On Mon, 2023-06-12 at 17:33 +0300, kirill.shutemov@xxxxxxxxxxxxxxx wrote:
> On Mon, Jun 12, 2023 at 02:33:58AM +0000, Huang, Kai wrote:
> >
> > >
> > > Maybe not even a pr_warn(), but something that's a bit ominous and has a
> > > chance of getting users to act.
> >
> > Sorry I am not sure how to do. Could you give some suggestion?
>
> Maybe something like this would do?
>
> I'm struggle with the warning message. Any suggestion is welcome.
I guess it would be helpful to print out the actual consumed TDMRs?
pr_warn("consumed TDMRs reaching limit: %d used (out of %d)\n",
tdmr_idx, tdmr_list->max_tdmrs);
>
> diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
> index 9cd4f6b58d4a..cc141025b249 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.c
> +++ b/arch/x86/virt/vmx/tdx/tdx.c
> @@ -627,6 +627,15 @@ static int fill_out_tdmrs(struct list_head *tmb_list,
> /* @tdmr_idx is always the index of last valid TDMR. */
> tdmr_list->nr_consumed_tdmrs = tdmr_idx + 1;
>
> + /*
> + * Warn early that kernel is about to run out of TDMRs.
> + *
> + * This is indication that TDMR allocation has to be reworked to be
> + * smarter to not run into an issue.
> + */
> + if (tdmr_list->max_tdmrs - tdmr_list->nr_consumed_tdmrs < TDMR_NR_WARN)
> + pr_warn("Low number of spare TDMRs\n");
> +
> return 0;
> }
>
> diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
> index 323ce744b853..17efe33847ae 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.h
> +++ b/arch/x86/virt/vmx/tdx/tdx.h
> @@ -98,6 +98,9 @@ struct tdx_memblock {
> int nid;
> };
>
> +/* Warn if kernel has less than TDMR_NR_WARN TDMRs after allocation */
> +#define TDMR_NR_WARN 4
> +
> struct tdmr_info_list {
> void *tdmrs; /* Flexible array to hold 'tdmr_info's */
> int nr_consumed_tdmrs; /* How many 'tdmr_info's are in use */
