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From: Paolo Bonzini <pbonzini@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>, kvm <kvm@vger.kernel.org>,
	Jan Kiszka <jan.kiszka@web.de>
Subject: Re: [PATCH v2] KVM: x86: Convert INIT and SIPI signals into synchronously handled requests
Date: Wed, 06 Mar 2013 23:43:30 +0100	[thread overview]
Message-ID: <5137C692.9090609@redhat.com> (raw)
In-Reply-To: <20130306211942.GA23299@amt.cnet>

Il 06/03/2013 22:19, Marcelo Tosatti ha scritto:
> Vcpu should only invoke kvm_emulate_halt if it has been through a
> KVM_MP_STATE_UNINITIALIZED ->  KVM_MP_STATE_INIT_RECEIVED ->
> KVM_MP_STATE_SIPI_RECEIVED -> KVM_MP_STATE_RUNNABLE transition.
> 
> If it has been through that, how can a KVM_MP_STATE_INIT_RECEIVED be
> overwritten? 
> 
> That is, KVM_MP_STATE_RUNNABLE (precondition for kvm_emulate_halt) is
> only reachable if KVM_MP_STATE_INIT_RECEIVED/KVM_MP_STATE_SIPI_RECEIVED
> have not been overwritten. 

You can always go back to the KVM_MP_STATE_INIT_RECEIVED state; either
by an APIC write or by various soft resets (port 92h, keyboard
controller, port cf9h) that aren't emulated correctly right now.

Paolo

> The point i'm trying to make is it appears the symptom is being fixed
> with the proposed patch, not the root cause (which, if the reasoning
> above is correct, is somewhere in nVMX code).


  reply	other threads:[~2013-03-06 22:43 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-04 21:41 [PATCH v2] KVM: x86: Convert INIT and SIPI signals into synchronously handled requests Jan Kiszka
2013-03-04 23:00 ` Jan Kiszka
2013-03-05  7:57   ` Gleb Natapov
2013-03-05  8:24     ` Jan Kiszka
2013-03-05  8:46       ` Gleb Natapov
2013-03-05  9:12         ` Jan Kiszka
2013-03-05  9:37           ` Gleb Natapov
2013-03-05 10:50             ` Paolo Bonzini
2013-03-05 13:25               ` Jan Kiszka
2013-03-05 13:33                 ` Gleb Natapov
2013-03-05 13:28               ` Gleb Natapov
2013-03-05 23:16 ` Marcelo Tosatti
2013-03-06  0:01   ` Marcelo Tosatti
2013-03-06  0:06   ` Marcelo Tosatti
2013-03-06  6:12     ` Paolo Bonzini
2013-03-06  7:57       ` Jan Kiszka
2013-03-06 21:30         ` Marcelo Tosatti
2013-03-06 21:39           ` Jan Kiszka
2013-03-06 21:50             ` Marcelo Tosatti
2013-03-06 21:58               ` Jan Kiszka
2013-03-06 21:19       ` Marcelo Tosatti
2013-03-06 22:43         ` Paolo Bonzini [this message]
2013-03-06 23:04           ` Marcelo Tosatti

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