Re: [PATCH 2/3 v2] KVM: nVMX: Enable VMFUNC for the L1 hypervisor
From: David Hildenbrand
Date: Mon Jul 10 2017 - 08:15:24 EST
On 10.07.2017 13:03, Paolo Bonzini wrote:
> On 10/07/2017 11:17, David Hildenbrand wrote:
>>> + vmcs12 = get_vmcs12(vcpu);
>>> + if ((vmcs12->vm_function_control & (1 << function)) == 0)
>> (learned that in c, shifting beyond the type size is undefined)
>> Should we check for function < 64 here? (as SDM mentions)
> It should be already. The manual says:
> The VMFUNC instruction causes an invalid-opcode exception (#UD) if the
> âenable VM functionsâ VM-execution controls is 0 1 or the value of EAX
> is greater than 63 (only VM functions 0â63 can be enable). Otherwise,
> the instruction causes a VM exit if the bit at position EAX is 0 in the
> VM-function controls (the selected VM function is not enabled).
Thanks, I missed that paragraph.