Re: [PATCH] cpu_x86: Probe host CPU for all MSR features
On Thu, Jan 16, 2025 at 14:38:26 +0100, Michal Prívozník wrote:
On 1/16/25 14:05, Jiri Denemark wrote:
> The list of CPU features we probe from various MSR grew significantly
> over time and the CPU map currently mentions 11 distinct MSR indexes.
> But the code for directly probing host CPU features was still reading
> only the original 0x10a index. Thus the CPU model in host capabilities
> was missing a lot of features.
>
> Instead of specifying a static list of indexes to read (which we would
> forget to update in the future), let's just read all indexes found in
> the CPU map.
>
> Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com>
> ---
> src/cpu/cpu_x86.c | 62 ++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 53 insertions(+), 9 deletions(-)
Reviewed-by: Michal Privoznik <mprivozn(a)redhat.com>
Thanks, I was reminded declaring more variables on a single line is bad
so I squashed the following trivial patch before pushing.
Jirka
@@ -2841,7 +2841,7 @@ virCPUx86ListMSRs(virCPUx86Map *map,
unsigned long **msrs)
{
size_t n = 0;
- size_t i, j, k;
+ size_t i;
/* These three nested loops look horrible, but data->len is always 1 here
* and thanks to grouping features in the CPU map by their MSR index the
@@ -2850,11 +2850,13 @@ virCPUx86ListMSRs(virCPUx86Map *map,
*/
for (i = 0; i < map->nfeatures; i++) {
virCPUx86Data *data = &map->features[i]->data;
+ size_t j;
for (j = 0; j < data->len; j++) {
virCPUx86DataItem *item = &data->items[j];
bool found = false;
unsigned long msr;
+ size_t k;
if (item->type != VIR_CPU_X86_DATA_MSR)
continue;