Re: [PATCH v3 2/6] KVM: arm64: maintain per VM value for CTR_EL0
From: Eric Auger
Date: Thu May 30 2024 - 08:17:49 EST
On 5/30/24 13:24, Sebastian Ott wrote:
> On Wed, 29 May 2024, Eric Auger wrote:
>> On 5/29/24 17:51, Sebastian Ott wrote:
>>> On Wed, 29 May 2024, Eric Auger wrote:
>>>>> @@ -3557,6 +3557,13 @@ void kvm_reset_sys_regs(struct kvm_vcpu *vcpu)
>>>>> struct kvm *kvm = vcpu->kvm;
>>>>> unsigned long i;
>>>>>
>>>>> + if (!kvm_vcpu_initialized(vcpu))
>>>> at this stage of the reading, why is the above check needed?
>>>
>>> To make sure that a later call to this function doesn't overwrite
>>> the value provided by userspace. (See e016333745c "KVM: arm64: Only
>>> reset vCPU-scoped feature ID regs once").
>> but isn't it overwritten through the .reset=reset_ctr() that is
>> populated in next patch?
>
> No, this is done via reset_vcpu_ftr_id_reg() and also guarded by
> kvm_vcpu_initialized().
OK thanks.
Eric
>
> Sebastian