Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

6 files changed, 1528 insertions, 0 deletions

diff --git a/plugins/api.c b/plugins/api.c
new file mode 100644
index 000000000..b143b09ce
--- /dev/null
+++ b/plugins/api.c
@@ -0,0 +1,393 @@
+/*
+ * QEMU Plugin API
+ *
+ * This provides the API that is available to the plugins to interact
+ * with QEMU. We have to be careful not to expose internal details of
+ * how QEMU works so we abstract out things like translation and
+ * instructions to anonymous data types:
+ *
+ *  qemu_plugin_tb
+ *  qemu_plugin_insn
+ *
+ * Which can then be passed back into the API to do additional things.
+ * As such all the public functions in here are exported in
+ * qemu-plugin.h.
+ *
+ * The general life-cycle of a plugin is:
+ *
+ *  - plugin is loaded, public qemu_plugin_install called
+ *    - the install func registers callbacks for events
+ *    - usually an atexit_cb is registered to dump info at the end
+ *  - when a registered event occurs the plugin is called
+ *     - some events pass additional info
+ *     - during translation the plugin can decide to instrument any
+ *       instruction
+ *  - when QEMU exits all the registered atexit callbacks are called
+ *
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ * Copyright (C) 2019, Linaro
+ *
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/plugin.h"
+#include "tcg/tcg.h"
+#include "exec/exec-all.h"
+#include "exec/ram_addr.h"
+#include "disas/disas.h"
+#include "plugin.h"
+#ifndef CONFIG_USER_ONLY
+#include "qemu/plugin-memory.h"
+#include "hw/boards.h"
+#endif
+
+/* Uninstall and Reset handlers */
+
+void qemu_plugin_uninstall(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
+{
+    plugin_reset_uninstall(id, cb, false);
+}
+
+void qemu_plugin_reset(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
+{
+    plugin_reset_uninstall(id, cb, true);
+}
+
+/*
+ * Plugin Register Functions
+ *
+ * This allows the plugin to register callbacks for various events
+ * during the translation.
+ */
+
+void qemu_plugin_register_vcpu_init_cb(qemu_plugin_id_t id,
+                                       qemu_plugin_vcpu_simple_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_INIT, cb);
+}
+
+void qemu_plugin_register_vcpu_exit_cb(qemu_plugin_id_t id,
+                                       qemu_plugin_vcpu_simple_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_EXIT, cb);
+}
+
+void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb,
+                                          qemu_plugin_vcpu_udata_cb_t cb,
+                                          enum qemu_plugin_cb_flags flags,
+                                          void *udata)
+{
+    if (!tb->mem_only) {
+        plugin_register_dyn_cb__udata(&tb->cbs[PLUGIN_CB_REGULAR],
+                                      cb, flags, udata);
+    }
+}
+
+void qemu_plugin_register_vcpu_tb_exec_inline(struct qemu_plugin_tb *tb,
+                                              enum qemu_plugin_op op,
+                                              void *ptr, uint64_t imm)
+{
+    if (!tb->mem_only) {
+        plugin_register_inline_op(&tb->cbs[PLUGIN_CB_INLINE], 0, op, ptr, imm);
+    }
+}
+
+void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn,
+                                            qemu_plugin_vcpu_udata_cb_t cb,
+                                            enum qemu_plugin_cb_flags flags,
+                                            void *udata)
+{
+    if (!insn->mem_only) {
+        plugin_register_dyn_cb__udata(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_REGULAR],
+                                      cb, flags, udata);
+    }
+}
+
+void qemu_plugin_register_vcpu_insn_exec_inline(struct qemu_plugin_insn *insn,
+                                                enum qemu_plugin_op op,
+                                                void *ptr, uint64_t imm)
+{
+    if (!insn->mem_only) {
+        plugin_register_inline_op(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
+                                  0, op, ptr, imm);
+    }
+}
+
+
+/*
+ * We always plant memory instrumentation because they don't finalise until
+ * after the operation has complete.
+ */
+void qemu_plugin_register_vcpu_mem_cb(struct qemu_plugin_insn *insn,
+                                      qemu_plugin_vcpu_mem_cb_t cb,
+                                      enum qemu_plugin_cb_flags flags,
+                                      enum qemu_plugin_mem_rw rw,
+                                      void *udata)
+{
+    plugin_register_vcpu_mem_cb(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR],
+                                    cb, flags, rw, udata);
+}
+
+void qemu_plugin_register_vcpu_mem_inline(struct qemu_plugin_insn *insn,
+                                          enum qemu_plugin_mem_rw rw,
+                                          enum qemu_plugin_op op, void *ptr,
+                                          uint64_t imm)
+{
+    plugin_register_inline_op(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE],
+                              rw, op, ptr, imm);
+}
+
+void qemu_plugin_register_vcpu_tb_trans_cb(qemu_plugin_id_t id,
+                                           qemu_plugin_vcpu_tb_trans_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_TB_TRANS, cb);
+}
+
+void qemu_plugin_register_vcpu_syscall_cb(qemu_plugin_id_t id,
+                                          qemu_plugin_vcpu_syscall_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL, cb);
+}
+
+void
+qemu_plugin_register_vcpu_syscall_ret_cb(qemu_plugin_id_t id,
+                                         qemu_plugin_vcpu_syscall_ret_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL_RET, cb);
+}
+
+/*
+ * Plugin Queries
+ *
+ * These are queries that the plugin can make to gauge information
+ * from our opaque data types. We do not want to leak internal details
+ * here just information useful to the plugin.
+ */
+
+/*
+ * Translation block information:
+ *
+ * A plugin can query the virtual address of the start of the block
+ * and the number of instructions in it. It can also get access to
+ * each translated instruction.
+ */
+
+size_t qemu_plugin_tb_n_insns(const struct qemu_plugin_tb *tb)
+{
+    return tb->n;
+}
+
+uint64_t qemu_plugin_tb_vaddr(const struct qemu_plugin_tb *tb)
+{
+    return tb->vaddr;
+}
+
+struct qemu_plugin_insn *
+qemu_plugin_tb_get_insn(const struct qemu_plugin_tb *tb, size_t idx)
+{
+    struct qemu_plugin_insn *insn;
+    if (unlikely(idx >= tb->n)) {
+        return NULL;
+    }
+    insn = g_ptr_array_index(tb->insns, idx);
+    insn->mem_only = tb->mem_only;
+    return insn;
+}
+
+/*
+ * Instruction information
+ *
+ * These queries allow the plugin to retrieve information about each
+ * instruction being translated.
+ */
+
+const void *qemu_plugin_insn_data(const struct qemu_plugin_insn *insn)
+{
+    return insn->data->data;
+}
+
+size_t qemu_plugin_insn_size(const struct qemu_plugin_insn *insn)
+{
+    return insn->data->len;
+}
+
+uint64_t qemu_plugin_insn_vaddr(const struct qemu_plugin_insn *insn)
+{
+    return insn->vaddr;
+}
+
+void *qemu_plugin_insn_haddr(const struct qemu_plugin_insn *insn)
+{
+    return insn->haddr;
+}
+
+char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn)
+{
+    CPUState *cpu = current_cpu;
+    return plugin_disas(cpu, insn->vaddr, insn->data->len);
+}
+
+const char *qemu_plugin_insn_symbol(const struct qemu_plugin_insn *insn)
+{
+    const char *sym = lookup_symbol(insn->vaddr);
+    return sym[0] != 0 ? sym : NULL;
+}
+
+/*
+ * The memory queries allow the plugin to query information about a
+ * memory access.
+ */
+
+unsigned qemu_plugin_mem_size_shift(qemu_plugin_meminfo_t info)
+{
+    MemOp op = get_memop(info);
+    return op & MO_SIZE;
+}
+
+bool qemu_plugin_mem_is_sign_extended(qemu_plugin_meminfo_t info)
+{
+    MemOp op = get_memop(info);
+    return op & MO_SIGN;
+}
+
+bool qemu_plugin_mem_is_big_endian(qemu_plugin_meminfo_t info)
+{
+    MemOp op = get_memop(info);
+    return (op & MO_BSWAP) == MO_BE;
+}
+
+bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info)
+{
+    return get_plugin_meminfo_rw(info) & QEMU_PLUGIN_MEM_W;
+}
+
+/*
+ * Virtual Memory queries
+ */
+
+#ifdef CONFIG_SOFTMMU
+static __thread struct qemu_plugin_hwaddr hwaddr_info;
+#endif
+
+struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
+                                                  uint64_t vaddr)
+{
+#ifdef CONFIG_SOFTMMU
+    CPUState *cpu = current_cpu;
+    unsigned int mmu_idx = get_mmuidx(info);
+    enum qemu_plugin_mem_rw rw = get_plugin_meminfo_rw(info);
+    hwaddr_info.is_store = (rw & QEMU_PLUGIN_MEM_W) != 0;
+
+    if (!tlb_plugin_lookup(cpu, vaddr, mmu_idx,
+                           hwaddr_info.is_store, &hwaddr_info)) {
+        error_report("invalid use of qemu_plugin_get_hwaddr");
+        return NULL;
+    }
+
+    return &hwaddr_info;
+#else
+    return NULL;
+#endif
+}
+
+bool qemu_plugin_hwaddr_is_io(const struct qemu_plugin_hwaddr *haddr)
+{
+#ifdef CONFIG_SOFTMMU
+    return haddr->is_io;
+#else
+    return false;
+#endif
+}
+
+uint64_t qemu_plugin_hwaddr_phys_addr(const struct qemu_plugin_hwaddr *haddr)
+{
+#ifdef CONFIG_SOFTMMU
+    if (haddr) {
+        if (!haddr->is_io) {
+            RAMBlock *block;
+            ram_addr_t offset;
+            void *hostaddr = haddr->v.ram.hostaddr;
+
+            block = qemu_ram_block_from_host(hostaddr, false, &offset);
+            if (!block) {
+                error_report("Bad host ram pointer %p", haddr->v.ram.hostaddr);
+                abort();
+            }
+
+            return block->offset + offset + block->mr->addr;
+        } else {
+            MemoryRegionSection *mrs = haddr->v.io.section;
+            return mrs->offset_within_address_space + haddr->v.io.offset;
+        }
+    }
+#endif
+    return 0;
+}
+
+const char *qemu_plugin_hwaddr_device_name(const struct qemu_plugin_hwaddr *h)
+{
+#ifdef CONFIG_SOFTMMU
+    if (h && h->is_io) {
+        MemoryRegionSection *mrs = h->v.io.section;
+        if (!mrs->mr->name) {
+            unsigned long maddr = 0xffffffff & (uintptr_t) mrs->mr;
+            g_autofree char *temp = g_strdup_printf("anon%08lx", maddr);
+            return g_intern_string(temp);
+        } else {
+            return g_intern_string(mrs->mr->name);
+        }
+    } else {
+        return g_intern_static_string("RAM");
+    }
+#else
+    return g_intern_static_string("Invalid");
+#endif
+}
+
+/*
+ * Queries to the number and potential maximum number of vCPUs there
+ * will be. This helps the plugin dimension per-vcpu arrays.
+ */
+
+#ifndef CONFIG_USER_ONLY
+static MachineState * get_ms(void)
+{
+    return MACHINE(qdev_get_machine());
+}
+#endif
+
+int qemu_plugin_n_vcpus(void)
+{
+#ifdef CONFIG_USER_ONLY
+    return -1;
+#else
+    return get_ms()->smp.cpus;
+#endif
+}
+
+int qemu_plugin_n_max_vcpus(void)
+{
+#ifdef CONFIG_USER_ONLY
+    return -1;
+#else
+    return get_ms()->smp.max_cpus;
+#endif
+}
+
+/*
+ * Plugin output
+ */
+void qemu_plugin_outs(const char *string)
+{
+    qemu_log_mask(CPU_LOG_PLUGIN, "%s", string);
+}
+
+bool qemu_plugin_bool_parse(const char *name, const char *value, bool *ret)
+{
+    return name && value && qapi_bool_parse(name, value, ret, NULL);
+}
diff --git a/plugins/core.c b/plugins/core.c
new file mode 100644
index 000000000..792262da0
--- /dev/null
+++ b/plugins/core.c
@@ -0,0 +1,558 @@
+/*
+ * QEMU Plugin Core code
+ *
+ * This is the core code that deals with injecting instrumentation into the code
+ *
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ * Copyright (C) 2019, Linaro
+ *
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qemu/config-file.h"
+#include "qapi/error.h"
+#include "qemu/lockable.h"
+#include "qemu/option.h"
+#include "qemu/rcu_queue.h"
+#include "qemu/xxhash.h"
+#include "qemu/rcu.h"
+#include "hw/core/cpu.h"
+#include "exec/cpu-common.h"
+
+#include "exec/exec-all.h"
+#include "exec/helper-proto.h"
+#include "tcg/tcg.h"
+#include "tcg/tcg-op.h"
+#include "plugin.h"
+#include "qemu/compiler.h"
+
+struct qemu_plugin_cb {
+    struct qemu_plugin_ctx *ctx;
+    union qemu_plugin_cb_sig f;
+    void *udata;
+    QLIST_ENTRY(qemu_plugin_cb) entry;
+};
+
+struct qemu_plugin_state plugin;
+
+struct qemu_plugin_ctx *plugin_id_to_ctx_locked(qemu_plugin_id_t id)
+{
+    struct qemu_plugin_ctx *ctx;
+    qemu_plugin_id_t *id_p;
+
+    id_p = g_hash_table_lookup(plugin.id_ht, &id);
+    ctx = container_of(id_p, struct qemu_plugin_ctx, id);
+    if (ctx == NULL) {
+        error_report("plugin: invalid plugin id %" PRIu64, id);
+        abort();
+    }
+    return ctx;
+}
+
+static void plugin_cpu_update__async(CPUState *cpu, run_on_cpu_data data)
+{
+    bitmap_copy(cpu->plugin_mask, &data.host_ulong, QEMU_PLUGIN_EV_MAX);
+    cpu_tb_jmp_cache_clear(cpu);
+}
+
+static void plugin_cpu_update__locked(gpointer k, gpointer v, gpointer udata)
+{
+    CPUState *cpu = container_of(k, CPUState, cpu_index);
+    run_on_cpu_data mask = RUN_ON_CPU_HOST_ULONG(*plugin.mask);
+
+    if (cpu->created) {
+        async_run_on_cpu(cpu, plugin_cpu_update__async, mask);
+    } else {
+        plugin_cpu_update__async(cpu, mask);
+    }
+}
+
+void plugin_unregister_cb__locked(struct qemu_plugin_ctx *ctx,
+                                  enum qemu_plugin_event ev)
+{
+    struct qemu_plugin_cb *cb = ctx->callbacks[ev];
+
+    if (cb == NULL) {
+        return;
+    }
+    QLIST_REMOVE_RCU(cb, entry);
+    g_free(cb);
+    ctx->callbacks[ev] = NULL;
+    if (QLIST_EMPTY_RCU(&plugin.cb_lists[ev])) {
+        clear_bit(ev, plugin.mask);
+        g_hash_table_foreach(plugin.cpu_ht, plugin_cpu_update__locked, NULL);
+    }
+}
+
+/*
+ * Disable CFI checks.
+ * The callback function has been loaded from an external library so we do not
+ * have type information
+ */
+QEMU_DISABLE_CFI
+static void plugin_vcpu_cb__simple(CPUState *cpu, enum qemu_plugin_event ev)
+{
+    struct qemu_plugin_cb *cb, *next;
+
+    switch (ev) {
+    case QEMU_PLUGIN_EV_VCPU_INIT:
+    case QEMU_PLUGIN_EV_VCPU_EXIT:
+    case QEMU_PLUGIN_EV_VCPU_IDLE:
+    case QEMU_PLUGIN_EV_VCPU_RESUME:
+        /* iterate safely; plugins might uninstall themselves at any time */
+        QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
+            qemu_plugin_vcpu_simple_cb_t func = cb->f.vcpu_simple;
+
+            func(cb->ctx->id, cpu->cpu_index);
+        }
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+/*
+ * Disable CFI checks.
+ * The callback function has been loaded from an external library so we do not
+ * have type information
+ */
+QEMU_DISABLE_CFI
+static void plugin_cb__simple(enum qemu_plugin_event ev)
+{
+    struct qemu_plugin_cb *cb, *next;
+
+    switch (ev) {
+    case QEMU_PLUGIN_EV_FLUSH:
+        QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
+            qemu_plugin_simple_cb_t func = cb->f.simple;
+
+            func(cb->ctx->id);
+        }
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+/*
+ * Disable CFI checks.
+ * The callback function has been loaded from an external library so we do not
+ * have type information
+ */
+QEMU_DISABLE_CFI
+static void plugin_cb__udata(enum qemu_plugin_event ev)
+{
+    struct qemu_plugin_cb *cb, *next;
+
+    switch (ev) {
+    case QEMU_PLUGIN_EV_ATEXIT:
+        QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
+            qemu_plugin_udata_cb_t func = cb->f.udata;
+
+            func(cb->ctx->id, cb->udata);
+        }
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static void
+do_plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev,
+                      void *func, void *udata)
+{
+    struct qemu_plugin_ctx *ctx;
+
+    QEMU_LOCK_GUARD(&plugin.lock);
+    ctx = plugin_id_to_ctx_locked(id);
+    /* if the plugin is on its way out, ignore this request */
+    if (unlikely(ctx->uninstalling)) {
+        return;
+    }
+    if (func) {
+        struct qemu_plugin_cb *cb = ctx->callbacks[ev];
+
+        if (cb) {
+            cb->f.generic = func;
+            cb->udata = udata;
+        } else {
+            cb = g_new(struct qemu_plugin_cb, 1);
+            cb->ctx = ctx;
+            cb->f.generic = func;
+            cb->udata = udata;
+            ctx->callbacks[ev] = cb;
+            QLIST_INSERT_HEAD_RCU(&plugin.cb_lists[ev], cb, entry);
+            if (!test_bit(ev, plugin.mask)) {
+                set_bit(ev, plugin.mask);
+                g_hash_table_foreach(plugin.cpu_ht, plugin_cpu_update__locked,
+                                     NULL);
+            }
+        }
+    } else {
+        plugin_unregister_cb__locked(ctx, ev);
+    }
+}
+
+void plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev,
+                        void *func)
+{
+    do_plugin_register_cb(id, ev, func, NULL);
+}
+
+void
+plugin_register_cb_udata(qemu_plugin_id_t id, enum qemu_plugin_event ev,
+                         void *func, void *udata)
+{
+    do_plugin_register_cb(id, ev, func, udata);
+}
+
+void qemu_plugin_vcpu_init_hook(CPUState *cpu)
+{
+    bool success;
+
+    qemu_rec_mutex_lock(&plugin.lock);
+    plugin_cpu_update__locked(&cpu->cpu_index, NULL, NULL);
+    success = g_hash_table_insert(plugin.cpu_ht, &cpu->cpu_index,
+                                  &cpu->cpu_index);
+    g_assert(success);
+    qemu_rec_mutex_unlock(&plugin.lock);
+
+    plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_INIT);
+}
+
+void qemu_plugin_vcpu_exit_hook(CPUState *cpu)
+{
+    bool success;
+
+    plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_EXIT);
+
+    qemu_rec_mutex_lock(&plugin.lock);
+    success = g_hash_table_remove(plugin.cpu_ht, &cpu->cpu_index);
+    g_assert(success);
+    qemu_rec_mutex_unlock(&plugin.lock);
+}
+
+struct plugin_for_each_args {
+    struct qemu_plugin_ctx *ctx;
+    qemu_plugin_vcpu_simple_cb_t cb;
+};
+
+static void plugin_vcpu_for_each(gpointer k, gpointer v, gpointer udata)
+{
+    struct plugin_for_each_args *args = udata;
+    int cpu_index = *(int *)k;
+
+    args->cb(args->ctx->id, cpu_index);
+}
+
+void qemu_plugin_vcpu_for_each(qemu_plugin_id_t id,
+                               qemu_plugin_vcpu_simple_cb_t cb)
+{
+    struct plugin_for_each_args args;
+
+    if (cb == NULL) {
+        return;
+    }
+    qemu_rec_mutex_lock(&plugin.lock);
+    args.ctx = plugin_id_to_ctx_locked(id);
+    args.cb = cb;
+    g_hash_table_foreach(plugin.cpu_ht, plugin_vcpu_for_each, &args);
+    qemu_rec_mutex_unlock(&plugin.lock);
+}
+
+/* Allocate and return a callback record */
+static struct qemu_plugin_dyn_cb *plugin_get_dyn_cb(GArray **arr)
+{
+    GArray *cbs = *arr;
+
+    if (!cbs) {
+        cbs = g_array_sized_new(false, false,
+                                sizeof(struct qemu_plugin_dyn_cb), 1);
+        *arr = cbs;
+    }
+
+    g_array_set_size(cbs, cbs->len + 1);
+    return &g_array_index(cbs, struct qemu_plugin_dyn_cb, cbs->len - 1);
+}
+
+void plugin_register_inline_op(GArray **arr,
+                               enum qemu_plugin_mem_rw rw,
+                               enum qemu_plugin_op op, void *ptr,
+                               uint64_t imm)
+{
+    struct qemu_plugin_dyn_cb *dyn_cb;
+
+    dyn_cb = plugin_get_dyn_cb(arr);
+    dyn_cb->userp = ptr;
+    dyn_cb->type = PLUGIN_CB_INLINE;
+    dyn_cb->rw = rw;
+    dyn_cb->inline_insn.op = op;
+    dyn_cb->inline_insn.imm = imm;
+}
+
+void plugin_register_dyn_cb__udata(GArray **arr,
+                                   qemu_plugin_vcpu_udata_cb_t cb,
+                                   enum qemu_plugin_cb_flags flags,
+                                   void *udata)
+{
+    struct qemu_plugin_dyn_cb *dyn_cb = plugin_get_dyn_cb(arr);
+
+    dyn_cb->userp = udata;
+    /* Note flags are discarded as unused. */
+    dyn_cb->f.vcpu_udata = cb;
+    dyn_cb->type = PLUGIN_CB_REGULAR;
+}
+
+void plugin_register_vcpu_mem_cb(GArray **arr,
+                                 void *cb,
+                                 enum qemu_plugin_cb_flags flags,
+                                 enum qemu_plugin_mem_rw rw,
+                                 void *udata)
+{
+    struct qemu_plugin_dyn_cb *dyn_cb;
+
+    dyn_cb = plugin_get_dyn_cb(arr);
+    dyn_cb->userp = udata;
+    /* Note flags are discarded as unused. */
+    dyn_cb->type = PLUGIN_CB_REGULAR;
+    dyn_cb->rw = rw;
+    dyn_cb->f.generic = cb;
+}
+
+/*
+ * Disable CFI checks.
+ * The callback function has been loaded from an external library so we do not
+ * have type information
+ */
+QEMU_DISABLE_CFI
+void qemu_plugin_tb_trans_cb(CPUState *cpu, struct qemu_plugin_tb *tb)
+{
+    struct qemu_plugin_cb *cb, *next;
+    enum qemu_plugin_event ev = QEMU_PLUGIN_EV_VCPU_TB_TRANS;
+
+    /* no plugin_mask check here; caller should have checked */
+
+    QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
+        qemu_plugin_vcpu_tb_trans_cb_t func = cb->f.vcpu_tb_trans;
+
+        func(cb->ctx->id, tb);
+    }
+}
+
+/*
+ * Disable CFI checks.
+ * The callback function has been loaded from an external library so we do not
+ * have type information
+ */
+QEMU_DISABLE_CFI
+void
+qemu_plugin_vcpu_syscall(CPUState *cpu, int64_t num, uint64_t a1, uint64_t a2,
+                         uint64_t a3, uint64_t a4, uint64_t a5,
+                         uint64_t a6, uint64_t a7, uint64_t a8)
+{
+    struct qemu_plugin_cb *cb, *next;
+    enum qemu_plugin_event ev = QEMU_PLUGIN_EV_VCPU_SYSCALL;
+
+    if (!test_bit(ev, cpu->plugin_mask)) {
+        return;
+    }
+
+    QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
+        qemu_plugin_vcpu_syscall_cb_t func = cb->f.vcpu_syscall;
+
+        func(cb->ctx->id, cpu->cpu_index, num, a1, a2, a3, a4, a5, a6, a7, a8);
+    }
+}
+
+/*
+ * Disable CFI checks.
+ * The callback function has been loaded from an external library so we do not
+ * have type information
+ */
+QEMU_DISABLE_CFI
+void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret)
+{
+    struct qemu_plugin_cb *cb, *next;
+    enum qemu_plugin_event ev = QEMU_PLUGIN_EV_VCPU_SYSCALL_RET;
+
+    if (!test_bit(ev, cpu->plugin_mask)) {
+        return;
+    }
+
+    QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
+        qemu_plugin_vcpu_syscall_ret_cb_t func = cb->f.vcpu_syscall_ret;
+
+        func(cb->ctx->id, cpu->cpu_index, num, ret);
+    }
+}
+
+void qemu_plugin_vcpu_idle_cb(CPUState *cpu)
+{
+    plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_IDLE);
+}
+
+void qemu_plugin_vcpu_resume_cb(CPUState *cpu)
+{
+    plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_RESUME);
+}
+
+void qemu_plugin_register_vcpu_idle_cb(qemu_plugin_id_t id,
+                                       qemu_plugin_vcpu_simple_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_IDLE, cb);
+}
+
+void qemu_plugin_register_vcpu_resume_cb(qemu_plugin_id_t id,
+                                         qemu_plugin_vcpu_simple_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_RESUME, cb);
+}
+
+void qemu_plugin_register_flush_cb(qemu_plugin_id_t id,
+                                   qemu_plugin_simple_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_FLUSH, cb);
+}
+
+static bool free_dyn_cb_arr(void *p, uint32_t h, void *userp)
+{
+    g_array_free((GArray *) p, true);
+    return true;
+}
+
+void qemu_plugin_flush_cb(void)
+{
+    qht_iter_remove(&plugin.dyn_cb_arr_ht, free_dyn_cb_arr, NULL);
+    qht_reset(&plugin.dyn_cb_arr_ht);
+
+    plugin_cb__simple(QEMU_PLUGIN_EV_FLUSH);
+}
+
+void exec_inline_op(struct qemu_plugin_dyn_cb *cb)
+{
+    uint64_t *val = cb->userp;
+
+    switch (cb->inline_insn.op) {
+    case QEMU_PLUGIN_INLINE_ADD_U64:
+        *val += cb->inline_insn.imm;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr,
+                             MemOpIdx oi, enum qemu_plugin_mem_rw rw)
+{
+    GArray *arr = cpu->plugin_mem_cbs;
+    size_t i;
+
+    if (arr == NULL) {
+        return;
+    }
+    for (i = 0; i < arr->len; i++) {
+        struct qemu_plugin_dyn_cb *cb =
+            &g_array_index(arr, struct qemu_plugin_dyn_cb, i);
+
+        if (!(rw & cb->rw)) {
+                break;
+        }
+        switch (cb->type) {
+        case PLUGIN_CB_REGULAR:
+            cb->f.vcpu_mem(cpu->cpu_index, make_plugin_meminfo(oi, rw),
+                           vaddr, cb->userp);
+            break;
+        case PLUGIN_CB_INLINE:
+            exec_inline_op(cb);
+            break;
+        default:
+            g_assert_not_reached();
+        }
+    }
+}
+
+void qemu_plugin_atexit_cb(void)
+{
+    plugin_cb__udata(QEMU_PLUGIN_EV_ATEXIT);
+}
+
+void qemu_plugin_register_atexit_cb(qemu_plugin_id_t id,
+                                    qemu_plugin_udata_cb_t cb,
+                                    void *udata)
+{
+    plugin_register_cb_udata(id, QEMU_PLUGIN_EV_ATEXIT, cb, udata);
+}
+
+/*
+ * Handle exit from linux-user. Unlike the normal atexit() mechanism
+ * we need to handle the clean-up manually as it's possible threads
+ * are still running. We need to remove all callbacks from code
+ * generation, flush the current translations and then we can safely
+ * trigger the exit callbacks.
+ */
+
+void qemu_plugin_user_exit(void)
+{
+    enum qemu_plugin_event ev;
+    CPUState *cpu;
+
+    QEMU_LOCK_GUARD(&plugin.lock);
+
+    start_exclusive();
+
+    /* un-register all callbacks except the final AT_EXIT one */
+    for (ev = 0; ev < QEMU_PLUGIN_EV_MAX; ev++) {
+        if (ev != QEMU_PLUGIN_EV_ATEXIT) {
+            struct qemu_plugin_ctx *ctx;
+            QTAILQ_FOREACH(ctx, &plugin.ctxs, entry) {
+                plugin_unregister_cb__locked(ctx, ev);
+            }
+        }
+    }
+
+    tb_flush(current_cpu);
+
+    CPU_FOREACH(cpu) {
+        qemu_plugin_disable_mem_helpers(cpu);
+    }
+
+    end_exclusive();
+
+    /* now it's safe to handle the exit case */
+    qemu_plugin_atexit_cb();
+}
+
+/*
+ * Call this function after longjmp'ing to the main loop. It's possible that the
+ * last instruction of a TB might have used helpers, and therefore the
+ * "disable" instruction will never execute because it ended up as dead code.
+ */
+void qemu_plugin_disable_mem_helpers(CPUState *cpu)
+{
+    cpu->plugin_mem_cbs = NULL;
+}
+
+static bool plugin_dyn_cb_arr_cmp(const void *ap, const void *bp)
+{
+    return ap == bp;
+}
+
+static void __attribute__((__constructor__)) plugin_init(void)
+{
+    int i;
+
+    for (i = 0; i < QEMU_PLUGIN_EV_MAX; i++) {
+        QLIST_INIT(&plugin.cb_lists[i]);
+    }
+    qemu_rec_mutex_init(&plugin.lock);
+    plugin.id_ht = g_hash_table_new(g_int64_hash, g_int64_equal);
+    plugin.cpu_ht = g_hash_table_new(g_int_hash, g_int_equal);
+    QTAILQ_INIT(&plugin.ctxs);
+    qht_init(&plugin.dyn_cb_arr_ht, plugin_dyn_cb_arr_cmp, 16,
+             QHT_MODE_AUTO_RESIZE);
+    atexit(qemu_plugin_atexit_cb);
+}
diff --git a/plugins/loader.c b/plugins/loader.c
new file mode 100644
index 000000000..a4ec28169
--- /dev/null
+++ b/plugins/loader.c
@@ -0,0 +1,421 @@
+/*
+ * QEMU Plugin Core Loader Code
+ *
+ * This is the code responsible for loading and unloading the plugins.
+ * Aside from the basic housekeeping tasks we also need to ensure any
+ * generated code is flushed when we remove a plugin so we cannot end
+ * up calling and unloaded helper function.
+ *
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ * Copyright (C) 2019, Linaro
+ *
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qemu/config-file.h"
+#include "qapi/error.h"
+#include "qemu/lockable.h"
+#include "qemu/option.h"
+#include "qemu/rcu_queue.h"
+#include "qemu/qht.h"
+#include "qemu/bitmap.h"
+#include "qemu/xxhash.h"
+#include "qemu/plugin.h"
+#include "hw/core/cpu.h"
+#include "exec/exec-all.h"
+#ifndef CONFIG_USER_ONLY
+#include "hw/boards.h"
+#endif
+#include "qemu/compiler.h"
+
+#include "plugin.h"
+
+/*
+ * For convenience we use a bitmap for plugin.mask, but really all we need is a
+ * u32, which is what we store in TranslationBlock.
+ */
+QEMU_BUILD_BUG_ON(QEMU_PLUGIN_EV_MAX > 32);
+
+struct qemu_plugin_desc {
+    char *path;
+    char **argv;
+    QTAILQ_ENTRY(qemu_plugin_desc) entry;
+    int argc;
+};
+
+struct qemu_plugin_parse_arg {
+    QemuPluginList *head;
+    struct qemu_plugin_desc *curr;
+};
+
+QemuOptsList qemu_plugin_opts = {
+    .name = "plugin",
+    .implied_opt_name = "file",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_plugin_opts.head),
+    .desc = {
+        /* do our own parsing to support multiple plugins */
+        { /* end of list */ }
+    },
+};
+
+typedef int (*qemu_plugin_install_func_t)(qemu_plugin_id_t, const qemu_info_t *, int, char **);
+
+extern struct qemu_plugin_state plugin;
+
+void qemu_plugin_add_dyn_cb_arr(GArray *arr)
+{
+    uint32_t hash = qemu_xxhash2((uint64_t)(uintptr_t)arr);
+    bool inserted;
+
+    inserted = qht_insert(&plugin.dyn_cb_arr_ht, arr, hash, NULL);
+    g_assert(inserted);
+}
+
+static struct qemu_plugin_desc *plugin_find_desc(QemuPluginList *head,
+                                                 const char *path)
+{
+    struct qemu_plugin_desc *desc;
+
+    QTAILQ_FOREACH(desc, head, entry) {
+        if (strcmp(desc->path, path) == 0) {
+            return desc;
+        }
+    }
+    return NULL;
+}
+
+static int plugin_add(void *opaque, const char *name, const char *value,
+                      Error **errp)
+{
+    struct qemu_plugin_parse_arg *arg = opaque;
+    struct qemu_plugin_desc *p;
+    bool is_on;
+    char *fullarg;
+
+    if (strcmp(name, "file") == 0) {
+        if (strcmp(value, "") == 0) {
+            error_setg(errp, "requires a non-empty argument");
+            return 1;
+        }
+        p = plugin_find_desc(arg->head, value);
+        if (p == NULL) {
+            p = g_new0(struct qemu_plugin_desc, 1);
+            p->path = g_strdup(value);
+            QTAILQ_INSERT_TAIL(arg->head, p, entry);
+        }
+        arg->curr = p;
+    } else {
+        if (arg->curr == NULL) {
+            error_setg(errp, "missing earlier '-plugin file=' option");
+            return 1;
+        }
+
+        if (g_strcmp0(name, "arg") == 0 &&
+                !qapi_bool_parse(name, value, &is_on, NULL)) {
+            if (strchr(value, '=') == NULL) {
+                /* Will treat arg="argname" as "argname=on" */
+                fullarg = g_strdup_printf("%s=%s", value, "on");
+            } else {
+                fullarg = g_strdup_printf("%s", value);
+            }
+            warn_report("using 'arg=%s' is deprecated", value);
+            error_printf("Please use '%s' directly\n", fullarg);
+        } else {
+            fullarg = g_strdup_printf("%s=%s", name, value);
+        }
+
+        p = arg->curr;
+        p->argc++;
+        p->argv = g_realloc_n(p->argv, p->argc, sizeof(char *));
+        p->argv[p->argc - 1] = fullarg;
+    }
+
+    return 0;
+}
+
+void qemu_plugin_opt_parse(const char *optarg, QemuPluginList *head)
+{
+    struct qemu_plugin_parse_arg arg;
+    QemuOpts *opts;
+
+    opts = qemu_opts_parse_noisily(qemu_find_opts("plugin"), optarg, true);
+    if (opts == NULL) {
+        exit(1);
+    }
+    arg.head = head;
+    arg.curr = NULL;
+    qemu_opt_foreach(opts, plugin_add, &arg, &error_fatal);
+    qemu_opts_del(opts);
+}
+
+/*
+ * From: https://en.wikipedia.org/wiki/Xorshift
+ * This is faster than rand_r(), and gives us a wider range (RAND_MAX is only
+ * guaranteed to be >= INT_MAX).
+ */
+static uint64_t xorshift64star(uint64_t x)
+{
+    x ^= x >> 12; /* a */
+    x ^= x << 25; /* b */
+    x ^= x >> 27; /* c */
+    return x * UINT64_C(2685821657736338717);
+}
+
+/*
+ * Disable CFI checks.
+ * The install and version functions have been loaded from an external library
+ * so we do not have type information
+ */
+QEMU_DISABLE_CFI
+static int plugin_load(struct qemu_plugin_desc *desc, const qemu_info_t *info, Error **errp)
+{
+    qemu_plugin_install_func_t install;
+    struct qemu_plugin_ctx *ctx;
+    gpointer sym;
+    int rc;
+
+    ctx = qemu_memalign(qemu_dcache_linesize, sizeof(*ctx));
+    memset(ctx, 0, sizeof(*ctx));
+    ctx->desc = desc;
+
+    ctx->handle = g_module_open(desc->path, G_MODULE_BIND_LOCAL);
+    if (ctx->handle == NULL) {
+        error_setg(errp, "Could not load plugin %s: %s", desc->path, g_module_error());
+        goto err_dlopen;
+    }
+
+    if (!g_module_symbol(ctx->handle, "qemu_plugin_install", &sym)) {
+        error_setg(errp, "Could not load plugin %s: %s", desc->path, g_module_error());
+        goto err_symbol;
+    }
+    install = (qemu_plugin_install_func_t) sym;
+    /* symbol was found; it could be NULL though */
+    if (install == NULL) {
+        error_setg(errp, "Could not load plugin %s: qemu_plugin_install is NULL",
+                   desc->path);
+        goto err_symbol;
+    }
+
+    if (!g_module_symbol(ctx->handle, "qemu_plugin_version", &sym)) {
+        error_setg(errp, "Could not load plugin %s: plugin does not declare API version %s",
+                   desc->path, g_module_error());
+        goto err_symbol;
+    } else {
+        int version = *(int *)sym;
+        if (version < QEMU_PLUGIN_MIN_VERSION) {
+            error_setg(errp, "Could not load plugin %s: plugin requires API version %d, but "
+                       "this QEMU supports only a minimum version of %d",
+                       desc->path, version, QEMU_PLUGIN_MIN_VERSION);
+            goto err_symbol;
+        } else if (version > QEMU_PLUGIN_VERSION) {
+            error_setg(errp, "Could not load plugin %s: plugin requires API version %d, but "
+                       "this QEMU supports only up to version %d",
+                       desc->path, version, QEMU_PLUGIN_VERSION);
+            goto err_symbol;
+        }
+    }
+
+    qemu_rec_mutex_lock(&plugin.lock);
+
+    /* find an unused random id with &ctx as the seed */
+    ctx->id = (uint64_t)(uintptr_t)ctx;
+    for (;;) {
+        void *existing;
+
+        ctx->id = xorshift64star(ctx->id);
+        existing = g_hash_table_lookup(plugin.id_ht, &ctx->id);
+        if (likely(existing == NULL)) {
+            bool success;
+
+            success = g_hash_table_insert(plugin.id_ht, &ctx->id, &ctx->id);
+            g_assert(success);
+            break;
+        }
+    }
+    QTAILQ_INSERT_TAIL(&plugin.ctxs, ctx, entry);
+    ctx->installing = true;
+    rc = install(ctx->id, info, desc->argc, desc->argv);
+    ctx->installing = false;
+    if (rc) {
+        error_setg(errp, "Could not load plugin %s: qemu_plugin_install returned error code %d",
+                   desc->path, rc);
+        /*
+         * we cannot rely on the plugin doing its own cleanup, so
+         * call a full uninstall if the plugin did not yet call it.
+         */
+        if (!ctx->uninstalling) {
+            plugin_reset_uninstall(ctx->id, NULL, false);
+        }
+    }
+
+    qemu_rec_mutex_unlock(&plugin.lock);
+    return rc;
+
+ err_symbol:
+    g_module_close(ctx->handle);
+ err_dlopen:
+    qemu_vfree(ctx);
+    return 1;
+}
+
+/* call after having removed @desc from the list */
+static void plugin_desc_free(struct qemu_plugin_desc *desc)
+{
+    int i;
+
+    for (i = 0; i < desc->argc; i++) {
+        g_free(desc->argv[i]);
+    }
+    g_free(desc->argv);
+    g_free(desc->path);
+    g_free(desc);
+}
+
+/**
+ * qemu_plugin_load_list - load a list of plugins
+ * @head: head of the list of descriptors of the plugins to be loaded
+ *
+ * Returns 0 if all plugins in the list are installed, !0 otherwise.
+ *
+ * Note: the descriptor of each successfully installed plugin is removed
+ * from the list given by @head.
+ */
+int qemu_plugin_load_list(QemuPluginList *head, Error **errp)
+{
+    struct qemu_plugin_desc *desc, *next;
+    g_autofree qemu_info_t *info = g_new0(qemu_info_t, 1);
+
+    info->target_name = TARGET_NAME;
+    info->version.min = QEMU_PLUGIN_MIN_VERSION;
+    info->version.cur = QEMU_PLUGIN_VERSION;
+#ifndef CONFIG_USER_ONLY
+    MachineState *ms = MACHINE(qdev_get_machine());
+    info->system_emulation = true;
+    info->system.smp_vcpus = ms->smp.cpus;
+    info->system.max_vcpus = ms->smp.max_cpus;
+#else
+    info->system_emulation = false;
+#endif
+
+    QTAILQ_FOREACH_SAFE(desc, head, entry, next) {
+        int err;
+
+        err = plugin_load(desc, info, errp);
+        if (err) {
+            return err;
+        }
+        QTAILQ_REMOVE(head, desc, entry);
+    }
+    return 0;
+}
+
+struct qemu_plugin_reset_data {
+    struct qemu_plugin_ctx *ctx;
+    qemu_plugin_simple_cb_t cb;
+    bool reset;
+};
+
+static void plugin_reset_destroy__locked(struct qemu_plugin_reset_data *data)
+{
+    struct qemu_plugin_ctx *ctx = data->ctx;
+    enum qemu_plugin_event ev;
+    bool success;
+
+    /*
+     * After updating the subscription lists there is no need to wait for an RCU
+     * grace period to elapse, because right now we either are in a "safe async"
+     * work environment (i.e. all vCPUs are asleep), or no vCPUs have yet been
+     * created.
+     */
+    for (ev = 0; ev < QEMU_PLUGIN_EV_MAX; ev++) {
+        plugin_unregister_cb__locked(ctx, ev);
+    }
+
+    if (data->reset) {
+        g_assert(ctx->resetting);
+        if (data->cb) {
+            data->cb(ctx->id);
+        }
+        ctx->resetting = false;
+        g_free(data);
+        return;
+    }
+
+    g_assert(ctx->uninstalling);
+    /* we cannot dlclose if we are going to return to plugin code */
+    if (ctx->installing) {
+        error_report("Calling qemu_plugin_uninstall from the install function "
+                     "is a bug. Instead, return !0 from the install function.");
+        abort();
+    }
+
+    success = g_hash_table_remove(plugin.id_ht, &ctx->id);
+    g_assert(success);
+    QTAILQ_REMOVE(&plugin.ctxs, ctx, entry);
+    if (data->cb) {
+        data->cb(ctx->id);
+    }
+    if (!g_module_close(ctx->handle)) {
+        warn_report("%s: %s", __func__, g_module_error());
+    }
+    plugin_desc_free(ctx->desc);
+    qemu_vfree(ctx);
+    g_free(data);
+}
+
+static void plugin_reset_destroy(struct qemu_plugin_reset_data *data)
+{
+    qemu_rec_mutex_lock(&plugin.lock);
+    plugin_reset_destroy__locked(data);
+    qemu_rec_mutex_lock(&plugin.lock);
+}
+
+static void plugin_flush_destroy(CPUState *cpu, run_on_cpu_data arg)
+{
+    struct qemu_plugin_reset_data *data = arg.host_ptr;
+
+    g_assert(cpu_in_exclusive_context(cpu));
+    tb_flush(cpu);
+    plugin_reset_destroy(data);
+}
+
+void plugin_reset_uninstall(qemu_plugin_id_t id,
+                            qemu_plugin_simple_cb_t cb,
+                            bool reset)
+{
+    struct qemu_plugin_reset_data *data;
+    struct qemu_plugin_ctx *ctx;
+
+    WITH_QEMU_LOCK_GUARD(&plugin.lock) {
+        ctx = plugin_id_to_ctx_locked(id);
+        if (ctx->uninstalling || (reset && ctx->resetting)) {
+            return;
+        }
+        ctx->resetting = reset;
+        ctx->uninstalling = !reset;
+    }
+
+    data = g_new(struct qemu_plugin_reset_data, 1);
+    data->ctx = ctx;
+    data->cb = cb;
+    data->reset = reset;
+    /*
+     * Only flush the code cache if the vCPUs have been created. If so,
+     * current_cpu must be non-NULL.
+     */
+    if (current_cpu) {
+        async_safe_run_on_cpu(current_cpu, plugin_flush_destroy,
+                              RUN_ON_CPU_HOST_PTR(data));
+    } else {
+        /*
+         * If current_cpu isn't set, then we don't have yet any vCPU threads
+         * and we therefore can remove the callbacks synchronously.
+         */
+        plugin_reset_destroy(data);
+    }
+}
diff --git a/plugins/meson.build b/plugins/meson.build
new file mode 100644
index 000000000..b3de57853
--- /dev/null
+++ b/plugins/meson.build
@@ -0,0 +1,15 @@
+plugin_ldflags = []
+# Modules need more symbols than just those in plugins/qemu-plugins.symbols
+if not enable_modules
+  if 'CONFIG_HAS_LD_DYNAMIC_LIST' in config_host
+    plugin_ldflags = ['-Wl,--dynamic-list=qemu-plugins-ld.symbols']
+  elif 'CONFIG_HAS_LD_EXPORTED_SYMBOLS_LIST' in config_host
+    plugin_ldflags = ['-Wl,-exported_symbols_list,qemu-plugins-ld64.symbols']
+  endif
+endif
+
+specific_ss.add(when: 'CONFIG_PLUGIN', if_true: [files(
+  'loader.c',
+  'core.c',
+  'api.c',
+), declare_dependency(link_args: plugin_ldflags)])
diff --git a/plugins/plugin.h b/plugins/plugin.h
new file mode 100644
index 000000000..b13677d0d
--- /dev/null
+++ b/plugins/plugin.h
@@ -0,0 +1,100 @@
+/*
+ * Plugin Shared Internal Functions
+ *
+ * Copyright (C) 2019, Linaro
+ *
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef PLUGIN_INTERNAL_H
+#define PLUGIN_INTERNAL_H
+
+#include <gmodule.h>
+#include "qemu/qht.h"
+
+#define QEMU_PLUGIN_MIN_VERSION 0
+
+/* global state */
+struct qemu_plugin_state {
+    QTAILQ_HEAD(, qemu_plugin_ctx) ctxs;
+    QLIST_HEAD(, qemu_plugin_cb) cb_lists[QEMU_PLUGIN_EV_MAX];
+    /*
+     * Use the HT as a hash map by inserting k == v, which saves memory as
+     * documented by GLib. The parent struct is obtained with container_of().
+     */
+    GHashTable *id_ht;
+    /*
+     * Use the HT as a hash map. Note that we could use a list here,
+     * but with the HT we avoid adding a field to CPUState.
+     */
+    GHashTable *cpu_ht;
+    DECLARE_BITMAP(mask, QEMU_PLUGIN_EV_MAX);
+    /*
+     * @lock protects the struct as well as ctx->uninstalling.
+     * The lock must be acquired by all API ops.
+     * The lock is recursive, which greatly simplifies things, e.g.
+     * callback registration from qemu_plugin_vcpu_for_each().
+     */
+    QemuRecMutex lock;
+    /*
+     * HT of callbacks invoked from helpers. All entries are freed when
+     * the code cache is flushed.
+     */
+    struct qht dyn_cb_arr_ht;
+};
+
+
+struct qemu_plugin_ctx {
+    GModule *handle;
+    qemu_plugin_id_t id;
+    struct qemu_plugin_cb *callbacks[QEMU_PLUGIN_EV_MAX];
+    QTAILQ_ENTRY(qemu_plugin_ctx) entry;
+    /*
+     * keep a reference to @desc until uninstall, so that plugins do not have
+     * to strdup plugin args.
+     */
+    struct qemu_plugin_desc *desc;
+    bool installing;
+    bool uninstalling;
+    bool resetting;
+};
+
+struct qemu_plugin_ctx *plugin_id_to_ctx_locked(qemu_plugin_id_t id);
+
+void plugin_register_inline_op(GArray **arr,
+                               enum qemu_plugin_mem_rw rw,
+                               enum qemu_plugin_op op, void *ptr,
+                               uint64_t imm);
+
+void plugin_reset_uninstall(qemu_plugin_id_t id,
+                            qemu_plugin_simple_cb_t cb,
+                            bool reset);
+
+void plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev,
+                        void *func);
+
+void plugin_unregister_cb__locked(struct qemu_plugin_ctx *ctx,
+                                  enum qemu_plugin_event ev);
+
+void
+plugin_register_cb_udata(qemu_plugin_id_t id, enum qemu_plugin_event ev,
+                         void *func, void *udata);
+
+void
+plugin_register_dyn_cb__udata(GArray **arr,
+                              qemu_plugin_vcpu_udata_cb_t cb,
+                              enum qemu_plugin_cb_flags flags, void *udata);
+
+
+void plugin_register_vcpu_mem_cb(GArray **arr,
+                                 void *cb,
+                                 enum qemu_plugin_cb_flags flags,
+                                 enum qemu_plugin_mem_rw rw,
+                                 void *udata);
+
+void exec_inline_op(struct qemu_plugin_dyn_cb *cb);
+
+#endif /* _PLUGIN_INTERNAL_H_ */
diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols
new file mode 100644
index 000000000..4834756ba
--- /dev/null
+++ b/plugins/qemu-plugins.symbols
@@ -0,0 +1,41 @@
+{
+  qemu_plugin_bool_parse;
+  qemu_plugin_get_hwaddr;
+  qemu_plugin_hwaddr_device_name;
+  qemu_plugin_hwaddr_is_io;
+  qemu_plugin_hwaddr_phys_addr;
+  qemu_plugin_insn_data;
+  qemu_plugin_insn_disas;
+  qemu_plugin_insn_haddr;
+  qemu_plugin_insn_size;
+  qemu_plugin_insn_symbol;
+  qemu_plugin_insn_vaddr;
+  qemu_plugin_mem_is_big_endian;
+  qemu_plugin_mem_is_sign_extended;
+  qemu_plugin_mem_is_store;
+  qemu_plugin_mem_size_shift;
+  qemu_plugin_n_max_vcpus;
+  qemu_plugin_n_vcpus;
+  qemu_plugin_outs;
+  qemu_plugin_register_atexit_cb;
+  qemu_plugin_register_flush_cb;
+  qemu_plugin_register_vcpu_exit_cb;
+  qemu_plugin_register_vcpu_idle_cb;
+  qemu_plugin_register_vcpu_init_cb;
+  qemu_plugin_register_vcpu_insn_exec_cb;
+  qemu_plugin_register_vcpu_insn_exec_inline;
+  qemu_plugin_register_vcpu_mem_cb;
+  qemu_plugin_register_vcpu_mem_inline;
+  qemu_plugin_register_vcpu_resume_cb;
+  qemu_plugin_register_vcpu_syscall_cb;
+  qemu_plugin_register_vcpu_syscall_ret_cb;
+  qemu_plugin_register_vcpu_tb_exec_cb;
+  qemu_plugin_register_vcpu_tb_exec_inline;
+  qemu_plugin_register_vcpu_tb_trans_cb;
+  qemu_plugin_reset;
+  qemu_plugin_tb_get_insn;
+  qemu_plugin_tb_n_insns;
+  qemu_plugin_tb_vaddr;
+  qemu_plugin_uninstall;
+  qemu_plugin_vcpu_for_each;
+};