Messages in this thread | | | Subject | Re: [PATCH 2/3 v2] KVM: nVMX: Enable VMFUNC for the L1 hypervisor | From | Paolo Bonzini <> | Date | Mon, 10 Jul 2017 13:03:53 +0200 |
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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 “enable VM functions” VM-execution controls is 0 1 or the value of EAX is greater than 63 (only VM functions 0–63 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).
Paolo
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