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Date: Wed, 16 Feb 2011 10:57:31 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: [Qemu-devel] Re: [PATCH] fix halt emulation with icount and
	CONFIG_IOTHREAD (v2)
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To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Marcelo Tosatti <mtosatti@redhat.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>

On 02/16/2011 10:46 AM, Jan Kiszka wrote:
> What should this be good for? The iothread already kicks the vcpu if it
> wants to acquire the contended global mutex.

Assuming the VCPU is in the timedwait that Marcelo changed, the global 
mutex is free and the iothread will not kick the VCPU.

> And when the vcpu thread is
> in halt state, kicking it should change no other state.

Kicking the VCPU will start running it, if an interrupt request from the 
devices caused cpu_has_work to become true (and hence 
all_cpu_threads_idle to become false).

So, perhaps the correct fix is to kick the cpu in cpu_interrupt, and all 
I wrote about timeouts and timers is wrong.  My patch would band-aid it.

Paolo