[RFC PATCH 7/9] hw/arm/smmuv3: Add plugin fault handler for CMDQ errors

[Ruslan Ruslichenko <ruslichenko.r@gmail.com>]

From: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>

Register custom 'smmu_gerror_cmdq' handler within plugin subsystem.

This enables external plugins to dynamically inject Command Queue
errors and trigger GERROR interrupts.

Signed-off-by: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>
---
 hw/arm/smmuv3.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index c08d58c579..e80b80e843 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -27,6 +27,8 @@
 #include "hw/pci/pci.h"
 #include "cpu.h"
 #include "exec/target_page.h"
+#include "qemu/plugin.h"
+#include "qom/object.h"
 #include "trace.h"
 #include "qemu/log.h"
 #include "qemu/error-report.h"
@@ -42,6 +44,55 @@
                                         ((ptw_info).stage == SMMU_STAGE_2 && \
                                         (cfg)->s2cfg.record_faults))
 
+static void smmuv3_trigger_irq(SMMUv3State *s, SMMUIrq irq,
+                               uint32_t gerror_mask);
+
+typedef struct {
+    uint64_t base_addr;
+    Object *found_obj;
+} SMMUSearchArgs;
+
+static int smmu_match_addr_cb(Object *obj, void *opaque)
+{
+    SMMUSearchArgs *args = (SMMUSearchArgs *)opaque;
+
+    if (object_dynamic_cast(obj, TYPE_ARM_SMMUV3)) {
+        SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+
+        if (sbd->mmio[0].addr == args->base_addr) {
+            args->found_obj = obj;
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+static void smmu_inject_gerror_cmdq(void *target_data, void *fault_data)
+{
+    uint64_t base_address = *(uint64_t *)target_data;
+    SMMUCmdError cmd_error = *(SMMUCmdError*)fault_data;
+    Object *obj = NULL;
+
+    if (base_address) {
+        SMMUSearchArgs args = { .base_addr = base_address, .found_obj = NULL };
+        object_child_foreach_recursive(object_get_root(), smmu_match_addr_cb, &args);
+
+        obj = args.found_obj;
+    } else {
+        obj = object_resolve_path_type("", TYPE_ARM_SMMUV3, NULL);
+    }
+
+    if (!obj) {
+        return;
+    }
+
+    SMMUv3State *s = ARM_SMMUV3(obj);
+
+    smmu_write_cmdq_err(s, cmd_error);
+    smmuv3_trigger_irq(s, SMMU_IRQ_GERROR, R_GERROR_CMDQ_ERR_MASK);
+}
+
 /**
  * smmuv3_trigger_irq - pulse @irq if enabled and update
  * GERROR register in case of GERROR interrupt
@@ -2130,6 +2181,9 @@ static void smmuv3_class_init(ObjectClass *klass, const void *data)
     dc->hotpluggable = false;
     dc->user_creatable = true;
 
+    plugin_register_custom_fault("smmu_gerror_cmdq",
+                              smmu_inject_gerror_cmdq);
+
     object_class_property_set_description(klass, "accel",
         "Enable SMMUv3 accelerator support. Allows host SMMUv3 to be "
         "configured in nested mode for vfio-pci dev assignment");
-- 
2.43.0