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.
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 */
--
Kiryl Shutsemau / Kirill A. Shutemov
