plugins: implement helpers for resolving hwaddr

We need to keep a local per-cpu copy of the data as other threads may
be running. Currently we can provide insight as to if the access was
IO or not and give the offset into a given device (usually the main
RAMBlock). We store enough information to get details such as the
MemoryRegion which might be useful in later expansions to the API.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

2 files changed, 48 insertions, 0 deletions

diff --git a/include/qemu/plugin-memory.h b/include/qemu/plugin-memory.h
new file mode 100644
index 0000000000..fbbe99474b
--- /dev/null
+++ b/include/qemu/plugin-memory.h
@@ -0,0 +1,40 @@
+/*
+ * Plugin Memory API
+ *
+ * Copyright (c) 2019 Linaro Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef _PLUGIN_MEMORY_H_
+#define _PLUGIN_MEMORY_H_
+
+struct qemu_plugin_hwaddr {
+    bool is_io;
+    bool is_store;
+    union {
+        struct {
+            MemoryRegionSection *section;
+            hwaddr    offset;
+        } io;
+        struct {
+            uint64_t hostaddr;
+        } ram;
+    } v;
+};
+
+/**
+ * tlb_plugin_lookup: query last TLB lookup
+ * @cpu: cpu environment
+ *
+ * This function can be used directly after a memory operation to
+ * query information about the access. It is used by the plugin
+ * infrastructure to expose more information about the address.
+ *
+ * It would only fail if not called from an instrumented memory access
+ * which would be an abuse of the API.
+ */
+bool tlb_plugin_lookup(CPUState *cpu, target_ulong addr, int mmu_idx,
+                       bool is_store, struct qemu_plugin_hwaddr *data);
+
+#endif /* _PLUGIN_MEMORY_H_ */
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
index b9a4a4b684..c213d1dd19 100644
--- a/include/qemu/qemu-plugin.h
+++ b/include/qemu/qemu-plugin.h
@@ -285,6 +285,14 @@ bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info);
 struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
                                                   uint64_t vaddr);
 
+/*
+ * The following additional queries can be run on the hwaddr structure
+ * to return information about it. For non-IO accesses the device
+ * offset will be into the appropriate block of RAM.
+ */
+bool qemu_plugin_hwaddr_is_io(struct qemu_plugin_hwaddr *hwaddr);
+uint64_t qemu_plugin_hwaddr_device_offset(const struct qemu_plugin_hwaddr *haddr);
+
 typedef void
 (*qemu_plugin_vcpu_mem_cb_t)(unsigned int vcpu_index,
                              qemu_plugin_meminfo_t info, uint64_t vaddr,