Re: [Qemu-devel] [PATCH v3 2/3] kvm: Add support to KVM_GET_MSR_FEATURE_INDEX_LIST and KVM_GET_MSRS system ioctl

[Eduardo Habkost]

On Thu, Aug 23, 2018 at 02:28:28PM +0800, Robert Hoo wrote:
> On Sat, 2018-08-18 at 12:05 -0300, Eduardo Habkost wrote:
[...]
> > We don't want QEMU to refuse to run if the kernel doesn't have
> > KVM_CAP_GET_MSR_FEATURES.  We can treat missing capability as
> > equivalent to returning an empty list of MSRs.
> Yes. I'll let caller (kvm_arch_init) ignore the return value but a
> simple warning.

Warnings tend to be ignored and are generally a sign that QEMU
isn't doing the right thing.  Sometimes we have no choice, but I
don't think that's the case here.

As far as I can see, we have only two possibilities here:
1) The host can run a VM that behaves exactly as requested on the
   command-line (no warning required).
2) The host can't run the requested configuration (fatal error,
   not a warning).

-- 
Eduardo