Re: [PATCH v2] x86/msr: add log messages to MSR state load error paths

[Jan Beulich <jbeulich@suse.com>]

On 08.10.2024 10:39, Roger Pau Monne wrote:
> Some error paths in the MSR state loading logic don't contain error messages,
> which makes debugging them quite hard without adding extra patches to print the
> information.
> 
> Add two new log messages to the MSR state load path that print information
> about the entry that failed to load, for both PV and HVM.
> 
> While there also adjust XEN_DOMCTL_set_vcpu_msrs to return -ENXIO in case the
> MSR is unhandled or can't be loaded, so it matches the error code used by HVM
> MSR loading (and it's less ambiguous than -EINVAL).
> 
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>

> ---
> Changes since v1:
>  - Add messages to PV MSR loading.
>  - Return -ENXIO from PV loading path also.

I'm not fully convinced of the need to change the error code, but I also don't
mind it.

Jan