KVM: nVMX: set rflags to specify success in handle_invvpid() default case

Quoted 8 lines · Vitaly Kuznetsov

Your patch seems to do the right thing, however, I started wondering if
WARN_ON_ONCE() is the right thing to do. SDM says that "If an unsupported INVVPID type is specified, the instruction fails." and this is similar to INVEPT and I decided to check what handle_invept() does. Well, it does BUG_ON().

Are we doing the right thing in any of these cases?

Yes, both INVEPT and INVVPID catch this earlier.

For INVEPT:

        types = (vmx->nested.msrs.ept_caps >> VMX_EPT_EXTENT_SHIFT) & 6;

        if (type >= 32 || !(types & (1 << type)))
                return nested_vmx_failValid(vcpu,
                                VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);

For INVVPID:

        types = (vmx->nested.msrs.vpid_caps &
                        VMX_VPID_EXTENT_SUPPORTED_MASK) >> 8;

        if (type >= 32 || !(types & (1 << type)))
                return nested_vmx_failValid(vcpu,
                        VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);

So I'm leaning towards not applying Miaohe's patch. Happy Mouse Year to everyone, here is an ASCII art (except for one Unicode character) mouse:

       __()()
      /     o)

~~~~\_,__,_>°

Thanks,