Re: [PATCH v3 COLOPre 12/26] tools/libxl: Update libxl_domain_unpause() to support qemu-xen

[Yang Hongyang <yanghy@cn.fujitsu.com>]

On 06/30/2015 06:00 PM, Ian Campbell wrote:
> On Thu, 2015-06-25 at 14:25 +0800, Yang Hongyang wrote:
>> Currently, libxl__domain_unpause() only supports
>> qemu-xen-traditional. Update it to support qemu-xen.
>> We use libxl__domain_resume_device_model to unpause guest dm.
>
> There appears to be at least two significant semantic changes to the
> libxl__domain_resume_device_model function (namely it now deals
> internally with stubdom and checks the current status before doing
> anything). What is the impact on the existing callers of those changes?

This change was suggested by Wei on last round(v2), he thought it is an
enhancement to the existing callers.

>
> I think those changes should be two separate preparatory patches.
>
>
>>
>> Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
>> ---
>>   tools/libxl/libxl.c             | 15 +++++----------
>>   tools/libxl/libxl_dom_suspend.c | 15 ++++++++++++---
>>   tools/libxl/libxl_internal.h    |  1 +
>>   3 files changed, 18 insertions(+), 13 deletions(-)
>>
>> diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
>> index 2ca59ea..59e2dfe 100644
>> --- a/tools/libxl/libxl.c
>> +++ b/tools/libxl/libxl.c
>> @@ -938,8 +938,6 @@ out:
>>   int libxl_domain_unpause(libxl_ctx *ctx, uint32_t domid)
>>   {
>>       GC_INIT(ctx);
>> -    char *path;
>> -    char *state;
>>       int ret, rc = 0;
>>
>>       libxl_domain_type type = libxl__domain_type(gc, domid);
>> @@ -949,14 +947,11 @@ int libxl_domain_unpause(libxl_ctx *ctx, uint32_t domid)
>>       }
>>
>>       if (type == LIBXL_DOMAIN_TYPE_HVM) {
>> -        uint32_t dm_domid = libxl_get_stubdom_id(ctx, domid);
>> -
>> -        path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
>> -        state = libxl__xs_read(gc, XBT_NULL, path);
>> -        if (state != NULL && !strcmp(state, "paused")) {
>> -            libxl__qemu_traditional_cmd(gc, domid, "continue");
>> -            libxl__wait_for_device_model_deprecated(gc, domid, "running",
>> -                                         NULL, NULL, NULL);
>> +        rc = libxl__domain_resume_device_model(gc, domid);
>> +        if (rc < 0) {
>> +            LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "failed to unpause device model "
>> +                       "for domain %u:%d", domid, rc);
>> +            goto out;
>>           }
>>       }
>>       ret = xc_domain_unpause(ctx->xch, domid);
>> diff --git a/tools/libxl/libxl_dom_suspend.c b/tools/libxl/libxl_dom_suspend.c
>> index 1c486c4..3edbd2e 100644
>> --- a/tools/libxl/libxl_dom_suspend.c
>> +++ b/tools/libxl/libxl_dom_suspend.c
>> @@ -376,13 +376,22 @@ static void domain_suspend_callback_common_done(libxl__egc *egc,
>>
>>   /*======================= Domain resume ========================*/
>>
>> -static int libxl__domain_resume_device_model(libxl__gc *gc, uint32_t domid)
>> +int libxl__domain_resume_device_model(libxl__gc *gc, uint32_t domid)
>>   {
>> +    char *path;
>> +    char *state;
>>
>>       switch (libxl__device_model_version_running(gc, domid)) {
>>       case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL: {
>> -        libxl__qemu_traditional_cmd(gc, domid, "continue");
>> -        libxl__wait_for_device_model_deprecated(gc, domid, "running", NULL, NULL, NULL);
>> +        uint32_t dm_domid = libxl_get_stubdom_id(CTX, domid);
>> +
>> +        path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
>> +        state = libxl__xs_read(gc, XBT_NULL, path);
>> +        if (state != NULL && !strcmp(state, "paused")) {
>> +            libxl__qemu_traditional_cmd(gc, domid, "continue");
>> +            libxl__wait_for_device_model_deprecated(gc, domid, "running",
>> +                                                    NULL, NULL, NULL);
>> +        }
>>           break;
>>       }
>>       case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
>> diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
>> index 0adc9b4..6960280 100644
>> --- a/tools/libxl/libxl_internal.h
>> +++ b/tools/libxl/libxl_internal.h
>> @@ -3326,6 +3326,7 @@ static inline bool libxl__save_helper_inuse(const libxl__save_helper_state *shs)
>>   /* Each time the dm needs to be saved, we must call suspend and then save */
>>   _hidden int libxl__domain_suspend_device_model(libxl__gc *gc,
>>                                              libxl__domain_suspend_state *dsps);
>> +_hidden int libxl__domain_resume_device_model(libxl__gc *gc, uint32_t domid);
>>   _hidden void libxl__domain_save_device_model(libxl__egc *egc,
>>                                        libxl__domain_save_state *dss,
>>                                        libxl__save_device_model_cb *callback);
>
>
> .
>

-- 
Thanks,
Yang.