Re: [Qemu-devel] [PULL 20/25] target/i386: kvm: Add support for save and restore nested state

[Paolo Bonzini]

On 21/06/19 14:29, Liran Alon wrote:
>> +    max_nested_state_len = kvm_max_nested_state_length();
>> +    if (max_nested_state_len > 0) {
>> +        assert(max_nested_state_len >= offsetof(struct kvm_nested_state, 
>> data));
>> +        env->nested_state = g_malloc0(max_nested_state_len);
>> +
>> +        env->nested_state->size = max_nested_state_len;
>> +
>> +        if (IS_INTEL_CPU(env)) {
> I think it’s better to change this to: “if (cpu_has_vmx(env))” {
> 
>> +            struct kvm_vmx_nested_state_hdr *vmx_hdr =
>> +                &env->nested_state->hdr.vmx;
>> +
>> +            env->nested_state->format = KVM_STATE_NESTED_FORMAT_VMX;
>> +            vmx_hdr->vmxon_pa = -1ull;
>> +            vmx_hdr->vmcs12_pa = -1ull;
>> +        }
>> +    }
> I think we should add here:
> } else if (cpu_has_svm(env)) {
>     env->nested_state->format = KVM_STATE_NESTED_FORMAT_SVM;
> }

Or even force max_nested_state_len to 0 for AMD hosts, so that
kvm_get/put_nested_state are dropped completely.

Paolo