Re: [PATCH 3/5] mmu: don't set the present bit unconditionally

Paolo Bonzini
2016-06-29T08:18:34Z

On 29/06/2016 05:17, Xiao Guangrong wrote:
>>
>> +++ b/arch/x86/kvm/mmu.c
>> @@ -2516,13 +2516,17 @@ static int set_spte(struct kvm_vcpu *vcpu, u64
>> *sptep,
>> gfn_t gfn, kvm_pfn_t pfn, bool speculative,
>> bool can_unsync, bool host_writable)
>> {
>> - u64 spte;
>> + u64 spte = 0;
>> int ret = 0;
>> + struct kvm_mmu *context = &vcpu->arch.mmu;
>> + bool execonly = !(context->guest_rsvd_check.bad_mt_xwr &
>> + (1ull << VMX_EPT_EXECUTABLE_MASK));
>
> Could we introduce a new field, say execonly, to "struct kvm_mmu"?
> That would make the code be more clearer.

Given how execonly is used, let's add shadow_present_mask instead.

Paolo