diff --git a/accel/tcg/Makefile.objs b/accel/tcg/Makefile.objs
index d381a02f347..a92f2c454b9 100644
--- a/accel/tcg/Makefile.objs
+++ b/accel/tcg/Makefile.objs
@@ -6,3 +6,4 @@ obj-y += translator.o
 
 obj-$(CONFIG_USER_ONLY) += user-exec.o
 obj-$(call lnot,$(CONFIG_SOFTMMU)) += user-exec-stub.o
+obj-$(CONFIG_PLUGIN) += plugin-gen.o
diff --git a/accel/tcg/plugin-gen.c b/accel/tcg/plugin-gen.c
new file mode 100644
index 00000000000..f93ee85d83a
--- /dev/null
+++ b/accel/tcg/plugin-gen.c
@@ -0,0 +1,977 @@
+/*
+ * plugin-gen.c - TCG-related bits of plugin infrastructure
+ *
+ * Copyright (C) 2018, Emilio G. Cota <cota@braap.org>
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ *
+ * We support instrumentation at an instruction granularity. That is,
+ * if a plugin wants to instrument the memory accesses performed by a
+ * particular instruction, it can just do that instead of instrumenting
+ * all memory accesses. Thus, in order to do this we first have to
+ * translate a TB, so that plugins can decide what/where to instrument.
+ *
+ * Injecting the desired instrumentation could be done with a second
+ * translation pass that combined the instrumentation requests, but that
+ * would be ugly and inefficient since we would decode the guest code twice.
+ * Instead, during TB translation we add "empty" instrumentation calls for all
+ * possible instrumentation events, and then once we collect the instrumentation
+ * requests from plugins, we either "fill in" those empty events or remove them
+ * if they have no requests.
+ *
+ * When "filling in" an event we first copy the empty callback's TCG ops. This
+ * might seem unnecessary, but it is done to support an arbitrary number
+ * of callbacks per event. Take for example a regular instruction callback.
+ * We first generate a callback to an empty helper function. Then, if two
+ * plugins register one callback each for this instruction, we make two copies
+ * of the TCG ops generated for the empty callback, substituting the function
+ * pointer that points to the empty helper function with the plugins' desired
+ * callback functions. After that we remove the empty callback's ops.
+ *
+ * Note that the location in TCGOp.args[] of the pointer to a helper function
+ * varies across different guest and host architectures. Instead of duplicating
+ * the logic that figures this out, we rely on the fact that the empty
+ * callbacks point to empty functions that are unique pointers in the program.
+ * Thus, to find the right location we just have to look for a match in
+ * TCGOp.args[]. This is the main reason why we first copy an empty callback's
+ * TCG ops and then fill them in; regardless of whether we have one or many
+ * callbacks for that event, the logic to add all of them is the same.
+ *
+ * When generating more than one callback per event, we make a small
+ * optimization to avoid generating redundant operations. For instance, for the
+ * second and all subsequent callbacks of an event, we do not need to reload the
+ * CPU's index into a TCG temp, since the first callback did it already.
+ */
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "tcg/tcg.h"
+#include "tcg/tcg-op.h"
+#include "trace/mem.h"
+#include "exec/exec-all.h"
+#include "exec/plugin-gen.h"
+#include "exec/translator.h"
+
+#ifdef CONFIG_SOFTMMU
+# define CONFIG_SOFTMMU_GATE 1
+#else
+# define CONFIG_SOFTMMU_GATE 0
+#endif
+
+/*
+ * plugin_cb_start TCG op args[]:
+ * 0: enum plugin_gen_from
+ * 1: enum plugin_gen_cb
+ * 2: set to 1 for mem callback that is a write, 0 otherwise.
+ */
+
+enum plugin_gen_from {
+    PLUGIN_GEN_FROM_TB,
+    PLUGIN_GEN_FROM_INSN,
+    PLUGIN_GEN_FROM_MEM,
+    PLUGIN_GEN_AFTER_INSN,
+    PLUGIN_GEN_N_FROMS,
+};
+
+enum plugin_gen_cb {
+    PLUGIN_GEN_CB_UDATA,
+    PLUGIN_GEN_CB_INLINE,
+    PLUGIN_GEN_CB_MEM,
+    PLUGIN_GEN_ENABLE_MEM_HELPER,
+    PLUGIN_GEN_DISABLE_MEM_HELPER,
+    PLUGIN_GEN_N_CBS,
+};
+
+/*
+ * These helpers are stubs that get dynamically switched out for calls
+ * direct to the plugin if they are subscribed to.
+ */
+void HELPER(plugin_vcpu_udata_cb)(uint32_t cpu_index, void *udata)
+{ }
+
+void HELPER(plugin_vcpu_mem_cb)(unsigned int vcpu_index,
+                                qemu_plugin_meminfo_t info, uint64_t vaddr,
+                                void *userdata)
+{ }
+
+static void do_gen_mem_cb(TCGv vaddr, uint32_t info)
+{
+    TCGv_i32 cpu_index = tcg_temp_new_i32();
+    TCGv_i32 meminfo = tcg_const_i32(info);
+    TCGv_i64 vaddr64 = tcg_temp_new_i64();
+    TCGv_ptr udata = tcg_const_ptr(NULL);
+
+    tcg_gen_ld_i32(cpu_index, cpu_env,
+                   -offsetof(ArchCPU, env) + offsetof(CPUState, cpu_index));
+    tcg_gen_extu_tl_i64(vaddr64, vaddr);
+
+    gen_helper_plugin_vcpu_mem_cb(cpu_index, meminfo, vaddr64, udata);
+
+    tcg_temp_free_ptr(udata);
+    tcg_temp_free_i64(vaddr64);
+    tcg_temp_free_i32(meminfo);
+    tcg_temp_free_i32(cpu_index);
+}
+
+static void gen_empty_udata_cb(void)
+{
+    TCGv_i32 cpu_index = tcg_temp_new_i32();
+    TCGv_ptr udata = tcg_const_ptr(NULL); /* will be overwritten later */
+
+    tcg_gen_ld_i32(cpu_index, cpu_env,
+                   -offsetof(ArchCPU, env) + offsetof(CPUState, cpu_index));
+    gen_helper_plugin_vcpu_udata_cb(cpu_index, udata);
+
+    tcg_temp_free_ptr(udata);
+    tcg_temp_free_i32(cpu_index);
+}
+
+/*
+ * For now we only support addi_i64.
+ * When we support more ops, we can generate one empty inline cb for each.
+ */
+static void gen_empty_inline_cb(void)
+{
+    TCGv_i64 val = tcg_temp_new_i64();
+    TCGv_ptr ptr = tcg_const_ptr(NULL); /* overwritten later */
+
+    tcg_gen_ld_i64(val, ptr, 0);
+    /* pass an immediate != 0 so that it doesn't get optimized away */
+    tcg_gen_addi_i64(val, val, 0xdeadface);
+    tcg_gen_st_i64(val, ptr, 0);
+    tcg_temp_free_ptr(ptr);
+    tcg_temp_free_i64(val);
+}
+
+static void gen_empty_mem_cb(TCGv addr, uint32_t info)
+{
+    do_gen_mem_cb(addr, info);
+}
+
+/*
+ * Share the same function for enable/disable. When enabling, the NULL
+ * pointer will be overwritten later.
+ */
+static void gen_empty_mem_helper(void)
+{
+    TCGv_ptr ptr;
+
+    ptr = tcg_const_ptr(NULL);
+    tcg_gen_st_ptr(ptr, cpu_env, offsetof(CPUState, plugin_mem_cbs));
+    tcg_temp_free_ptr(ptr);
+}
+
+static inline
+void gen_plugin_cb_start(enum plugin_gen_from from,
+                         enum plugin_gen_cb type, unsigned wr)
+{
+    TCGOp *op;
+
+    tcg_gen_plugin_cb_start(from, type, wr);
+    op = tcg_last_op();
+    QSIMPLEQ_INSERT_TAIL(&tcg_ctx->plugin_ops, op, plugin_link);
+}
+
+static void gen_wrapped(enum plugin_gen_from from,
+                        enum plugin_gen_cb type, void (*func)(void))
+{
+    gen_plugin_cb_start(from, type, 0);
+    func();
+    tcg_gen_plugin_cb_end();
+}
+
+static inline void plugin_gen_empty_callback(enum plugin_gen_from from)
+{
+    switch (from) {
+    case PLUGIN_GEN_AFTER_INSN:
+        gen_wrapped(from, PLUGIN_GEN_DISABLE_MEM_HELPER,
+                    gen_empty_mem_helper);
+        break;
+    case PLUGIN_GEN_FROM_INSN:
+        /*
+         * Note: plugin_gen_inject() relies on ENABLE_MEM_HELPER being
+         * the first callback of an instruction
+         */
+        gen_wrapped(from, PLUGIN_GEN_ENABLE_MEM_HELPER,
+                    gen_empty_mem_helper);
+        /* fall through */
+    case PLUGIN_GEN_FROM_TB:
+        gen_wrapped(from, PLUGIN_GEN_CB_UDATA, gen_empty_udata_cb);
+        gen_wrapped(from, PLUGIN_GEN_CB_INLINE, gen_empty_inline_cb);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+union mem_gen_fn {
+    void (*mem_fn)(TCGv, uint32_t);
+    void (*inline_fn)(void);
+};
+
+static void gen_mem_wrapped(enum plugin_gen_cb type,
+                            const union mem_gen_fn *f, TCGv addr,
+                            uint32_t info, bool is_mem)
+{
+    int wr = !!(info & TRACE_MEM_ST);
+
+    gen_plugin_cb_start(PLUGIN_GEN_FROM_MEM, type, wr);
+    if (is_mem) {
+        f->mem_fn(addr, info);
+    } else {
+        f->inline_fn();
+    }
+    tcg_gen_plugin_cb_end();
+}
+
+void plugin_gen_empty_mem_callback(TCGv addr, uint32_t info)
+{
+    union mem_gen_fn fn;
+
+    fn.mem_fn = gen_empty_mem_cb;
+    gen_mem_wrapped(PLUGIN_GEN_CB_MEM, &fn, addr, info, true);
+
+    fn.inline_fn = gen_empty_inline_cb;
+    gen_mem_wrapped(PLUGIN_GEN_CB_INLINE, &fn, 0, info, false);
+}
+
+static TCGOp *find_op(TCGOp *op, TCGOpcode opc)
+{
+    while (op) {
+        if (op->opc == opc) {
+            return op;
+        }
+        op = QTAILQ_NEXT(op, link);
+    }
+    return NULL;
+}
+
+static TCGOp *rm_ops_range(TCGOp *begin, TCGOp *end)
+{
+    TCGOp *ret = QTAILQ_NEXT(end, link);
+
+    QTAILQ_REMOVE_SEVERAL(&tcg_ctx->ops, begin, end, link);
+    return ret;
+}
+
+/* remove all ops until (and including) plugin_cb_end */
+static TCGOp *rm_ops(TCGOp *op)
+{
+    TCGOp *end_op = find_op(op, INDEX_op_plugin_cb_end);
+
+    tcg_debug_assert(end_op);
+    return rm_ops_range(op, end_op);
+}
+
+static TCGOp *copy_op_nocheck(TCGOp **begin_op, TCGOp *op)
+{
+    *begin_op = QTAILQ_NEXT(*begin_op, link);
+    tcg_debug_assert(*begin_op);
+    op = tcg_op_insert_after(tcg_ctx, op, (*begin_op)->opc);
+    memcpy(op->args, (*begin_op)->args, sizeof(op->args));
+    return op;
+}
+
+static TCGOp *copy_op(TCGOp **begin_op, TCGOp *op, TCGOpcode opc)
+{
+    op = copy_op_nocheck(begin_op, op);
+    tcg_debug_assert((*begin_op)->opc == opc);
+    return op;
+}
+
+static TCGOp *copy_extu_i32_i64(TCGOp **begin_op, TCGOp *op)
+{
+    if (TCG_TARGET_REG_BITS == 32) {
+        /* mov_i32 */
+        op = copy_op(begin_op, op, INDEX_op_mov_i32);
+        /* movi_i32 */
+        op = copy_op(begin_op, op, INDEX_op_movi_i32);
+    } else {
+        /* extu_i32_i64 */
+        op = copy_op(begin_op, op, INDEX_op_extu_i32_i64);
+    }
+    return op;
+}
+
+static TCGOp *copy_mov_i64(TCGOp **begin_op, TCGOp *op)
+{
+    if (TCG_TARGET_REG_BITS == 32) {
+        /* 2x mov_i32 */
+        op = copy_op(begin_op, op, INDEX_op_mov_i32);
+        op = copy_op(begin_op, op, INDEX_op_mov_i32);
+    } else {
+        /* mov_i64 */
+        op = copy_op(begin_op, op, INDEX_op_mov_i64);
+    }
+    return op;
+}
+
+static TCGOp *copy_movi_i64(TCGOp **begin_op, TCGOp *op, uint64_t v)
+{
+    if (TCG_TARGET_REG_BITS == 32) {
+        /* 2x movi_i32 */
+        op = copy_op(begin_op, op, INDEX_op_movi_i32);
+        op->args[1] = v;
+
+        op = copy_op(begin_op, op, INDEX_op_movi_i32);
+        op->args[1] = v >> 32;
+    } else {
+        /* movi_i64 */
+        op = copy_op(begin_op, op, INDEX_op_movi_i64);
+        op->args[1] = v;
+    }
+    return op;
+}
+
+static TCGOp *copy_const_ptr(TCGOp **begin_op, TCGOp *op, void *ptr)
+{
+    if (UINTPTR_MAX == UINT32_MAX) {
+        /* movi_i32 */
+        op = copy_op(begin_op, op, INDEX_op_movi_i32);
+        op->args[1] = (uintptr_t)ptr;
+    } else {
+        /* movi_i64 */
+        op = copy_movi_i64(begin_op, op, (uint64_t)(uintptr_t)ptr);
+    }
+    return op;
+}
+
+static TCGOp *copy_const_i64(TCGOp **begin_op, TCGOp *op, uint64_t v)
+{
+    return copy_movi_i64(begin_op, op, v);
+}
+
+static TCGOp *copy_extu_tl_i64(TCGOp **begin_op, TCGOp *op)
+{
+    if (TARGET_LONG_BITS == 32) {
+        /* extu_i32_i64 */
+        op = copy_extu_i32_i64(begin_op, op);
+    } else {
+        /* mov_i64 */
+        op = copy_mov_i64(begin_op, op);
+    }
+    return op;
+}
+
+static TCGOp *copy_ld_i64(TCGOp **begin_op, TCGOp *op)
+{
+    if (TCG_TARGET_REG_BITS == 32) {
+        /* 2x ld_i32 */
+        op = copy_op(begin_op, op, INDEX_op_ld_i32);
+        op = copy_op(begin_op, op, INDEX_op_ld_i32);
+    } else {
+        /* ld_i64 */
+        op = copy_op(begin_op, op, INDEX_op_ld_i64);
+    }
+    return op;
+}
+
+#if 0 /* XXX: no longer needed? */
+static TCGOp *copy_ld_ptr(TCGOp **begin_op, TCGOp *op)
+{
+    if (UINTPTR_MAX == UINT32_MAX) {
+        /* ld_i32 */
+        op = copy_op(begin_op, op, INDEX_op_ld_i32);
+    } else {
+        /* ld_i64 */
+        op = copy_ld_i64(begin_op, op);
+    }
+    return op;
+}
+
+static TCGOp *skip_ld_i64(TCGOp *begin_op)
+{
+    TCGOp *op;
+
+    if (TCG_TARGET_REG_BITS == 32) {
+        /* 2x ld_i32 */
+        op = QTAILQ_NEXT(begin_op, link);
+        tcg_debug_assert(op->opc == INDEX_op_ld_i32);
+        op = QTAILQ_NEXT(op, link);
+        tcg_debug_assert(op->opc == INDEX_op_ld_i32);
+    } else {
+        /* ld_i64 */
+        op = QTAILQ_NEXT(begin_op, link);
+        tcg_debug_assert(op->opc == INDEX_op_ld_i64);
+    }
+    return op;
+}
+
+static TCGOp *skip_ld_ptr(TCGOp *begin_op)
+{
+    TCGOp *op;
+
+    if (UINTPTR_MAX == UINT32_MAX) {
+        /* ld_i32 */
+        op = QTAILQ_NEXT(begin_op, link);
+        tcg_debug_assert(op->opc == INDEX_op_ld_i32);
+    } else {
+        /* ld_i64 */
+        op = skip_ld_i64(begin_op);
+    }
+    return op;
+}
+#endif
+
+static TCGOp *copy_st_i64(TCGOp **begin_op, TCGOp *op)
+{
+    if (TCG_TARGET_REG_BITS == 32) {
+        /* 2x st_i32 */
+        op = copy_op(begin_op, op, INDEX_op_st_i32);
+        op = copy_op(begin_op, op, INDEX_op_st_i32);
+    } else {
+        /* st_i64 */
+        op = copy_op(begin_op, op, INDEX_op_st_i64);
+    }
+    return op;
+}
+
+static TCGOp *copy_add_i64(TCGOp **begin_op, TCGOp *op)
+{
+    if (TCG_TARGET_REG_BITS == 32) {
+        /* all 32-bit backends must implement add2_i32 */
+        g_assert(TCG_TARGET_HAS_add2_i32);
+        op = copy_op(begin_op, op, INDEX_op_add2_i32);
+    } else {
+        op = copy_op(begin_op, op, INDEX_op_add_i64);
+    }
+    return op;
+}
+
+static TCGOp *copy_st_ptr(TCGOp **begin_op, TCGOp *op)
+{
+    if (UINTPTR_MAX == UINT32_MAX) {
+        /* st_i32 */
+        op = copy_op(begin_op, op, INDEX_op_st_i32);
+    } else {
+        /* st_i64 */
+        op = copy_st_i64(begin_op, op);
+    }
+    return op;
+}
+
+static TCGOp *copy_call(TCGOp **begin_op, TCGOp *op, void *empty_func,
+                        void *func, unsigned tcg_flags, int *cb_idx)
+{
+    /* copy all ops until the call */
+    do {
+        op = copy_op_nocheck(begin_op, op);
+    } while (op->opc != INDEX_op_call);
+
+    /* fill in the op call */
+    op->param1 = (*begin_op)->param1;
+    op->param2 = (*begin_op)->param2;
+    tcg_debug_assert(op->life == 0);
+    if (*cb_idx == -1) {
+        int i;
+
+        /*
+         * Instead of working out the position of the callback in args[], just
+         * look for @empty_func, since it should be a unique pointer.
+         */
+        for (i = 0; i < MAX_OPC_PARAM_ARGS; i++) {
+            if ((uintptr_t)(*begin_op)->args[i] == (uintptr_t)empty_func) {
+                *cb_idx = i;
+                break;
+            }
+        }
+        tcg_debug_assert(i < MAX_OPC_PARAM_ARGS);
+    }
+    op->args[*cb_idx] = (uintptr_t)func;
+    op->args[*cb_idx + 1] = tcg_flags;
+
+    return op;
+}
+
+static TCGOp *append_udata_cb(const struct qemu_plugin_dyn_cb *cb,
+                              TCGOp *begin_op, TCGOp *op, int *cb_idx)
+{
+    /* const_ptr */
+    op = copy_const_ptr(&begin_op, op, cb->userp);
+
+    /* copy the ld_i32, but note that we only have to copy it once */
+    begin_op = QTAILQ_NEXT(begin_op, link);
+    tcg_debug_assert(begin_op && begin_op->opc == INDEX_op_ld_i32);
+    if (*cb_idx == -1) {
+        op = tcg_op_insert_after(tcg_ctx, op, INDEX_op_ld_i32);
+        memcpy(op->args, begin_op->args, sizeof(op->args));
+    }
+
+    /* call */
+    op = copy_call(&begin_op, op, HELPER(plugin_vcpu_udata_cb),
+                   cb->f.vcpu_udata, cb->tcg_flags, cb_idx);
+
+    return op;
+}
+
+static TCGOp *append_inline_cb(const struct qemu_plugin_dyn_cb *cb,
+                               TCGOp *begin_op, TCGOp *op,
+                               int *unused)
+{
+    /* const_ptr */
+    op = copy_const_ptr(&begin_op, op, cb->userp);
+
+    /* ld_i64 */
+    op = copy_ld_i64(&begin_op, op);
+
+    /* const_i64 */
+    op = copy_const_i64(&begin_op, op, cb->inline_insn.imm);
+
+    /* add_i64 */
+    op = copy_add_i64(&begin_op, op);
+
+    /* st_i64 */
+    op = copy_st_i64(&begin_op, op);
+
+    return op;
+}
+
+static TCGOp *append_mem_cb(const struct qemu_plugin_dyn_cb *cb,
+                            TCGOp *begin_op, TCGOp *op, int *cb_idx)
+{
+    enum plugin_gen_cb type = begin_op->args[1];
+
+    tcg_debug_assert(type == PLUGIN_GEN_CB_MEM);
+
+    /* const_i32 == movi_i32 ("info", so it remains as is) */
+    op = copy_op(&begin_op, op, INDEX_op_movi_i32);
+
+    /* const_ptr */
+    op = copy_const_ptr(&begin_op, op, cb->userp);
+
+    /* copy the ld_i32, but note that we only have to copy it once */
+    begin_op = QTAILQ_NEXT(begin_op, link);
+    tcg_debug_assert(begin_op && begin_op->opc == INDEX_op_ld_i32);
+    if (*cb_idx == -1) {
+        op = tcg_op_insert_after(tcg_ctx, op, INDEX_op_ld_i32);
+        memcpy(op->args, begin_op->args, sizeof(op->args));
+    }
+
+    /* extu_tl_i64 */
+    op = copy_extu_tl_i64(&begin_op, op);
+
+    if (type == PLUGIN_GEN_CB_MEM) {
+        /* call */
+        op = copy_call(&begin_op, op, HELPER(plugin_vcpu_mem_cb),
+                       cb->f.vcpu_udata, cb->tcg_flags, cb_idx);
+    }
+
+    return op;
+}
+
+typedef TCGOp *(*inject_fn)(const struct qemu_plugin_dyn_cb *cb,
+                            TCGOp *begin_op, TCGOp *op, int *intp);
+typedef bool (*op_ok_fn)(const TCGOp *op, const struct qemu_plugin_dyn_cb *cb);
+
+static bool op_ok(const TCGOp *op, const struct qemu_plugin_dyn_cb *cb)
+{
+    return true;
+}
+
+static bool op_rw(const TCGOp *op, const struct qemu_plugin_dyn_cb *cb)
+{
+    int w;
+
+    w = op->args[2];
+    return !!(cb->rw & (w + 1));
+}
+
+static inline
+void inject_cb_type(const GArray *cbs, TCGOp *begin_op, inject_fn inject,
+                    op_ok_fn ok)
+{
+    TCGOp *end_op;
+    TCGOp *op;
+    int cb_idx = -1;
+    int i;
+
+    if (!cbs || cbs->len == 0) {
+        rm_ops(begin_op);
+        return;
+    }
+
+    end_op = find_op(begin_op, INDEX_op_plugin_cb_end);
+    tcg_debug_assert(end_op);
+
+    op = end_op;
+    for (i = 0; i < cbs->len; i++) {
+        struct qemu_plugin_dyn_cb *cb =
+            &g_array_index(cbs, struct qemu_plugin_dyn_cb, i);
+
+        if (!ok(begin_op, cb)) {
+            continue;
+        }
+        op = inject(cb, begin_op, op, &cb_idx);
+    }
+    rm_ops_range(begin_op, end_op);
+}
+
+static void
+inject_udata_cb(const GArray *cbs, TCGOp *begin_op)
+{
+    inject_cb_type(cbs, begin_op, append_udata_cb, op_ok);
+}
+
+static void
+inject_inline_cb(const GArray *cbs, TCGOp *begin_op, op_ok_fn ok)
+{
+    inject_cb_type(cbs, begin_op, append_inline_cb, ok);
+}
+
+static void
+inject_mem_cb(const GArray *cbs, TCGOp *begin_op)
+{
+    inject_cb_type(cbs, begin_op, append_mem_cb, op_rw);
+}
+
+/* we could change the ops in place, but we can reuse more code by copying */
+static void inject_mem_helper(TCGOp *begin_op, GArray *arr)
+{
+    TCGOp *orig_op = begin_op;
+    TCGOp *end_op;
+    TCGOp *op;
+
+    end_op = find_op(begin_op, INDEX_op_plugin_cb_end);
+    tcg_debug_assert(end_op);
+
+    /* const ptr */
+    op = copy_const_ptr(&begin_op, end_op, arr);
+
+    /* st_ptr */
+    op = copy_st_ptr(&begin_op, op);
+
+    rm_ops_range(orig_op, end_op);
+}
+
+/*
+ * Tracking memory accesses performed from helpers requires extra work.
+ * If an instruction is emulated with helpers, we do two things:
+ * (1) copy the CB descriptors, and keep track of it so that they can be
+ * freed later on, and (2) point CPUState.plugin_mem_cbs to the descriptors, so
+ * that we can read them at run-time (i.e. when the helper executes).
+ * This run-time access is performed from qemu_plugin_vcpu_mem_cb.
+ *
+ * Note that plugin_gen_disable_mem_helpers undoes (2). Since it
+ * is possible that the code we generate after the instruction is
+ * dead, we also add checks before generating tb_exit etc.
+ */
+static void inject_mem_enable_helper(struct qemu_plugin_insn *plugin_insn,
+                                     TCGOp *begin_op)
+{
+    GArray *cbs[2];
+    GArray *arr;
+    size_t n_cbs, i;
+
+    cbs[0] = plugin_insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR];
+    cbs[1] = plugin_insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE];
+
+    n_cbs = 0;
+    for (i = 0; i < ARRAY_SIZE(cbs); i++) {
+        n_cbs += cbs[i]->len;
+    }
+
+    plugin_insn->mem_helper = plugin_insn->calls_helpers && n_cbs;
+    if (likely(!plugin_insn->mem_helper)) {
+        rm_ops(begin_op);
+        return;
+    }
+
+    arr = g_array_sized_new(false, false,
+                            sizeof(struct qemu_plugin_dyn_cb), n_cbs);
+
+    for (i = 0; i < ARRAY_SIZE(cbs); i++) {
+        g_array_append_vals(arr, cbs[i]->data, cbs[i]->len);
+    }
+
+    qemu_plugin_add_dyn_cb_arr(arr);
+    inject_mem_helper(begin_op, arr);
+}
+
+static void inject_mem_disable_helper(struct qemu_plugin_insn *plugin_insn,
+                                      TCGOp *begin_op)
+{
+    if (likely(!plugin_insn->mem_helper)) {
+        rm_ops(begin_op);
+        return;
+    }
+    inject_mem_helper(begin_op, NULL);
+}
+
+/* called before finishing a TB with exit_tb, goto_tb or goto_ptr */
+void plugin_gen_disable_mem_helpers(void)
+{
+    TCGv_ptr ptr;
+
+    if (likely(tcg_ctx->plugin_insn == NULL ||
+               !tcg_ctx->plugin_insn->mem_helper)) {
+        return;
+    }
+    ptr = tcg_const_ptr(NULL);
+    tcg_gen_st_ptr(ptr, cpu_env, offsetof(CPUState, plugin_mem_cbs));
+    tcg_temp_free_ptr(ptr);
+    tcg_ctx->plugin_insn->mem_helper = false;
+}
+
+static void plugin_gen_tb_udata(const struct qemu_plugin_tb *ptb,
+                                TCGOp *begin_op)
+{
+    inject_udata_cb(ptb->cbs[PLUGIN_CB_REGULAR], begin_op);
+}
+
+static void plugin_gen_tb_inline(const struct qemu_plugin_tb *ptb,
+                                 TCGOp *begin_op)
+{
+    inject_inline_cb(ptb->cbs[PLUGIN_CB_INLINE], begin_op, op_ok);
+}
+
+static void plugin_gen_insn_udata(const struct qemu_plugin_tb *ptb,
+                                  TCGOp *begin_op, int insn_idx)
+{
+    struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+
+    inject_udata_cb(insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_REGULAR], begin_op);
+}
+
+static void plugin_gen_insn_inline(const struct qemu_plugin_tb *ptb,
+                                   TCGOp *begin_op, int insn_idx)
+{
+    struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+    inject_inline_cb(insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
+                     begin_op, op_ok);
+}
+
+static void plugin_gen_mem_regular(const struct qemu_plugin_tb *ptb,
+                                   TCGOp *begin_op, int insn_idx)
+{
+    struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+    inject_mem_cb(insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR], begin_op);
+}
+
+static void plugin_gen_mem_inline(const struct qemu_plugin_tb *ptb,
+                                  TCGOp *begin_op, int insn_idx)
+{
+    const GArray *cbs;
+    struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+
+    cbs = insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE];
+    inject_inline_cb(cbs, begin_op, op_rw);
+}
+
+static void plugin_gen_enable_mem_helper(const struct qemu_plugin_tb *ptb,
+                                         TCGOp *begin_op, int insn_idx)
+{
+    struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+    inject_mem_enable_helper(insn, begin_op);
+}
+
+static void plugin_gen_disable_mem_helper(const struct qemu_plugin_tb *ptb,
+                                          TCGOp *begin_op, int insn_idx)
+{
+    struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
+    inject_mem_disable_helper(insn, begin_op);
+}
+
+static void plugin_inject_cb(const struct qemu_plugin_tb *ptb, TCGOp *begin_op,
+                             int insn_idx)
+{
+    enum plugin_gen_from from = begin_op->args[0];
+    enum plugin_gen_cb type = begin_op->args[1];
+
+    switch (from) {
+    case PLUGIN_GEN_FROM_TB:
+        switch (type) {
+        case PLUGIN_GEN_CB_UDATA:
+            plugin_gen_tb_udata(ptb, begin_op);
+            return;
+        case PLUGIN_GEN_CB_INLINE:
+            plugin_gen_tb_inline(ptb, begin_op);
+            return;
+        default:
+            g_assert_not_reached();
+        }
+    case PLUGIN_GEN_FROM_INSN:
+        switch (type) {
+        case PLUGIN_GEN_CB_UDATA:
+            plugin_gen_insn_udata(ptb, begin_op, insn_idx);
+            return;
+        case PLUGIN_GEN_CB_INLINE:
+            plugin_gen_insn_inline(ptb, begin_op, insn_idx);
+            return;
+        case PLUGIN_GEN_ENABLE_MEM_HELPER:
+            plugin_gen_enable_mem_helper(ptb, begin_op, insn_idx);
+            return;
+        default:
+            g_assert_not_reached();
+        }
+    case PLUGIN_GEN_FROM_MEM:
+        switch (type) {
+        case PLUGIN_GEN_CB_MEM:
+            plugin_gen_mem_regular(ptb, begin_op, insn_idx);
+            return;
+        case PLUGIN_GEN_CB_INLINE:
+            plugin_gen_mem_inline(ptb, begin_op, insn_idx);
+            return;
+        default:
+            g_assert_not_reached();
+        }
+    case PLUGIN_GEN_AFTER_INSN:
+        switch (type) {
+        case PLUGIN_GEN_DISABLE_MEM_HELPER:
+            plugin_gen_disable_mem_helper(ptb, begin_op, insn_idx);
+            return;
+        default:
+            g_assert_not_reached();
+        }
+    default:
+        g_assert_not_reached();
+    }
+}
+
+/* #define DEBUG_PLUGIN_GEN_OPS */
+static void pr_ops(void)
+{
+#ifdef DEBUG_PLUGIN_GEN_OPS
+    TCGOp *op;
+    int i = 0;
+
+    QTAILQ_FOREACH(op, &tcg_ctx->ops, link) {
+        const char *name = "";
+        const char *type = "";
+
+        if (op->opc == INDEX_op_plugin_cb_start) {
+            switch (op->args[0]) {
+            case PLUGIN_GEN_FROM_TB:
+                name = "tb";
+                break;
+            case PLUGIN_GEN_FROM_INSN:
+                name = "insn";
+                break;
+            case PLUGIN_GEN_FROM_MEM:
+                name = "mem";
+                break;
+            case PLUGIN_GEN_AFTER_INSN:
+                name = "after insn";
+                break;
+            default:
+                break;
+            }
+            switch (op->args[1]) {
+            case PLUGIN_GEN_CB_UDATA:
+                type = "udata";
+                break;
+            case PLUGIN_GEN_CB_INLINE:
+                type = "inline";
+                break;
+            case PLUGIN_GEN_CB_MEM:
+                type = "mem";
+                break;
+            case PLUGIN_GEN_ENABLE_MEM_HELPER:
+                type = "enable mem helper";
+                break;
+            case PLUGIN_GEN_DISABLE_MEM_HELPER:
+                type = "disable mem helper";
+                break;
+            default:
+                break;
+            }
+        }
+        printf("op[%2i]: %s %s %s\n", i, tcg_op_defs[op->opc].name, name, type);
+        i++;
+    }
+#endif
+}
+
+static void plugin_gen_inject(const struct qemu_plugin_tb *plugin_tb)
+{
+    TCGOp *op;
+    int insn_idx;
+
+    pr_ops();
+    insn_idx = -1;
+    QSIMPLEQ_FOREACH(op, &tcg_ctx->plugin_ops, plugin_link) {
+        enum plugin_gen_from from = op->args[0];
+        enum plugin_gen_cb type = op->args[1];
+
+        tcg_debug_assert(op->opc == INDEX_op_plugin_cb_start);
+        /* ENABLE_MEM_HELPER is the first callback of an instruction */
+        if (from == PLUGIN_GEN_FROM_INSN &&
+            type == PLUGIN_GEN_ENABLE_MEM_HELPER) {
+            insn_idx++;
+        }
+        plugin_inject_cb(plugin_tb, op, insn_idx);
+    }
+    pr_ops();
+}
+
+bool plugin_gen_tb_start(CPUState *cpu, const TranslationBlock *tb)
+{
+    struct qemu_plugin_tb *ptb = tcg_ctx->plugin_tb;
+    bool ret = false;
+
+    if (test_bit(QEMU_PLUGIN_EV_VCPU_TB_TRANS, cpu->plugin_mask)) {
+        ret = true;
+
+        QSIMPLEQ_INIT(&tcg_ctx->plugin_ops);
+        ptb->vaddr = tb->pc;
+        ptb->vaddr2 = -1;
+        get_page_addr_code_hostp(cpu->env_ptr, tb->pc, &ptb->haddr1);
+        ptb->haddr2 = NULL;
+
+        plugin_gen_empty_callback(PLUGIN_GEN_FROM_TB);
+    }
+    return ret;
+}
+
+void plugin_gen_insn_start(CPUState *cpu, const DisasContextBase *db)
+{
+    struct qemu_plugin_tb *ptb = tcg_ctx->plugin_tb;
+    struct qemu_plugin_insn *pinsn;
+
+    pinsn = qemu_plugin_tb_insn_get(ptb);
+    tcg_ctx->plugin_insn = pinsn;
+    pinsn->vaddr = db->pc_next;
+    plugin_gen_empty_callback(PLUGIN_GEN_FROM_INSN);
+
+    /*
+     * Detect page crossing to get the new host address.
+     * Note that we skip this when haddr1 == NULL, e.g. when we're
+     * fetching instructions from a region not backed by RAM.
+     */
+    if (likely(ptb->haddr1 != NULL && ptb->vaddr2 == -1) &&
+        unlikely((db->pc_next & TARGET_PAGE_MASK) !=
+                 (db->pc_first & TARGET_PAGE_MASK))) {
+        get_page_addr_code_hostp(cpu->env_ptr, db->pc_next,
+                                 &ptb->haddr2);
+        ptb->vaddr2 = db->pc_next;
+    }
+    if (likely(ptb->vaddr2 == -1)) {
+        pinsn->haddr = ptb->haddr1 + pinsn->vaddr - ptb->vaddr;
+    } else {
+        pinsn->haddr = ptb->haddr2 + pinsn->vaddr - ptb->vaddr2;
+    }
+}
+
+void plugin_gen_insn_end(void)
+{
+    plugin_gen_empty_callback(PLUGIN_GEN_AFTER_INSN);
+}
+
+void plugin_gen_tb_end(CPUState *cpu)
+{
+    struct qemu_plugin_tb *ptb = tcg_ctx->plugin_tb;
+    int i;
+
+    /* collect instrumentation requests */
+    qemu_plugin_tb_trans_cb(cpu, ptb);
+
+    /* inject the instrumentation at the appropriate places */
+    plugin_gen_inject(ptb);
+
+    /* clean up */
+    for (i = 0; i < PLUGIN_N_CB_SUBTYPES; i++) {
+        if (ptb->cbs[i]) {
+            g_array_set_size(ptb->cbs[i], 0);
+        }
+    }
+    ptb->n = 0;
+    tcg_ctx->plugin_insn = NULL;
+}
diff --git a/accel/tcg/plugin-helpers.h b/accel/tcg/plugin-helpers.h
new file mode 100644
index 00000000000..1916ee79206
--- /dev/null
+++ b/accel/tcg/plugin-helpers.h
@@ -0,0 +1,5 @@
+#ifdef CONFIG_PLUGIN
+/* Note: no TCG flags because those are overwritten later */
+DEF_HELPER_2(plugin_vcpu_udata_cb, void, i32, ptr)
+DEF_HELPER_4(plugin_vcpu_mem_cb, void, i32, i32, i64, ptr)
+#endif
diff --git a/include/exec/helper-gen.h b/include/exec/helper-gen.h
index 22381a17088..236ff405243 100644
--- a/include/exec/helper-gen.h
+++ b/include/exec/helper-gen.h
@@ -70,6 +70,7 @@ static inline void glue(gen_helper_, name)(dh_retvar_decl(ret)          \
 #include "trace/generated-helpers.h"
 #include "trace/generated-helpers-wrappers.h"
 #include "tcg-runtime.h"
+#include "plugin-helpers.h"
 
 #undef DEF_HELPER_FLAGS_0
 #undef DEF_HELPER_FLAGS_1
diff --git a/include/exec/helper-proto.h b/include/exec/helper-proto.h
index 74943edb13a..1c4ba9bc788 100644
--- a/include/exec/helper-proto.h
+++ b/include/exec/helper-proto.h
@@ -33,6 +33,7 @@ dh_ctype(ret) HELPER(name) (dh_ctype(t1), dh_ctype(t2), dh_ctype(t3), \
 #include "helper.h"
 #include "trace/generated-helpers.h"
 #include "tcg-runtime.h"
+#include "plugin-helpers.h"
 
 #undef DEF_HELPER_FLAGS_0
 #undef DEF_HELPER_FLAGS_1
diff --git a/include/exec/helper-tcg.h b/include/exec/helper-tcg.h
index 268e0f804be..573c2ce2e98 100644
--- a/include/exec/helper-tcg.h
+++ b/include/exec/helper-tcg.h
@@ -55,6 +55,7 @@
 #include "helper.h"
 #include "trace/generated-helpers.h"
 #include "tcg-runtime.h"
+#include "plugin-helpers.h"
 
 #undef str
 #undef DEF_HELPER_FLAGS_0
diff --git a/include/exec/plugin-gen.h b/include/exec/plugin-gen.h
new file mode 100644
index 00000000000..de519883b16
--- /dev/null
+++ b/include/exec/plugin-gen.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ *
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ *
+ * plugin-gen.h - TCG-dependent definitions for generating plugin code
+ *
+ * This header should be included only from plugin.c and C files that emit
+ * TCG code.
+ */
+#ifndef QEMU_PLUGIN_GEN_H
+#define QEMU_PLUGIN_GEN_H
+
+#include "qemu/plugin.h"
+#include "tcg/tcg.h"
+
+struct DisasContextBase;
+
+#ifdef CONFIG_PLUGIN
+
+bool plugin_gen_tb_start(CPUState *cpu, const TranslationBlock *tb);
+void plugin_gen_tb_end(CPUState *cpu);
+void plugin_gen_insn_start(CPUState *cpu, const struct DisasContextBase *db);
+void plugin_gen_insn_end(void);
+
+void plugin_gen_disable_mem_helpers(void);
+void plugin_gen_empty_mem_callback(TCGv addr, uint32_t info);
+
+#else /* !CONFIG_PLUGIN */
+
+static inline
+bool plugin_gen_tb_start(CPUState *cpu, const TranslationBlock *tb)
+{
+    return false;
+}
+
+static inline
+void plugin_gen_insn_start(CPUState *cpu, const struct DisasContextBase *db)
+{ }
+
+static inline void plugin_gen_insn_end(void)
+{ }
+
+static inline void plugin_gen_tb_end(CPUState *cpu)
+{ }
+
+static inline void plugin_gen_disable_mem_helpers(void)
+{ }
+
+static inline void plugin_gen_empty_mem_callback(TCGv addr, uint32_t info)
+{ }
+
+#endif /* CONFIG_PLUGIN */
+
+#endif /* QEMU_PLUGIN_GEN_H */
+
diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
index 698f3111eb2..edf12de1f31 100644
--- a/tcg/tcg-op.h
+++ b/tcg/tcg-op.h
@@ -833,6 +833,17 @@ void tcg_gen_goto_tb(unsigned idx);
  */
 void tcg_gen_lookup_and_goto_ptr(void);
 
+static inline void tcg_gen_plugin_cb_start(unsigned from, unsigned type,
+                                           unsigned wr)
+{
+    tcg_gen_op3(INDEX_op_plugin_cb_start, from, type, wr);
+}
+
+static inline void tcg_gen_plugin_cb_end(void)
+{
+    tcg_emit_op(INDEX_op_plugin_cb_end);
+}
+
 #if TARGET_LONG_BITS == 32
 #define tcg_temp_new() tcg_temp_new_i32()
 #define tcg_global_reg_new tcg_global_reg_new_i32
diff --git a/tcg/tcg-opc.h b/tcg/tcg-opc.h
index 242d608e6db..9288a049468 100644
--- a/tcg/tcg-opc.h
+++ b/tcg/tcg-opc.h
@@ -198,6 +198,9 @@ DEF(goto_tb, 0, 0, 1, TCG_OPF_BB_EXIT | TCG_OPF_BB_END)
 DEF(goto_ptr, 0, 1, 0,
     TCG_OPF_BB_EXIT | TCG_OPF_BB_END | IMPL(TCG_TARGET_HAS_goto_ptr))
 
+DEF(plugin_cb_start, 0, 0, 3, TCG_OPF_NOT_PRESENT)
+DEF(plugin_cb_end, 0, 0, 0, TCG_OPF_NOT_PRESENT)
+
 DEF(qemu_ld_i32, 1, TLADDR_ARGS, 1,
     TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS)
 DEF(qemu_st_i32, 0, TLADDR_ARGS + 1, 1,
diff --git a/tcg/tcg.c b/tcg/tcg.c
index be2c33c400c..516128dc21a 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -737,6 +737,15 @@ void tcg_region_init(void)
 #endif
 }
 
+static void alloc_tcg_plugin_context(TCGContext *s)
+{
+#ifdef CONFIG_PLUGIN
+    s->plugin_tb = g_new0(struct qemu_plugin_tb, 1);
+    s->plugin_tb->insns =
+        g_ptr_array_new_with_free_func(qemu_plugin_insn_cleanup_fn);
+#endif
+}
+
 /*
  * All TCG threads except the parent (i.e. the one that called tcg_context_init
  * and registered the target's TCG globals) must register with this function
@@ -781,6 +790,10 @@ void tcg_register_thread(void)
     g_assert(n < ms->smp.max_cpus);
     atomic_set(&tcg_ctxs[n], s);
 
+    if (n > 0) {
+        alloc_tcg_plugin_context(s);
+    }
+
     tcg_ctx = s;
     qemu_mutex_lock(&region.lock);
     err = tcg_region_initial_alloc__locked(tcg_ctx);
@@ -977,6 +990,8 @@ void tcg_context_init(TCGContext *s)
         indirect_reg_alloc_order[i] = tcg_target_reg_alloc_order[i];
     }
 
+    alloc_tcg_plugin_context(s);
+
     tcg_ctx = s;
     /*
      * In user-mode we simply share the init context among threads, since we
@@ -1682,6 +1697,13 @@ void tcg_gen_callN(void *func, TCGTemp *ret, int nargs, TCGTemp **args)
     flags = info->flags;
     sizemask = info->sizemask;
 
+#ifdef CONFIG_PLUGIN
+    /* detect non-plugin helpers */
+    if (tcg_ctx->plugin_insn && unlikely(strncmp(info->name, "plugin_", 7))) {
+        tcg_ctx->plugin_insn->calls_helpers = true;
+    }
+#endif
+
 #if defined(__sparc__) && !defined(__arch64__) \
     && !defined(CONFIG_TCG_INTERPRETER)
     /* We have 64-bit values in one register, but need to pass as two
diff --git a/tcg/tcg.h b/tcg/tcg.h
index b411e17a28f..2385e758e55 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -625,6 +625,9 @@ typedef struct TCGOp {
 
     /* Next and previous opcodes.  */
     QTAILQ_ENTRY(TCGOp) link;
+#ifdef CONFIG_PLUGIN
+    QSIMPLEQ_ENTRY(TCGOp) plugin_link;
+#endif
 
     /* Arguments for the opcode.  */
     TCGArg args[MAX_OPC_PARAM];
@@ -726,6 +729,23 @@ struct TCGContext {
 
     TCGLabel *exitreq_label;
 
+#ifdef CONFIG_PLUGIN
+    /*
+     * We keep one plugin_tb struct per TCGContext. Note that on every TB
+     * translation we clear but do not free its contents; this way we
+     * avoid a lot of malloc/free churn, since after a few TB's it's
+     * unlikely that we'll need to allocate either more instructions or more
+     * space for instructions (for variable-instruction-length ISAs).
+     */
+    struct qemu_plugin_tb *plugin_tb;
+
+    /* descriptor of the instruction being translated */
+    struct qemu_plugin_insn *plugin_insn;
+
+    /* list to quickly access the injected ops */
+    QSIMPLEQ_HEAD(, TCGOp) plugin_ops;
+#endif
+
     TCGTempSet free_temps[TCG_TYPE_COUNT * 2];
     TCGTemp temps[TCG_MAX_TEMPS]; /* globals first, temps after */
 
