[PATCH] numa: hmat: require parent cache description before the next level one

[PATCH] numa: hmat: require parent cache description before the next level one

[Igor Mammedov]

Spec[1] defines 0 - 3 level memory side cache, however QEMU
CLI allows to specify an intermediate cache level without
specifying previous level. Such option(s) silently ignored
when building HMAT table, which leads to incomplete cache
information.
Make sure that previous level exists and error out
if it hasn't been provided.

1) ACPI 6.2A 5.2.27.5 Memory Side Cache Information Structure

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1842877
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 hw/core/numa.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/hw/core/numa.c b/hw/core/numa.c
index f9593ec716..8282e0b2e6 100644
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -424,7 +424,13 @@ void parse_numa_hmat_cache(MachineState *ms, NumaHmatCacheOptions *node,
     }
 
     if ((node->level > 1) &&
-        ms->numa_state->hmat_cache[node->node_id][node->level - 1] &&
+        ms->numa_state->hmat_cache[node->node_id][node->level - 1] == NULL) {
+        error_setg(errp, "Cache level=%" PRIu8 " shall be defined first",
+                   node->level - 1);
+        return;
+    }
+
+    if ((node->level > 1) &&
         (node->size <=
             ms->numa_state->hmat_cache[node->node_id][node->level - 1]->size)) {
         error_setg(errp, "Invalid size=%" PRIu64 ", the size of level=%" PRIu8
-- 
2.27.0

Re: [PATCH] numa: hmat: require parent cache description before the next level one

[Eduardo Habkost]

On Thu, Sep 24, 2020 at 05:14:06AM -0400, Igor Mammedov wrote:
> Spec[1] defines 0 - 3 level memory side cache, however QEMU
> CLI allows to specify an intermediate cache level without
> specifying previous level. Such option(s) silently ignored
> when building HMAT table, which leads to incomplete cache
> information.
> Make sure that previous level exists and error out
> if it hasn't been provided.
> 
> 1) ACPI 6.2A 5.2.27.5 Memory Side Cache Information Structure
> 
> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1842877
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

Queueing on machine-next, thanks!

-- 
Eduardo