[PATCH] klog.json: add an "Unable ... IOMMU perf counter" message

[Alex Hung]

This message shows performance counters are not supported on AMD IOMMU
hardware.

Reported-by: Paul Menzel <pmenzel at molgen.mpg.de>
Signed-off-by: Alex Hung <alex.hung at canonical.com>
---
 data/klog.json | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/data/klog.json b/data/klog.json
index 15043658..eb78fe47 100644
--- a/data/klog.json
+++ b/data/klog.json
@@ -2697,6 +2697,13 @@ atform Communications Channel Table (PCCT) and find the PCC subspace communicati
     "advice": "BIOS setup is configured to enable IOMMU, but BIOS lacks IVRS table that is describing which is the address of IOMMU",
     "label": "KlogAmdIommuNoIVRS"
   },
+  {
+    "compare_mode": "string",
+    "log_level": "LOG_LEVEL_MEDIUM",
+    "pattern": "Unable to read/write to IOMMU perf counter",
+    "advice": "AMD IOMMU performance counter is not accessible and not supported due to firmware limitations.",
+    "label": "KlogAmdIommuPCNotSupported"
+  },
   {
     "compare_mode": "string",
     "log_level": "LOG_LEVEL_HIGH",
-- 
2.25.1