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Sender: Richard Henderson <rth7680@gmail.com>
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Date: Mon, 29 Jul 2013 07:41:18 -1000
From: Richard Henderson <rth@twiddle.net>
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Subject: Re: [Qemu-devel] [PULL for-1.6 1/3] cpu: Partially revert "cpu:
 Change qemu_init_vcpu() argument to CPUState"
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To: =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= <afaerber@suse.de>
Cc: Peter Maydell <peter.maydell@linaro.org>, Jia Liu <proljc@gmail.com>, Anthony Green <green@moxielogic.com>, qemu-devel@nongnu.org, Alexander Graf <agraf@suse.de>, Blue Swirl <blauwirbel@gmail.com>, Max Filippov <jcmvbkbc@gmail.com>, Michael Walle <michael@walle.cc>, PowerPC <qemu-ppc@nongnu.org>, Paul Brook <paul@codesourcery.com>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Guan Xuetao <gxt@mprc.pku.edu.cn>, Aurelien Jarno <aurelien@aurel32.net>

On 07/29/2013 05:32 AM, Andreas Färber wrote:
> Commit c643bed99 moved qemu_init_vcpu() calls to common CPUState code.
> This causes x86 cpu-add to fail with "KVM: setting VAPIC address failed".
> 
> The reason for the failure is that CPUClass::kvm_fd is not yet
> initialized in the following call graph:
> ->x86_cpu_realizefn
>  ->x86_cpu_apic_realize
>   ->qdev_init
>    ->device_set_realized
>     ->device_reset (hotplugged == 1)
>      ->apic_reset_common
>       ->vapic_base_update
>        ->kvm_apic_vapic_base_update
> This causes attempted KVM vCPU ioctls to fail.
> 
> By contrast, in the non-hotplug case the APIC is reset much later, when
> the vCPU is already initialized.
> 
> As a quick and safe solution, move the qemu_init_vcpu() call back into
> the targets' realize functions.
> 
> Reported-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
> Acked-by: Igor Mammedov <imammedo@redhat.com> (for i386)
> Tested-by: Jia Liu <proljc@gmail.com> (for openrisc)
> Signed-off-by: Andreas Färber <afaerber@suse.de>

Tested-by: Richard Henderson <rth@twiddle.net> (for Alpha)


r~