diff mbox series

[v3,08/50] plugin: add core code

Message ID 20190614171200.21078-9-alex.bennee@linaro.org
State Superseded
Headers show
Series tcg plugin support | expand

Commit Message

Alex Bennée June 14, 2019, 5:11 p.m. UTC
From: "Emilio G. Cota" <cota@braap.org>


Signed-off-by: Emilio G. Cota <cota@braap.org>

[AJB: moved directory and merged various fixes]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>


---
v3
  - moved to plugins/
  - merged
    plugin: remove uninstall_cb_t and just use simple_cb_t
    plugin: handle uninstall when !current_cpu
    plugin: introduce qemu_plugin_reset
  - split into core/loader
  - use GArray/GByteArray/GPtrArray instead of homegrown funcs
---
 Makefile              |  10 +-
 Makefile.target       |   2 +
 include/qemu/plugin.h | 261 +++++++++++++++++++++
 include/qom/cpu.h     |   6 +
 plugins/Makefile.objs |   6 +
 plugins/core.c        | 524 ++++++++++++++++++++++++++++++++++++++++++
 plugins/loader.c      | 353 ++++++++++++++++++++++++++++
 plugins/plugin.h      |  95 ++++++++
 8 files changed, 1256 insertions(+), 1 deletion(-)
 create mode 100644 include/qemu/plugin.h
 create mode 100644 plugins/Makefile.objs
 create mode 100644 plugins/core.c
 create mode 100644 plugins/loader.c
 create mode 100644 plugins/plugin.h

-- 
2.20.1

Comments

Alex Bennée June 19, 2019, 11:46 a.m. UTC | #1
Pranith Kumar <bobby.prani@gmail.com> writes:

> On Fri, Jun 14, 2019 at 10:30 AM Alex Bennée <alex.bennee@linaro.org> wrote:

>>

>> From: "Emilio G. Cota" <cota@braap.org>

>>

>> Signed-off-by: Emilio G. Cota <cota@braap.org>

>> [AJB: moved directory and merged various fixes]

>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

>>

>> ---

>> v3

>>   - moved to plugins/

>>   - merged

>>     plugin: remove uninstall_cb_t and just use simple_cb_t

>>     plugin: handle uninstall when !current_cpu

>>     plugin: introduce qemu_plugin_reset

>>   - split into core/loader

>>   - use GArray/GByteArray/GPtrArray instead of homegrown funcs

>> ---

>>  Makefile              |  10 +-

>>  Makefile.target       |   2 +

>>  include/qemu/plugin.h | 261 +++++++++++++++++++++

>>  include/qom/cpu.h     |   6 +

>>  plugins/Makefile.objs |   6 +

>>  plugins/core.c        | 524 ++++++++++++++++++++++++++++++++++++++++++

>>  plugins/loader.c      | 353 ++++++++++++++++++++++++++++

>>  plugins/plugin.h      |  95 ++++++++

>>  8 files changed, 1256 insertions(+), 1 deletion(-)

>>  create mode 100644 include/qemu/plugin.h

>>  create mode 100644 plugins/Makefile.objs

>>  create mode 100644 plugins/core.c

>>  create mode 100644 plugins/loader.c

>>  create mode 100644 plugins/plugin.h

>>

>> diff --git a/Makefile b/Makefile

>> index 8e2fc6624c..37d396ab88 100644

>> --- a/Makefile

>> +++ b/Makefile

>> @@ -827,8 +827,13 @@ endif

>>

>>  ICON_SIZES=16x16 24x24 32x32 48x48 64x64 128x128 256x256 512x512

>>

>> -install: all $(if $(BUILD_DOCS),install-doc) install-datadir install-localstatedir \

>> +install-includedir:

>> +       $(INSTALL_DIR) "$(DESTDIR)$(includedir)"

>> +

>> +install: all $(if $(BUILD_DOCS),install-doc) \

>> +       install-datadir install-localstatedir install-includedir \

>>         $(if $(INSTALL_BLOBS),$(edk2-decompressed))

>> +

>>  ifneq ($(TOOLS),)

>>         $(call install-prog,$(subst qemu-ga,qemu-ga$(EXESUF),$(TOOLS)),$(DESTDIR)$(bindir))

>>  endif

>> @@ -888,6 +893,9 @@ endif

>>                 "$(DESTDIR)/$(qemu_desktopdir)/qemu.desktop"

>>  ifdef CONFIG_GTK

>>         $(MAKE) -C po $@

>> +endif

>> +ifeq ($(CONFIG_PLUGIN),y)

>> +       $(INSTALL_DATA) $(SRC_PATH)/include/qemu/qemu-plugin.h "$(DESTDIR)$(includedir)/qemu-plugin.h"

>>  endif

>>         $(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)/keymaps"

>>         set -e; for x in $(KEYMAPS); do \

>> diff --git a/Makefile.target b/Makefile.target

>> index ecd856e3a3..d492e24da2 100644

>> --- a/Makefile.target

>> +++ b/Makefile.target

>> @@ -118,6 +118,8 @@ obj-y += target/$(TARGET_BASE_ARCH)/

>>  obj-y += disas.o

>>  obj-$(call notempty,$(TARGET_XML_FILES)) += gdbstub-xml.o

>>

>> +obj-$(CONFIG_PLUGIN) += plugins/

>> +

>>  #########################################################

>>  # Linux user emulator target

>>

>> diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h

>> new file mode 100644

>> index 0000000000..93e39f44d2

>> --- /dev/null

>> +++ b/include/qemu/plugin.h

>> @@ -0,0 +1,261 @@

>> +/*

>> + * 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.

>> + */

>> +#ifndef QEMU_PLUGIN_H

>> +#define QEMU_PLUGIN_H

>> +

>> +#include "qemu/config-file.h"

>> +#include "qemu/qemu-plugin.h"

>> +#include "qemu/error-report.h"

>> +#include "qemu/queue.h"

>> +#include "qemu/option.h"

>> +

>> +/*

>> + * Option parsing/processing.

>> + * Note that we can load an arbitrary number of plugins.

>> + */

>> +struct qemu_plugin_desc;

>> +typedef QTAILQ_HEAD(, qemu_plugin_desc) QemuPluginList;

>> +

>> +#ifdef CONFIG_PLUGIN

>> +extern QemuOptsList qemu_plugin_opts;

>> +

>> +static inline void qemu_plugin_add_opts(void)

>> +{

>> +    qemu_add_opts(&qemu_plugin_opts);

>> +}

>> +

>> +void qemu_plugin_opt_parse(const char *optarg, QemuPluginList *head);

>> +int qemu_plugin_load_list(QemuPluginList *head);

>> +#else /* !CONFIG_PLUGIN */

>> +static inline void qemu_plugin_add_opts(void)

>> +{ }

>> +

>> +static inline void qemu_plugin_opt_parse(const char *optarg,

>> +                                         QemuPluginList *head)

>> +{

>> +    error_report("plugin interface not enabled in this build");

>> +    exit(1);

>> +}

>> +

>> +static inline int qemu_plugin_load_list(QemuPluginList *head)

>> +{

>> +    return 0;

>> +}

>> +#endif /* !CONFIG_PLUGIN */

>> +

>> +/*

>> + * Events that plugins can subscribe to.

>> + */

>> +enum qemu_plugin_event {

>> +    QEMU_PLUGIN_EV_VCPU_INIT,

>> +    QEMU_PLUGIN_EV_VCPU_EXIT,

>> +    QEMU_PLUGIN_EV_VCPU_TB_TRANS,

>> +    QEMU_PLUGIN_EV_VCPU_IDLE,

>> +    QEMU_PLUGIN_EV_VCPU_RESUME,

>> +    QEMU_PLUGIN_EV_VCPU_SYSCALL,

>> +    QEMU_PLUGIN_EV_VCPU_SYSCALL_RET,

>> +    QEMU_PLUGIN_EV_FLUSH,

>> +    QEMU_PLUGIN_EV_ATEXIT,

>> +    QEMU_PLUGIN_EV_MAX,

>> +};

>

> All the events but for MAX are descriptive. Care to add a comment for

> the last one?


Ok.

>

>> +

>> +union qemu_plugin_cb_sig {

>> +    qemu_plugin_simple_cb_t          simple;

>> +    qemu_plugin_udata_cb_t           udata;

>> +    qemu_plugin_vcpu_simple_cb_t     vcpu_simple;

>> +    qemu_plugin_vcpu_udata_cb_t      vcpu_udata;

>> +    qemu_plugin_vcpu_tb_trans_cb_t   vcpu_tb_trans;

>> +    qemu_plugin_vcpu_mem_cb_t        vcpu_mem;

>> +    qemu_plugin_vcpu_mem_haddr_cb_t  vcpu_mem_haddr;

>> +    qemu_plugin_vcpu_syscall_cb_t    vcpu_syscall;

>> +    qemu_plugin_vcpu_syscall_ret_cb_t vcpu_syscall_ret;

>> +    void *generic;

>> +};

>> +

>> +enum plugin_dyn_cb_type {

>> +    PLUGIN_CB_INSN,

>> +    PLUGIN_CB_MEM,

>> +    PLUGIN_CB_HADDR,

>> +    PLUGIN_N_CB_TYPES,

>> +};

>

> This might be better to have the types as powers of 2. It will allow

> us to define a plugin by comibining multiple types using OR.


To what end? It's not like you can have multiple prototypes to the call back.

>

>

>> +

>> +enum plugin_dyn_cb_subtype {

>> +    PLUGIN_CB_REGULAR,

>> +    PLUGIN_CB_INLINE,

>> +    PLUGIN_N_CB_SUBTYPES,

>> +};

>> +

>> +/*

>> + * A dynamic callback has an insertion point that is determined at run-time.

>> + * Usually the insertion point is somewhere in the code cache; think for

>> + * instance of a callback to be called upon the execution of a particular TB.

>> + */

>> +struct qemu_plugin_dyn_cb {

>> +    union qemu_plugin_cb_sig f;

>> +    void *userp;

>> +    unsigned tcg_flags;

>> +    enum plugin_dyn_cb_type type;

>> +    /* @rw applies to mem callbacks only (both regular and inline) */

>> +    enum qemu_plugin_mem_rw rw;

>> +    /* fields specific to each dyn_cb type go here */

>> +    union {

>> +        struct {

>> +            bool haddr;

>> +        } mem;

>> +        struct {

>> +            enum qemu_plugin_op op;

>> +            uint64_t imm;

>> +        } inline_insn;

>> +    };

>> +};

>> +

>> +struct qemu_plugin_insn {

>> +    GByteArray *data;

>> +    uint64_t vaddr;

>> +    void *haddr;

>> +    GArray *cbs[PLUGIN_N_CB_TYPES][PLUGIN_N_CB_SUBTYPES];

>> +    bool calls_helpers;

>> +    bool mem_helper;

>> +};

>> +

>> +/*

>> + * qemu_plugin_insn allocate and cleanup functions. We don't expect to

>> + * cleanup many of these structures. They are reused for each fresh

>> + * translation.

>> + */

>> +

>> +static inline void qemu_plugin_insn_cleanup_fn(gpointer data)

>> +{

>> +    struct qemu_plugin_insn *insn = (struct qemu_plugin_insn *) data;

>> +    g_byte_array_free(insn->data, true);

>> +}

>> +

>> +static inline struct qemu_plugin_insn * qemu_plugin_insn_alloc(void)

>> +{

>> +    int i, j;

>> +    struct qemu_plugin_insn *insn = g_new0(struct qemu_plugin_insn, 1);

>> +    insn->data = g_byte_array_sized_new(4);

>> +

>> +    for (i = 0; i < PLUGIN_N_CB_TYPES; i++) {

>> +        for (j = 0; j < PLUGIN_N_CB_SUBTYPES; j++) {

>> +            insn->cbs[i][j] = g_array_new(false, false,

>> +                                          sizeof(struct qemu_plugin_dyn_cb));

>> +        }

>> +    }

>> +    return insn;

>> +}

>> +

>> +struct qemu_plugin_tb {

>> +    GPtrArray *insns;

>> +    size_t n;

>> +    uint64_t vaddr;

>> +    uint64_t vaddr2;

>> +    void *haddr1;

>> +    void *haddr2;

>> +    GArray *cbs[PLUGIN_N_CB_SUBTYPES];

>> +};

>> +

>> +/**

>> + * qemu_plugin_tb_insn_get(): get next plugin record for translation.

>> + *

>> + */

>> +static inline

>> +struct qemu_plugin_insn *qemu_plugin_tb_insn_get(struct qemu_plugin_tb *tb)

>> +{

>> +    struct qemu_plugin_insn *insn;

>> +    int i, j;

>> +

>> +    if (unlikely(tb->n == tb->insns->len)) {

>> +        struct qemu_plugin_insn *new_insn = qemu_plugin_insn_alloc();

>> +        g_ptr_array_add(tb->insns, new_insn);

>> +    }

>> +    insn = g_ptr_array_index(tb->insns, tb->n++);

>> +    g_byte_array_set_size(insn->data, 0);

>> +    insn->calls_helpers = false;

>> +    insn->mem_helper = false;

>> +

>> +    for (i = 0; i < PLUGIN_N_CB_TYPES; i++) {

>> +        for (j = 0; j < PLUGIN_N_CB_SUBTYPES; j++) {

>> +            g_array_set_size(insn->cbs[i][j], 0);

>> +        }

>> +    }

>> +

>> +    return insn;

>> +}

>> +

>> +#ifdef CONFIG_PLUGIN

>> +

>> +void qemu_plugin_vcpu_init_hook(CPUState *cpu);

>> +void qemu_plugin_vcpu_exit_hook(CPUState *cpu);

>> +void qemu_plugin_tb_trans_cb(CPUState *cpu, struct qemu_plugin_tb *tb);

>> +void qemu_plugin_vcpu_idle_cb(CPUState *cpu);

>> +void qemu_plugin_vcpu_resume_cb(CPUState *cpu);

>> +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);

>> +void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret);

>> +

>> +void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr, void *haddr,

>> +                             uint32_t meminfo);

>> +

>> +void qemu_plugin_flush_cb(void);

>> +

>> +void qemu_plugin_atexit_cb(void);

>> +

>> +void qemu_plugin_add_dyn_cb_arr(GArray *arr);

>> +

>> +void qemu_plugin_disable_mem_helpers(CPUState *cpu);

>> +

>> +#else /* !CONFIG_PLUGIN */

>> +

>> +static inline void qemu_plugin_vcpu_init_hook(CPUState *cpu)

>> +{ }

>> +

>> +static inline void qemu_plugin_vcpu_exit_hook(CPUState *cpu)

>> +{ }

>> +

>> +static inline void qemu_plugin_tb_trans_cb(CPUState *cpu,

>> +                                           struct qemu_plugin_tb *tb)

>> +{ }

>> +

>> +static inline void qemu_plugin_vcpu_idle_cb(CPUState *cpu)

>> +{ }

>> +

>> +static inline void qemu_plugin_vcpu_resume_cb(CPUState *cpu)

>> +{ }

>> +

>> +static inline 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)

>> +{ }

>> +

>> +static inline

>> +void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret)

>> +{ }

>> +

>> +static inline void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr,

>> +                                           void *haddr, uint32_t meminfo)

>> +{ }

>> +

>> +static inline void qemu_plugin_flush_cb(void)

>> +{ }

>> +

>> +static inline void qemu_plugin_atexit_cb(void)

>> +{ }

>> +

>> +static inline

>> +void qemu_plugin_add_dyn_cb_arr(GArray *arr)

>> +{ }

>> +

>> +static inline void qemu_plugin_disable_mem_helpers(CPUState *cpu)

>> +{ }

>> +

>> +#endif /* !CONFIG_PLUGIN */

>> +

>> +#endif /* QEMU_PLUGIN_H */

>> diff --git a/include/qom/cpu.h b/include/qom/cpu.h

>> index 08481ad304..27b67a4e49 100644

>> --- a/include/qom/cpu.h

>> +++ b/include/qom/cpu.h

>> @@ -29,6 +29,7 @@

>>  #include "qemu/rcu_queue.h"

>>  #include "qemu/queue.h"

>>  #include "qemu/thread.h"

>> +#include "qemu/plugin.h"

>>

>>  typedef int (*WriteCoreDumpFunction)(const void *buf, size_t size,

>>                                       void *opaque);

>> @@ -345,6 +346,7 @@ struct qemu_work_item;

>>   * @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes

>>   *                        to @trace_dstate).

>>   * @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask).

>> + * @plugin_mask: Plugin event bitmap. Modified only via async work.

>>   * @ignore_memory_transaction_failures: Cached copy of the MachineState

>>   *    flag of the same name: allows the board to suppress calling of the

>>   *    CPU do_transaction_failed hook function.

>> @@ -430,6 +432,10 @@ struct CPUState {

>>      DECLARE_BITMAP(trace_dstate_delayed, CPU_TRACE_DSTATE_MAX_EVENTS);

>>      DECLARE_BITMAP(trace_dstate, CPU_TRACE_DSTATE_MAX_EVENTS);

>>

>> +    DECLARE_BITMAP(plugin_mask, QEMU_PLUGIN_EV_MAX);

>> +

>> +    GArray *plugin_mem_cbs;

>> +

>>      /* TODO Move common fields from CPUArchState here. */

>>      int cpu_index;

>>      int cluster_index;

>> diff --git a/plugins/Makefile.objs b/plugins/Makefile.objs

>> new file mode 100644

>> index 0000000000..58940335bc

>> --- /dev/null

>> +++ b/plugins/Makefile.objs

>> @@ -0,0 +1,6 @@

>> +#

>> +# Plugin Support

>> +#

>> +

>> +obj-y += loader.o

>> +obj-y += core.o

>> diff --git a/plugins/core.c b/plugins/core.c

>> new file mode 100644

>> index 0000000000..8c46373773

>> --- /dev/null

>> +++ b/plugins/core.c

>> @@ -0,0 +1,524 @@

>> +/* plugin.c - QEMU Plugin interface

>> + *

>> + * 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.

>> + */

>> +#include "qemu/osdep.h"

>> +#include "qemu/error-report.h"

>> +#include "qemu/config-file.h"

>> +#include "qapi/error.h"

>> +#include "qemu/option.h"

>> +#include "qemu/rcu_queue.h"

>> +#include "qemu/xxhash.h"

>> +#include "qemu/rcu.h"

>> +#include "qom/cpu.h"

>> +#include "exec/cpu-common.h"

>> +#include <dlfcn.h>

>> +

>> +#include "cpu.h"

>> +#include "exec/exec-all.h"

>> +#include "exec/helper-proto.h"

>> +/* #include "exec/plugin-gen.h" */

>> +#include "sysemu/sysemu.h"

>> +#include "tcg/tcg.h"

>> +#include "tcg/tcg-op.h"

>> +#include "trace/mem-internal.h" /* mem_info macros */

>> +#include "plugin.h"

>> +

>> +struct qemu_plugin_cb {

>> +    struct qemu_plugin_ctx *ctx;

>> +    union qemu_plugin_cb_sig f;

>> +    void *udata;

>> +    QLIST_ENTRY(qemu_plugin_cb) entry;

>> +};

>> +

>> +QLIST_HEAD(qemu_plugin_cb_head, qemu_plugin_cb);

>> +

>> +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);

>> +    }

>> +}

>> +

>> +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();

>> +    }

>> +}

>> +

>> +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();

>> +    }

>> +}

>> +

>> +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_rec_mutex_lock(&plugin.lock);

>> +    ctx = plugin_id_to_ctx_locked(id);

>> +    /* if the plugin is on its way out, ignore this request */

>> +    if (unlikely(ctx->uninstalling)) {

>> +        goto out_unlock;

>> +    }

>> +    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);

>> +    }

>> + out_unlock:

>> +    qemu_rec_mutex_unlock(&plugin.lock);

>> +}

>> +

>> +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;

>> +}

>> +

>> +static inline uint32_t cb_to_tcg_flags(enum qemu_plugin_cb_flags flags)

>> +{

>> +    uint32_t ret;

>> +

>> +    switch (flags) {

>> +    case QEMU_PLUGIN_CB_RW_REGS:

>> +        ret = 0;

>> +    case QEMU_PLUGIN_CB_R_REGS:

>> +        ret = TCG_CALL_NO_WG;

>> +        break;

>> +    case QEMU_PLUGIN_CB_NO_REGS:

>> +    default:

>> +        ret = TCG_CALL_NO_RWG;

>> +    }

>> +    return ret;

>> +}

>> +

>> +inline 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;

>> +    dyn_cb->tcg_flags = cb_to_tcg_flags(flags);

>> +    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, bool haddr)

>> +{

>> +    struct qemu_plugin_dyn_cb *dyn_cb;

>> +

>> +    dyn_cb = plugin_get_dyn_cb(arr);

>> +    dyn_cb->userp = udata;

>> +    dyn_cb->tcg_flags = cb_to_tcg_flags(flags);

>> +    dyn_cb->type = PLUGIN_CB_REGULAR;

>> +    dyn_cb->rw = rw;

>> +    dyn_cb->mem.haddr = haddr;

>> +    dyn_cb->f.generic = cb;

>> +}

>> +

>> +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, cpu->cpu_index, tb);

>> +    }

>> +}

>> +

>> +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);

>> +    }

>> +}

>> +

>> +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, void *haddr,

>> +                             uint32_t info)

>> +{

>> +    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);

>> +        int w = !!(info & TRACE_MEM_ST) + 1;

>> +

>> +        if (!(w & cb->rw)) {

>> +                break;

>> +        }

>> +        switch (cb->type) {

>> +        case PLUGIN_CB_REGULAR:

>> +

>> +            if (cb->mem.haddr) {

>> +                cb->f.vcpu_mem_haddr(cpu->cpu_index, info, vaddr, haddr,

>> +                                     cb->userp);

>> +            } else {

>> +                cb->f.vcpu_mem(cpu->cpu_index, info, 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);

>> +}

>> +

>> +uint64_t qemu_plugin_ram_addr_from_host(void *haddr)

>> +{

>> +#ifdef CONFIG_SOFTMMU

>> +    ram_addr_t ram_addr;

>> +

>> +    g_assert(haddr);

>> +    ram_addr = qemu_ram_addr_from_host(haddr);

>> +    if (ram_addr == RAM_ADDR_INVALID) {

>> +        error_report("Bad ram pointer %p", haddr);

>> +        abort();

>> +    }

>> +    return ram_addr;

>> +#else

>> +    return 0;

>> +#endif

>> +}

>> +

>> +/*

>> + * 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 0000000000..bdd875868f

>> --- /dev/null

>> +++ b/plugins/loader.c

>> @@ -0,0 +1,353 @@

>> +#include "qemu/osdep.h"

>> +#include "qemu/error-report.h"

>> +#include "qemu/config-file.h"

>> +#include "qapi/error.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 "qom/cpu.h"

>> +#include <dlfcn.h>

>> +#include "cpu.h"

>> +#include "exec/exec-all.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, 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;

>> +

>> +    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 (strcmp(name, "arg") == 0) {

>> +        if (arg->curr == NULL) {

>> +            error_setg(errp, "missing earlier '-plugin file=' option");

>> +            return 1;

>> +        }

>> +        p = arg->curr;

>> +        p->argc++;

>> +        p->argv = g_realloc_n(p->argv, p->argc, sizeof(char *));

>> +        p->argv[p->argc - 1] = g_strdup(value);

>> +    } else {

>> +        error_setg(errp, "-plugin: unexpected parameter '%s'; ignored", name);

>> +    }

>> +    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);

>> +}

>> +

>> +static int plugin_load(struct qemu_plugin_desc *desc)

>> +{

>> +    qemu_plugin_install_func_t install;

>> +    struct qemu_plugin_ctx *ctx;

>> +    char *err;

>> +    int rc;

>> +

>> +    ctx = qemu_memalign(qemu_dcache_linesize, sizeof(*ctx));

>> +    memset(ctx, 0, sizeof(*ctx));

>> +    ctx->desc = desc;

>> +

>> +    ctx->handle = dlopen(desc->path, RTLD_NOW);

>> +    if (ctx->handle == NULL) {

>> +        error_report("%s: %s", __func__, dlerror());

>> +        goto err_dlopen;

>> +    }

>> +

>> +    /* clear any previous dlerror, call dlsym, then check dlerror */

>> +    dlerror();

>> +    install = dlsym(ctx->handle, "qemu_plugin_install");

>> +    err = dlerror();

>> +    if (err) {

>> +        error_report("%s: %s", __func__, err);

>> +        goto err_symbol;

>> +    }

>> +    /* symbol was found; it could be NULL though */

>> +    if (install == NULL) {

>> +        error_report("%s: %s: qemu_plugin_install is NULL",

>> +                     __func__, desc->path);

>> +        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, desc->argc, desc->argv);

>> +    ctx->installing = false;

>> +    if (rc) {

>> +        error_report("%s: qemu_plugin_install returned error code %d",

>> +                     __func__, 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) { */

>> +        /*     qemu_plugin_uninstall(ctx->id, NULL); */

>> +        /* } */

>> +    }

>> +

>> +    qemu_rec_mutex_unlock(&plugin.lock);

>> +    return rc;

>> +

>> + err_symbol:

>> +    if (dlclose(ctx->handle)) {

>> +        warn_report("%s: %s", __func__, dlerror());

>> +    }

>> + 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)

>> +{

>> +    struct qemu_plugin_desc *desc, *next;

>> +

>> +    QTAILQ_FOREACH_SAFE(desc, head, entry, next) {

>> +        int err;

>> +

>> +        err = plugin_load(desc);

>> +        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 (dlclose(ctx->handle)) {

>> +        warn_report("%s: %s", __func__, dlerror());

>> +    }

>> +    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_work_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;

>> +

>> +    qemu_rec_mutex_lock(&plugin.lock);

>> +    ctx = plugin_id_to_ctx_locked(id);

>> +    if (ctx->uninstalling || (reset && ctx->resetting)) {

>> +        qemu_rec_mutex_unlock(&plugin.lock);

>> +        return;

>> +    }

>> +    ctx->resetting = reset;

>> +    ctx->uninstalling = !reset;

>> +    qemu_rec_mutex_unlock(&plugin.lock);

>> +

>> +    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/plugin.h b/plugins/plugin.h

>> new file mode 100644

>> index 0000000000..e89f9ef0ea

>> --- /dev/null

>> +++ b/plugins/plugin.h

>> @@ -0,0 +1,95 @@

>> +/*

>> + * 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_

>> +

>> +/* 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 {

>> +    void *handle; /* dlopen */

>> +    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, bool haddr);

>> +

>> +void exec_inline_op(struct qemu_plugin_dyn_cb *cb);

>> +

>> +#endif /* _PLUGIN_INTERNAL_H_ */

>> --

>> 2.20.1

>>

>>



--
Alex Bennée
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 8e2fc6624c..37d396ab88 100644
--- a/Makefile
+++ b/Makefile
@@ -827,8 +827,13 @@  endif
 
 ICON_SIZES=16x16 24x24 32x32 48x48 64x64 128x128 256x256 512x512
 
-install: all $(if $(BUILD_DOCS),install-doc) install-datadir install-localstatedir \
+install-includedir:
+	$(INSTALL_DIR) "$(DESTDIR)$(includedir)"
+
+install: all $(if $(BUILD_DOCS),install-doc) \
+	install-datadir install-localstatedir install-includedir \
 	$(if $(INSTALL_BLOBS),$(edk2-decompressed))
+
 ifneq ($(TOOLS),)
 	$(call install-prog,$(subst qemu-ga,qemu-ga$(EXESUF),$(TOOLS)),$(DESTDIR)$(bindir))
 endif
@@ -888,6 +893,9 @@  endif
 		"$(DESTDIR)/$(qemu_desktopdir)/qemu.desktop"
 ifdef CONFIG_GTK
 	$(MAKE) -C po $@
+endif
+ifeq ($(CONFIG_PLUGIN),y)
+	$(INSTALL_DATA) $(SRC_PATH)/include/qemu/qemu-plugin.h "$(DESTDIR)$(includedir)/qemu-plugin.h"
 endif
 	$(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)/keymaps"
 	set -e; for x in $(KEYMAPS); do \
diff --git a/Makefile.target b/Makefile.target
index ecd856e3a3..d492e24da2 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -118,6 +118,8 @@  obj-y += target/$(TARGET_BASE_ARCH)/
 obj-y += disas.o
 obj-$(call notempty,$(TARGET_XML_FILES)) += gdbstub-xml.o
 
+obj-$(CONFIG_PLUGIN) += plugins/
+
 #########################################################
 # Linux user emulator target
 
diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h
new file mode 100644
index 0000000000..93e39f44d2
--- /dev/null
+++ b/include/qemu/plugin.h
@@ -0,0 +1,261 @@ 
+/*
+ * 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.
+ */
+#ifndef QEMU_PLUGIN_H
+#define QEMU_PLUGIN_H
+
+#include "qemu/config-file.h"
+#include "qemu/qemu-plugin.h"
+#include "qemu/error-report.h"
+#include "qemu/queue.h"
+#include "qemu/option.h"
+
+/*
+ * Option parsing/processing.
+ * Note that we can load an arbitrary number of plugins.
+ */
+struct qemu_plugin_desc;
+typedef QTAILQ_HEAD(, qemu_plugin_desc) QemuPluginList;
+
+#ifdef CONFIG_PLUGIN
+extern QemuOptsList qemu_plugin_opts;
+
+static inline void qemu_plugin_add_opts(void)
+{
+    qemu_add_opts(&qemu_plugin_opts);
+}
+
+void qemu_plugin_opt_parse(const char *optarg, QemuPluginList *head);
+int qemu_plugin_load_list(QemuPluginList *head);
+#else /* !CONFIG_PLUGIN */
+static inline void qemu_plugin_add_opts(void)
+{ }
+
+static inline void qemu_plugin_opt_parse(const char *optarg,
+                                         QemuPluginList *head)
+{
+    error_report("plugin interface not enabled in this build");
+    exit(1);
+}
+
+static inline int qemu_plugin_load_list(QemuPluginList *head)
+{
+    return 0;
+}
+#endif /* !CONFIG_PLUGIN */
+
+/*
+ * Events that plugins can subscribe to.
+ */
+enum qemu_plugin_event {
+    QEMU_PLUGIN_EV_VCPU_INIT,
+    QEMU_PLUGIN_EV_VCPU_EXIT,
+    QEMU_PLUGIN_EV_VCPU_TB_TRANS,
+    QEMU_PLUGIN_EV_VCPU_IDLE,
+    QEMU_PLUGIN_EV_VCPU_RESUME,
+    QEMU_PLUGIN_EV_VCPU_SYSCALL,
+    QEMU_PLUGIN_EV_VCPU_SYSCALL_RET,
+    QEMU_PLUGIN_EV_FLUSH,
+    QEMU_PLUGIN_EV_ATEXIT,
+    QEMU_PLUGIN_EV_MAX,
+};
+
+union qemu_plugin_cb_sig {
+    qemu_plugin_simple_cb_t          simple;
+    qemu_plugin_udata_cb_t           udata;
+    qemu_plugin_vcpu_simple_cb_t     vcpu_simple;
+    qemu_plugin_vcpu_udata_cb_t      vcpu_udata;
+    qemu_plugin_vcpu_tb_trans_cb_t   vcpu_tb_trans;
+    qemu_plugin_vcpu_mem_cb_t        vcpu_mem;
+    qemu_plugin_vcpu_mem_haddr_cb_t  vcpu_mem_haddr;
+    qemu_plugin_vcpu_syscall_cb_t    vcpu_syscall;
+    qemu_plugin_vcpu_syscall_ret_cb_t vcpu_syscall_ret;
+    void *generic;
+};
+
+enum plugin_dyn_cb_type {
+    PLUGIN_CB_INSN,
+    PLUGIN_CB_MEM,
+    PLUGIN_CB_HADDR,
+    PLUGIN_N_CB_TYPES,
+};
+
+enum plugin_dyn_cb_subtype {
+    PLUGIN_CB_REGULAR,
+    PLUGIN_CB_INLINE,
+    PLUGIN_N_CB_SUBTYPES,
+};
+
+/*
+ * A dynamic callback has an insertion point that is determined at run-time.
+ * Usually the insertion point is somewhere in the code cache; think for
+ * instance of a callback to be called upon the execution of a particular TB.
+ */
+struct qemu_plugin_dyn_cb {
+    union qemu_plugin_cb_sig f;
+    void *userp;
+    unsigned tcg_flags;
+    enum plugin_dyn_cb_type type;
+    /* @rw applies to mem callbacks only (both regular and inline) */
+    enum qemu_plugin_mem_rw rw;
+    /* fields specific to each dyn_cb type go here */
+    union {
+        struct {
+            bool haddr;
+        } mem;
+        struct {
+            enum qemu_plugin_op op;
+            uint64_t imm;
+        } inline_insn;
+    };
+};
+
+struct qemu_plugin_insn {
+    GByteArray *data;
+    uint64_t vaddr;
+    void *haddr;
+    GArray *cbs[PLUGIN_N_CB_TYPES][PLUGIN_N_CB_SUBTYPES];
+    bool calls_helpers;
+    bool mem_helper;
+};
+
+/*
+ * qemu_plugin_insn allocate and cleanup functions. We don't expect to
+ * cleanup many of these structures. They are reused for each fresh
+ * translation.
+ */
+
+static inline void qemu_plugin_insn_cleanup_fn(gpointer data)
+{
+    struct qemu_plugin_insn *insn = (struct qemu_plugin_insn *) data;
+    g_byte_array_free(insn->data, true);
+}
+
+static inline struct qemu_plugin_insn * qemu_plugin_insn_alloc(void)
+{
+    int i, j;
+    struct qemu_plugin_insn *insn = g_new0(struct qemu_plugin_insn, 1);
+    insn->data = g_byte_array_sized_new(4);
+
+    for (i = 0; i < PLUGIN_N_CB_TYPES; i++) {
+        for (j = 0; j < PLUGIN_N_CB_SUBTYPES; j++) {
+            insn->cbs[i][j] = g_array_new(false, false,
+                                          sizeof(struct qemu_plugin_dyn_cb));
+        }
+    }
+    return insn;
+}
+
+struct qemu_plugin_tb {
+    GPtrArray *insns;
+    size_t n;
+    uint64_t vaddr;
+    uint64_t vaddr2;
+    void *haddr1;
+    void *haddr2;
+    GArray *cbs[PLUGIN_N_CB_SUBTYPES];
+};
+
+/**
+ * qemu_plugin_tb_insn_get(): get next plugin record for translation.
+ *
+ */
+static inline
+struct qemu_plugin_insn *qemu_plugin_tb_insn_get(struct qemu_plugin_tb *tb)
+{
+    struct qemu_plugin_insn *insn;
+    int i, j;
+
+    if (unlikely(tb->n == tb->insns->len)) {
+        struct qemu_plugin_insn *new_insn = qemu_plugin_insn_alloc();
+        g_ptr_array_add(tb->insns, new_insn);
+    }
+    insn = g_ptr_array_index(tb->insns, tb->n++);
+    g_byte_array_set_size(insn->data, 0);
+    insn->calls_helpers = false;
+    insn->mem_helper = false;
+
+    for (i = 0; i < PLUGIN_N_CB_TYPES; i++) {
+        for (j = 0; j < PLUGIN_N_CB_SUBTYPES; j++) {
+            g_array_set_size(insn->cbs[i][j], 0);
+        }
+    }
+
+    return insn;
+}
+
+#ifdef CONFIG_PLUGIN
+
+void qemu_plugin_vcpu_init_hook(CPUState *cpu);
+void qemu_plugin_vcpu_exit_hook(CPUState *cpu);
+void qemu_plugin_tb_trans_cb(CPUState *cpu, struct qemu_plugin_tb *tb);
+void qemu_plugin_vcpu_idle_cb(CPUState *cpu);
+void qemu_plugin_vcpu_resume_cb(CPUState *cpu);
+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);
+void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret);
+
+void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr, void *haddr,
+                             uint32_t meminfo);
+
+void qemu_plugin_flush_cb(void);
+
+void qemu_plugin_atexit_cb(void);
+
+void qemu_plugin_add_dyn_cb_arr(GArray *arr);
+
+void qemu_plugin_disable_mem_helpers(CPUState *cpu);
+
+#else /* !CONFIG_PLUGIN */
+
+static inline void qemu_plugin_vcpu_init_hook(CPUState *cpu)
+{ }
+
+static inline void qemu_plugin_vcpu_exit_hook(CPUState *cpu)
+{ }
+
+static inline void qemu_plugin_tb_trans_cb(CPUState *cpu,
+                                           struct qemu_plugin_tb *tb)
+{ }
+
+static inline void qemu_plugin_vcpu_idle_cb(CPUState *cpu)
+{ }
+
+static inline void qemu_plugin_vcpu_resume_cb(CPUState *cpu)
+{ }
+
+static inline 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)
+{ }
+
+static inline
+void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret)
+{ }
+
+static inline void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr,
+                                           void *haddr, uint32_t meminfo)
+{ }
+
+static inline void qemu_plugin_flush_cb(void)
+{ }
+
+static inline void qemu_plugin_atexit_cb(void)
+{ }
+
+static inline
+void qemu_plugin_add_dyn_cb_arr(GArray *arr)
+{ }
+
+static inline void qemu_plugin_disable_mem_helpers(CPUState *cpu)
+{ }
+
+#endif /* !CONFIG_PLUGIN */
+
+#endif /* QEMU_PLUGIN_H */
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 08481ad304..27b67a4e49 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -29,6 +29,7 @@ 
 #include "qemu/rcu_queue.h"
 #include "qemu/queue.h"
 #include "qemu/thread.h"
+#include "qemu/plugin.h"
 
 typedef int (*WriteCoreDumpFunction)(const void *buf, size_t size,
                                      void *opaque);
@@ -345,6 +346,7 @@  struct qemu_work_item;
  * @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes
  *                        to @trace_dstate).
  * @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask).
+ * @plugin_mask: Plugin event bitmap. Modified only via async work.
  * @ignore_memory_transaction_failures: Cached copy of the MachineState
  *    flag of the same name: allows the board to suppress calling of the
  *    CPU do_transaction_failed hook function.
@@ -430,6 +432,10 @@  struct CPUState {
     DECLARE_BITMAP(trace_dstate_delayed, CPU_TRACE_DSTATE_MAX_EVENTS);
     DECLARE_BITMAP(trace_dstate, CPU_TRACE_DSTATE_MAX_EVENTS);
 
+    DECLARE_BITMAP(plugin_mask, QEMU_PLUGIN_EV_MAX);
+
+    GArray *plugin_mem_cbs;
+
     /* TODO Move common fields from CPUArchState here. */
     int cpu_index;
     int cluster_index;
diff --git a/plugins/Makefile.objs b/plugins/Makefile.objs
new file mode 100644
index 0000000000..58940335bc
--- /dev/null
+++ b/plugins/Makefile.objs
@@ -0,0 +1,6 @@ 
+#
+# Plugin Support
+#
+
+obj-y += loader.o
+obj-y += core.o
diff --git a/plugins/core.c b/plugins/core.c
new file mode 100644
index 0000000000..8c46373773
--- /dev/null
+++ b/plugins/core.c
@@ -0,0 +1,524 @@ 
+/* plugin.c - QEMU Plugin interface
+ *
+ * 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.
+ */
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qemu/config-file.h"
+#include "qapi/error.h"
+#include "qemu/option.h"
+#include "qemu/rcu_queue.h"
+#include "qemu/xxhash.h"
+#include "qemu/rcu.h"
+#include "qom/cpu.h"
+#include "exec/cpu-common.h"
+#include <dlfcn.h>
+
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "exec/helper-proto.h"
+/* #include "exec/plugin-gen.h" */
+#include "sysemu/sysemu.h"
+#include "tcg/tcg.h"
+#include "tcg/tcg-op.h"
+#include "trace/mem-internal.h" /* mem_info macros */
+#include "plugin.h"
+
+struct qemu_plugin_cb {
+    struct qemu_plugin_ctx *ctx;
+    union qemu_plugin_cb_sig f;
+    void *udata;
+    QLIST_ENTRY(qemu_plugin_cb) entry;
+};
+
+QLIST_HEAD(qemu_plugin_cb_head, qemu_plugin_cb);
+
+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);
+    }
+}
+
+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();
+    }
+}
+
+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();
+    }
+}
+
+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_rec_mutex_lock(&plugin.lock);
+    ctx = plugin_id_to_ctx_locked(id);
+    /* if the plugin is on its way out, ignore this request */
+    if (unlikely(ctx->uninstalling)) {
+        goto out_unlock;
+    }
+    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);
+    }
+ out_unlock:
+    qemu_rec_mutex_unlock(&plugin.lock);
+}
+
+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;
+}
+
+static inline uint32_t cb_to_tcg_flags(enum qemu_plugin_cb_flags flags)
+{
+    uint32_t ret;
+
+    switch (flags) {
+    case QEMU_PLUGIN_CB_RW_REGS:
+        ret = 0;
+    case QEMU_PLUGIN_CB_R_REGS:
+        ret = TCG_CALL_NO_WG;
+        break;
+    case QEMU_PLUGIN_CB_NO_REGS:
+    default:
+        ret = TCG_CALL_NO_RWG;
+    }
+    return ret;
+}
+
+inline 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;
+    dyn_cb->tcg_flags = cb_to_tcg_flags(flags);
+    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, bool haddr)
+{
+    struct qemu_plugin_dyn_cb *dyn_cb;
+
+    dyn_cb = plugin_get_dyn_cb(arr);
+    dyn_cb->userp = udata;
+    dyn_cb->tcg_flags = cb_to_tcg_flags(flags);
+    dyn_cb->type = PLUGIN_CB_REGULAR;
+    dyn_cb->rw = rw;
+    dyn_cb->mem.haddr = haddr;
+    dyn_cb->f.generic = cb;
+}
+
+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, cpu->cpu_index, tb);
+    }
+}
+
+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);
+    }
+}
+
+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, void *haddr,
+                             uint32_t info)
+{
+    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);
+        int w = !!(info & TRACE_MEM_ST) + 1;
+
+        if (!(w & cb->rw)) {
+                break;
+        }
+        switch (cb->type) {
+        case PLUGIN_CB_REGULAR:
+
+            if (cb->mem.haddr) {
+                cb->f.vcpu_mem_haddr(cpu->cpu_index, info, vaddr, haddr,
+                                     cb->userp);
+            } else {
+                cb->f.vcpu_mem(cpu->cpu_index, info, 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);
+}
+
+uint64_t qemu_plugin_ram_addr_from_host(void *haddr)
+{
+#ifdef CONFIG_SOFTMMU
+    ram_addr_t ram_addr;
+
+    g_assert(haddr);
+    ram_addr = qemu_ram_addr_from_host(haddr);
+    if (ram_addr == RAM_ADDR_INVALID) {
+        error_report("Bad ram pointer %p", haddr);
+        abort();
+    }
+    return ram_addr;
+#else
+    return 0;
+#endif
+}
+
+/*
+ * 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 0000000000..bdd875868f
--- /dev/null
+++ b/plugins/loader.c
@@ -0,0 +1,353 @@ 
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qemu/config-file.h"
+#include "qapi/error.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 "qom/cpu.h"
+#include <dlfcn.h>
+#include "cpu.h"
+#include "exec/exec-all.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, 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;
+
+    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 (strcmp(name, "arg") == 0) {
+        if (arg->curr == NULL) {
+            error_setg(errp, "missing earlier '-plugin file=' option");
+            return 1;
+        }
+        p = arg->curr;
+        p->argc++;
+        p->argv = g_realloc_n(p->argv, p->argc, sizeof(char *));
+        p->argv[p->argc - 1] = g_strdup(value);
+    } else {
+        error_setg(errp, "-plugin: unexpected parameter '%s'; ignored", name);
+    }
+    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);
+}
+
+static int plugin_load(struct qemu_plugin_desc *desc)
+{
+    qemu_plugin_install_func_t install;
+    struct qemu_plugin_ctx *ctx;
+    char *err;
+    int rc;
+
+    ctx = qemu_memalign(qemu_dcache_linesize, sizeof(*ctx));
+    memset(ctx, 0, sizeof(*ctx));
+    ctx->desc = desc;
+
+    ctx->handle = dlopen(desc->path, RTLD_NOW);
+    if (ctx->handle == NULL) {
+        error_report("%s: %s", __func__, dlerror());
+        goto err_dlopen;
+    }
+
+    /* clear any previous dlerror, call dlsym, then check dlerror */
+    dlerror();
+    install = dlsym(ctx->handle, "qemu_plugin_install");
+    err = dlerror();
+    if (err) {
+        error_report("%s: %s", __func__, err);
+        goto err_symbol;
+    }
+    /* symbol was found; it could be NULL though */
+    if (install == NULL) {
+        error_report("%s: %s: qemu_plugin_install is NULL",
+                     __func__, desc->path);
+        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, desc->argc, desc->argv);
+    ctx->installing = false;
+    if (rc) {
+        error_report("%s: qemu_plugin_install returned error code %d",
+                     __func__, 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) { */
+        /*     qemu_plugin_uninstall(ctx->id, NULL); */
+        /* } */
+    }
+
+    qemu_rec_mutex_unlock(&plugin.lock);
+    return rc;
+
+ err_symbol:
+    if (dlclose(ctx->handle)) {
+        warn_report("%s: %s", __func__, dlerror());
+    }
+ 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)
+{
+    struct qemu_plugin_desc *desc, *next;
+
+    QTAILQ_FOREACH_SAFE(desc, head, entry, next) {
+        int err;
+
+        err = plugin_load(desc);
+        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 (dlclose(ctx->handle)) {
+        warn_report("%s: %s", __func__, dlerror());
+    }
+    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_work_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;
+
+    qemu_rec_mutex_lock(&plugin.lock);
+    ctx = plugin_id_to_ctx_locked(id);
+    if (ctx->uninstalling || (reset && ctx->resetting)) {
+        qemu_rec_mutex_unlock(&plugin.lock);
+        return;
+    }
+    ctx->resetting = reset;
+    ctx->uninstalling = !reset;
+    qemu_rec_mutex_unlock(&plugin.lock);
+
+    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/plugin.h b/plugins/plugin.h
new file mode 100644
index 0000000000..e89f9ef0ea
--- /dev/null
+++ b/plugins/plugin.h
@@ -0,0 +1,95 @@ 
+/*
+ * 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_
+
+/* 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 {
+    void *handle; /* dlopen */
+    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, bool haddr);
+
+void exec_inline_op(struct qemu_plugin_dyn_cb *cb);
+
+#endif /* _PLUGIN_INTERNAL_H_ */