Re: [PATCH] KVM: x86: allow KVM_REQ_GET_NESTED_STATE_PAGES outside guest mode for VMX

On 25/01/21 20:16, Sean Christopherson wrote:

...

} +static bool vmx_get_nested_state_pages(struct kvm_vcpu *vcpu) +{

• if (!nested_get_evmcs_page(vcpu))

• return false;
  

• if (is_guest_mode(vcpu) && !nested_get_vmcs12_pages(vcpu))

• return false;
  

nested_get_evmcs_page() will get called twice in the common case of is_guest_mode() == true. I can't tell if that will ever be fatal, but it's definitely weird. Maybe this?

if (!is_guest_mode(vcpu)) return nested_get_evmcs_page(vcpu);

return nested_get_vmcs12_pages(vcpu);

I wouldn't say there is a common case; however the idea was to remove the call to nested_get_evmcs_page from nested_get_vmcs12_pages, since that one is only needed after KVM_GET_NESTED_STATE and not during VMLAUNCH/VMRESUME.

Paolo