[PATCH 2/4] KVM: VMX: Add functions to fill VMCSINFO

zhangyanfei zhangyanfei at cn.fujitsu.com
Wed Apr 11 06:34:36 EDT 2012

于 2012年04月11日 16:48, Avi Kivity 写道:
> On 04/11/2012 04:50 AM, zhangyanfei wrote:
>> This patch is to implement the feature that at initialization of
>> kvm_intel module, fills VMCSINFO with a VMCS revision identifier,
>> and encoded offsets of VMCS fields. The reason why we put the
>> VMCSINFO processing at the initialization of kvm_intel module
>> is that it's dangerous to rob VMX resources while kvm module is
>> loaded.
> Maybe it should be done by a separate module.

If we put vmcsinfo processing at the initialization of kvm_intel module,
as soon as the kvm_intel module is loaded, VMCSINFO is filled. And it is
because vmcsinfo processing is at the initialization of kvm_intel module,
no kvm guests are running, so it will not rob any VMX resources.

If it is done by a separate module, I am afraid this module may not be
loaded when the kernel needs VMCSINFO.

>> +
>> +	kvm_cpu_vmxon(__pa(per_cpu(vmxarea, raw_smp_processor_id())));
>> +	vmcs_load(vmcs);
> Should do this after writing into the vmcs directly (vmcs_load() may
> cache some information for vmcs_read()).

Hmm, thanks for pointing this.

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