Commit 3fb356cc authored by Alex Bennée's avatar Alex Bennée
Browse files

tcg plugins: expose an API version concept 



This is a very simple versioning API which allows the plugin
infrastructure to check the API a plugin was built against. We also
expose a min/cur API version to the plugin via the info block in case
it wants to avoid using old deprecated APIs in the future.

Signed-off-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: default avatarRobert Foley <robert.foley@linaro.org>
parent 05273a43

include/qemu/qemu-plugin.h

+19 −0
Original line number Diff line number Diff line
@@ -38,9 +38,28 @@ 


typedef uint64_t qemu_plugin_id_t;



/*

 * Versioning plugins:

 *

 * The plugin API will pass a minimum and current API version that

 * QEMU currently supports. The minimum API will be incremented if an

 * API needs to be deprecated.

 *

 * The plugins export the API they were built against by exposing the

 * symbol qemu_plugin_version which can be checked.

 */



extern QEMU_PLUGIN_EXPORT int qemu_plugin_version;



#define QEMU_PLUGIN_VERSION 0



typedef struct {

    /* string describing architecture */

    const char *target_name;

    struct {

        int min;

        int cur;

    } version;

    /* is this a full system emulation? */

    bool system_emulation;

    union {

plugins/loader.c

+21 −0
Original line number Diff line number Diff line
@@ -178,6 +178,25 @@ static int plugin_load(struct qemu_plugin_desc *desc, const qemu_info_t *info) 
        goto err_symbol;

    }



    if (!g_module_symbol(ctx->handle, "qemu_plugin_version", &sym)) {

        error_report("TCG plugin %s does not declare API version %s",

                     desc->path, g_module_error());

        goto err_symbol;

    } else {

        int version = *(int *)sym;

        if (version < QEMU_PLUGIN_MIN_VERSION) {

            error_report("TCG plugin %s requires API version %d, but "

                         "this QEMU supports only a minimum version of %d",

                         desc->path, version, QEMU_PLUGIN_MIN_VERSION);

            goto err_symbol;

        } else if (version > QEMU_PLUGIN_VERSION) {

            error_report("TCG plugin %s requires API version %d, but "

                         "this QEMU supports only up to version %d",

                         desc->path, version, QEMU_PLUGIN_VERSION);

            goto err_symbol;

        }

    }



    qemu_rec_mutex_lock(&plugin.lock);



    /* find an unused random id with &ctx as the seed */
@@ -248,6 +267,8 @@ int qemu_plugin_load_list(QemuPluginList *head) 
    g_autofree qemu_info_t *info = g_new0(qemu_info_t, 1);



    info->target_name = TARGET_NAME;

    info->version.min = QEMU_PLUGIN_MIN_VERSION;

    info->version.cur = QEMU_PLUGIN_VERSION;

#ifndef CONFIG_USER_ONLY

    MachineState *ms = MACHINE(qdev_get_machine());

    info->system_emulation = true;

plugins/plugin.h

+2 −0
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 


#include <gmodule.h>



#define QEMU_PLUGIN_MIN_VERSION 0



/* global state */

struct qemu_plugin_state {

    QTAILQ_HEAD(, qemu_plugin_ctx) ctxs;

tests/plugin/bb.c

+2 −0
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 


#include <qemu-plugin.h>



QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;



static uint64_t bb_count;

static uint64_t insn_count;

static bool do_inline;

tests/plugin/empty.c

+2 −0
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ 


#include <qemu-plugin.h>



QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;



/*

 * Empty TB translation callback.

 * This allows us to measure the overhead of injecting and then