcpu
is sleeping) or an IPI (if it is running).
Paolo
next prev parent reply other threads:[~2013-12-17 11:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-17 6:11 How to get to know vcpu status from outside Arthur Chunqi Li
2013-12-17 11:21 ` Paolo Bonzini [this message]
2013-12-17 11:43 ` Arthur Chunqi Li
2013-12-17 12:28 ` Paolo Bonzini
2013-12-20 8:05 ` Arthur Chunqi Li
2013-12-20 11:57 ` Paolo Bonzini
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