Re: [PATCH v9 09/12] KVM: x86: Introduce a function to initialize the PT configuration

[Paolo Bonzini]

On 08/06/2018 16:56, Kang, Luwei wrote:
>>> +   /* Initialize and clear the no dependency bits */
>>> +   vmx->pt_desc.ctl_bitmask = ~0ULL;
>> This looks redundant, doesn't it?
> This is a bit mask for RTIT_CTL MSR and it will make & with the value of 
> RTIT_CLT from guest.
> The reserved bits will be 1 in this bit mask and the setable  bits are 0.
> 
>>> +   vmx->pt_desc.ctl_bitmask = ~(RTIT_CTL_TRACEEN | RTIT_CTL_OS |
>>> +                   RTIT_CTL_USR | RTIT_CTL_TSC_EN |
>> RTIT_CTL_DISRETC);

But it's set twice, so the first assignment is superfluous.

Paolo