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From: Zachary Amsden <zamsden@redhat.com>
To: Avi Kivity <avi@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [PATCH: kvm 3/5] Fix hotadd of CPUs for KVM.
Date: Sun, 27 Sep 2009 15:39:51 -1000	[thread overview]
Message-ID: <4AC013E7.1030508@redhat.com> (raw)
In-Reply-To: <4ABF27C8.2000406@redhat.com>

On 09/26/2009 10:52 PM, Avi Kivity wrote:
> On 09/25/2009 03:47 AM, Zachary Amsden wrote:
>>
>> --- a/virt/kvm/kvm_main.c
>> +++ b/virt/kvm/kvm_main.c
>> @@ -1716,9 +1716,6 @@ static int kvm_cpu_hotplug(struct 
>> notifier_block *notifier, unsigned long val,
>>   {
>>       int cpu = (long)v;
>>
>> -    if (!kvm_usage_count)
>> -        return NOTIFY_OK;
>> -
>
> Why?  You'll now do hardware_enable() even if kvm is not in use.

Because otherwise you'll never allocate and hardware_enable_all will fail:

Switch to broadcast mode on CPU1
svm_hardware_enable: svm_data is NULL on 1
kvm: enabling virtualization on CPU1 failed
qemu-system-x86[8698]: segfault at 20 ip 00000000004db22f sp 
00007fff0a3b4560 error 6 in qemu-system-x86_64[400000+21f000]

Perhaps I can make this work better by putting the allocation within 
hardware_enable_all.

Zach

      reply	other threads:[~2009-09-28  1:39 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-24  3:29 [PATCH: kvm 1/6] Code motion. Separate timer intialization into an indepedent function Zachary Amsden
2009-09-24  3:29 ` [PATCH: kvm 2/6] Kill the confusing tsc_ref_khz and ref_freq variables Zachary Amsden
2009-09-24  3:29   ` [PATCH: kvm 3/6] Fix hotadd of CPUs for KVM Zachary Amsden
2009-09-24  3:29     ` [PATCH: kvm 4/6] Fix hotremove " Zachary Amsden
2009-09-24  3:29       ` [PATCH: kvm 5/6] Don't unconditionally clear cpu_khz_tsc in hardware_enable Zachary Amsden
2009-09-24  3:29         ` [PATCH: kvm 6/6] Math is hard; let's do some cooking Zachary Amsden
2009-09-24 15:52     ` [PATCH: kvm 3/6] Fix hotadd of CPUs for KVM Marcelo Tosatti
2009-09-24 20:32       ` Zachary Amsden
2009-09-27  8:44         ` Avi Kivity
2009-09-24 15:10   ` [PATCH: kvm 2/6] Kill the confusing tsc_ref_khz and ref_freq variables Marcelo Tosatti
2009-09-25  0:47     ` Hotplug patches for KVM Zachary Amsden
2009-09-25  0:47       ` [PATCH: kvm 1/5] Code motion. Separate timer intialization into an indepedent function Zachary Amsden
2009-09-25  0:47         ` [PATCH: kvm 2/5] Kill the confusing tsc_ref_khz and ref_freq variables Zachary Amsden
2009-09-25  0:47           ` [PATCH: kvm 3/5] Fix hotadd of CPUs for KVM Zachary Amsden
2009-09-25  0:47             ` [PATCH: kvm 4/5] Fix hotremove " Zachary Amsden
2009-09-25  0:47               ` [PATCH: kvm 5/5] Math is hard; let's do some cooking Zachary Amsden
2009-09-27  8:54               ` [PATCH: kvm 4/5] Fix hotremove of CPUs for KVM Avi Kivity
2009-09-28  1:42                 ` Zachary Amsden
2009-09-27  8:52             ` [PATCH: kvm 3/5] Fix hotadd " Avi Kivity
2009-09-28  1:39               ` Zachary Amsden [this message]

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